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Through a pilot study which includes a clinical, molecular and immunopathological approach to the chronic Hepatitis induced by HBV or by HCV, we determined that 66% of HBsAg carriers are in the "non viremic" phase. The positive HBeAg "viremic" carriers showed HBV-DNA quantitation which varies between > 50 pg to > 100 pg. Both types of carries are infected with the "wild" type HBV. Each subgroup of positive surface antigemia carriers demonstrated a differential immunopathological response. So far, 96% of the HCV carriers investigated, showed HCV-RNA associated to repeatedly positive anti-HCV antibodies. Those patients with increased ALT values uniformly expressed liver histopathological signs of inflammation caused by HCV; demonstrating also the presence of peripheral blood mononuclear cells infected with HCV. At the present, the genotypes investigation indicates a predominance of HCV genotype II (1b). Autoimmune phenomenons associated to HCV have been detected only in 3 patients. The therapeutic approach with interferon alpha applied to the HCV infection preliminary showed similar results to those reported worldwide. Currently, a comprehensive approach to the chronic HBV and chronic HCV infections requires the application of Immunochemistry, Molecular Biology and Cellular Immunology combined technologies.

The presence of detectable levels of aFP was investigated through RIA in 78 serum samples classified as follows: 32 samples from healthy volunteers (group A), 15 anti-HCV positive sera, 19 samples from HBV Chronic carriers (Group B), and 12 sera from a group of anti-core positive individuals, (Group C). Increased aFP levels, upper to the calculated maximal limit (Above 2.6 ng/ml) were detected in 2 individuals from Group A, in 2 HCV positive sera and in 6 HBV chronic carriers. None of the Group C demonstrated increased aFP value. Two B positive sera with augmented aFP activity showed significantly elevated values of this protein 13 and 20 fold upper than maximal limit. In Venezuela, aFP levels the HBV chronic carriers do not appear to be comparable to the reported values in HBV hyper-endemic countries. The need to analyze aFP values in normal groups is emphasised.

Five hundred serum samples from volunteers blood donors were investigated in order to determine the presence of anti-HCV antibodies by an enzyme-linked immunoassay recently developed worldwide. Prevalence of true-positive samples was 1.2% (6/500), 2 fold higher than the reported prevalence in most of the industrialized countries. From these 6 sera, one (16.6%) showed simultaneous reactivity for HBV anticore antibody. Three sera (25%) from 12 patients with diagnosis of Non-A Non-B hepatitis were reactive for anti-HCV antibodies while in a group of 32 sera with negative HAV and HBV screening, 4 (12.5%) showed anti-HCV antibodies. Two samples out of 16 sera persistently positive for anticore demonstrated the presence of anti-HCV antibodies. The anti-HCV antibodies were undetectable in two cases of autoimmune chronic hepatitis. Our results indicate that in Venezuela, HCV represents a significant problem of public health coexisting in certain cases with HBV infection.

Immunoclinical correlation of the HBV circulating DNA was performed. The DNA was detected by means of a hybridization technique set-up in fluid phase using a complementary DNA probe labelled with 125I (Abbott-Genostics). The correlation was carried-out in 12 serum including 8 from known HBV carriers with or without liver disease. Only the positive HBeAg serum shown circulating viral DNA in ranges between 60 to 2800 pcg/ml. The assay shows to be easy to perform, however the expensive cost plus the use of a short-life isotope makes difficult in routine use, which still is under research. The immunopathogenic significance of the findings is discussed.

Sixty per cent of the patients with immuno-compromise of the humoral compartment may show chronic diarrhoea, specially seen in the common variable hypogammaglobulinemia (CVH). We presented 3 cases of late-onset CVH who referred chronic diarrhoea as the main symptom. The immunodiagnosis revealed undetectable or subnormal immunoglobulins levels (G, M, A), preserved total haemolytic complement and a negative autoimmune screening. The cell compartment analysis showed increased number of suppressor T lymphocytes (CD8) plus hyporesponsiveness of the total peripheral lymphocytes to polyclonal mitogens such PHA. The clinical approach of the CVH patients should be performed by a multispecialized team including the clinical immunologist and the gastrointestinal and infectious diseases specialists.