Evaluation of anti-Schistosoma mansoni igG antibodies in patients with chronic schistosomiasis mansoni before and after specific treatment

Abstract

The circumoval precipitin test (COPT), enzyme-linked immunosorbent assay (ELISA) and the immunoblotting anti-adult worm antigen (AWA) and soluble egg antigen (SEA) tests were applied to 17 chronically schistosome-infected patients for the detection of anti-Schistosoma mansoni antibodies before and on four occasions after oxamniquine administration over a period of six months. Compared to a control group, schistosomiasis patients showed high levels of IgG antibodies in AWA and SEA-ELISA. A decrease in IgG levels was observed six months after treatment, although negative reactions were not obtained. Significant decreases in IgG1, IgG3 and, mainly, IgG4, but not anti-SEA IgG2 levels were observed six months after treatment, again without negativity. Analysis of anti-AWA IgG antibodies by immunoblotting before treatment showed a 31 kDa strand in 14 patients (82%) which disappeared in three cases up to six months after treatment; furthermore, anti-SEA IgG antibodies showed the same band in nine patients (53%) before treatment, which disappeared in only four cases up to six months after treatment.

Predicted Impact of Mass Drug Administration on the Development of Protective Immunity against Schistosoma haematobium

“…The rate of decay of protective immunity is particularly important. Some studies (mainly on S. mansoni ) suggest that schistosome-specific antibody levels may decline below pre-treatment levels following an initial boost, behaviour predicted for medium- or short-lived antibody responses in our model [42], [43], but this is not always seen and more accurate estimates are required.…”

Detection of Schistosoma mansoni Antibodies in a Low-Endemicity Area Using Indirect Immunofluorescence and Circumoval Precipitin Test

“…The level of agreement between COPT (K = 0.224) and parasitological techniques was higher than that with IFA-IgM. 42 The higher COPT positivity compared with parasitological techniques may be caused by oviposition occurrence, where eggs deposited in the deepest layers of the intestine can be detected even in the absence of eggs in feces, especially in chronic infections in patients over 40 years of age 43 and with low parasite load. 13 However, in this study, COPT was positive in four of the five individuals who were positive for S. mansoni using parasitology techniques.…”

“…The COPT detects antibodies against excretion and secretion products of miracidia, the fluid that surrounds the parasite, 17 whereas IFA-IgM reactions detect antibodies against antigens of the internal lining of the adult worms' digestive tract. 42 The antibodies detected by COPT appear early, matching the beginning of egg dissemination into feces. 43,45,46 In this way, the antibodies are detected only when the infection is caused by worms of both sexes.…”

SDS-PAGE Protein Pattern and Antigenicity Cross Reaction of Human Schistosomes

“…Thus it is considered of high diagnostic importance and could therefore be used as a serologic marker (Valli et al, 1999;Basyoni and Abd ElWahab, 2013). At the same time, Vendrame et al (2001) reported that when sera of S. mansoni infected patients were analyzed by immunobloting against both S. mansoni AWA and SEA elucidated an intense reaction identifying the bands of 204, 194, 164, 152, 130, 115, 92, 67, 55, 50, 40, 36, 31, 25 and 22 kDa. Ludolf et al (2014) by using two dimensional electrophoresis and WB techniques were able to identify 47 different antigenic proteins in S. mansoni AWA and SEA, a slightly larger number when compared to previous S. mansoni serological-proteomic studies.…”