ABSTRACT
Objective:To evaluate the auxiliary diagnosis value of bacterial culture, polymerase chain reaction (PCR) and serum anti-pertussis toxin immunoglobulin G (AntiPT-IgG) level detection in suspected pertussis.Methods:A total of 110 suspected cases of pertussis treated in the Department of Pediatrics of Wuhu No.1 People′s Hospital from June 2018 to May 2019 were recruited for the study.The nasopharyngeal swabs of all cases were collected for Bordetella pertussis culture and specific nucleic acid PCR detection.Serum samples of 78 cases were collected for the detection of AntiPT-IgG level by enzyme linked immunosorbent assays.Results:The positive rates of bacterial culture group and PCR group were 21.8% and 30.0%, respectively, with no statistically significant difference ( χ2=1.198, P>0.05). The culture positive rate of cases with the duration of cough<2 weeks was 32.1%, which was signi-ficantly higher than that of cases with the duration of cough about 2-4 weeks (14.3%) or >4 weeks (9.1%) ( χ2=6.522, P<0.05). The PCR positive rate of cases with the duration of cough <2 weeks was 39.6%, which was also significantly higher than that of cases with the duration of cough about 2-4 weeks (25.7%) or > 4 weeks (13.6%) ( χ2=6.126, P<0.05). The mean value for serum AntiPT-IgG level of 78 cases was (75.727±78.454) IU/mL, the median AntiPT-IgG levels of cases with the duration of cough<2 weeks and about 2-4 weeks were 5.909 IU/mL and 20.948 IU/mL, respectively, and the positive rates were 14.7% and 38.1%, respectively.The AntiPT-IgG level of cases with the duration of cough> 4 weeks and that at convalescent stage were (79.281±68.254) IU/mL and (107.242±75.750) IU/mL, and the positive rates were 39.1% and 57.1%, respectively. Conclusions:In the vaccine era, the results of pathogenic and serological tests should be combined to assist the clinical diagnosis of pertussis.The positive rate of bacterial culture and specific nucleic acid pathogen detection in children with cough duration less than 2 weeks is high, and the serological diagnosis is more effective after the duration of cough is over 4 weeks.
ABSTRACT
Objective To explore the transmission chain of COVID-19 by serum antibody detection, and to provide scientific evidence for the prevention and control of the epidemic. Methods Field epidemiological investigation was used to determine the COVID-19 cases and their close contacts. The 2019-nCoV nucleic acid in throat swabs and anal swabs were examined by RT-PCR. Serum specimens were collected for anti-2019-nCoV IgM antibody detection and combined IgM/IgG detection. Results Case A had no confirmed exposure to COVID-19. However, case C and D had dinner and lived together with case A; they reported contact history and dinner history with other confirmed COVID-19 cases(H, L). Case A tested positive for 2019-nCoV nucleic acid, whereas case C and D were negative. Moreover, case A and C were IgM antibody positive, while case D was negative. Case A, C and D were all positive for combined IgM/IgG. In addition, case D had clinical symptom, while case C did not. Conclusion Serum antibody detection can be used as an effective supplement to the inference of transmission chain of COVID-19, which may facilitate determining the source of infection and improving the evidence.
ABSTRACT
Evaluation of diagnostic tests requires reference standards, which are often unavailable. Latent class analysis (LCA) can be used to evaluate diagnostic tests without reference standards, using a combination of observed and estimated results. Conditionally independent diagnostic tests for Helicobacter pylori infection are required. We used LCA to construct a reference standard and evaluate the capability of non-invasive tests (stool antigen test and serum antibody test) to diagnose H. pylori infection compared with the conventional method, where histology is the reference standard. A total of 96 healthy subjects with endoscopy histology results were enrolled from January to July 2016. Sensitivity and specificity were determined for the LCA approach (i.e., using a combination of three tests as the reference standard) and the conventional method. When LCA was used, sensitivity and specificity were 83.8% and 99.4% for histology, 80.0% and 81.9% for the stool antigen test, and 63.6% and 89.3% for the serum antibody test, respectively. When the conventional method was used, sensitivity and specificity were 75.8% and 71.1% for the stool antigen test and 77.7% and 60.7% for the serum antibody test, respectively. LCA can be applied to evaluate diagnostic tests that lack a reference standard.
