Serum samples from 316 patients visiting the Dutch National Hemophilia Center were collected from 1979 to 1993 and stored at -30 degrees C. Patients were placed into three different groups: 1) patients ever treated with large pool non-hepatitis C virus (HCV)-safe concentrate (n = 179); 2) patients treated with cryoprecipitate (n = 125); and 3) patients treated exclusively with HCV-save concentrate (n = 12). In order to examine the prevalence of HCV infection in the different treatment groups serum samples were tested retrospectively for anti-HCV antibody using second generation enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA-2). Significant differences in the prevalence of HCV infection were found between these 3 groups (group 1: 99%, group 2: 66%, group 3: 0%). The safety of currently administered clotting products is demonstrated in 57 patients who remained without HCV markers between 1989 and 1993. To examine the natural course of HCV infection fresh-frozen plasma samples were obtained recently from a subgroup of 277 hemophilia patients for HCV-RNA detection by a well-validated cDNA-PCR assay. In contrast to other reports, no evidence was found for seronegative HCV carriers. None of 52 patients without anti-HCV had detectable HCV-RNA. Of 225 patients with anti-HCV, 182 (81%) were HCV-RNA positive. None of 39 anti-HCV positive patients with a negative HCV-RNA reaction had serum alanine aminotransferase (ALT) levels above 50 U/l, whereas 44% of HCV-RNA positive patients had persistently elevated ATL levels above 50 U/l.(ABSTRACT TRUNCATED AT 250 WORDS)

To establish the value of the second-generation recombinant immunoblot assay (RIBA-2) and cDNA polymerase chain reaction (cDNA PCR) for confirmation of hepatitis C virus (HCV) infection, anti-HCV reaction patterns and the presence of HCV RNA were examined in 610 blood donors and 255 non-A, non-B hepatitis patients who were positive or indeterminate in RIBA-2. Of RIBA-2-positive donors (n = 191) and patients (n = 224), 75.4 and 89.7 percent, respectively, were HCV RNA positive. The most frequently observed anti-HCV recognition patterns in HCV RNA-positive donors and patients were c22, c33c, and c100 and/or 5-1-1 (67.3%, 57.7%) and c22, c33c (24.8%, 29.3%). Among subjects with a RIBA-2-indeterminate result, HCV RNA was detected more often in patients (n = 31) than in donors (n = 419): 67.7 and 2.1 percent, respectively. In viremic persons with single-band reactivity in RIBA-2, this reactivity was always directed against either c22 or c33c. HCV RNA was detected by cDNA PCR in none of 162 persons with only anti-c100 and/or anti-5-1-1 reactivity. Therefore, RIBA-2 reactivity against c100 in combination with 5-1-1 should not be considered positive but indeterminate. In RIBA-2-indeterminate persons, HCV RNA detection is necessary for reliable confirmation of HCV infection.

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Background and Objectives: Human parvovirus B19 is a potential risk to hemophiliac patients receiving blood products. Materials and Methods: To determine the prevalence of the corresponding antibody in patients with hemophilia A or B or von Willebrand’s disease, we tested 326 hemophilia patients for anti-B19 IgG. The results were compared with those of 203 age-matched controls (male blood donors and children). Results: The overall prevalence of B19 IgG in the hemophilia patients was 302/326, and in the controls 123/203. Below the age of 10, hemophilia patients had a higher prevalence of B19 IgG (76%, 42/55) than the controls (23%, 11/48; p < 0.00001). In those below the age of 5 who had been treated exclusively with monoclonally purified concentrate, it made no difference whether the product was pasteurized or solvent-detergent treated. There was a significantly lower incidence in patients who were rarely treated. Conclusion: Parvovirus B19 is frequently transmitted in blood products. Existing virus-inactivating methods do not prevent transmission.

SummaryRecently, clotting factor preparations transmitted hepatitis A virus (HAV) to hemophilia patients. To study the risk of HAV infection in Dutch hemophilia patients, serum samples of 341 patients with hemophilia were tested for HAV antibodies (anti-HAV).197/341 patients (group 1) were treated with clotting factor concentrates produced from large plasma pools, 144/341 patients (group 2) were treated with small pool cryoprecipitate. The test results were compared to those of healthy blood donors (n = 19,746) of the same age. In addition stored serum samples (1983-1994) from hemophilia patients were tested for HAV antibodies.No increased risk of HAV infection was found in Dutch hemophilia patients. The anti-HAV prevalence in group 1 was 20%, in group 213% and in blood donors 41%. A significantly (p <0.002) lower percentage of HAV antibodies was found in hemophilia patients born in the 1950s using cryoprecipitate (11%) as compared to blood donors of the same age (40%), probably caused by passive administration of anti-HAV through clotting product. Passive immunization in the past was significantly (p <0.02) more often found in group 2 (41.7%) than in group 1 (28%).In the period 1983 till 1988 five seroconversions were seen in group 1 (2%) and one in group 2 (0.7%). Anti-HAV seroconversions were not observed after 1988.In a risk analysis we estimated that 2 plasma pools of 10,000 Dutch blood donors per year may contain HAV. The absence of HAV among Dutch hemophilia patients suggests that this contamination is successfully inactivated.