SARS-CoV-2 Infectivity and Antibody Titer Reduction for 6 Months After Second Dose of BNT162b2 mRNA Vaccine in Health Care Workers: A Prospective Cohort Study.

Several studies reported that severe acute respiratory syndrome coronavirus-2 antibody levels change over 6 months in participants receiving the vaccination. From the enrolled 272 health care workers (HCWs), blood samples were obtained at 2, 16, and 24 weeks after the second vaccination dose. In the 267 noninfected HCWs, the neutralizing antibodies decreased by 23.9%, and the anti-spike/receptor binding domain antibody decreased by 53.8% at 24 weeks. We observed no significant difference in antibody reduction between the sexes; however, in younger individuals, there was higher antibody formation and lower reduction rates of the neutralizing antibody. In 3 HCWs with breakthrough infections, the antibody levels were relatively low just before the coronavirus disease 2019 infection. In conclusion, as antibody titers decrease over time after the second vaccination dose and HCWs with low antibody titers tend to have a high probability of breakthrough infection, an additional dose should be considered after several months. Blood samples were obtained from health care workers at 2, 16, and 24 weeks after a second vaccination dose. Antibody titers decreased over time and the participants with low antibody titers tended to have a high probability of breakthrough infection.

Characteristics of Korean BCR-ABL1-Negative Myeloproliferative Neoplasms Related to the 2016 WHO Criteria Revision.

BACKGROUND: We aimed to identify changes in the diagnosis and subtype classification of Korean patients with BCR-ABL1-negative MPN related to the revision of the WHO classification in 2016. METHODS: We evaluated 76 Korean patients with BCR-ABL1-negative MPN who underwent diagnostic work-ups, including bone marrow (BM) examinations and JAK2 V617F mutation analysis, from January 2013 to June 2018. Additionally, we reclassified the subtype of 43 patients who were diagnosed based on the WHO 2008 classification. RESULTS: From January 2013 to April 2016, 43 patients were diagnosed with BCR-ABL1-negative MPN (12 PV, 17 ET, 14 PMF) according to the 2008 WHO classification, and from May 2016 to June 2018, 33 patients were diagnosed according to the 2016 classification (15 PV, 11 ET, 7 PMF). With the application of 2016 classification, 3 cases of ET were reclassified as pre-PMF, and the proportion of PV increased from 27.9% to 45.5%. There were significant differences in CBC between pre-PMF and overt PMF, between ET and overt-PMF, but no difference between ET and pre-PMF. CONCLUSIONS: The overall characteristics of BCR-ABL1-negative MPN patients were not significantly different from those of previous reports. 'Masked PV', which could not be diagnosed according to the WHO 2008 classification, may have been diagnosed as PV since 2016 due to the increase in the diagnostic value of the BM findings and the lowering of the hemoglobin (Hb) threshold.

Strong SARS-CoV-2 Antibody Response After Booster Dose of BNT162b2 mRNA Vaccines in Uninfected Healthcare Workers.

Despite strict guidelines for coronavirus disease 2019 (COVID-19), South Korea is facing its fourth pandemic wave. In this study, by using an automated electrochemiluminescence immunoassay assay, we tracked anti-spike protein receptor-binding domain (anti-S-RBD) antibody titer from the second dose to 2 weeks after the booster dose vaccination. After the second dose, 234 participants had their anti-S-RBD antibody titers decrease over time. We also showed the booster dose (the third dose) increased antibody titer by average 14 (min-max, 2-255)-fold higher compared to the second dose among the 211-booster group participants, therefore, the booster dose could be recommended for low responders to the second dose. Our findings showed a distinct humoral response after booster doses of BNT162b2 mRNA vaccines and may provide further evidence of booster vaccination efficacy. These data will also be helpful in vaccination policy decisions that determine the need for the booster dose.

Evaluation of Five User-Friendly Whole Genome Sequencing Software for Mycobacterium tuberculosis in Clinical Application.

