IL4, IL13, GSTM1 and T1 variants and susceptibility to Schistosomiasis and associated bladder pathologies in Eggua, Nigeria

Abstract

Failure of the human host to elicit adequate immune responses to the adult Schistosoma haematobium worm and continuous strong inflammatory responses to the eggs have been the main causes of bladder pathology in chronic Schistosomiasis. Identification of susceptibility biomarkers for schistosomiasis- associated bladder pathology is necessary in order to detect genetic factors responsible for the infection and spread of the disease. The aim of this study was to identify candidate-biomarkers for susceptibility to schistosomiasis and its associated pathologies. A total of 371 adult participants, comprising 130 males and 241 females from Eggua community, Ogun State, Nigeria, were randomly recruited into a cross sectional study from August 2012 to May 2014. They were screened for S. haematobium ova and bladder pathologies by microscopy and ultrasonography, respectively. Human host susceptibility to schistosomiasis and its associated bladder pathologies were determined by PCR genotyping of Interleukin (IL4 and IL13) genes, and glutathione-S-transferase (GSTT1 and GSTM1) genes. The overall prevalence of S. haematobium in the population was 29.3% (108/369). Bladder pathologies were observed in 32.3% (117/362) of the population. Polymorphisms in IL 4-590 and IL 13-1055 were observed in 24.1% and 9.3% schistosomiasis cases, respectively. The IL 13-1055 polymorphism did not indicate susceptibility to schistosomiasis in males (OR 0.7, 95% CI 0.3-2.1) but a slight risk was found in females (OR 1.1, 95% CI 0.7-1.7). Participants with GSTM1 and GSTT1 polymorphisms expressed elevated risks of bladder pathologies (OR = 4.3, 95% CI 2.0 - 9.2 and OR = 4.2, 95% CI 1.5 – 12.0, respectively), with the pathology and schistosomiasis group having more GST polymorphisms than bladder pathologies.