Seroreactivity of antibodies to hepatitis B core antigen among hepatitis B surface antigen-screened negative blood donors and its implications for blood safety in a resource-constrained country.

BACKGROUND AND OBJECTIVES: Transfusion-related hepatitis B infections have been reduced significantly with the implementation of blood screening using both serology and nucleic acid amplification technology (NAT) in developed countries. However, in resource-constrained countries, where NAT is inaccessible, the risk persists from early acute and occult cases. This study aimed to determine the antibodies to hepatitis B core antigen (anti-HBc) reactive rate among hepatitis B surface antigen (HBsAg)-screened negative blood donors and its impact on blood safety in the Philippines. MATERIALS AND METHODS: A total of 1602 HBsAg-negative samples, randomly collected from nine leading blood service facilities representative of each region in the Philippines, were tested for anti-HBc immunoglobulin M (IgM), Total and antibodies to HBsAg (anti-HBs) using the Architect i2000SR Immunoassay Analyser (Abbott Laboratories, IL). Anti-HBc IgM and/or Total repeat reactive were further tested for hepatitis B virus (HBV) NAT using the Cobas TaqScreen MPX v2.0 (Roche Diagnostics, Basel). RESULTS: Overall, 19.16% HBsAg-negative samples (n = 307/1602) were reactive for either anti-HBc IgM or Total or a combination of both, of which 1.3% (n = 4/307) had detectable HBV-DNA and 80.5% (n = 247/307) were anti-HBs positive. About the anti-HBs titres, 30.27% (n = 485/1602) were positive (≥10 IU/L) with 55.67% (n = 270/485) having titres ≥100 IU/L. Anti-HBs-only-positive samples were 14.85% (n = 238/1602). CONCLUSION: We observed a high anti-HBc reactive rate (19.16%) with 3.7% anti-HBc-only reactive (anti-HBs negative) and 1.3% HBV-DNA positive. This warrants the need to reconsider existing screening practices to improve blood safety in the country.

Anti-SARS-CoV-2 antibody among SARS-CoV-2 vaccinated vs post-infected blood donors in a tertiary hospital, Bangkok, Thailand.

SARS-CoV-2 virus infection has imposed a significant healthcare burden globally. To contain its spread and decrease infection-related mortality, several vaccines have been deployed worldwide in the past 3 years. We conducted a cross-sectional seroprevalence study to assess the immune response against the virus among blood donors at a tertiary care hospital, Bangkok, Thailand. From December 2021 to March 2022, total of 1,520 participants were enrolled, and their past history of SARS-CoV-2 infection and vaccination was recorded. Two serology test, namely, quantitative IgG spike protein (IgGSP) and qualitative IgG nucleocapsid antibody (IgGNC) were performed. The median age of study participants was 40 years (IQR 30-48) and 833 (54.8%) were men. Vaccine uptake was reported in 1,500 donors (98.7%) and 84 (5.5%) reported the past infection history. IgGNC was detected in 46/84 donors with the past infection history (54.8%) and in 36 out of the rest 1,436 (2.5%) with no past history. IgGSP positivity was observed in 1484 donors (97.6%). When compared to unvaccinated donors (n = 20), IgGSP level was higher in the donors who had received one vaccine dose (p< 0.001) and these antibody levels increased significantly among those with 3rd and 4th vaccine doses. Factors associated with low IgGSP (lowest quartile) by multivariate analysis included: no past infection history, homologous vaccination, < 3 vaccine doses, and > 90 days duration since last vaccination. In conclusion, vaccine uptake among our study donors was high (98.7%) and IgGSP antibody was observed in nearly all the vaccinated donors (97.6%). Previous SARS-CoV-2 infection, use of heterologous vaccination, vaccines ≥ 3 doses, and duration of the last vaccination >90 days affected IgGSP levels. Use of serological assays were found beneficial in the evaluation and differentiation of immune response to vaccination, and natural infection including the identification of previous asymptomatic infections.

Seroprevalence of HTLV-1/2 Among Voluntary Blood Donors in Vietnam.

