Evaluation of a rapid assay as an alternative to conventional enzyme immunoassays for detection of hepatitis C virus-specific antibodies.

A rapid membrane flow-through immunoassay to detect antibodies to hepatitis C virus was compared with a commercial enzyme immunoassay (EIA) and microparticle enzyme immunoassay (MEIA) using 2,590 serum samples. Sensitivity and specificity of the "rapid assay" in comparison to the EIA/MEIA were 99.3 and 99.0%; the correlation coefficient being 0.91. This assay is suitable where infrastructure and laboratory expertise are limited.

High frequency of the 1896 precore mutation in patients and blood donors with hepatitis B virus infection from the Indian subcontinent.

AIM: Hepatitis B virus (HBV) e antigen (HBeAg)-negative variants are reported to harbor 1896 precore mutants, and predict a worse clinical outcome. The aim of this study was to estimate the incidence of a precore mutation (1896) in both patients with chronic hepatitis B (CH-B) infection and blood donors in a tertiary care hospital in south India. METHODS: One hundred and twenty-two consecutive HBV DNA-positive CH-B patients (group I) and 102 HBsAg-positive 'healthy' blood donors (group II) were recruited. Samples found to be positive for HBV DNA were further studied. A nested PCR was used for the detection of HBV DNA. The 1896 precore mutation was detected using PCR-restriction fragment length polymorphism (RFLP). Nucleotide sequencing was performed on representative samples to confirm PCR-RFLP findings. The study population was stratified comprising: group IA: 17 HBeAg-positive CH-B patients; group IB: 105 HBeAg-negative CH-B patients; group IIA: 12 HBeAg-positive blood donors; and group IIB: 55 HBeAg-negative blood donors. RESULTS: There was no significant difference in the HBeAg-positive status between groups I and II. Significantly higher levels of alanine transaminase (ALT) were seen in groups IA and IB than in groups IIA and IIB, respectively (p = 0.033; p = 0.004). A significantly higher proportion of CH-B patients (32.7%) were positive for anti-HBc IgM compared with the blood donor groups (10.4%; p = 0.0006). Among the HBeAg-negative subjects, 69% of the CH-B patients and 65% of the blood donors showed evidence of 1896 precore mutant. This infection included the 1896 mutant exclusively or mixed infection involving the 1896 mutant and 1896 wild-type. DISCUSSION: The absence of detectable HBeAg in most of the viremic blood donors and patients emphasizes the need for HBV DNA testing irrespective of HBeAg status. Mixed infection was detected in a higher proportion (42.6%) of CH-B patients than in blood donors (26.8%; p = 0.031). Among those with mixed infection, a significant proportion (44.2%) of CH-B patients, had ALT levels greater than the upper limit of normal (ULN), as compared with the blood donor groups (16.6%; p = 0.036). CONCLUSIONS: The majority of CH-B patients and blood donors were negative for HBeAg despite their positive HIV DNA status. About two-thirds of the HBsAg-positive blood donors were viremic. Mixed infection was detected more frequently in CH-B patients and appears to be associated with more pronounced liver damage, as indicated by increased ALT levels.

Distribution of hepatitis B virus genotypes in blood donors and chronically infected patients in a tertiary care hospital in southern India.

Hepatitis B virus (HBV) genotypes differ in their potential for causing disease. Consecutive patients with chronic HBV infection (CHBV) (n=122) and blood donors (n=67) positive for hepatitis B surface antigen and HBV DNA were genotyped using polymerase chain reaction-restriction fragment-length polymorphism. The ratio of male to female subjects was significantly higher in the blood donor group than in the group of patients with CHBV (P=.0004). Among patients with CHBV, genotype D was detected in 57.3%, genotype A was detected in 18%, and genotype C was detected in 11.5%. Only genotypes D and A were detected in blood donors. The difference between the detection rate of genotype C in patients with CHBV and in blood donors was significant (11.5% vs. 0%; P=.009). Patients with CHBV who had genotype C had higher alanine transaminase (ALT) levels than those who had genotype A (P=.044) or genotype D (P=.014). Detection of genotype C in patients with CHBV and the association of genotype C with higher ALT levels may predict that this genotype has a greater potential for causing disease than other genotypes.

Occurrence of false positives during testing for antibodies to hepatitis C virus among volunteer blood donors in India.

The hepatitis C virus antibody statuses of only 11 (21.5%) of 51 initially reactive samples from volunteer blood donors could be confirmed by using additional screening and confirmatory assays; 23 (45%) were negative by all subsequent assays. Seventeen samples (33.3%) gave variable results in the different assays. The core and NS5 antigens were most immunogenic. An algorithm for serological screening of volunteer blood donors in blood banks of developing countries is suggested.