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@#Abstract: Objective To detect the antibody levels of hantavirus in serum samples from patients suspected with hemorrhagic fever with renal syndrome (HFRS) in Heilongjiang Province from 2019 to 2021, and to provide scientific basis for the prevention and control of disease. Methods Enzyme-linked immunosorbent assays (ELISA) were used to detect the IgM antibodies to hantavirus in serum samples collected from suspected patients with HFRS in the acute-phase, and IgM and IgG antibody in convalescent-phase serum samples. The positive rate of IgM antibody in acute-phase serum samples of patients in different years was analyzed with χ2 test by SPSS 19.0, and the data were sorted out and analyzed about patients' gender, occupation, age, date of onset and interval from onset to initial diagnosis by EpiData 3.1, Excel 2003 software. Results A total of 351 acute-phase serum samples and 208 convalescent-phase serum samples were detected in patients suspected with HFRS, respectively. There were 317 positive IgM antibodies of serum samples in the acute stage, with the positive rate of 90.31%. There was no significant difference in the positive rate of IgM antibodies in the acute stage between different years (χ2=0.895, P=0.639). T The IgM antibodies and IgG antibodies were positive in 32 (15.39%) and 28 (13.46%) of the convalescent-phase serum samples, respectively. Moreover, 148 patients (71.15%) were double-positive for IgM and IgG antibodies at the convalescent stage. The ratio of male to female patients was 4.56∶1, for which male patients were much more than female patients. Occupation was dominated by farmers (253 cases, 79.81%), followed by workers (19 cases, 5.99%) and the unemployed (17 cases, 5.36%), respectively. The age of patients ranged from 10 to 88 years old, with a median age of 49 years old. Most of the patients were in the age group from 30 years old to 60 years old (209 cases, 65.93%), among which the age group from 40 years old to 50 years old (86 cases, 27.13%) had the highest proportion, and the age group from 60 years old to 90 years old had a proportion of 20.18% (19 cases). May and November were the peak periods of HFRS in Heilongjiang Province. The median interval between onset and initial diagnosis was 4 days. Conclusions There is a gap of about 10% between the clinical diagnosis of HFRS cases and the confirmed cases detected by laboratory in Heilongjiang Province from 2019 to 2021. The virus-specific detection results are important for confirming the diagnosis of local patients with HFRS.
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@#Abstract：Objective To carry out serological analysis of varicella⁃zoster virus（VZV）IgG antibody level in healthy people aged 1 ~ 30 years in Liaoning Province. Methods In October 2020，3～5 mL venous blood samples were collected from 617 healthy people aged 1～30 years selected from six counties and districts in Shenyang，Fuxin and Dandong of Liaoning Province by stratified random sampling method，of which serum samples were collected and determined for VZV IgG antibody level by ELISA. The positive rate of serum antibody and geometric mean concentration（GMC）of antibody were calculated and compared. Results Among 617 serum samples，302 samples were positive for VZV IgG antibody，the positive rate was 48. 947%，and the GMC was 112. 772 mIU／mL. The positive rate of VZV IgG antibody was 29. 670%～75. 789% and the GMC was 45. 508～366. 559 mIU／mL in healthy people of various ages. Both of the antibody positive rate（χ2 = 67. 104， P < 0. 001）and GMC（F = 20. 685，P < 0. 001）showed significant differences. The positive rates of VZV IgG antibody in male and female were 44. 817% and 53. 633% respectively，which showed significant difference（χ2 = 4. 779，P = 0. 029）， while the GMCs were 96. 983 and 133. 829 mIU／mL respectively（t = -1. 958，P = 0. 051）with no significant difference. The positive rates of VZV IgG antibody of healthy people in Shenyang，Fuxin and Dandong of Liaoning Province were 55. 224%，40. 201% and 51. 152% respectively with significant differences（χ2 = 9. 683，P = 0. 008），of which the positive rate of FuxinwassignificantlylowerthanthoseofShenyangandDandong（χ2 =9. 046and5. 013，P =0. 003and0. 025，respectively）； While the GMCs were 133. 523，85. 953 and 123. 713 mIU／mL respectively with no significant difference（F = 0. 514， P = 0. 598）. Among 617 serum samples，54 sampleswere suspicious，which remained within the criticalrange afterre⁃examina⁃ tion，while the gap between positive rate and the total percentage of positive and suspicious results gradually decreased with the increase of age，indicating that the immunity to varicella gradually increased with the increase of age. Conclusion The VZV⁃IgG antibody level of healthy people aged 1～30 years in Liaoning Province increased gradually with age，while the overall level was low. To control the spread of varicella virus，it is recommended to increase varicella vaccine coverage in vulnerable areas and susceptible population to build VZV immune barrier.