Subject(s)
Diagnosis , Diagnostic Tests, Routine , Endoscopy , Healthy Volunteers , Helicobacter pylori , Helicobacter , Methods , Sensitivity and SpecificityABSTRACT
Objective@#To detect norovirus (NoV) GⅠ.1- and GⅡ.4-specific IgG, IgA and histo-blood group antigen (HBGA)-blocking antibodies in healthy populations of all age groups in China for better understanding the epidemiological features of norovirus in China from a serological point of view and providing basic data for vaccine development and clinical trial design.@*Methods@#Indirect ELISA and HBGA-blocking assay were used to detect NoV-specific IgG, IgA and HBGA-blocking antibodies in serum samples collected from healthy natural populations (n=839, aged from six months to 88 years old) in Guangzhou, Fuyang and Yantai. The results were statistically analyzed.@*Results@#The total positive rates of NoV GⅠ.1- and GⅡ.4-specific IgG antibodies were 91.9% and 93.0%. The positive rates of GⅠ.1- and GⅡ.4-specific IgA antibodies were 48.6% and 75.6%, and the titers of HBGA-blocking antibodies to GⅠ.1 and GⅡ.4 norovirus were 5.04 (95%CI: 4.63-5.49) and 18.15 (95%CI: 16.11-20.44). The positive rates of IgG and IgA antibodies generally showed an increasing trend with age. The positive rates of GⅠ.1- and GⅡ.4-specific IgG antibodies ranged from 79.2% to 100.0% and 76.7% to 100.0% in different age groups. They were 81.7% and 85.0% in the age group of 0.5-<1 year, 79.2% and 76.7% in the age group of 1-<2 years, and 98.1% and 96.3% in the age group of 12-<18 years, and maintained at 96% and 98% in the older age groups. The positive rates of GⅠ.1-specific IgA antibody ranged from 11.7% to 93.8% in different age groups and rapidly increased with age. It was 11.7% in the age group of 0.5-<1 year, and reached 93.3% in people aged 45-<60 years and 93.8% in people aged ≥60 years. The positive rates of GⅡ.4-specific IgA antibody ranged from 50.8% to 88.8% in different age groups with 50.8% in people aged 0.5-<1 year, and 86.7%-90.7% in people aged 12-<18 years and older. The titer of GⅠ.1 HBGA-blocking antibody generally increased with age. The antibody titer in populations aged 0.5-<12 years old was lower than that in those aged 18 years and above (GMT: 2.98-4.07 vs 8.21-11.62, P<0.001), and the titer in people of 12-<18 years old was lower than that in those of 45 years old and above (GMT: 5.21 vs 11.03-11.62, P<0.05). No obvious change with age was observed in the titer of GⅡ.4 HBGA-blocking antibody excepting the significant difference between populations of 2-<5 and 22-<45 years old (GMT: 26.73 vs 11.87, P<0.01).@*Conclusions@#This study revealed the characteristics of serum NoV GⅠ.1- and GⅡ.4-specific IgG, IgA and HBGA blocking antibodies in populations of different age groups in central and eastern China through analyzing their positive rates and titers and provided preliminary seroepidemiological data for the development of NoV vaccines in China.
ABSTRACT
Objective To investigate the relationship between the level of serum iron-cofactored superoxide dismutase (SodB) antibody encoded by Helicobacter pylori (H.pylori) genome in infected populations of H.pylori and the occurrence of gastric cancer.Methods Serum samples from 114 cases and 104 control were collected.Indirect ELISA was used to detect serum SodB antibody level in case group and control group.The relationship between serum SodB antibody level and GC risk was analyzed by conditional logistic regression.The value of SodB in serological screening of gastric cancer was analyzed and evaluated by the receiver operating characteristic (ROC) curve.Results The level of serum SodB antibody was correlated with the occurrence of gastric cancer in subjects with OR=2.287 (95％CI:1.191～4.391)(P＜0.05).The optimal cutoff value of SodB for screening gastric cancer was determined by using receiver operating characteristic (ROC) curve,and it was 0.028 0.The area under the ROC curve for subjects was 0.575 (95 ％ CI:0.501 ～ 0.649).Conclusion The level of serum H.pylori SodB antibody was associated with the occurrence of gastric cancer.SodB alone was not effective in screening gastric cancer.It might be used in combination with other biomarkers of gastric cancer to improve further screening of gastric cancer.