BACKGROUND: Whole genome sequencing (WGS) is an increasingly useful tool for tuberculosis (TB) diagnosis and disease management. In this study, we evaluated the utility of user-friendly WGS tools in reporting resistance profiles and identifying lineages of clinical TB isolates from South Korea. METHODS: Forty clinical samples from TB patients showing discrepancies between their rapid molecular and conventional drug susceptibility tests were used in this study. Among these clinical isolates, 37 strains were successfully evaluated via WGS software, using the GenTB, TB Profiler, PhyResSE, CASTB, and Mykrobe. RESULTS: More accurate and faster susceptibility results could be obtained with isoniazid than with rifampin. Using the phenotypic test as the gold standard, the isoniazid concordance rate between phenotypic drug susceptibility test (DST) and WGS (GenTB: 45.9%, TB profiler: 40.5%, PhyResSE: 40.5%, CASTB: 48.6%, and Mykrobe: 43.2%) was much higher than between phenotypic DST and rapid molecular genotypic DST (18.9%) among the 37 strains. In contrast, the rifampin concordance rate between phenotypic DST and WGS and that between phenotypic DST and rapid molecular genotypic DST was similar (81.1-89.2%). We also found novel mutations associated with INH in katG and ahpC gene region, not covered by the line probe assay. In addition, lineage analysis identified 81.1% of these samples as L2 East Asian lineage strains, and 18.9% as L4 Euro-American lineage strains. CONCLUSION: WGS may play a pivotal role in TB diagnosis and the detection of drug resistance, genetic diversity, and transmission dynamics in the near future because of its accuracy, speed, and extensibility.

Prevalence of granular corneal dystrophy type 2-related TGFBI p.R124H variant in a South Korean population.

Purpose: Granular corneal dystrophy type 2 (GCD2) is an autosomal dominant disorder and is associated with the arginine to histidine substitution at codon 124 (p.R124H) of the TGFBI gene. Although TGFBI p.R124H is known to be the most common corneal dystrophy-related pathogenic variant, there are few data on the frequency of this variant in the South Korean population. Methods: In total, 2,060 anonymous DNA samples from a public umbilical cord blood bank were tested for the TFGBI p.R124H variant using real-time PCR. Results: Six of the 2,060 samples [0.29%; 95% confidence interval (CI), 0.12-0.67%] were heterozygous for the TGFBI p.R124H variant. The prevalence of the GCD2-related TGFBI p.R124H variant in this population was estimated to be 291.3 per 100,000 [95% confidence interval (CI), 118.5-667.0]. Conclusions: To our knowledge, this is the largest study that has estimated the prevalence of the GCD2-related TGFBI p.R124H variant in South Korea.

Voxel-wise partial volume correction method for accurate estimation of tissue sodium concentration in 23 Na-MRI at 7 T.

Sodium is crucial for the maintenance of cell physiology, and its regulation of the sodium-potassium pump has implications for various neurological conditions. The distribution of sodium concentrations in tissue can be quantitatively evaluated by means of sodium MRI (23 Na-MRI). Despite its usefulness in diagnosing particular disease conditions, tissue sodium concentration (TSC) estimated from 23 Na-MRI can be strongly biased by partial volume effects (PVEs) that are induced by broad point spread functions (PSFs) as well as tissue fraction effects. In this work, we aimed to propose a robust voxel-wise partial volume correction (PVC) method for 23 Na-MRI. The method is based on a linear regression (LR) approach to correct for tissue fraction effects, but it utilizes a 3D kernel combined with a modified least trimmed square (3D-mLTS) method in order to minimize regression-induced inherent smoothing effects. We acquired 23 Na-MRI data with conventional Cartesian sampling at 7 T, and spill-over effects due to the PSF were considered prior to correcting for tissue fraction effects using 3D-mLTS. In the simulation, we found that the TSCs of gray matter (GM) and white matter (WM) were underestimated by 20% and 11% respectively without correcting tissue fraction effects, but the differences between ground truth and PVE-corrected data after the PVC using the 3D-mLTS method were only approximately 0.6% and 0.4% for GM and WM, respectively. The capability of the 3D-mLTS method was further demonstrated with in vivo 23 Na-MRI data, showing significantly lower regression errors (ie root mean squared error) as compared with conventional LR methods (p < 0.001). The results of simulation and in vivo experiments revealed that 3D-mLTS is superior for determining under- or overestimated TSCs while preserving anatomical details. This suggests that the 3D-mLTS method is well suited for the accurate determination of TSC, especially in small focal lesions associated with pathological conditions.

