Protective role of IL-22 against Schistosoma mansoni soluble egg antigen-induced granuloma in Vitro.

The role of T helper-17 (Th17) lymphocytes in the regulation of Schistosoma mansoni soluble egg antigen (SEA)-induced granuloma is unknown. This study examined the effect of Th17 cytokines (IL-17 and IL-22) on granulocyte recruitment and functions during SEA-induced granuloma formation in vitro in Schistosoma-infected and noninfected individuals. Granulocytes were isolated from 27 Schistosoma-infected patients and 13 controls and were used for granuloma induction using SEA-conjugated polyacrylamide beads in the presence of Th17 cytokines. Granuloma index was assessed, and granulocyte mediators such as tumour necrosis factor (TNF-α), hydrogen peroxide (H2 O2 ) and nitric oxide (NO) were measured in the culture supernatant at the 7th day using enzyme-linked immunosorbent assay (ELISA). Schistosoma-infected patients had significant larger SEA-induced granuloma than controls. IL-17 (125 pg/mL) induced the optimum size for granuloma within 3-7 days. However, IL-22 at different concentrations up to 300 pg/mL had no effect on granuloma formation. Using both cytokines simultaneously, IL-22 suppressed the effect of IL-17 and prevented granuloma formation. IL-17 significantly decreased TNF-α, H2 O2 and NO levels in Schistosoma-infected individuals. In contrast, IL-22 increased TNF-α and H2 O2 levels. In conclusion, IL-17 accelerates SEA-induced granuloma formation and inhibits granulocytes functions in Schistosoma-infected patients, while IL-22 inhibited the granuloma formation, but enhanced granulocyte functions.

Prevalence of anti-HEV IgM among blood donors in Egypt.

Hepatitis E virus (HEV) is a common cause of acute viral hepatitis (AVH) in developing countries. In Egypt; where up to 80% of the inhabitants of rural villages have anti-HEV antibodies denoting past infection, most of these infections are asymptomatic with little evidence that the infection causes AVH. There are accumulating reports which suggest potential risk of HEV transmission by blood transfusion. However, detection of serological markers for HEV infection or HEV RNA in Egyptian blood banks is not routinely performed. 760 blood samples from apparently healthy donors at the National blood bank were tested for markers of acute HEV infection to estimate the seroprevalence of acute HEV infection, and potential risk of infection by blood transfusion. They included 124 females (16.82%) and 636 males (83.68%), with a mean age of 23.8 +/- 5.3 years and mean ALT value of 23.3 +/- 13.2 IU/ml. Samples were tested as pools of 10 subjects. Pools with highest reactivity were retested individually to determine the frequency of positive subjects. Out of the 760 samples, three (0.45%) samples were positive for anti-HEV IgM and two of them had HEV RNA as determined by RT-PCR. In conclusion, this study suggests that the tested blood donors have low prevalence of ongoing subclinical infection with HEV and that the potential risk of transfusion may be low.