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@#Objective To develop and verify an indirect ELISA method for determination of specific IgG antibody of rhesus monkey serum against SARS-CoV-2 variant strain. Methods An indirect ELISA method for the determination of specific IgG antibody was developed using inactivated SARS-CoV-2 Beta variant strain inactivated vaccine as coating antigen,and optimized for the coating antigen concentration(1,2 and 4 μg/mL),dilution of serum(1∶800～1∶12 800),blocking solution(PBST containing 1% BSA,2% BSA,1% skim milk,2% skim milk and 1% BSA + 1% skim milk),blocking time(30,60 and 90 min),dilution of secondary antibody(1∶5 000,1∶10 000,1∶15 000 and 1∶20 000),incubation time of serum and secondary antibody(30,60 and 90 min),and TMB reaction time(5,10,15,20,25 and 30 min). 60 negative serum samples of rhesus monkeys were detected by the developed method,and the negative and positive critical values were determined. The sensitivity and precision of the methodology were verified. In addition,the specific IgG antibody and neutralizing antibody against SARS-CoV-2 Beta variant strain in 44 serum samples of rhesus monkey were detected by the developed method and microneutralization method,and the correlation and consistency between the two methods were compared. Results The optimum detection conditions were determined:the coating antigen concentration was 1 μg/mL;the blocking solution was PBST containing 1% skim milk,and the blocking time was 30 min;the serum samples to be tested were diluted to 1∶1 600 and incubated for 90 min,and the secondary antibody was diluted to 1∶10 000 and incubated for 30 min;the color development time of substrate was 25 min. The positive critical value and negative critical value of the method was 0. 093 and 0. 084 respectively,and the detection values between them were judged as suspicious. The dilution of5 positive serum samples that showed positive results was 1∶51 200;the coefficients of variation(CVs)of precision were all less than 15%. There was a strong correlation between IgG antibody titer and neutralizing antibody level in the 44 rhesus monkey serum samples(r = 0. 858 0,P < 0. 000 1);the total coincidence rate of the two methods was 90. 9%,the positive coincidence rate was 93. 6%,and the negative coincidence rate was 84. 6%;the consistency test Kappa value was 0. 783 8(95% CI:0. 586 5～0. 981 0). Conclusion The developed indirect ELISA method for eletermination of specific IgG antibody against SARS-CoV-2 Beta variant strain in rhesus monkey serum has good sensitivity and precision,and has strong consistency with microneutralization method,which can be used for the determination of IgG antibody in rhesus monkey serum.
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Objective:To evaluate the diagnostic value of 1, 3-β-D glucan (BDG), mannan IgM antibody (Mn-IgM) and mannan IgG antibody (Mn-IgG) in invasive candidiasis and to compare the differences in the diagnostic capability of serological markers used alone or in combination.Methods:Serum samples of 126 patients with invasive candidiasis and 104 healthy people who took physical examination during the same period were collected. BDG was detected by dynamic chromogenic method, and Mn-IgM and Mn-IgG were detected by ELISA. The sensitivity, specificity, positive predictive value, negative predictive value, Youden index, coincidence rate and Kappa value of the three serological markers used alone or in combination in the diagnosis of invasive candidiasis were analyzed and compared. The receiver operating characteristic (ROC) curves were drawn and the areas under the curves (AUCs) were calculated.Results:The levels of BDG, Mn-IgM and Mn-IgG in patients with invasive candidiasis were significantly higher than those in healthy people ( P<0.01). The sensitivity, specificity, Kappa value and AUC of BDG were 48.41%, 92.31%, 0.389 and 0.842. The sensitivity, specificity, Kappa value and AUC of Mn-IgM were 64.29%, 91.35%, 0.540 and 0.829. The sensitivity, specificity, Kappa value and AUC of Mn-IgG were 27.78%, 95.19%, 0.214 and 0.737. The sensitivity, specificity, Kappa value and AUC of BDG+ Mn-IgM were 76.19%, 88.46%, 0.637 and 0.921. The sensitivity, specificity, Kappa value and AUC of BDG+ Mn-IgG were 59.52%, 91.35%, 0.491 and 0.856. The sensitivity, specificity, Kappa value and AUC of Mn-IgM+ Mn-IgG were 69.84%, 90.38%, 0.588 and 0.891. The sensitivity, specificity, Kappa value and AUC of BDG+ Mn-IgM+ Mn-IgG were 80.16%, 88.46%, 0.679 and 0.922. Conclusions:The sensitivity of Mn-IgM was higher than that of BDG and Mn-IgG in the diagnosis of invasive candidiasis. When the serological biomarkers were used in combination, BDG+ Mn-IgM and BDG+ Mn-IgM+ Mn-IgG had relatively high Kappa value and AUC, showing high accuracy. The clinical diagnostic value of multiple serological biomarkers used in combination was significantly higher than that of any serological biomarkers used alone. Early combined detection and continuous monitoring of multiple serological biomarkers in patients with high risk of invasive candidiasis could be used clinically to adjust antifungal treatment strategies timely.