Positivity of SARS-CoV-2 Antibodies among Korean Healthy Healthcare Workers 1 and 2 Weeks after Second Dose of Pfizer-BioNTech Vaccination.

The antibody titer of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was observed in 289 healthy healthcare workers who had completed the second dose of the Pfizer-BioNTech coronavirus disease 2019 (COVID-19) vaccine. Antibody tests were performed using both the automated electrochemiluminescence immunoassay (ECLIA) and the chromatographic lateral flow immunoassay (LFIA). All subjects had antibodies against the receptor binding domain of the spike protein of SARS-CoV-2 only one week after completing the vaccination, and the antibody titer became significantly higher after another week (P < 0.001). Since there was a large amount of antibody formation within two weeks after completion of vaccination, the less sensitive method, LFIA, also showed high sensitivity. There was no significant difference between whole blood and serum in detecting SARS-CoV-2 antibodies after vaccination. This is an early study of vaccinations among Koreans and is expected to contribute to the establishment of national guidelines on COVID-19 vaccination.

Evaluation of Three Multiplex Real-time Reverse Transcription PCR Assays for Simultaneous Detection of SARS-CoV-2, Influenza A/B, and Respiratory Syncytial Virus in Nasopharyngeal Swabs.

BACKGROUND: In the coronavirus disease 2019 (COVID-19) pandemic era, the simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), influenza virus (Flu), and respiratory syncytial virus (RSV) is important in the rapid differential diagnosis in patients with respiratory symptoms. Three multiplex real-time reverse transcription polymerase chain reaction (rRT-PCR) assays have been recently developed commercially in Korea: PowerChek™ SARS-CoV-2, Influenza A&B Multiplex Real-time PCR Kit (PowerChek; KogeneBiotech); STANDARD™ M Flu/SARS-CoV-2 Real-time Detection Kit (STANDARD M; SD BioSensor); and Allplex™ SARS-CoV-2/FluA/FluB/RSV Assay (Allplex; Seegene). We evaluated the analytical and clinical performances of these kits. METHODS: A limit of detection tests were performed and cross-reactivity analysis was executed using clinical respiratory samples. Ninety-seven SARS-CoV-2-positive, 201 SARS-CoV-2-negative, 71 influenza A-positive, 50 influenza B-positive, 78 RSV-positive, and 207 other respiratory virus-positive nasopharyngeal swabs were tested using the three assays. The AdvanSure™ respiratory viruses rRT-PCR assay (AdvanSure; LG Life Sciences) was used as a comparator assay for RSV. RESULTS: Except in influenza B, in SARS-CoV-2 and influenza A, there were no significant differences in detecting specific genes of the viruses among the three assays. All three kits did not cross-react with common respiratory viruses. All three kits had greater than 92% positive percent agreement and negative percent agreement and ≥ 0.95 kappa value in the detection of SARS-CoV-2 and flu A/B. Allplex detected RSV more sensitively than AdvanSure. CONCLUSION: The overall performance of three multiplex rRT-PCR assays for the concurrent detection of SARS-CoV-2, influenza A/B, and RSV was comparable. These kits will promote prompt differential diagnosis of COVID-19, influenza, and RSV infection in the COVID-19 pandemic era.

Fifteen new nucleotide substitutions in variants of human papillomavirus 18 in Korea : Korean HPV18 variants and clinical manifestation.