Infection with human T lymphotropic virus (HTLV), although asymptomatic in most cases, can lead to severe illnesses, such as adult T cell leukemia/lymphoma or myelopathy/tropical spastic paraparesis. HTLV can be transmitted by whole-blood (WB) transfusion. The prevalence of HTLV among blood donor populations has not been characterized in Vietnam, although the screening has been partially implemented on voluntary basis since 2016. To determine the seroprevalence of HTLV-1/2 among blood donors, a total of 14,819 healthy blood donors in northern, central, and southern Vietnam and 1,003 samples from hepatitis B surface antigen (HbsAg), anti-hepatitis C (anti-HCV), or HIV Ag/Ab reactive blood donors were screened for anti-HTLV-1/2 antibodies by a chemiluminescence immunoassay using the Abbott ARCHITECT rHTLV-I/II assay. The anti-HTLV-1/2 repeat reactive (RR) samples were further tested by immunoblot (IB) method using MP Biomedicals HTLV Blot 2.4 for confirmation and differentiation of HTLV-1/2 infection. Proviral HTLV subgenomic amplification of the gag and tax regions was performed on the available WB RR samples (N = 11) by polymerase chain reaction (PCR). Among 14,819 blood donors, 34 samples (0.23%) were RR for anti-HTLV-1/2 antibodies, but only 1 case was confirmed HTLV-2 positive (0.0067%) and 5 cases were classified as indeterminate (0.034%) by IB. The RR rate was 0.39% among HBsAg/anti-HCV/HIV reactive sample groups, but none of them was confirmed by IB. Subgenomic PCR failed to amplify proviral DNA from WB samples of 11 RR samples. HTLV-1/2 prevalence was found to be low among blood donors in the study. Continued vigilance remains essential to maintain a low transfusion-transmitted risk in Vietnam.

Human T-cell lymphotropic virus type I and II seroprevalence among volunteer blood donors in Thailand.

Human T-cell lymphotrophic virus type I and II (HTLV-I/II) are closely related but distinct retroviruses that can infect humans. Both the viruses can be transmitted via transfusion of contaminated blood components. HTLV pre-transfusion screening is not mandatory in Thailand until now. Current epidemiological data for HTLV prevalence is still lacking since the past surveys were done more than a decade ago. The main objective of this study was to determine the seroprevalence of HTLV-I/II among voluntary blood donors in Thailand. 11,057 volunteer blood donors were screened for HTLV-I/II antibodies using the ARCHITECT rHTLV-I/II chemiluminescent immunoassay (CLIA). Initial-reactive (IR)  samples were subjected to repeat duplicate testing and were also sent for confirmatory testing at Korean Red Cross Society (KRC), Seoul or National Serology Reference Laboratories (NRL), Australia using alternate HTLV serological assays and immunoblot and/or specific nucleic acid testing respectively. Out of 11,057 plasma samples, 10,080 were low-risk seronegative donors and 977 were first-time/high-risk donors. Twenty of 24 IR samples were repeatedly reactive (RR) in low-risk seronegative donors group. On confirmatory testing of these 24 IR by immunoblot, 13 indeterminate and 11 negative results were observed. One out of 977 samples from first-time/high-risk donors was RR for anti-HTLV-I/II antibodies. This sample was co-reactive for HBsAg, but negative for HTLV by EIA or in-house HTLV-I qPCR. The ARCHITECT rHTLV-I/II assay exhibited a specificity of 99.93% in low-risk donors and 99.90% among high-risk donors. This study concluded that HTLV-I/II prevalence is low among blood donors in Thailand. But periodic surveillance should be continually conducted to ensure high blood safety standards in the country.

Interleukin-6 as a predictor of subclinical chorioamnionitis in preterm premature rupture of membranes.

