Contribution of Anti-hsp70.1 IgG Antibody Levels to the Biological Diagnosis of Clinically Suspected Ocular Toxoplasmosis

Abstract

Introduction: : Background:Heat shock protein (Hsp) 70 is involved in cellular infection by Toxoplasma gondii but also in the immune response to this parasite. We postulate that infected patients could exhibit serum IgG anti-Hsp70.1 antibodies and that these could be used to improve the diagnosis of suspected ocular toxoplasmosis cases.Patients and

Methods: : This retrospective study included 26 laboratory confirmed ocular toxoplasmosis cases (Group A), 41 clinically suspected cases (Group B) and 67 healthy blood donors chronically infected with T. gondii (Group C). Serum was sampled at the time of uveitis and anti-Hsp70.1 antibody levels were obtained by ELISA. Laboratory and clinical data were analyzed according to the ocular presentation and Goldmann-Witmer’s coefficient. The probability of ocular toxoplasmosis was estimated by a logistic regression analysis that combined data from serum IgG anti-Hsp70.1 and aqueous-humor IgG anti-T. gondii antibody levels.

Results: : Serum IgG anti-Hsp70.1 antibody levels were significantly increased in laboratory confirmed ocular toxoplasmosis cases (group A) and in clinically suspected cases (group B) when compared to the control group (group C) (p≤ 0.0034). These levels were correlated to the retinal lesion size (r= 0.301; p<0.0349). In Group B, 23 cases were classified as true-clinically suspected ocular toxoplasmosis. The logistic probability and anti-Hsp70.1 antibodies in sera biologically validated 9 out of these 23 cases.

Conclusions: : Hsp70 may play a role in the immuno-pathogenesis of ocular Toxoplasma infection. This study showed that the anti-Hsp70.1 antibody and the logistic probability test can help to confirm clinically suspected ocular toxoplasmosis.

Keywords: toxoplasmosis • uveitis-clinical/animal model