THE VALUE OF AN ENZYME-LINKED-IMMUNOSORBENT-ASSAY FOR THE DIAGNOSIS OF SCHISTOSOMIASIS-MANSONI MYELORADICULOPATHY

The role of serological tests on cerebrospinal fluid (CSF) in the diag nosis of neuroschistosomiasis has not been fully elucidated; the condi tion is essentially diagnosed on the basis of circumstantial evidence, which may lead to an erroneous diagnosis, especially in highly endemi c areas. We therefore carried out a prospective case-control study in which we compared the concentrations of immunoglobulin G (IgG) specifi c for schistosome soluble egg antigen (SEA) present in the CSF of 54 p atients with schistosomiasis mansoni myeloradiculopathy (SMMR) with th ose observed in a control group consisting of 41 patients with epidemi ological and serological evidence of exposure to schistosomes, and wit h other neurological disorders that result in mild to moderate impairm ent of the blood-brain barrier. Anti-SEA IgG was estimated by an enzym e-linked immunosorbent assay. The sensitivity, specificity and positiv e and negative predictive values were 56%, 95%, 94% and 62% respective ly. Likelihood ratios and the corresponding post-test probabilities we re determined for 4 levels of anti-SEA IgG in CSF. A value below 0.1 m u g/mL practically excluded the possibility of SMMR (post-test probabi lity < 5%), a value above 1.4 mu g/mL practically confirmed the diagno sis of SMMR (post-test probability > 96%), values of 0.1 to 0.5 mu g/m L had no diagnostic value (post-test probability approximately 45%), a nd values of 0.6 to 1.4 mu g/mL were useful in some situations (post-t est probability approximately 70%). We conclude that the estimation of anti-SEA IgG in the CSF is useful for the diagnosis of SMMR.