Non-specific and specific anti-HCV results correlated to age, sex, transaminase, rhesus blood group and follow-up in blood donors

Abstract

Second generation enzyme immunoassays (EIA-2) for antibodies to hepatitis C virus (anti-HCV) have a higher specificity and sensitivity than first generation enzyme immunoassays (EIA-1). We studied how many anti-HCV-positive blood donors were missed by the EIA-1, how many were false positive, how false-positive donors should be dealt with and how the results of the EIA-2 correlate to demographic data and serum alanine aminotransferase (ALT) level. A total of 208, 544 northern German blood donors, not preselected for anti-HCV negativity, were tested for anti-HCV with EIA-2 and, if repeatability reactive (rr), were retested with a licensed supplementary test (RIBA-2). 0.43% of the donors were EIA-2 rr, but only 0.12% of women and 0.09% of men were RIBA-2 positive. RIBA-2 positivity rates were very low in donors 18 to 27 years old (0.03% and 0.05%) and rose with age in women but not in men. Infected women were significantly more often Rhesus-negative than men. The rate of unspecifically positive EIA-2 results (entirely negative in RIBA-2) increased with age in both sexes and did not correlate with ALT. The ALT distribution was age-dependent with a different pattern for men and women. Confirmation of EIA-2 results with RIBA was rare when ALT was low and frequent when ALT was high. ALT screening before introduction of Anti-HCV detected one out of six infected donors. To exclude this one infectious donation, 46 uninfected donations had to be excluded in addition. Only 8% of the then RIBA-2-positive donors were not detected by EIA-1. Apparent seroconversions in EIA-2 are usually not specific; only 1 out of 66 apparent seroconversions could be confirmed by RIBA-2 suggesting recent HCV infection. 0.15% of the donor population showed an inconsistent EIA-2 pattern during follow-up. We conclude that donors should not be excluded from further donations, even on the basis of multiple EIA-1 positive results or on the basis of only one EIA-2 positive donation. Anti-D-immunoglobulin prophylaxis may have been a source of infection in some Rhesus-negative women. ALT screening should not be discontinued because recent HCV infection can be detected earlier by ALT than by anti-HCV, but exclusion limits should be elevated to increase specificity and limit unnecessary exclusion of donations.

A cohort study of hepatitis C virus (HCV) infection in an HCV epidemic area of Japan: age and sex-related seroprevalence of anti-HCV antibody, frequency of viremia, biochemical abnormality and histological changes

“…Therefore, we cannot definitively tell whether or not anti-HCV positive but HCV RNA negative reflects past contact with the virus or represents a false positivity. Caspari (26) reported that anti-HCV was positive with secondgeneration enzyme immmunoassys, but entirely negative in RIBA-2, and was unspecifically positive with second-generation enzyme immunoassays. Smith (27) showed that resolved hepatitis C was significantly more common in women (p<0.05) and tended to be associated with younger individuals at the time of transfusion based on the study of recipients of blood products from hepatitis C antibody (anti-HCV) positive donors.…”

Epidemiology of Hepatitis C: Geographic Differences and Temporal Trends

“…1) , the lowest anti-HCV prevalence rates (0.01-0.1%) have been reported from the United Kingdom [2][3][4] and Scandanavia. 5,6 Low but slightly higher rates (0.2-0.0.5%) have been reported from Western Europe, [7][8][9][10] North America, [11][12][13] most areas of Central and South America, [14][15][16][17][18] Australia, 19 and limited regions of Africa, including South Africa. [20][21][22] Intermediate rates of anti-HCV prevalence (1-5%) have been reported from Brazil, 23,24 Eastern Europe, the Mediterranean, [25][26][27][28][29][30] the Mideast, the Indian subcontinent, [31][32][33][34][35] parts of Africa, [36][37][38][39][40][41] and Asia.…”

Long‐term serologic follow‐up of blood donors with biologic false reactivity on an anti‐human T‐cell lymphotropic virus Types I and II chemiluminescent immunoassay and implications for donor management

“…Although contemporary viral screening immunoassays (IAs) have excellent sensitivity and specificity, their positive predictive value in low‐risk populations such as nonremunerated voluntary blood donors is low 1‐9 . Therefore, most repeatedly reactive (RR) results on screening IAs in blood donor populations do not confirm as positive and usually represent biologic false‐reactive (BFR) results that are not indicative of past or current infection with the virus in question.…”

“…A lthough contemporary viral screening immunoassays (IAs) have excellent sensitivity and specificity, their positive predictive value in low-risk populations such as nonremunerated voluntary blood donors is low. [1][2][3][4][5][6][7][8][9] Therefore, most repeatedly reactive (RR) results on screening IAs in blood donor populations do not confirm as positive and usually represent biologic false-reactive (BFR) results that are not indicative of past or current infection with the virus in question. Although the number of BFR results is usually a very low proportion of the total number of donations tested, they nevertheless present a challenge for blood services in terms of donor and product management.…”