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Objective:To investigate the correlation between food-specific IgG (sIgG) antibodies and phenotypes of chronic spontaneous urticaria (CSU) .Methods:Serum samples were collected from outpatients with active CSU, symptomatic dermographism (SD) , or acute urticaria (AU) , and healthy controls from 5 third-grade class-A hospitals such as the First Hospital of China Medical University between April 2014 and March 2015. Enzyme-linked immunosorbent assay was conducted to detect serum levels of 90 food-sIgG antibodies and total IgE, Western blot analysis to detect levels of 20 allergen-specific IgE antibodies, and chemiluminescent microparticle immunoassay to detect levels of anti-thyroid peroxidase IgG antibodies and anti-thyroglobulin IgG antibodies. Comparisons of normally distributed quantitative data between two groups and among several groups were performed by t test and one-way analysis of variance, respectively; comparisons of non-normally distributed quantitative data between two groups were performed by Mann-Whitney U test; for comparisons of proportions, chi-square test and Fisher′s exact test were used. Results:A total of 248 patients with CSU, 22 with SD, 15 with AU and 13 healthy controls were recruited. The cut-off level for sIgG positivity was 100 U/ml (at least 2+) , and the positive rate of food-sIgG antibodies was slightly higher in the patients with CSU (176/248, 70.97%) , SD (15/22, 68.18%) and AU (11/15) than in the healthy controls (7/13; χ2 = 1.80, P = 0.615) . Among the 248 CSU patients, the proportion of patients with family history of allergic diseases was significantly higher in the sIgG-positive group (71/176, 40.34%) than in the sIgG-negative group (19/72, 26.39%; χ2 = 4.30, P = 0.042) , while no significant difference was observed in the 1-day urticaria activity score (UASday) between the two groups ( Z = 0.18, P = 0.859) . Totally, 177 CSU patients completed 12- to 40-week treatment; their condition could be completely controlled by second-generation H1-antihistamines, and there was no significant difference in the required dosage of second-generation H1-antihistamines between the sIgG-positive group (128 cases) and sIgG-negative group (49 cases; Z = -1.06, P = 0.298) . Conclusions:The prevalence of family history of allergic diseases was relatively high in food-sIgG-positive patients with CSU. However, food-sIgG could not be used as an indicator to reflect the disease activity of CSU and treatment response.
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Purpose: To elucidate the clinico?epidemiologic characteristics of optic neuritis based on the status of serum aquaporin?4 antibody (AQP4?Ab) in patients with optic neuritis (ON). Methods: Medical records of 106 patients with ON and a follow?up of 3 years were reviewed. For each patient, the following data were extracted: medical history, findings of the ocular examination, brain, orbital or spinal MRI, and serological tests for AQP4. The ON was classified as typical or atypical based on disc examination and improvement in vision after intravenous methylprednisolone (IVMP). The clinical findings (typical or atypical), disease course, and outcomes were analyzed according to the serostatus of the ON. Results: 10 patients ((9.4%) were seropositive for AQP4?Ab; all had atypical ON. 96 patients (91%) were seronegative for AQP4?Ab: 36 atypical ON and 60 typical ON. Profound visual impairment at presentation was seen in all patients. However, at the end of the study period, seropositive and seronegative atypical ON had poor visual outcomes as compared to seronegative typical ON (P = 0.002). Five seropositive and four seronegative patients with atypical ON developed transverse myelitis. Bilateral disease with relapse was more in seropositive patients (80%); however, seronegative with atypical ON also had bilateral presentation and relapse in 42% and 41%, respectively. Conclusion: AQP4?Ab seropositive patients mostly present with atypical features such as bilateral recurrent ON, poor visual outcome, and increased incidence of transverse myelitis. However, atypical clinical features can also be seen in seronegative ON with a poor visual outcome and a recalcitrant course.
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Objective To determine the serum IgM and IgG antibody levels post-COVID-19 vaccination， and provide scientific evidence for COVID-19 antibody response after vaccination. Methods A total of 980 healthy persons were included in Kunming Third People’s Hospital from July through August， 2021， which had been vaccinated with COVID-19 vaccines and then tested for anti-SARS-CoV-2 IgM and IgG antibodies. Results After the COVID-19 vaccination， 469 persons （positive rate， 47.86%） were positive for anti-IgG antibody. Of them， 75 were males with （positive rate， 39.06%）， and the average IgG level was 0.618 （0.180， 2.526） AU·mL-1［M（Q1，Q3）］； 394 were females （50.00%）， and the IgG level was 0.999 （0.305， 3.334） AU·mL-1. In addition， 53 persons （5.41%） were anti-IgM antibody positive. Of them， 14 were males （positive rate， 7.29%）， and the average IgM level was 0.057 （0.026， 0.195） AU·mL-1； 39 were females （4.95%）， and the IgM level was 0.047 （0.027， 0.110） AU·mL-1. The positive rate of anti-IgG antibody was highest in those aged ≤30 years， which was 51.02% in male （n=25） and 55.88% in female （n=133）. The anti-IgG response differed significantly by gender （χ2=7.401， D=0.135 1， P<0.05）， whereas the anti-IgM response was not significantly different （χ2=1.656， P>0.05）. Among the age groups， anti-IgG antibody level was higher in those aged ≤30 and 51-70 years， with 158 （55.05%） and 122 （52.36%） persons， respectively； the average antibody level was 1.209 （0.426， 4.386） AU·mL-1 and 1.074 （0.191， 7.670） AU·mL-1， respectively. The differences in the positive rates of IgG and IgM antibodies and the levels of IgG antibodies among different age groups were statistically significant （P<0.05）. Using Kruskal-Wallis test and Spearman correlation analysis， it showed a high correlation between the IgG and IgM antibodies （r=0.836 4， H=64.82， 20.09， P<0.05）. Conclusion The Anti-SARS-CoV-2 IgG antibody remains high six months post-COVID-19 vaccination， while anti-IgM antibody is low. The IgM and IgG response are higher in the young and elderly. The response differs by gender and age， demonstrating a correlation.