PROBLEM: One of the major challenges faced by the clinicians in preterm premature rupture of the membranes (PPROM) is to correctly identify when a significant chorioamnionitis is evolving and decide timely delivery of the fetus. Measuring interleukin-6 levels in maternal serum can be useful for the identification of asymptomatic intrauterine infections in subjects with PPROM. METHOD OF STUDY: A total of 75 pregnant women, of which 45 pregnant women presenting with PPROM between 24 and 34 weeks gestation and 30 healthy pregnant women without PPROM, were included in the study. Serum IL-6 levels were determined by solid-phase sandwich enzyme-linked immunosorbent assay (Diaclone Research, Besancon, France). RESULTS: The mean serum IL-6 value at admission in the control group was 2.48 ± 2.7 pg/mL and in the study group was 11.86 ± 14.5 pg/mL (P = 0.001). Mean serum IL-6 concentrations at admission in subjects without histological chorioamnionitis were 3.98 ± 3.9 pg/mL and in those who had histological chorioamnionitis were 20.09 ± 16.8 pg/ml (P < 0.001). CONCLUSION: Maternal serum IL-6 levels were significantly elevated in subjects with PPROM with infectious morbidity as compared to those without infectious morbidity in the present study. There was a significant rise in maternal serum IL-6 levels with increased duration of rupture of membranes and with evidence of histological chorioamnionitis and funisitis in the placenta.

Serum cytokine profile in psoriasis-a case-control study in a tertiary care hospital from northern India.

Psoriasis is chronic autoimmune hyperproliferative skin disease with a population prevalence of 1.5-3%. The cause of psoriasis is still not fully understood. It has been hypothesized to be an immune-mediated disorder in which the excessive reproduction of keratinocytes is due to cytokines such as interferon (IFN)-gamma and tumour necrosis factor (TNF)-alpha, secreted by infiltrating CD4(+) and CD8(+) T cells and natural killer cells. The aim of our study was to determine the serum levels of TNF-α, IL-4, IL-6 & IL-10 in psoriasis patients and compare it with healthy controls. 30 clinically diagnosed psoriasis patients and 30 age and sex matched healthy controls were included in the study. The serum cytokine levels were measured by solid phase sandwich ELISA (DIACLONE Research, France). TNF-α and IL-6 levels were significantly raised in patients and the results were statistically significant (P < 0.001). IL-4 levels were higher in patients than in controls (1.91 ± 4.7 pg/ml in cases & 0.9 ± 0.3 pg/ml in controls) but were not statistically significant. Interestingly, IL-10 levels were found to be higher in controls than in patients but again, it was not statistically significant. Pro-inflammatory cytokines play a pivotal role in the pathogenesis of psoriasis and it is the type 1(TH1) cytokine pattern, i.e., IL-6 & TNF-α, which predominate in the psoriatic T cell response. Further studies on IL-10 levels in psoriasis are recommended to establish their exact role in the pathogenesis of the disease.

Inducible nitric oxide synthase (iNOS) gene polymorphism in pre-eclampsia: a pilot study in North India.

BACKGROUND: Pre-eclampsia is one of the most frequent complications of pregnancy, however, little is known about its aetiology. AIMS: The objective of this study was to investigate the association between inducible nitric oxide synthase (iNOS) genotypes and pre-eclampsia. We also measured the concentrations of tumour necrosis factor-alpha (TNF-alpha), nitric oxide (NO) and superoxide dismutase (SOD) in patients with pre-eclampsia to evaluate their relations to the single nucleotide polymorphisms (SNPs) observed. METHODS: This cross-sectional study included 30 pregnant women with pre-eclampsia and 30 healthy pregnant women. They were screened at 28th, 36th weeks of gestation and just after delivery (within 48 h), and their blood samples were analysed for NO, SOD, TNF-alpha and iNOS gene polymorphism. RESULTS: Patients with pre-eclampsia at 36 weeks gestation showed significantly increased serum NO levels (P=0.007), whereas SOD activity was decreased significantly (P=0.004). A doublefold increase was observed in TNF-alpha levels at 36 weeks in patients with pre-eclampsia (P=0.003) which decreased significantly (P=0.001) after delivery. A total of four SNPs were observed, of which two (G300A exon 8 and G274T exon 16) showed statistically significant association with pre-eclampsia. When compared, G274T exon 16 SNP also showed association with TNF-alpha levels and SOD activity in pre-eclamptic patients. CONCLUSION: As pre-eclampsia is a disease of multifactorial aetiopathology, NO, TNF-alpha, SOD activity and NOS2A polymorphism might play an intermingled role in its development.