Third-generation assays for hepatitis C antibodies: a four-year study of pattern changes in patients with chronic and past infection.
BACKGROUND
Many advances have been made in the sensitivity of assays for hepatitis C virus antibodies (HCV-Ab). Nevertheless, polymerase chain reaction (PCR) is still the best method to establish if infection has become chronic. In this study we utilised third-generation assays for HCV-Ab in a four-year follow-up to determine the trend in antibody levels in currently and past infected patients.


METHODS
Seventy-two multitransfused subjects were enrolled. All the patients were reactive at the first test with third-generation screening and confirmatory assays (ELISA-3 and RIBA-3) for HCV-Ab. They were subsequently retested in a follow-up ranging from 41 to 47 months. Viraemia was investigated with a standardised PCR kit; negative samples were reevaluated with nested PCR. Differences in antibody trend were calculated with the Wilcoxon signed-rank test.


RESULTS
No statistical variation in antibody titre was found in the 41 HCV-RNA positive patients, although some of these showed a decrease in anti-c100p level. In contrast, anti-c22p, anti-c33c and anti-c100p levels decreased significantly in the 19 past infected patients. Twelve patients were HCV-RNA negative or intermittently positive with commercial PCR test, and consistently or intermittently positive in nested PCR: in these patients, antibody trend varied.


CONCLUSIONS
Although resolving hepatitis is associated with a decrease in antibody titre, the trend should be observed for a long period to distinguish between chronic and past infection. However, the evaluation in a single patient can be unreliable. Since a doubtful response for HCV-RNA is in some cases obtained, further improvements in the diagnosis of chronic HCV infection are needed.
Perniola
R
R
Paediatric Unit, Vito Fazzi Regional Hospital, Lecce, Italy.
De Rinaldis
C
C
Leo
G
G
D000293:Adolescent; D000328:Adult; D001483:Base Sequence; D002648:Child; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005500:Follow-Up Studies; D016174:Hepacivirus / Q000235:genetics / Q000302:isolation & purification; D006526:Hepatitis C / Q000276:immunology* / Q000821:virology; D018937:Hepatitis C Antibodies / Q000032:analysis*; D019698:Hepatitis C, Chronic / Q000276:immunology / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood / Q000235:genetics
D017931:DNA Primers; D018937:Hepatitis C Antibodies; D012367:RNA, Viral