ABSTRACT
More than 60% of active tuberculosis(TB) patients are smear- and culture-negative, constituting a prime group in the prevention and control of TB in China. In the existing laboratory testing technologies, immunological diagnosis is more advantageous than etiological diagnosis in the detection of smear-and culture-negative TB. Serum antibody detection reagents are cheap,easy to operate and time-sav-ing,and have been widely used in China. However,these agents are not stable in sensitivity and specificity, and because of that their accuracy in the diagnosis of smear-and culture-negative TB is doubtful. In this re-view,we summarize some problems in the use of serum antibody detection among smear- and culture-nega-tive pulmonary TB patients and discuss possible methods to solve these problems expecting to provide some ideas for promoting its development,application and policy formulation.
ABSTRACT
Objective:To investigate the expression pattern of microRNA-146a in Brucella patients and its correlation with antibody titers.Methods: By using real time PCR assay, expression levels of microRNA-146a in sera samples from 20 brucellosis patients and 20 healthy volunteers were analyzed.The correlation between expression level of microRNA-146a and serum antibody titers were analyzed with SPSS17.0.Results: A quantification curve of microRNA-146a was constructed with synthesized standard.Expression levels of microRNA-146a among brucellosis patients were significantly lower than those in 20 healthy volunteers (P<0.001).For brucellosis patients,the expression level of microRNA-146a was negatively related with antibody titers (P<0.05). Conclusion:Expression of miRNA-146a in brucellosis patients was significantly inhibited and negatively related with antibody titer.
ABSTRACT
Cystic echinococcosis (CE) is one of the most widespread zoonotic helminthiases, which can last an asymptomatic infection for several years. The purpose of this study was to demonstrate serum antibody prevalence of CE among asymptomatic people in Uzbekistan using ELISA. A total of 2,547 serum samples were collected, 66 from confirmed CE patients and 2,481 of patients with other diseases than CE at a hospital in Tashkent, Uzbekistan. The serum samples were screened for CE specific IgG antibodies by ELISA using cystic fluid antigen obtained from sheep. The serum antibody positive rate was 89.4% (59/66) in CE and 3.6% (89/2,481) in other disease patients. The present ELISA recognized 89.4% sensitivity and 96.4% specificity. The ELISA absorbance of positive samples was distributed 0.271-0.971 for CE and 0.273-0.887 for other disease patients. The other disease patients with high absorbance over 0.3 were 50 (2.0%) who were presumed to be active CE patients. The patients in their 40s showed the highest positive rate of 5.2% (P=0.181), and women were 4.4% while men were 3.1% positive (P=0.136). The data confirmed that there are many asymptomatic patients of CE in Tashkent. It is indicated that CE is an endemic disease of public health importance in Uzbekistan.
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Animals , Child , Child, Preschool , Female , Humans , Male , Middle Aged , Young Adult , Antibodies, Helminth/blood , Echinococcosis/blood , Echinococcus/immunology , Emergency Service, Hospital , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G/blood , Prevalence , Uzbekistan/epidemiologyABSTRACT
Objective To explore the distribution of serum antibodies against human papillomavirus(HPV)16/18 among women at high-risk for cervical cancer. Methods All women when tested positive for anyone of the cervical cancer screening programs,from Xinmi county of Henan province in 2011,were recruited as the subjects of this study. Cervical exfoliated cells were collected,using cervical brush for HPV DNA testing,and 10 ml venous blood was drawn for HPV-16, 18 serum antibodies testing,by enzyme-linked immunosorbent assay. Results Among the 952 women unders study,230 cases(24.2%)showed HPV DNA positive,with positivity rates of HPV16 and 18 L1 virus-like particle(VLP)antibodies as 23.2%and 6.5%,respectively. The overall positivity rate of any type of HPV16,18 VLP antibodies was 26.8%. Geometric means of HPV16,18 VLP antibody titers were 79.1(Yangshengtang Unit,YU/ml)and 125.0(YU/ml). Positivity rate of HPV16 antibody was significantly associated with age,viral load of HPV DNA,and cervical lesion severity (P<0.05). Seropositvity of HPV18 was also increasing with the increase of viral load (P<0.01) with different cervical lesion significantly showing different titer of HPV18 antibody (P<0.01). Based on the results of HPV DNA detection among the two years of study,women with HPV persistent infection showed significant higher positive rate of HPV16/18 antibodies than women who did not have HPV infection or emerging infection (P<0.001). When comparing to those women without HPV infection,the ones with transient infection showed higher seropositivity rates on both HPV16 antibodies and titer of HPV16 antibody (P<0.001). Conclusion Seroprevalence rates on HPV16 and 18 among the unvaccinated high-risk women in Henan were high. Prevalence of both HPV16 and 18 antibodies were correlated with age,viral load,cervical lesion and history of infection. Women with high viral load,high grade cervical lesion or history of infection would more likely to be seropositive.
