Infecção pelo HCV em uma unidade de diálise em Belém-Pará: desempenho de testes imunoenzimáticos em relação à técnica de biologia molecular

Abstract

The main objective of this study was to make a comparative evaluation of four 3rd generation enzyme-linked immunosorbent assay (ELISA) kits (Ortho, Ubi, BioChem and Abbott), for the detection of HCV antibody and Roche polymerase chain reaction (PCR) kit. Serum samples were obtained from 19 members of the staff (grupo A) and 66 patients (grupo B), who were undergoing either hemodialysis (n=54) or peritoneal dialisys (n=12) in a dialysis unit in Belém, Pará. Altogether, the four ELISA kits agreed in 89,5% and 81,8% when results of groups A and B were compared, respectively. Overall rates of HCV antibody ranged from 34,1% to 37,5%. These rates among the patients ranged from 42,4% to 47%. While HCV-RNA was detected by PCR in 25 (37,9%) of the patients (of whom 24 in the hemodialysis subgroup), no PCR-positive results could be yielded among the staff members. When compared with the PCR, the four ELISA kits showed sensitivity, specificity and predictive values with differences that were not statistically significant. Of interest, serum samples from 12,5% to 20% of HCV-infected patients – as diagnosed by PCR – yielded negative results when tested by the four ELISA kits. An additional finding was that increase in the aminotransferasis levels does not seem occur as a result of HCV infection, it is notable that the risk of HCV infection increases following hemodialysis procedure during six months or more, among those patients who are older than fifty years. In addition, among patients subjected to hemodialysis, a high rate (13%) of HBV carriers was found.