High-risk human papillomavirus (HPV) infection is an essential factor for the development of cervical cancer. HPV18 is the second most common carcinogenic HPV type following HPV16, but the lineages of HPV18 have been less well studied than those of HPV 16. The purpose of this study was to analyze the nucleotide variants in the E6, E7, and L1 genes of HPV18, to assess the prevalence of HPV18 variants in Korea and to explore the relationship between HPV18 genetic variants and the risk for cervical cancer.A total of 170 DNA samples from HPV18-positive cervical specimens were collected from women admitted to a secondary referral hospital located in Seoul. Among them, the lineages of the 97 samples could be successfully determined by historical nomenclature.All the studied HPV 18 variants were lineage A. Sublineages A1 and A4 comprised 91.7% (89/97) and 1.0% (1/97), respectively. Sublineages other than A1 or A4 comprised 7.2% (7/97). We identified 15 new nucleotide substitutions among 44 nucleotide substitutions: C158T, T317G, T443G, A560G, A5467G, A5560C, A5678C, A6155G, G6462A, T6650G, G6701A, T6809C, A6823G, T6941C and T6953C. Among them, 6 substitutions at positions 317, 443, 5467, 5560, 6462, and 6823 resulted in amino acid changes (E6: F71L and N113K; L1: H13R, H44P, A345T, and N465S, respectively). The pathologic results were classified as normal in 25.8% (25/97) of the women, atypical squamous cells of undermined significance (ASCUS) in 7.2% (7/97), cervical intraepithelial neoplasia (CIN) 1 in 36.1% (35/97), CIN2/3 in 19.6% (18/97), and carcinoma in 12.4% (12/97). There was no significant association between the HPV18 sublineages and the severity of pathologic lesion or the disease progression.This study is the first to analyze the distribution of HPV18 variants in Korean and to associate the results with pathologic findings. Although the HPV18 variants had no significant effect on the degree and progression of the disease, the newly discovered nonsynonymous mutation in L1 might serve as a database to determine vaccine efficacy in Korean women.

Total nucleated cell counts are driving clinician's choice rather than cryopreservation period: Lesson for cord blood banks.

According to the increase in both the number of cryopreserved cord blood (CB) units and the cryopreservation period for each CB unit in the largest public CB bank in Korea, we are pursuing greater efficiency in CB bank management. Thus, we analyzed whether the cryopreservation period has a negative impact on the selection of CB units for CB transplantation (CBT). Until December 2019, 468 CB units were used for transplantation. The cryopreservation period, total nucleated cell (TNC), and CD34+ cell counts were analyzed among the CB units according to the CBT-year and the donation year. The results showed that the cryopreservation period was increased in recent CBT-year groups. The transplanted CB units showed similar TNC counts irrespective of the donation year, and the mean TNC count was 13.9 × 108/unit. CB units cryopreserved for a relatively long period were transplanted consistently. The mean TNC count of CB units cryopreserved for over 10 years was 16.4 × 108/unit. The mean CD34+ cell counts were not significantly different among the CB units transplanted after CBT-2013 and among the CB units donated after CBT-2011. Through an analysis of the CB units selected by clinicians for CBT, this study revealed that clinicians placed more weight on the TNC counts than on the cryopreservation period of cryopreserved CB units. Therefore, the minimum TNC count of CB units suitable for cryopreservation should be increased up to 13.0 × 108/unit to balance the satisfaction of clinicians' needs with the efficiency of the CB bank.

GWAS identifying HLA-DPB1 gene variants associated with responsiveness to hepatitis B virus vaccination in Koreans: Independent association of HLA-DPB1*04:02 possessing rs1042169 G - rs9277355 C - rs9277356 A.

Recently, HLA class II loci, including HLA-DPB1, have been reported to be associated with interindividual variance in the hepatitis B (HB) vaccine response. In this study, we investigated significant single nucleotide polymorphisms (SNPs) for anti-HBs antibody levels in 6867 healthy Koreans using a genome-wide association study (GWAS). In GWAS, the top 20 SNPs that showed significant association with anti-HBs levels (P < 1.0 × 10-29 ) all resided in HLA-DPB1. Utilizing PCR sequencing, we verified the relationship of the top 3 most significant SNPs (rs1042169, rs9277355 and rs9277356) from the GWAS and genotypes of HLA-DPB1 with the HB vaccine response in Korean infants who received a scheduled vaccination. The DPB1*04:02 allele has G, C and A nucleotides for the 3SNP sites, and was significantly more frequent in responders than in nonresponders (10.9% vs 1.0%, Pc  = 0.018). DPB1*05:01 was significantly more frequent in nonresponders than in responders (49.0% vs 31.1%, Pc  = 0.018). In multivariate logistic regression, DPB1*04:02 showed a significant association with both vaccine response (P = 0.037, OR = 8.465) and high-titre response (P = 0.027, OR = 9.860). The haplotypes rs1042169 G - rs9277355 C - rs9277356 A showed a significant association with a high-titre response only (P = 0.002, OR = 2.941). In conclusion, DPB1*04:02 possessing rs1042169 G - rs9277355 C - rs9277356 A is an independent predictor of the HB vaccine response in Koreans.

