Does schistosomiasis affect cellular proliferation of hepatocytes in hepatitis C infection?

ABSTRACT

The role of schistosomal co-infection with HCV in affecting the course of chronic viral hepatitis is not clear. This study aims at evaluating the effects of schistosomal co-infection on histopathoiogical changes as well as cellular proliferation in liver biopsies of HCV infected patients. The study included 49 cases of chronic liver disease [14 cases of pure hepatitis C [HCV], 26 cases of combined HCV and shistosomiasis and 9 cases of pure schistosomal hepatic affection] .Histopathoiogical assessment of liver biopsies in cases of chronic viral hepatitis was done according to the Ishak's modification of Knodell's score for grading and staging system. Cellular proliferation was evaluated by immunohistochemical staining with the proliferation marker ki-67 [MIB-1] as well as by counting the mean number of argyrophilic nu-cleolar organizer regions [Ag NOR[s]]. Of the 14 cases of pure HCV, 9 cases [64.3%] showed minimal to mild chronic hepatitis and 5 cases [35.7%] showed moderate to severe chronic hepatitis.4 cases [28.6%] were cirrhotic. On the other hand,16 out of 26 cases of combined HCV and schistosomal infection [61.5%] showed minimal to mild chronic hepatitis while 10 cases [38.5%] showed moderate to severe chronic hepatitis. 8 cases [30.76%] were cirrhotic. These figures did not differ significantly from those of pure HCV infection with pvalues [0.236], [0.111] and [0.863] respecrively. As regards cellular proliferation, by using the immunohistochemical marker ki-67 [MIB-1], cases of pure HCV showed nuclear staining in 8/14 cases [57.14%]. The mean proliferation index PI was [5.14 +/- 5.66].In cases of combined HCV and schistosomal affection, 16 out 26 cases [61.5%] showed positive staining with PI [5.6 +/- 5.9]. The difference between the two groups was non significant [p=0.834]. In the group of pure schistosomal affection of the liver, 4/9 cases [44.4%] showed positive staining.The PI of this group was [3.11 +/- 4.25]. This figure does not differ significantly neither from the group of pure HCV [p = 0.254] nor from the group of combined HCV and schistosomiasis [p=0.195]. By using the traditional method for assessment of cellular proliferation by counting the mean number of Ag NOR[s], in the group of pure HCV, the PI was [1.62 +/- 0.13], that of combined HCV and schistosomiasis was [1.61 +/- 0.13] while that of pure schistosomal hepatic affection was [1.57 +/- 0.09]. The difference between the three groups was statistically not significant. This work shows that on the histopathological level, schistosomiasis does not significantly affect hepatic lesions induced by HCV. Moreover; shistosomiasis does not alter the proliferation index of hepatocytes of HCV infected patients. This work showed also that on assessing cellular proliferation, both the immunohistochemical method using ki-67 and counting the mean numbers of Ag NOR[s] give similar results: