Humoral response to schistosomiasis in diabetes: its implications on serodiagnosis

ABSTRACT

The antibody response to schistosomiasis was assessed, using the E.L.I.S.A. technique, in diabetics with active schistosomiasis [positive stools and/or rectal snip for schistosomiasis]. n=20; diabetics with past schistosomiasis [n=15]; non diabetics with active schistosomiasis [n=15]; non diabetics with past schistosomiasis [n=10] and normal controls [n=25]. The antibody response against both soluble egg antigen [SEA] and soluble worm antigen preparation [SWAP] was lower in diabetics with active schistosomiasis and past schistosomiasis compared to the non diabetic groups [P<0.01] regarding both SEA and SWAP. The antibody response was not influenced by the level of plasma glucose, age or type of diabetes but was negatively correlated to the duration of diabetes [r=-0.53; P<0.01 for SEA and r=-046; P<0.01 for SWAP]. The antibody responses to SEA and SWAP were positively correlated in diabetics with active [r=0.64; P<0.01] and past [r=0.79; P<0.01] schistosomiasis. The sensitivity of serodiagnosis of schistosomiasis was higher in non diabetics 93% for SEA and SWAP compared to 70% and 40% [P<0.05 and 0.01] respectively. The specificity was comparable in diabetics and nondiabetics for SEA but was lower for SWAP in diabetics [65.2% v.s. 100% P<0.01]. It is to be concluded that the antibody response to schistosomiasis is decreased in diabetics leading to decreased reliability of serodiagnosis