Effects of interleukin-4 and interleukin-12B gene polymorphisms on hepatitis B virus vaccination.

 Approximately 10% of individuals do not respond to hepatitis B virus (HBV) vaccination, i.e. non-responders (NRs). We aimed to investigate the association of interleukin (IL)-4 and IL-12B gene polymorphisms with responsiveness to the HBV vaccine in Korean infants. Among 300 healthy infants (9-12 month), SNPs for the IL-4 gene (rs2243250, rs2070874, and rs2227284) and for the IL-12B gene (rs3213094 and rs17860508) were compared between subgroups in terms of the response to HBV vaccination. The percentages of NRs (< 10 mIU/mL), low-titer responders (LRs, 10-100 mIU/mL), and high-titer responders (HRs, ≥ 100 mIU/mL) were 20.3%, 37.7% and 42.0%, respectively. No SNPs differed in frequency between NRs and responders or between LRs and HRs. We divided the subjects into two groups according to the time interval from the 3rd dose of HBV vaccination to Ab quantification: > 6 months from the 3rd dose (n = 87) and ≤ 6 months from the 3rd dose (n = 213). In the ≤ 6 month subjects, rs2243250C and rs2227284G were significantly frequent in the lower-titer individuals (NRs + LR) than HRs (40.1 vs. 25.9%, p = 0.014 and 45.1 vs. 33.0%, p = 0.018, respectively), and the rs2243250C and rs2227284G frequencies were significantly different among the three subgroups (13.2 vs. 26.9 vs. 25.9%, p = 0.040 and 15.5 vs. 29.6 vs. 33.0%, p = 0.038, respectively). In conclusion, those results suggest that IL-4 gene polymorphisms may play a role in the response to the HBV vaccine in Korean infants.

Single nucleotide polymorphisms in the TGF-ß1 gene are associated with polycystic ovary syndrome susceptibility and characteristics: a study in Korean women.

PURPOSE: Although many hypotheses regarding the pathogenesis of polycystic ovary syndrome (PCOS) have been generated, genetic studies have not identified specific genes that play a role in PCOS etiopathogenesis. This study aimed to investigate the relationship between TGF-ß1 gene polymorphism and PCOS in Koreans. METHOD: A total of 51 Korean women with PCOS and 69 healthy women were enrolled. We analyzed 4 single nucleotide polymorphisms (SNPs) of the TGF-ß1 gene (rs11466313, rs1800469, rs2317130, and rs4803457). We also analyzed laboratory measurements, such as free testosterone, glucose, and cholesterol. RESULTS: The frequencies of rs1800469T allele negativity, rs4803457T allele negativity, the rs1800469CC genotype, and the rs4803457CC genotype showed positive associations with PCOS (P = 0.003, P = 0.027, P = 0.009, and P=0.031, respectively), whereas the haplotypes rs1800469C-rs4803457T and rs1800469T-rs4803457T showed negative associations with PCOS. A strong protective effect of the "rs1800469CT-rs4803457TT" combination (OR = 0.09) and a strong risk effect of "rs1800469CC-rs4803457CC" (OR = 6.23) for PCOS were observed. The rs1800469C/T and rs2317130C/T SNPs exhibited associations with several laboratory measurements with various levels of significance. CONCLUSION: The results demonstrated an association of TGF-ß1 gene polymorphisms with the development and/or characteristics of PCOS in the Korean population.

Evaluation of LABType® SSO HLA Typing using the Luminex Platform: Cord Blood Registry Typing for the Korean Population.

