Modified range of alanine aminotransferase is insufficient for screening of hepatitis C virus infection in hemodialysis patients

OBJECTIVE

A moderate increase in serum alanine aminotransferase (ALT) has been reported to be a helpful, low-cost tool for predicting viremia in anti-hepatitis C virus (HCV)-positive hemodialysis (HD) patients. This study focused on evaluating the effectiveness of a lowered normal serum ALT value as a screening method for HCV infection in HD patients.

MATERIAL AND METHODS

Serum ALT levels were compared with HCV virologic status in 125 patients on maintenance HD.

RESULTS

The prevalence of HCV antibodies was 23%. A total of 3.7% of viremic HD patients did not have a detectable antibody response. Using the conventional upper limit of normal for ALT of 37 IU, there was no significant difference in the frequency of elevated ALT levels between HCV RNA-positive and-negative patients. However, if the upper limit of normal for ALT was lowered to 27 IU, the difference was significant. Nevertheless, 60% of viremic patients still fell within the normal range.

CONCLUSION

Although inexpensive and widely available, the monitoring of serum ALT levels is not useful as a screening method for HCV infection in HD patients.

Cytokine serum levels in patients with chronic HCV infection

The pathogenic role of immune-mediated mechanisms in chronic hepatitis C virus (HCV) infection has not yet been elucidated. In this study, we report different cytokine expression profiles from hemodialysis (HD) and non-HD HCV (+) patients. IL-1beta, IL-2, IL-4, IL-6, TNF-alpha, and TGF-beta1 serum levels, and liver biochemical parameters were determined in 85 individuals (41 HD patients and 44 non-HD patients). Screening for HCV RNA and anti-HCV antibodies was performed using qualitative and quantitative reverse transcription polymerase chain reaction (RT-PCR), and standardized enzyme-linked immunosorbent assay (ELISA) and recombinant immunoblot assay (RIBA) methods, respectively. IL-4 and IL-1beta demonstrated decreased serum levels in non-HD HCV carriers compared with healthy controls. Both T helper (Th) 1 and Th2 lymphocytes were highly associated with chronic HCV infection, as indicated by the increased IL-2, IL-4, and IL-6 cytokine circulating levels in all chronic active hepatitis (CAH) patients examined. An enhanced Th2 response (IL-4 and IL-6) coupled with increased TNF-alpha and IL-1beta serum levels was reported in HD HCV (-) patients. In conclusion, our data show that a virus-induced Th2 and IL-1beta immunosuppression is an early event in HCV-related chronicity. Long-term HD specifically exerts a chronic effect on IL-6, IL-1beta, and TNF-alpha serum circulating levels. Irrespective of the HD status, HCV viremia, and liver biochemistry parameters, both Th1 and Th2 responses are highly associated with chronic HCV infection.