Associations Between Antibodies Against the Endothelial Cell and T.gondii; Cytomegalovirus in Serum of Children with Cochlear Implant Surgery

Background: Cytomegalovirus (CMV) and T. gondii are two common causes of SNHL (Sensorineural hearing loss) in Iranian children. Immune-mediated vascular damage induced by endothelial cell antibodies may have a prominent role in sensorineural hearing loss. Objectives: To determine the serum CMV and T. gondii antibodies against endothelial cell in children with profound SNHL and cochlear implant surgery. Materials & Methods: A cross sectional study was performed on 76 cases with severe SNHL (mean age 32 ± 30.6 months) at cochlear implant ward of Rasoul hospital, Tehran Iran (2008-2010). The titers of antibodies against endothelial cell (Indirect immunofluorescence assay); were determined in sera of 66 cases. Specific antibodies (IgG & IgM) against T. gondi, CMV (Enzyme linked immunosorbent assay) determined in Idiopathic SNHL cases. Results: Idiopathic type of SNHL was diagnosed in 28.8% (19/66) of younger cases (mean age=20 months; PV=0.05). Positive AECAs was detected in 14.4% (11/76) of cases (with mean age 50 vs. 32 months in cases with negative test; P value=0.047). Positive AECAs had not significant differences between Idiopathic and Non idiopathic type of SNHL [10.5% vs. 9%; PV=0.1]. Positive AECAs were more frequent in cases with known postnatal infections (e.g. mumps, meningitis, chicken pox, etc.) in comparison with non-infection cases (P-value=0.05). Positive T. gondii -IgM (recent infection) was found in 8 /19 (%42); 1 case also had positive T. gondii -IgG. Positive CMV-IgM I 17/19 (%89) respectively. A meaningful correlation was observed between positive AECAs and those infections (Toxo, CMV) in Idiopathic (and unclassified) SNHL cases. Conclusion: Idiopathic type of SNHL with a poor outcome is common (28.8%) in children with cochlear implant surgery Positive AECAs cases had not differences between 2 type of SNHL but were more frequent in older cases with known postnatal infections (meningitis, mumps, chicken pox etc.). A good correlation (p=0.05) between the positive AECAs and known infections determined in studied cases. In contrast, those younger cases ( 2 year old) with Idiopathic SNHL and concomitant positive AECAs.