BACKGROUND: The performance of a new intermediate-resolution method using a PCR-Luminex platform and LABType® SSO A, B DRB1 kits as an HLA typing method for the cord blood (CB) registry of the Korean population was investigated. METHODS: A total of 1,413 cord blood units (CBUs) were enrolled - 1,382 from Koreans and 31 from non-Koreans or mixed-ancestry individuals. HLA-A, -B, and -DRB1 typing was performed using the LABType® SSO typing kits. HLA typing with the DNA method and 2-digit results are mandatory for the public CB bank in Korea according to the "CB Act." RESULTS: The proportions of ambiguous results in the 2-digit assignment were 14.6% (206/1,413) and 14.8% (205/ 1,382) among the total subjects and the Korean donors, respectively. In the 2-digit resolution, 3 different HLA-A types (69 CBUs), 31 HLA-B types (124 CBUs), and 3 HLA-DRB1 types (13 CBUs) showed ambiguous results. The 'most probable type' to the ambiguous results based on the reported Korean HLA allele frequencies were able to be assigned. The most probable results were 100% consistent with the confirmed types as determined by the HD kits (DRB1) and additional PCR-SBT or PCR-SSP tests (A and B). Luminex technology is more automated and less labor intensive than the conventional SSO typing method, and the results are less affected by differences between inspectors. CONCLUSIONS: Although it is not satisfactory as a sole confirmation test and cannot be used as a replacement for the PCR-SBT test, the combination of Luminex technology with LABType® SSO kits and population frequency data provides a proper typing platform that can be used as a qualifying test for CB registries.

Frequency of the moyamoya-related RNF213 p.Arg4810Lys variant in 1,516 Korean individuals.

BACKGROUND: Moyamoya disease (MMD) is a progressive steno-occlusive vasculopathy that involves large intracranial arteries accompanied by abnormal collateral vessels. Recently, RNF213 was identified as a susceptibility gene for MMD and p.Arg4810Lys (rs112735431) is the most common variant in East Asian MMD patients. Interestingly, many studies have reported that a certain proportion of the general population in Japan, Korea, and China also has this variant. In this study, we investigated the frequency of this variant and estimated an odds ratio of MMD using two different Korean populations. METHODS: A total of 1,516 anonymous DNA samples, 799 from an umbilical cord blood bank and 717 from routine health-checked adults, were genotyped using targeted Sanger sequencing. RESULTS: The p.Arg4810Lys variant was detected at genotype frequencies of 2.25% (18/799; 95% confidence interval (CI), 1.43-3.53%) in cord blood samples and 2.65% (19/717; 95% CI, 1.70-4.10%) in adult samples, respectively. This variant showed a strong association with MMD (P < 0.001), giving an odds ratio of 162.7 (95% CI, 65.5-403.9) and 137.8 (95% CI, 55.8-339.9) based on the cord blood and adults samples, respectively. CONCLUSIONS: These results confirm that the RNF213 p.Arg4810Lys variant is not uncommon in the general Korean population and provide reference data for the association of this variant and MMD.

Stiffness measurement using terahertz and acoustic waves for biological samples.

A method is proposed to measure sample stiffness using terahertz wave and acoustic stimulation. The stiffness-dependent vibration is measured using terahertz wave (T-ray) during an acoustic stimulation. To quantify the vibration, time of the peak amplitude of the reflected T-ray is measured. In our experiment, the T-ray is asynchronously applied during the period of the acoustic stimulation, and multiple measurements are taken to use the standard deviation and the maximum difference in the peak times to estimate the amplitude of the vibration. Some preliminary results are shown using biological samples.

Plasma CC-chemokine ligand 28 level is correlated with hematopoietic stem cells in human cord blood.