ABSTRACT
Objective To explore the distribution of serum antibodies against human papillomavirus(HPV)16/18 among women at high-risk for cervical cancer. Methods All women when tested positive for anyone of the cervical cancer screening programs,from Xinmi county of Henan province in 2011,were recruited as the subjects of this study. Cervical exfoliated cells were collected,using cervical brush for HPV DNA testing,and 10 ml venous blood was drawn for HPV-16, 18 serum antibodies testing,by enzyme-linked immunosorbent assay. Results Among the 952 women unders study,230 cases(24.2%)showed HPV DNA positive,with positivity rates of HPV16 and 18 L1 virus-like particle(VLP)antibodies as 23.2%and 6.5%,respectively. The overall positivity rate of any type of HPV16,18 VLP antibodies was 26.8%. Geometric means of HPV16,18 VLP antibody titers were 79.1(Yangshengtang Unit,YU/ml)and 125.0(YU/ml). Positivity rate of HPV16 antibody was significantly associated with age,viral load of HPV DNA,and cervical lesion severity (P<0.05). Seropositvity of HPV18 was also increasing with the increase of viral load (P<0.01) with different cervical lesion significantly showing different titer of HPV18 antibody (P<0.01). Based on the results of HPV DNA detection among the two years of study,women with HPV persistent infection showed significant higher positive rate of HPV16/18 antibodies than women who did not have HPV infection or emerging infection (P<0.001). When comparing to those women without HPV infection,the ones with transient infection showed higher seropositivity rates on both HPV16 antibodies and titer of HPV16 antibody (P<0.001). Conclusion Seroprevalence rates on HPV16 and 18 among the unvaccinated high-risk women in Henan were high. Prevalence of both HPV16 and 18 antibodies were correlated with age,viral load,cervical lesion and history of infection. Women with high viral load,high grade cervical lesion or history of infection would more likely to be seropositive.
ABSTRACT
Aim In order to understand infective conditions of Clonorchis sinensis in different populations in Nantong.Methods The antibodies of Clonorchis sinensis in fishermen area and cooks and shopkeepers et al. were investigated with PVC-Fast-Dot-ELISA. Results The average detective rate of Clonorchis sinensis antibodies was 3.92％ (17/434),the detective rate of Clonorchis sinensis in residents of fishermen area, cooks and shopkeepers (6.45％ ,2/31,5.59％ ,9/161、4.29％ ,3/70)was obviously higher than that of in the normal control group(0. 86％ ,1/115). There was a significant difference in the statistics (X2 = 3.52,X2 = 4.01,X2 = 2.28,P＜0. 01 ). Conclusions ①There is human infection of Clonorchis sinensis in Nantong area. ②The data emphasizes that the infection of Clonorchis sinensis has a strong association to do with occupation and contacting with raw fishes and opportunity of eating raw fishes and shrimps. ③It is recommended that the people of common eating raw fishes and shrimps must be examined and treated regularly.
ABSTRACT
In this study the ability of the monoclonal anti-idiotypic antibody NP30 was tested as a substitute of diagnostic antigen in detecting antibody of Schistosoma japonicum from human sera by use of ELISA. The results showed that the seropositive rate was 98% with NP30 in the group of acute infection, which was comparable to 94% with gut associated antigens (GAA)and 98% with the soluble egg antigens (SEA); 87% with NP30 in the group of chronic infection which was comparable to 86% with GAA but lower than that of 98% with SEA. The false positive rate was about 3% for all three diagnostic antigens. The results also showed that the geometric mean titer (GMT) of antibody to NP30 was higher than that to GAA but lower than that to SEA in the acute infection group and the GMT of antibody to NP30 was lower than both those to GAA and to SEA in the chronic infection group,suggesting that the antibody to NP30 appeared earlier and decayed more quickly during the process of infection. The authors suggested that NP30 could be used for the diagnosis of schistosomiasis japonica.
ABSTRACT
A 43-year-old man with generalized lichen planus demonstrated serum antibodies against autologous lesional skin. Indirect immunofluorescence using serum and papular lesional skin revealed a lichen planus specific antigen found only in the granular layer. The specific tissue antigen was not detected in normal skin from this patient, in normal skin from patients with skin disorders other than lichen planus or in skin from normal control persons. When titers of the serum antibodies against lichen planus antigen were examined before and after a successful therapy a positive correlation of the titer could be found in this patient.