Perspectives on hepatitis B infections and the efficacy of vaccination (hepatitis B and pneumococci) in dialysis patients.

Hepatitis B is a well known problem in dialysis units. We therefore examined the historical frequency of hepatitis B carriers in our unit, our vaccination program to hepatitis B virus (HBV), the response to hepatitis B vaccine, the IgG subclass response of anti-HBs and the response and IgG subclass response to pneumococcal vaccination (another vaccine) in dialysis patients. From 1970 and onwards 23 HBV carriers were found, but no new cases of hepatitis B occurred during the study period, i.e. from 1980 and onwards. Only one of the carriers was alive by the end of 2001. In four patients liver disease (in one of them liver cirrhosis) may have been a concomitant cause of death. The antibody response to hepatitis B vaccine was significantly lower in patients than in staff. In four patients a fourth injection was cancelled due to transplantation and bad health, while such data were lacking in 8 cases. In anti-HBs positive patients and controls a significant difference in the response of healthy adults was observed in anti-HBs IgG1 (p < 0.001) vs all other IgG subclasses. Dialysis patients had low levels, or negative findings, in all cases, with IgG1 as the highest proportion found (3/11 patients). An antibody response to pneumococcal vaccination was registered in 25 out of 29 dialysis patients (in all 86%). The IgG-subclass vaccination response to pneumococci in 28 dialysis patients was mainly IgG2 and IgG1 but also occurred in IgG3 and IgG4. Prevaccination antibody levels of the controls were higher in IgG1 and IgG2 (p < 0.01) (n = 21) than in dialysis patients (n = 28). Hepatitis B is nowadays a rare, but still dangerous disease in nephrology units. Dialysis patients have a reduced response to hepatitis B vaccine and vaccination schedules should be started early as some patients otherwise may not receive a fourth injection. The adequate antibody response to pneumococcal vaccination mainly due to IgG2 and IgG1 antibodies indicates that the antigen involved is important in vaccination responses in dialysis patients.

Detection and prevention of hepatitis C in dialysis patients and renal transplant recipients. A long-term follow up (1989-January 1997).

BACKGROUND: Hepatitis C is frequent problem in dialysis wards. DESIGN: A long time (1989-97) follow up of hepatitis C virus (HCV) infection in a Swedish nephrology unit was performed with anti-HCV screening, confirmatory antibody tests, viral RNA detection and molecular characterization. Case histories were reviewed with focus, onset of infection, liver morbidity and mortality. RESULTS: In October 1991, 10% (19 of 184) of the patients in the unit (haemodialysis-, peritoneal dialysis and transplanted patients) were verified or suspected HCV carriers, whilst the number at the end of 1996 was 8%, (13 of 157). Most patients were infected before 1991 but only in one case from a known HCV-infected blood donor. No new HCV infections associated with haemodialysis occurred during the study period. A total of 13 of 24 viremic patients had HCV genotype 2b, a pattern suggesting nosocomial transmission. This was further supported by phylogenetic analysis of HCV viral isolates in seven. HCV viremia was also common in patients with an incomplete anti-HCV antibody pattern as 8 of the 12 indeterminant sera were HCV-RNA positive. CONCLUSIONS: Awareness, prevention, identification of infected patients and donor testing limited transmission. Indeterminant recombinant immunoblot assays (RIBA)-results should be regarded with caution as a result of the relative immunodeficiency in uremic patients. Our data indicate nosocomial transmission in several patients.

Hepatitis C virus transmission, 1988-1991, via blood components from donors subsequently found to be anti-HCV-positive.

The recipients of blood components, from the first 12 anti-hepatitis C virus (HCV) positive donors identified by blood donor screening, 1985-1991, were traced retrospectively and tested to assess the HCV transmission rate, HCV genotypes and disease severity. Three enzyme-linked immunosorbent assay (ELISA) positive but RIBA-indeterminate and HCV RNA-negative donors did not transmit HCV to their 9 traced recipients. Nine RIBA- and HCV RNA-positive donors had donated blood to 27 now living recipients of whom 16/27 (59%) were viraemic 1-5 years later. Nine recipients had resolved infection, as determined by PCR HCV RNA. Five of these were RIBA-2 positive but HCV RNA-negative and 4 recipients were RIBA-2-indeterminate and HCV RNA-negative. Two recipients negative in all tests had probably received blood before the donor became infected with HCV. The HCV genotype in each case was identical between the donor and the recipient. Of the viraemic recipients, 50% (8/16) were unsuitable for further investigation or therapy due to their high age and/or underlying severe disease. At most, only 30% (8/27) of the recipients were suitable for further investigation and/or treatment. Two of these were already diagnosed as being infected with HCV before being traced. It is concluded that the benefit of a general tracing of recipients of blood components from HCV-infected donors is doubtful since only a few of them are suitable candidates for treatment. Our results seem to indicate that it is more appropriate to recommend anti-HCV testing to those seeking medical care who have received transfusions or undergone major surgery before 1992, i.e. before anti-HCV-screening was initiated.

Anti-hepatitis C virus screening will reduce the incidence of post-transfusion hepatitis C also in low-risk areas.

The incidence of post-transfusion hepatitis non-A, non-B (PTH-NANB) was prospectively assessed in two areas in the southeast region of Sweden. Patients undergoing hip arthroplasty were studied with blood sampling for alanine aminotransferase analysis before and at 2, 3, and 4 months after transfusion. Of the patients 97% and 82% were transfused and received a mean of 5.5 and 3.4 units in Linköping and Oskarshamn, respectively. None of 38 patients in Oskarshamn but 4 of 144 patients (2.8%) in Linköping contracted PTH-NANB. Two of these four patients developed antibodies against hepatitis C virus (HCV) by the first-generation anti-HCV enzyme-linked immunosorbent assay (ELISA) (C100). The other two patients remained negative by this test. HCV infection was, however, indicated in all four patients by positive second-generation anti-HCV ELISA confirmed by positive second-generation recombinant immunoblot assay (4-RIBA). Three of the patients were positive by polymerase chain reaction (PCR). Serum from one blood donor to the four hepatitis patients (altogether three donors) was found positive by first- and second-generation anti-HCV ELISA and 4-RIBA and was also PCR-positive. Three other blood donors, who did not transmit hepatitis, were anti-HCV ELISA (C100)-positive. This study shows that if anti-HCV ELISA had been available at the start of the trial, all cases of PTH would have been avoided at the expense of only 0.7% transfusion units discarded. Routine anti-HCV ELISA testing of all transfusion units will reduce the incidence of PTH-C even in low-risk areas.

Antibody responses to hepatitis C virus and its modes of transmission in dialysis patients.

Five of 72 patients dialysed at the same dialysis unit developed elevated alanine aminotranspherase (ALT) levels attributed to acute non-A, non-B hepatitis (NANBH). Histopathologic findings consistent with NANBH were present in four of them. Serological screening for antibodies to hepatitis C virus (anti-HCV) was performed in all 72 cases. Three of the patients with NANBH and 2 of the other 67 patients had positive tests. Low and transient levels of anti-HCV were noted in 2 patients with NANBH in spite of chronic hepatitis. Only 1 of 5 patients with NANBH was known to have had blood transfusions indicating other, as yet undefined, modes of transmission of HCV for the others. Although antibody responses to HCV might be transient or low, testing for anti-HCV should be considered in dialysis populations.