BACKGROUND: CC-chemokine ligand 28 (CCL28) was previously identified as a novel growth factor in vitro for hematopoietic stem cells (HSCs) from cord blood (CB). However, there is no report on the relationship between CCL28 and HSCs in a human body. STUDY DESIGN AND METHODS: To reveal the effect of CCL28 on hematopoietic cells in human CB at birth, we measured CCL28 in frozen CB plasma, which was preserved as a reference sample for cryopreserved CB units for HSC transplantation. We also evaluated the correlation of CCL28 level with CB components. RESULTS: A total of 81 cryopreserved nonconforming CB units for transplantation were selected. The level of CCL28 was 2540 ± 377 pg/mL. The CCL28 levels correlated with the number of CD34+ cells (r = 0.222, p = 0.047) and white blood cells (r = 0.254, p = 0.022) in the CB units. The CCL28 levels also correlated with hemoglobin levels (r = 0.221, p = 0.048) in fresh CB. CONCLUSION: This finding of positive correlation between CCL28 level and CD34+ cell numbers in vivo, together with the previous report that CCL28 influences the proliferation of hematopoietic cells in CB in vitro, may give a clue for better understanding the variability in HSC content in CB that is cryopreserved for HSC transplantation.

Setting the Gray Zone of Near-Cutoff Values in a Real-Time PCR Test for the Detection of Mycobacterium tuberculosis in an Intermediate Burden Country.

BACKGROUND: Recently, molecular detection of Mycobacterium tuberculosis in a respiratory specimens is accepted as one of the standard procedures for diagnosis of tuberculosis in Korea. When detecting tuberculosis using a real-time polymerase chain reaction (PCR), results showed the repeated near-cutoff values in a specimen make it difficult for the laboratory to give definitive reports as positive or negative. METHODS: We retrospectively evaluated clinical state of ninety-eight patients who were not currently taking antituberculosis medications and had near-cutoff values of respiratory specimens using a real-time PCR test. RESULTS: Sixty-eight percent of the patients had clinical tuberculosis. In subgroup analysis, patients less than the age of 50, 94.3% had tuberculosis while only 55.6% of the patients with the age of equal and over 50 had tuberculosis (p < 0.001). CONCLUSIONS: Setting a gray zone for real-time PCR result and give additional tailored information onto the interpretative report would be suggested for the clinical practice in an intermediate burden of tuberculosis country.

CCL28 Cannot Replace IgE for Severity by Objective SCORAD Index in Atopic Dermatitis in Children.

BACKGROUND: Recently, CC chemokine ligand28 (CCL28) has been reported as a severity marker in atopic dermatitis. We studied the association between objectively observed lesions and the level of CCL28 in children patients. METHODS: A total of 105 children patients were grouped by the objective Scoring Atopic Dermatitis index (SCORAD). Total IgE, specific IgE, complete blood count, and serum level of CCL28 were evaluated. RESULTS: The mean age of the subjects was 5.3 (range, 0 - 12 years). The median SCORAD was 21.4 and consisted of mild 70%, moderate 25%, and severe 6% disease. There were no statistical differences among severity groups for CCL28 or for total IgE. Total IgE showed positive correlation with eosinophil count (r = 0.429, p < 0.01), and SCORAD (r = 0.210, p < 0.05). CONCLUSIONS: The disease severity of atopic dermatitis in children is not correlated to the level of CCL28, but rather related to that of total IgE.

Acceptability of sputum specimens for diagnosing pulmonary tuberculosis.

The evaluation of the quality of a sputum specimen prior to bacterial culture has been an accepted practice. However, optimal sputum criteria for pulmonary tuberculosis (TB) are not well established. We investigated indicators for sputum acceptability in tuberculosis cultures and acid-fast bacilli (AFB) smear. A post-hoc analysis of a randomized trial with 228 sputum specimens from 77 patients was conducted. In the trial, pulmonary TB suspects were requested for collecting three sputum specimens. We performed both TB study (AFB smear and M. tuberculosis culture) and Gram staining in each specimen. By using generalized estimating equations, the association between sputum characteristics and positive TB testings were analyzed. Although acceptable specimens for bacterial pneumonia showed higher TB-culture positive rates than unacceptable specimens (adjusted odds ratio [aOR]=1.66; 95% confidence interval [CI]=1.11-2.49), a specimen with ≥25 white blood cells/low-power field was the better predictor for positive M. tuberculosis cultures (aOR=2.30; 95% CI=1.48-3.58) and acid-fast bacilli smears (aOR=1.85; 95% CI=1.05-3.25). Sputum leukocytosis could be an indicator of sputum acceptability for diagnosing pulmonary tuberculosis.