Different cytokine profiles of peripheral blood mononuclear cells from patients with persistent and self-limited hepatitis C virus infection.

An imbalance between T helper cell Th1 and Th2 like cytokines has been described in several chronic infectious diseases. In an attempt to characterise the mechanism responsible for viral persistence in hepatitis C virus (HCV)-related chronic infection, we analyzed Th1 cytokines (IL-2, IL-12, IFN-gamma) and Th2 cytokines (IL-4, IL-10) production by phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMC) derived from ten patients with viremic chronic hepatitis C, five healthy HCV seropositive individuals and four HCV seronegative individuals. Cytokine production was determined by enzyme-linked immunosorbent assay (ELISA) after 72 h of stimulation. The results showed that the production of IFN-gamma by PHA-stimulated PBMC was decreased in patients with hepatitis C infection (P=0.05). IL-4 production was not detected in both patients and controls, while no difference was observed for IL-2, IL-10 and IL-12 production between patients and controls. Furthermore, IL-12 and IFN-gamma production was weaker in patients with viremic chronic hepatitis C than in subjects who were able to clear the virus (P=0.01; P=0.03, respectively). These results clearly indicate that a defect both in IL-12 and IFN-gamma production may contribute to the persistence of HCV infection.

Seroepidemiological study of an acute hepatitis E outbreak in Morocco.

This study clearly shows that hepatitis E virus (HEV) was the major aetiological virus in an outbreak in the south of Morocco, in 1994. Acute hepatitis E was diagnosed using recombinant antigen-based enzyme immunoassays and reverse transcription polymerase chain reaction in 77.3% of patients. In the west of Morocco, 6.1% of controls were positive for anti-HEV IgG. The anti-HEV prevalence in patients was significantly higher than that of controls (84.0% vs. 6.1%) (P < 0.001). In healthy contacts residing in southern Morocco, 10.4% had anti-HEV IgG, indicating past HEV infection. Furthermore, HEV-specific IgM was associated with subclinical HEV infection in 9 contacts and was noted in 10 others who were convalescent. Faecal contamination of drinking water samples collected from the epidemic city was observed. It also appeared that primary infection with HEV accounted for more than 86% of the cases. A longitudinal study showed waning of anti-HEV antibodies in patients and healthy contacts six months after the initial testing. Subclinical HEV infection was significantly prevalent in a paediatric population younger than 10 years (P < 0.05). Our results also showed that anti-HEV IgG in healthy contacts decreased significantly after 30 years of age (P < 0.01), whereas the clinical acute HEV infection incidence increased significantly with age (P < 0.01). From this study, it appears that HEV is present in both the west and the south of Morocco.