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Objective To evaluate the diagnostic efficiency of four anti-cysticercus IgG, IgG4 or IgM antibody test kits (enzyme-linked immunosorbent assay, ELISA) by different manufacturers, so as to provide insights into the epidemiological investigation and clinical detection of cysticercosis. Methods Forty serum samples from cerebral cysticercosis patients, 100 serum samples from healthy volunteers, 30 serum samples from paragonimiasis skrjabini patients, 17 serum samples from cystic echinococcosis and 19 serum samples from subcutaneous or cerebral sparganosis patients were collected and detected using anti-cysticercus IgG, IgG4 or IgM antibody test kits (brand A) and the anti-cysticercus IgG antibody test kit (brand B). The sensitivity, specificity and false negative rate of the four kits for detection of cysticercosis were estimated. Results The anti-cysticercus IgG, IgG4 or IgM antibody test kits (brand A) showed 95.00% (38/40), 87.50% (35/40), 7.50% (3/40) sensitivities and 98.00% (98/100), 100.00% (100/100) and 100.00% (100/100) for detection of cysticercosis, while the anti-cysticercus IgG antibody test kit (brand B) presented a 75.00% (30/40) sensitivity and 100.00% (100/100) specificity for detection of cysticercosis. The sensitivity for detection of cysticercosis was significantly higher by the anti-cysticercus IgG antibody test kit (brand A) than by the anti-cysticercus IgG antibody test kit (brand B) (χ2 = 6.28, P < 0.05); however, no significant difference was seen in the specificity by two kits (χ2 = 2.01, P > 0.05). The four ELISA kits showed overall false positive rates of 37.88% (25/66), 22.73% (15/66), 62.12% (41/66) and 15.15% (10/66) for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 37.61, P < 0.05), and the anti-cysticercus IgG antibody test kit (brand A) presented the highest overall false positive rate for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 7.56, P’ < 0.008), while a higher overall false positive rate was seen for detection of paragonimiasis, echinococcosis and sparganosis by the anti-cysticercus IgG antibody test kit (brand A) than by the anti-cysticercus IgG antibody test kit (brand B) (χ2 = 8.75, P’ < 0.008). The four ELISA kits showed false positive rates of 40.00% (12/30), 16.67% (5/30), 76.67% (23/30) and 13.33% (4/30) for detection of paragonimiasis (χ2 = 32.88, P < 0.05) and 21.05% (4/19), 26.32% (5/19), 73.68% (14/19) and 15.79% (3/19) for detection of sparganosis (χ2 = 19.97, P < 0.05), and the highest false positive rates were found by the anti-cysticercus IgM antibody test kit (brand A) for detection of paragonimiasis and sparganosis (all P’ < 0.008). However, the four ELISA kits showed comparable false positive rates of 52.94% (9/17), 29.41% (5/17), 23.53% (4/17) and 17.65% (3/17) for detection of echinococcosis (χ2 = 8.24, P > 0.05). In addition, the anti-cysticercus IgM anti-body test kit (brand A) showed false positive rates of 76.67% (23/30), 23.53% (4/17) and 73.68% (14/19) for detection of paragonimiasis, echinococcosis and sparganosis (χ2 = 14.537, P < 0.05), with the lowest false positive rate seen for detection of echinococcosis (χ2 = 14.537, P’ < 0.014), while no significant differences were seen in the false positive rate for detection of paragonimiasis, echinococcosis and sparganosis by other three ELISA kits (all P > 0.05). Conclusions The four anti-cysticercus IgG, IgG4 or IgM antibody test kits exhibit various efficiencies for serodiagnosis of cysticercosis. The anti-cysticercus IgG antibody test kit (brand A) has a high sensitivity for serodiagnosis of cysticercosis; however, it still needs to solve the problems of cross-reaction with other parasitic diseases and stability.
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@#Abstract: Objective To analyze the clinical characteristics and changes of serum IgG, IgM antibodies in patients infected with the SARS-CoV-2 B.1.1.529 (Omicron) variant. Methods The clinical data of 82 patients with SARS-CoV-2 B.1.1.529 variant was analyzed retrospectively. Based on the presence of pneumonia on chest CT, the patients were divided into pneumonia group and non-pneumonia group. Serum IgG, IgM antibodies were observed at 5 time points T1 (1~<4 d), T2 (4~<8 d), T3 (8~<15 d), T4 (15~<22 d) and T5 (22~<30 d) after admission. Results Among the 82 patients infected with the SARS-CoV-2 B.1.1.529 variant strain, there were 62 cases of cough, 31 cases of fever, 33 cases of throat discomfort, 5 cases of muscle soreness and 3 cases of diarrhea. The serum IgG antibody levels at 5 time points were 50.22 (142.20) AU/mL, 326.50 (220.63) AU/mL, 368.23 (76.21) AU/mL, 368.65 (79) AU/mL, and 385.26 (113.10) AU/mL, respectively. The level of serum IgG antibody in the pneumonia group was lower than that of the non-pneumonia group at T1 and T4 time points, and the differences were statistically significant (P<0.05) , the positive rate of serum IgG antibody in the pneumonia group was lower than that of the non-pneumonia group at the T1 time point, and the difference was statistically significant (P<0.05) . The serum IgM antibody levels at 5 time points were 0.41 (0.81) AU/mL, 0.95 (1.62) AU/mL, 1.09 (2.42) AU/mL, 0.74 (3) AU/mL, and 0.81 (3.10) AU/mL respectively, and there was no significant difference between the two groups. Conclusion The clinical symptoms of patients infected with the SARS-CoV-2 B.1.1.529 variant strain are mild. Serum IgG antibodies increased after infection, but there are some differences between the pneumonia group and the non-pneumonia group, whether serum IgG has a protective effect needs further research; the serum IgM antibodies do not increase highly after infection, there are some differences between individuals.
