RESUMO
It is unclear whether the combined interferon-ribavirin treatment of chronic hepatitis C [CHC] results in complete elimination of the virus or whether small quantities of virus persist. Early identification of non responders is desirable, because treatment might be terminated to avoid the expense and inconvenience of unnecessary therapy. Evaluation of serum level of hepatitis C virus [HCV] RNA does not always correctly reflect the actual response to antiviral therapy. Analysis of peripheral blood mononuclear cells [PBMCs] for detection of viral RNA should provide more accurate prognostic information. The aim of this study was to investigate the predictive value of clearance of HCV-RNA in serum and PBMCs of patients with CHC after combined Interferon-Ribavirin treatment. Twenty patients with CHC were treated with pegylated Interferon, alfa-2b plus Ribavirin for 6 months. Viral dynamics were assessed by measurement HCV RNA loads in serum and PBMCs at one and six months of therapy by using "real time PCR". Viral load was also measured in liver biopsy of four selected cases at the end of treatment. The complete responders with clearance of HCV RNA in serum and PBMCs at the end of treatment were followed up 6 months after treatment. Early virologic response [EVR]; clearance of serum HCV RNA and normalization of alanine aminotransferase [ALT] at the first month of treatment occurred in 12/20 patients [60%] and persisted to the end of treatment, but six of them [30%] showed positive HCV-RNA in PBMCs. The clearance of HCV RNA from PBMCs at one month of treatment had a negative predictive value of 100%, a positive predictive value of 57.1%, with a sensitivity of 100%, specificity of 50% and accuracy of 70%. After six months of antiviral therapy; clearance of serum HCV RNA was increased to 13/20 [65%], four of them had HCV RNA positive in PBMCs. So, the end of treatment response was achieved in 9/20 [45%]. Negative results of a PBMCs HCV RNA test at the end of treatment had a negative predictive value of 100%, a positive predictive value of 63.6%, with a sensitivity of 100%, specificity of 69.2% and accuracy of 80%. The results of liver biopsy were consistent with that of PBMCs at the end of treatment where two cases showed clearance of HCV RNA from both hepatocytes and PBMCs; while in the other 2 cases, the HCV RNA was detectable in PBMCs and liver biopsy samples. After 6 months follow up; sustained virologic response [SVR] was observed in 7/20 [35%] of the total group. Only 2/20 [10%] showed viral relapse in PBMCs. Conclusion: HCV may persist and replicate in the hepatocytes and PBMCs of serum HCV-RNA negative patients who have persistently normal ALT levels. These patients should be followed up, because they have an ongoing viral infection. The duration of treatment may be tailored according to the early clearance of HCV RNA in both serum and PBMCs at one month of treatment
RESUMO
Antigenicity of the tegumental extract, excretory-secretory products and the whole somatic extract of Fasciola gigantica were evaluated to detect the most sensitive and specific antigen out of them that could be used as an immunodiagnostic tool. Scanning electron microscopic study was carried out to have a full picture for the tegumental structure. The immunohistochemical staining technique was done using the indirect immunoperoxidase method on F. gigantica sections before and after removal of the tegument to recognize the most antigenic parts by using patients sera. Counter immunoelectrophoresis was carried out by using sera from patients with fascioliasis [positive control], patients with schistosomiasis and healthy individuals [control group]. In addition, antibody response against the three types of antigens was detected as ELISA absorbance readings. The results revealed that antigens of F. Gigantica that cause antibody formation in hosts are those generated and released mainly from the tegument and they were the most sensitive and specific