De novo HCV infection among dialysis patients: a prospective study by HCV core antigen ELISA assay
Authors: Fabrizi F. , De Vecchi A. F. , Como G. , Lunghi G. , Martin P. 
Published: March 2005

Background : Dialysis patients remain a high‐risk group for hepatitis C virus infection. The current diagnosis of hepatitis C virus in dialysis patients includes serological measurement of anti‐hepatitis C virus antibody; however, nucleic acid amplification technology for assessing hepatitis C virus viraemia is commonly used in other populations. An enzyme‐linked immunosorbent assay test for detecting antibody to hepatitis C nucleocapsid core antigen (hepatitis C virus core antigen) in human serum has been recently developed (hepatitis C virus Core Antigen enzyme‐linked immunosorbent assay test). It is conceived for screening of donor blood products to significantly reduce the ‘serologic window’ occurring before seroconversion during acute hepatitis C virus.

Aim and methods : A cohort (n = 72) of patients on maintenance haemodialysis in a single unit in the years 2000–2003 was included. Study patients were tested monthly by hepatitis C virus Core Antigen enzyme‐linked immunosorbent assay in a prospective, clinical trial. Routine results obtained by hepatitis C virus Core Antigen enzyme‐linked immunosorbent assay test were confirmed by assessing hepatitis C virus viraemia by branched‐chain DNA (bDNA) signal amplification assay.

Results : De novo hepatitis C virus infection was identified in three patients during the study period; the hepatitis C virus incidence was 1.38% (95% confidence intervals, 1.31–4.09) per year. In each patient, hepatitis C virus core antigen testing allowed the serological identification of acute hepatitis C virus before anti‐hepatitis C virus seroconversion. Hepatitis C virus RNA testing confirmed the results obtained by hepatitis C virus Core Antigen enzyme‐linked immunosorbent assay in all cases. The time from initial hepatitis C virus detection by hepatitis C virus Core Antigen Assay and anti‐hepatitis C virus seroconversion was not greater than four weeks. Two (67%) of three patients with de novo hepatitis C virus acquisition were HBsAg negative; both these patients underwent an initial phase of hepatitis C virus viraemia that was associated with an increase in alanine aminotransferase activity and preceded the seroconversion to anti‐hepatitis C virus antibody. Nosocomial transmission of hepatitis C virus between haemodialysis patients was implicated in at least two (67%) of these three patients.

Conclusions : Serological testing for hepatitis C virus core antigen can identify acute hepatitis C virus infection before anti‐hepatitis C virus seroconversion. The time from initial hepatitis C virus detection by hepatitis C virus core antigen assay and anti‐hepatitis C virus seroconversion was not >4 weeks. De novo acquisition of hepatitis C virus in haemodialysis was associated with a rise in alanine aminotransferase levels. Hepatitis C virus core antigen enzyme‐linked immunosorbent assay test results can be obtained in routine laboratories without the need of special equipment or training. Hepatitis C virus core antigen testing among anti‐hepatitis C virus negative patients on maintenance dialysis is suggested in order to early assess de novo hepatitis C virus within dialysis units.