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Objective:To improve the consistency of test results through reducing inter-laboratory variation in SARS-CoV-2 antibody detection with WHO SARS-CoV-2 antibody candidate international standard (IS, sample G) and antibody reference panel (samples E, F, H, I, J).Methods:Ten WHO samples (A-J) including the candidate IS and reference panel were evaluated using different methods, such as microneutralization tests based on live SARS-CoV-2, pseudovirus neutralization assay and commercial ELISA kits. The test results were compared using statistical analysis.Results:Using IS (sample G) as a reference, the relative concentrations of other samples could be determined with less variation. ELISA and pseudovirus neutralization assay had consistent results with those obtained with the microneutralization test based on SARS-COV-2 strain HB02. Weakly positive samples could be detected only by a certain kit.Conclusions:The availability of an IS for antibodies would facilitate the standardization of SARS-CoV-2 antibody detection methods. The reference panel fitted all the assays based on the SARS-CoV-2 prototype Wuhan strain. Pseudovirus neutralization assay and ELISA could be used as alternatives to live SARS-CoV-2-based neutralization test to some extent.
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Objective@#To investigate the measles antibody level among residents in Quzhou City, Zhejiang Province in 2018, so as to provide the evidence for improving the measles control strategy.@*Methods@#The permanent residents aged 0 to 59 years were randomly sampled from 10 townships ( streets ) in Kecheng District and Changshan County of Quzhou City. Residents' demographics and vaccination of measles-containing vaccine ( MCV ) were collected, and serum anti- measles IgG antibody was detected using enzyme-linked immunosorbent assay ( ELISA ). The positive rate, protective rate and geometric mean concentration (GMC) of anti-measles antibody were estimated. @*Results@#A total of 606 residents were tested, with a male to female ratio of 0.83∶1. The subjects had a median age ( interquartile range ) of 17.36 ( 29.07 ) years, and 399 residents ( 65.84% ) had a vaccination history of MCV. The positive rate, protective rate and GMC of anti-measles IgG antibody were 94.88%, 48.68%, and 784.51 ( 95%CI: 731.14-841.40) mIU/mL, respectively. The positive rate of anti-measles IgG antibody was higher in men than in women ( 97.08% vs. 93.07%, χ2=4.968, P=0.026 ), and the protection rate was lower in men than in women ( 44.16% vs. 52.41%, χ2=4.089, P=0.043 ). The protective rate and GMC of anti-measles IgG antibody showed a“U”-shaped distribution with age, and a low protective rate was seen in residents aged 10 to 39 years ( 23.53% to 46.67% ), which the GMC of anti-measles IgG antibody that did not reach the protective level. A total of 233 residents at age of 15 years and below had with a history of two-dose MCV vaccination, and the positive rate ( χ2trend=7.260, P=0.007 ), protective rate ( χ2trend=12.756, P<0.001 ) and GMC ( rs=-0.289, P<0.001 ) of anti-measles IgG antibody presented a tendency towards a reduction with time <1 to 11 years after vaccination of the last dose of MCV.@*Conclusions@#A high positive rate of anti-measles antibody was detected among residents in Quzhou City in 2018; however, the protection rate of anti-measles antibody was low among residents at ages of 10 to 39 years. The coverage of MCV vaccination is recommended to be improved among residents at ages of 10 to 39 years in Quzhou City.
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ObjectiveTo investigate the specific anti-SARS-CoV-2 antibody in adults and above after initial vaccination with inactivated COVID-19 vaccine， and determine the influencing factors. MethodsIn this study， residents aged 18 and above who had completed two doses of inactivated COVID-19 vaccine in Deqing County， Huzhou City， Zhejiang Province were included. Information such as gender， age， type of vaccine and vaccination time were collected， and serum specimens were sampled. Anti-SARS-CoV-2 receptor binding domain （RBD） antibody was quantitatively examined by enzyma-linked immunosorbent assay （ELISA） and influencing factors were determined. ResultsThe median concentration of anti-SARS-CoV-2 IgG antibody in the residents vaccinated with an inactivated booster vaccine was higher than that in those vaccinated with only two doses of COVID-19 vaccine or single dose （P<0.05）. The median concentration of IgG antibody in males was 9.73 （4.01‒23.70） RU‧mL-1， lower than 17.76 （7.07‒49.23） RU‧mL-1 in females （P<0.05）. The median concentration in the residents vaccinated with BBIBP-CorV （Sinopharm） was 6.53 （0.97‒13.69） RU‧mL-1， which was lower than that in those vaccinated with CoronaVac （Sinovac） that was 17.29 （8.54‒43.73） RU‧mL-1 （P<0.05）. The median concentration in those with BBIBP-CorV was also lower than 12 （5.45‒40.06） RU‧mL-1 in those with heterologous booster vaccine （P<0.05）. The median concentration was 9.73 （3.83‒23.63） RU‧mL-1 in the residents with an interval of more than 6 months from the second dose， which was lower than 14.66 （6.36‒35.98） RU‧mL-1 in those with an interval of 3‒6 months （P<0.05）. Moreover， immune effect was better in females （χ²=16.464， P<0.05）， 18‒45 years（χ²=7.158， P<0.05）， and those vaccinated with CornaVac （χ²=49.637， P<0.05）， while decreased in those with an interval of more than 6 months from the second dose （χ²=8.447， P<0.05）. ConclusionGender， age， and type of vaccine may affect the effect of immunization. The COVID-19 vaccination shows an acceptable immunogenicity in adults； however， it declines in 6 months after vaccination. It warrants strengthening the booster vaccination to maintain the immune response.
