High ALT levels predict viremia in anti-HCV-positive HD patients if a modified normal range of ALT is applied.
OBJECTIVE
Some studies have reported that ALT determination is of little value in the study of chronic hepatitis C in hemodialysis (HD) patients. This could be due to the fact that ALT values are lower in HD patients than in healthy individuals; ALT in HCV infection follows a fluctuating pattern and the HCV viremia may be intermittent. The aim of this study was to establish the reference ALT values in a large group of hepatitis-free HD patients, and to determine their role in predicting viremia in anti-HCV-positive HD patients.


METHODS
Four subject groups were studied: group I, patients with normal renal function (n = 88); group II, hepatitis-free HD patients (n = 218); group III, non-viremic anti-HCV+ HD patients (n = 9); and group IV, viremic anti-HCV+ HD patients (n = 24). The ALT used for calculation purposes was the mean value of the twelve previous months for each individual patient. PCR screening for HCV-RNA was performed at least twice for anti-HCV+ patients; these were deemed viremic (HCV-RNA+) if at least one screening was positive, and non-viremic (HCV-RNA) if all PCR results were negative.


RESULTS
Mean ALT in group II was lower than in subjects with normal renal function (15.6 +/- 12 vs. 22.7 +/- 18 IU/l, p < 0.05). No significant differences were observed between group III and group II (17.7 +/- 6 vs. 15.6 +/- 6 IU/l, ns). ALT levels in group IV patients were higher than those of groups II and III (38.5 +/- 39 IU/l, p < 0.05). The upper limit (mean + 2 SD and 95th percentile) for ALT in hepatitis-free HD patients was 27 IU/l. Sensitivity of a mean ALT value > or = 27 IU/l in the diagnosis of HCV viremia was 50%, and specificity was 100%. The positive predictive value of this test in the diagnosis of hepatitis C viremia was 100%.


CONCLUSIONS
ALT values are lower in HD patients and a high ALT level can constitute an excellent tool in predicting viremia in anti-HCV-positive HD patients once other causes of liver disease have been excluded.
Espinosa
M
M
Servicio de Nefrologia, Hospital Universitario Reina Sofia, Cordoba, Spain.
Martin-Malo
A
A
Alvarez de Lara
M A
MA
Soriano
S
S
Aljama
P
P
D000410:Alanine Transaminase / Q000097:blood*; D016022:Case-Control Studies; D004796:Clinical Enzyme Tests; D005260:Female; D006526:Hepatitis C / Q000175:diagnosis* / Q000276:immunology; D018937:Hepatitis C Antibodies / Q000032:analysis*; D006801:Humans; D008297:Male; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012367:RNA, Viral / Q000032:analysis; D012016:Reference Values; D006435:Renal Dialysis; D012680:Sensitivity and Specificity; D014766:Viremia / Q000175:diagnosis* / Q000821:virology
D018937:Hepatitis C Antibodies; D012367:RNA, Viral; D000410:Alanine Transaminase