Arginase activity in peripheral blood of patients with intestinal schistosomiasis, Wonji, Central Ethiopia

Summary Morbidity and mortality caused by schistosomiasis usually results from immunopathology. But the underlying mechanisms are not yet clearly understood. Th2‐type immune response is thought to be dominant during chronic schistosomiasis, and upregulation of arginase‐I is one component of this milieu. A cohort study was conducted to assess arginase activity in peripheral blood of humans with intestinal schistosomiasis in Wonji‐Shoa Sugar Estate, Central Ethiopia. Laboratory‐confirmed 30 Schistosoma mansoni‐infected patients and 18 apparently healthy controls were recruited. Faecal egg count was carried out by Kato‐Katz technique. Plasma and peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. Activity of arginase in plasma and PBMC lysates was measured, and results were compared with that of controls. Twenty‐one of 30 patients had light infection, whereas moderate and heavy intensity infections were observed in eight and only one patient(s), respectively. A significant increase in both PBMC (patients: 59·96 + 82·99, controls: 25·44 + 24·6 mU/mg protein, P