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【Objective】 To investigate the immune status of blood donors in Yangzhou area after SARS-COV-2 vaccinating. 【Methods】 Among 112 voluntary blood donors from August 29 to September 22, 2021, 111 were vaccinated with SARS-COV-2 vaccine.IgM antibody(by enzyme-linked immunocapture method), IgG antibody(by indirect method of combined immunoassay)and IgG antibody titer were detected. 【Results】 A total of 99.11% (111/112 ) voluntary blood donors were vaccinated, two-shot(n=103), one-shot(n=1) and three-shot (n=7) accounting for 91.96%, 0.89% and 6.25%, respectively.Eighty-eight (78.57%) were positive for IgG antibodies, and 14 (12.5%) were positive for IgM antibodies.No statistically significant difference was found in IgG and IgM positive yielding between males and females (P>0.05). The proportion (0.89%, 1/112) of positive IgM in blood donors with blood type A was significantly lower than that of other blood types (P<0.01). The IgG antibody titer of blood donors maintained rather high level within 6 months after vaccinating.47.66% of the donors presented antibody titer more than 160, and 5.60% had IgM antibody been detected within 1 month after vaccinating. 【Conclusion】 At present, the SARS-COV-2 vaccination effect in China is generally good.Since IgG antibodies cannot be detected after 6 months, it is suggested to perform IgG antibody testing for donors who have completed the second dose for more than 6 months.For those IgG antibody negative, booster shots should be conducted.For donors with high IgG antibody titer, their plasma may be considered to replace with COVID-19 convalescent plasma for the treatment of patients with rapid disease progression, or severe/critically ill patients diagnosed with COVID-19, so as to avoid the risk of COVID-19 re-spreading during convalescent plasma collection in blood centers. For blood donors with positive IgM antibodies, it is recommended to follow up the NAT results to minimize the risk of transmission.
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【Objective】 To assess three severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2) enzyme linked immunosorbent assays (ELISA) and one pseudotype lentivirus-based neutralization test (ppNAT) in detecting the convalescent plasma antibody levles from COVID-19. 【Methods】 30 COVID-19 convalescent plasma samples were screened for antibodies against SARS-CoV-2 using three kinds of SARS-CoV-2 ELISA reagents and one ppNAT test in Shenzhen. The controls consisted of plasma samples from 32 healthy blood donors in February 2019. The diagnostic efficacy analysis of various SARS-CoV-2 ELISA reagents was performed using real-time fluorescent Polymerase Chain Reaction (RT-PCR). We also analyzed correlation between different immunological reagents and the age, gender, hospitalization, and severity of illness. 【Results】 The positive yielding rate of ppNAT and three kinds of IgG ELISA was higher than that of IgM ELISA. The positive yielding rates of three kinds of IgG ELISA were 100%(30/30), 93.33%(28/30), and 96.67%(29/30) respectively, while the yielding rates in control group were all 0. The positive yielding rate of three IgM ELISAs were 93.33%(28/30), 70%(21/30)and 46.67% (14/30). All the cases from negative control group were negative for IgG and IgM. Pearson correlation coefficient was calculated; there was a strong correlation between ELISA reagent 2 IgG and ELISA reagent 3 IgG (r=0.765, P0.05). 【Conclusion】 In the convalescent plasma with nucleic acid confirmed covid-19, the yielding rates of different IgM antibodies varied greatly. Antibody levels were influenced by age to some extent.
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Objective:To detect IgG and neutralizing antibodies response to SARS-CoV-2 vaccine by comparing enzyme-linked immunosorbent assay (ELISA), commercial magnetic particle chemiluminescence assay(CLIA) and neutralization test(NT).Methods:ELISA, CLIA and NT were used to detect 143 healthy people before and after 28 days immunization with 2 doses of SARS-CoV-2 vaccine, and calculate the positive conversion rate, quantitative results and analysis the consistency of the three methods.Results:The positive conversion rate of SARS-CoV-2 vaccine antibody detected by ELISA, CLIA and NT were respectively 97.9%, 98.6% and 85.3%. The geometric mean of the highest dilution of the serum quantitatively detected by ELISA was 586.6; The mean of CLIA S/CO value was 11.26; The geometric mean titer of the NT was 7.6. The correlation coefficient between ELISA, CLIA and NT were respectively 0.69( P<0.01) and 0.65( P<0.01), and the correlation coefficient between ELISA and CLIA was 0.79( P<0.01). Conclusions:The three methods all detected high levels of antibodies response to SARS-CoV-2 vaccine immunization. ELISA and CLIA are more consistent to detect IgG antibody, and have a good correlation with the quantitative detection results of the NT.
