Protein isolated from biopharmaceutical formulations cannot be used for comparative studies: Follow-up to "a case study using Epoetin Alfa from Epogen and EPREX".

In the biotechnology area, the issue of comparability with an innovator product is complex. Ideally, a side-by-side comparison of physical properties would be part of the demonstration of comparability. However, biogeneric companies do not have access to the bulk drug substance from the innovator company for biophysical comparison, and isolation of protein from marketed product cannot be guaranteed to produce material that is identical to the bulk drug substance from which it was prepared. In a recently published study, protein was isolated from marketed product and comparative studies performed. In a follow-up investigation of the published work, we demonstrate here that even a simple isolation procedure can significantly compromise the protein, which raises serious questions about the interpretation of that study, and in a broader context the value of any studies done with such "out-of-process" protein.

Detection of hepatitis C core antigen in serum or plasma as a marker of hepatitis C viraemia in the serological window-phase.

A new immunoassay for the detection of hepatitis C core antigen (HCVcoreAg) in peripheral blood during serological window-phase was evaluated among healthy blood donors, commercially available hepatitis C virus (HCV) seroconversion panels and in-house specimens from individuals undergoing seroconversion. Among 1964 low-risk blood donor samples, seven samples were initially reactive but only one was repeat reactive. Reactivity of this specimen was not confirmable by neutralization with specific anti-HCV core antibody, and the sample was negative for HCV RNA by polymerase chain reaction (PCR). The specificity of the HCVcoreAg enzyme-linked immunosorbent assay (ELISA) was 99.95%. In seven commercially available HCV seroconversion panels, HCVcoreAg appeared 23-46 days earlier than anti-HCV antibody by third generation assay. Additional testing with specimens from patients undergoing anti-HCV seroconversion indicated that HCVcoreAg becomes undetectable by the present test format soon after the onset of antibody. This test may be considered as an alternative to nucleic amplification techniques (NAT) for blood donor HCV screening. Additional development of technology for detecting HCVcoreAg may be useful for patient diagnosis and therapy monitoring.

Use of overlapping synthetic peptides to characterize samples from blood donors with indeterminate results to hepatitis C virus core antigen.

BACKGROUND AND OBJECTIVES: Despite recent improvements in supplemental assays, isolated reactivity to the hepatitis C virus (HCV) core antigen continues as one of the main problems in the confirmation of anti-HCV in blood donors. Reactivity against individual peptides from the c22-3 HCV recombinant antigen has been described as a useful tool for anti-HCV confirmation and donor counseling in such cases. MATERIALS AND METHODS: We used a previously described set of overlapping peptides spanning the entire sequence of the c22-3 antigen to study 87 single serum samples from blood donors with reactivity for c22-3 antigen alone in second generation recombinant immunoblot assay (RIBA-2). All of them had been previously studied by RIBA-3, anti-HCV E2 EIA and HCV PCR. RESULTS: 66 of the 87 samples studied could be classified as positive or negative for anti-HCV core using the multipeptide assay and such classification correlated well with the results obtained with RIBA-3 and the anti-E2 EIA. However, some discrepancies were found. The epitopes located along the N-terminal half of the molecule were mainly responsible for the specific antibody recognition but those enclosed within amino acids 1-15 were frequently involved in nonspecific reactivity. Some 38% of samples were considered to have specific antibody to the c22-3 antigen and a further 9% reacted for both anti-E2 and single core peptides that were often involved in specific antibody recognition. CONCLUSION: Testing of blood donor samples indeterminate to the HCV c22-3 antigen for reactivity against individual core peptides can confirm the presence of specific antibody and recognize nonspecific reactivity with certain cross-reacting epitopes. Third generation supplemental tests have reduced such false reactivity, but confirmation of samples with anticore alone is still necessary. Single reactivity to the HCV core antigen is likely to reflect prior exposure to the virus, but rarely active infection, either acute or chronic.

Seroprevalence of human immunodeficiency virus-1, hepatitis B virus, and hepatitis C virus in patients having major surgery.

OBJECTIVE: To determine the proportion of major surgical procedures that involve patients having serologic evidence of infection with human immunodeficiency virus-1 (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) in a single center in Westchester County, New York. METHODS: Blood samples sent for transfusion screening or cross-match were tested blindly for HIV antibody (anti-HIV), HBV core antibody, HBV surface antigen (HBsAg), and HCV antibody (anti-HCV). Demographic characteristics and operation category were correlated with serologic results by univariate and regression analyses. RESULTS: Of 1,062 operations evaluated, 71 (6.7%, 95% confidence interval [CI95], 5.2% to 8.4%) were performed on patients with either anti-HIV, HBsAg, or anti-HCV. In 17 (1.6%, CI95, .93% to 2.5%) of these operations, the patient evidenced anti-HIV; in 15 (1.4%; CI95, .79% to 2.3%), HBsAg; and in 55 (5.2%, CI95, 3.9% to 6.7%), anti-HCV. Anti-HCV was detected significantly more often than anti-HIV (5.2% versus 1.6%, P < .001) or HBsAg (5.2% versus 1.4%, P < .001). Operations involving women aged 25 to 44 years had the highest proportion with serologic evidence of at least one of the three viruses (17.2%); of anti-HCV (15.3%); and of anti-HIV (6.7%). Logistic regression analysis found that being in the 25- to 44-year age group was associated significantly with infection with any virus (P < .001) and with anti-HCV (P < .001). The strongest logistic predictors of anti-HIV seropositivity were having anti-HCV seropositivity (P < .001), being age 25 to 44 years (P < .001), and having a general surgery operation (P = .002). CONCLUSION: The prevalences of serologic evidence of at least one of the three viruses (16.7%), of anti-HCV (14.5%), and of anti-HIV (5.6%) are high in patients aged 25 to 44 years undergoing major surgery at a tertiary-care medical center located in Westchester County, New York. Anti-HCV is more prevalent than anti-HIV or HBsAg and is predictive of anti-HIV seropositivity. Testing for anti-HIV alone would have detected only 24% of patients infected with a bloodborne pathogen. These data strongly underscore the importance of universal precautions.