Prospective study of serum and aqueous humor anti-Hsp70.1 IgG antibody levels in ocular toxoplasmosis.

AIMS We evaluate whether the serum and aqueous humor (AH) level of IgG anti-Hsp70.1 antibodies improved the biological diagnosis of ocular toxoplasmosis. METHODS AND RESULTS In this prospective cross-sectional and multicentre study, serum and AH were collected at the time of active uveitis. Anti-Hsp70.1-antibody levels were determined by ELISA. Patients with confirmed (Group A1, n= 21) or suspected ocular toxoplasmosis (Group A2, n= 30) were enrolled, as well as a control group of patients with cataract (Group B, n = 42). Serum IgG anti-Hsp70.1 antibody levels were not significantly different within the group of uveitis patients (A1, n= 21 vs A2, n=30, p= 0.8) and was significantly associated with the affected retinal zone (p=0.006) as well as with the size of the retinal lesion (p=0.03). Serum anti-Hsp70.1 antibody level was positive in 10 out of the 18 patients of Group A2. Significant Anti-Hsp-70.1 antibody level in AH was reported in only three patients (3 eyes) with confirmed ocular toxoplasmosis. CONCLUSION While the level of IgG anti-Hsp-70.1 antibody in AH did not improve the laboratory diagnosis of ocular toxoplasmosis, its level in serum was of major significance for retinal damage diagnosis.