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@#Objective To summarize the results of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG antibody, total antibody and cellular immune function of COVID-19 convalescent patients one year after discharge, and to analyze the correlation between the SARS-CoV-2 antibody and the indexes of immune function. Methods A total of 41 confirmed COVID-19 patients discharged from Chengdu Public Health Clinical Medical Center from January to April 2020 and followed up one year after discharge were included in the study as the research group, including 18 males and 23 females with an average age of 47.83±12.95 years. The results of SARS-CoV-2 IgG, total antibody and immune function indexes one year after discharge were collected in order to discuss the correlation of SARS-CoV-2 and cellular immune function. A total of 40 healthy employees of the hospital vaccinated against COVID-19 were randomly selected as the vaccine group, including 10 males and 30 females with an average age of 43.90±6.86 years. The SARS-CoV-2 antibodies between the two groups were compared. Results CD8+T cell count was higher and CD4+T/CD8+T was lower in male patients than those in female patients (all P<0.05). The IgG and total antibodies in patients with re-detectable positive RNA test were both higher than those in patients without re-detectable positive RNA test, but the differences were not statistically significant (P=0.158, 0.060). The positive rate of SARS-CoV-2 IgG in the research group was 80.5% (33/41). SARS-CoV-2 IgG was positively correlated with total antibody (P<0.001). There was a positive correlation between CD4+T cell count and SARS-CoV-2 IgG (r=0.455, P=0.003). The positive rate of SARS-CoV-2 IgG, SARS-CoV-2 IgG amount and total antibody amount in the research group were significantly higher than those in the vaccine group (all P<0.001). Conclusion SARS-CoV-2 IgG of most COVID-19 patients one year after discharge is positive, and their SARS-CoV-2 total antibody is significantly higher than people vaccinated against COVID-19, which suggests that patients infected with SARS-CoV-2 can obtain lasting protection, but the protection may be gradually weaken over time. The degree of antibody attenuation in patients with re-detectable positive RNA test may be weaker. In the convalescence stage, the dynamics of SARS-CoV-2 IgG may be closely related to cellular immune function.
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Introduction@#The Severe Acute Respiratory Syndrome coronavirus-2 has a major impact in solid organ transplant recipients and the effect of established mRNA based SARS-CoV-2 vaccines have to be evaluated for solid organ transplant patients (SOT) since they are known to have poor responses after vaccination. @*Method@#We investigated the SARSCoV-2 immune response via SARS-CoV-2 S IgG detection in the serum of 17 renal transplant recipients and 11 liver transplant recipients after two doses of the mRNA based SARS-CoV-2 vaccine BNT162b2 following the standart protocol.@*Result@#The median age was 52.5±12 years. Nineteen (67.8%) of the 28 patients were male, and 9 (32.2%) were female. The mean time after organ transplantation was 6.3±5 years (5 months-16 years). The immunosuppressive regimen included mycophenolate (19 of 28; 67.8%), tacrolimus (27 of 28; 96.4%), and corticosteroids (15 of 28; 53.6%).</br> The antibody response was evaluated once with an anti- SARS-CoV-2-S IgG CLIA (Elecsys Roche, Germany) 30±2 days after the second dose. Only 19 of 28 (67.8%) SOTRs were tested positive for SARS-CoV-2-S IgG after the second dose of vaccine and median titer was 119.5±106.4 Н/мл. @*Conclusion@#Thus, the humoral response of SOTRs after two doses of the mRNA based SARS-CoV-2 vaccine BNT162b2 is impaired. Individual vaccination strategies and third dose of vaccine might be beneficial in these vulnerable patients.
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Objective:To investigate the levels and influencing factors of serum pertussis toxin (PT)-IgG antibody in children with pertussis.Methods:The clinical data including age, course of disease and vaccination status of children with laboratory-confirmed pertussis and tested for PT-IgG antibody in Shenzhen Children′s Hospital from July 2015 to December 2018 were collected. Venous blood samples were obtained to detect PT-IgG antibody levels. Nasopharyngeal swabs were taken for polymerase chain reaction (PCR) test to detect Bordetella pertussis nucleic acid and culture of Bordetella pertussis. Mann-Whitney U test was used for comparison between two groups.Kruskal-Wallis test was used for comparison among multiple groups. Multiple linear regression was used to analyze the influencing factors of PT-IgG antibody levels. Results:A total of 871 children aged 4(2, 7) months were included, among whom, 592(68.0%) cases were under six months and 754 (86.6%) cases were under one year old. The course of disease was 15 (11, 20) days. Among 871 cases, 864 (99.2%) cases were PCR test and (or) culture positive, including 696 cases positive only for PCR test, 35 cases positive only for culture and 133 cases positive for both PCR test and culture. There were 452 (51.9%) children who were not vaccinated and 346 (39.7%) children vaccinated with at least one dose. In terms of age, the PT-IgG amtibody levels of children aged 0 to two months, three to five months, six months to two years and ≥three years were 0.7 (0, 8.2) IU/mL, 2.3 (0, 23.0) IU/mL, 24.6 (0, 112.3) IU/mL and 24.9 (0, 114.7) IU/mL, respectively. The PT-IgG antibody levels of children after onset of symptoms at 0 to two weeks, more than two to four weeks, more than four to eight weeks and more than eight weeks were 0(0, 7.9) IU/mL, 8.7(0, 56.0) IU/mL, 26.6(5.1, 82.9) IU/mL and 68.0(15.3, 118.8) IU/mL, respectively. The differences were both statistically significant ( H=88.346 and 94.076, respectively, both P<0.01). The PT-IgG antibody levels in children who were unvaccinated and vaccinated with at least one dose were 0.9 (0, 12.7) IU/mL and 14.6(0, 86.3) IU/mL, respectively. The difference was statistically significant ( Z=-8.520, P<0.01) PT-IgG≥80 IU/mL accounted for 16%(139/871) in the whole range of age, 34.3%(12/35) in children ≥three years old. There were 13 patients aged ≥three years old with a disease course >two weeks, among whom, six patients had PT-IgG≥80 IU/mL. Age, course of disease and vaccination status were independent influencing factors of PT-IgG levels ( β=0.108, 0.189 and 0.250, respectively, all P<0.01). Conclusions:The levels of PT-IgG antibody in children with pertussis are influenced by age, course of disease and vaccination status. The single serum PT-IgG of 80 IU/mL as cut-off value in the diagnosis of pertussis may lead to a increase of missed diagnosis. Therefore, it is necessary to further explore the standards suitable for children in China.
