Correlation of morphological alterations of light and electron microscopy in chronic type B and C hepatitis

Chronic type B and C hepatitis involves inflammatory lesions of a variable intensity and variably advanced fibrosis. Considering current, progressively growing requirements for correct evaluation of lesions in liver biopsies, an attempt was made to appraise suitability of selected techniques for a broadened histopathological diagnosis. The lesions were evaluated at the level of light and electron microscopy. Material for the study consisted of liver biopsies obtained from adults and children (n = 60) with serological markers of chronic type B or type C hepatitis. Routine techniques of staining for light and electron microscopy, as well as the techniques of Brachet and Feulgen, were applied. HBcAg expression and HBV-DNA detection in children with chronic type B hepatitis were studied employing the avidin-biotin peroxidase complex (ABC) technique and in situ hybridisation with the ImmunoMax signal amplification. Slight or moderately intense inflammatory lesions (grading of 1 to 2 points) and a low level of fibrosis advancement (staging of 1 to 2 points) prevailed in the material, independently of the etiologic agent involved and age of the patient. Both in children and in adults, extensive lesions in the nuclear chromatin represented the common trait of chronic type B and type C hepatitis examined by light microscopy. Ultrastructural patterns confirmed the lesions and demonstrated virus-resembling particles in the cell nuclei. In HCV infection, hepatocyte cytoplasm contained tubular and horseshoe-shaped structures with lesions of mitochondria, while in HBV infection Dane's particles and tubular forms of HBsAg were detected. For cognitive reasons and due to frequently equivocal literature data, our data on ultrastructural lesions in chronic type C hepatitis seem to be of particular interest. Using the ImmunoMax signal amplification, we were able to diagnose HBV infection under light microscope and to define stage of the infection. Their sensitivity, specificity and relatively short time required for performing the tests makes them advisable in the routine diagnosis of the two infections.