Haptoglobin Phenotypes in School-age Children Infected with Schistosoma haematobium: A case-control study

Background: Acute phase proteins (APPs), including haptoglobin (Hp), are a large and varied group of plasma proteins that can be used as biomarkers for disease diagnosis/detection/severity. Objective: The main objective was to assess the levels of haptoglobin (Hp) in serum and detect Hp phenotypes using polyacrylamide gel electrophoresis in 100 school -aged children infected with Schistosoma haematobium compared with 60 healthy control. Methods: We conducted a case -control study on 160 schoolchildren (ages 9-15 years) recruited from Tayba Eltejania village, Sinar state, Sudan. Unrelated children with Schistosoma haematobium (case group 100) and unrelated healthy children (control group 60) were included, while those with both Schistosoma types were excluded. The enrolled subjects were evaluated for the levels of Hp and its phenotypes as early markers for disease severity. ELISA quantified biochemical analysis for the serum Hp level. Hp phenotypes were determined, and their frequency was compared between cases and controls. Results: The Hp 2-1 was the highest frequency among cases and controls 72/143 (50.3%), followed by Hp 2-2 (28%), while Hp 1-1 phenotype was 22%. The Hp 2-1 and Hp 2-2 frequency did not differ significantly between cases and controls, considering the Hp 1-1 as the reference group. Multiple comparisons were executed between Hp phenotypes; the differences between these groups were not statistically different. The disease severity was set according to the egg count (Group I: moderate infection <= 35/10 ml, Group II: severe infection >= 36/10 ml), the Hp 2-2 was four times more frequent in cases with severe infection considering Hp 1-1 as the reference phenotype (OR=3.85, 95% CI: 1.044-14.24). Confirming the result, Hp 2-2 was significantly associated with disease severity than Hp 1-1 and Hp 2-1 (OR= 3.77 95% CI: 1.39-10.20). Conclusion: There was evident that the egg count increased in subjects with Hp 2-2 indicating severe infection.