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Abstract Aimed with this study to evaluate vertical transmission of Neospora caninum in naturally infected sheep and to monitor the kinetics of antibodies against this protozoon in their lambs. Therefore, 48 pregnant ewes, from five herds, were divided into two groups: G1 - positive for anti-N. caninum antibodies, with 19 animals; and G2 - seronegative, with 29 animals. Blood samples were taken from the ewes and their lambs, immediately after birth, before ingesting colostrum, and 2, 7, 14, 21, 28, 35, 42, 49 and 56 days after birth. Analysis on serum antibodies was performed using the indirect immunofluorescent antibody test. Among the 19 seropositive mothers, six (31.6%) gave birth to lambs seropositive before ingesting colostrum and it was found that these lambs remained positive until the end of the study (56 days). Only one of the lambs, from a ewe that presented an antibody titer of 200, seroconverted after ingestion of colostrum. All the lambs that had been born from negative mothers remained negative throughout the experimental period. It was concluded that transplacental transmission was an important form of diffusion of N. caninum in the herds studied and that seropositive lambs maintained circulating antibodies during the period analyzed.
Resumo Objetivou-se avaliar a ocorrência da transmissão vertical de Neospora caninum em ovelhas naturalmente infectadas e monitorar a cinética de anticorpos para esse protozoário nos cordeiros. Portanto, foram selecionadas 48 matrizes prenhes, provenientes de cinco propriedades, e estas foram divididas em dois grupos: G1- 19 matrizes positivas para anticorpos anti-N. caninum antes da prenhez; e G2 - 29 matrizes soronegativas. Foram realizadas colheitas sanguíneas nas mães e cordeiros, no G1 e G2, imediatamente após a parição, antes da ingestão do colostro. Também foi possível realizar colheitas de sangue com 2, 7, 14, 21, 28, 35, 42, 49 e 56 dias após o nascimento. A pesquisa de anticorpos séricos foi realizada por meio da Reação de Imunofluorescência Indireta (RIFI). Das 19 matrizes soropositivas, seis (31,6%) pariram cordeiros soropositivos antes da ingestão do colostro, os quais mantiveram-se positivos até o final do experimento (56 dias). Apenas um dos cordeiros, filho de uma ovelha com título de anticorpos 200, soroconverteu após ingestão do colostro. Todos os cordeiros, filhos de mães negativas, mantiveram-se negativos durante todo o período experimental. Conclui-se que a transmissão transplacentária é uma importante forma de difusão do N. caninum nos rebanhos estudados e que os descendentes infectados, durante a gestação, mantiveram anticorpos circulantes durante o período analisado.
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Animals , Female , Pregnancy , Sheep Diseases , Coccidiosis/veterinary , Neospora , Brazil , Sheep , Antibodies, Protozoan , Kinetics , Infectious Disease Transmission, Vertical/veterinaryABSTRACT
【Objective】 To retrospectively analyze the irregular antibodies in 6 blood group systems other than the Rh blood group system in 53 pregnant women and analyze its correlation with the occurrence of hemolytic disease of the newborn(HDN). 【Methods】 19 473 pregnant women were screened for irregular antibodies by microgel detection technology combined with anti-human globulin (IgG+ C3d), and the positive samples screened out were further confirmed to understand the types and titers of irregular antibodies. Irregular antibody type determination experiment: IgG type irregular antibody titer was determined after mercaptoethanol (2-Me) inactivated the serum of the irregular antibody positive specimen, and then IgG and IgM type were determined by comparing the titer levels of irregular antibody. Three hemolysis tests and total bilirubin tests were performed on umbilical cord blood during delivery to analyze the level of jaundice and the occurrence of HDN. 【Results】 53 cases of irregular antibodies other than the Rh blood group system were detected in 19 473 pregnant women, with a positive rate of 0.27%, mainly MNS and Lewis blood group system.The incidence of HDN was 39.6% (21/53). There were 27 cases of IgM, 7 IgG, and 19 IgM + IgG. Comparison of total bilirubin detection between the low titer group (≤8) and the high titer group (>8) : the latter was significantly higher than the former (P<0.05); IgG antibody subtypes: IgG1 of the latter significantly increased (P<0.05), and so was IgG3 in former (P<0.05). There was a significant positive correlation between IgG1, IgG3 and total bilirubin. The area under the curve of IgG1+ IgG3 for HDN diagnosis, the sensitivity and specificity were 0.953, 0.900, and 0.967, respectively. 【Conclusion】 Other than Rh blood group system, irregular antibodies are mainly distributed in MNS and Lewis blood group system. The incidence of HDN is higher in Kell, Duffy and Kidd blood group systems after producing irregular antibodies. Non-antibody types are mostly IgM type or IgM + IgG mixed, and the incidence of HDN is not high; Patients with poor maternal history, either high or low titer, can be classified into IgG1 and IgG3 in early stages, and those with Abnormal results should be included into the perinatal management of high-risk women with regular checking.