Introduction: Serum Anti endothelial Cell Antibodies (AECAs) play a prominent role in idiopathic Sensorineural Hearing Loss (SNHL) in that they induce vascular damage (immune mediated).The of the current study is  To compare AECAs in serum and perilymphatic .uid of idiopathic SNHL children (<15y) undergoing cochlear implant surgery.

Methods: This was a cross sectional study performed in the cochlear implant ward in Rasoul Akram hospital, Tehran, Iran (2008 -2010) on 99 SNHL children undergoing cochlear implant surgery. The data collected from47 idiopathic and 52 non-idiopathic SNHL cases. AECAs were measured by indirect immuno .uorescence assay and compared in sera and perilymphatic .uids between the two groups. P-value<0.05 was considered signi.cant.

Results: Idiopathic SNHL was diagnosed in 47.5% of cases. Positive AECA results in serum and perilymphatic .uid were 10% and 12%, respectively. Although AECA results in perilymphatic .uids were different between idiopathic and non-Idiopathic SNHL patients (PV<0.05), AECAs in serum showed no signi.cant difference between the two (PV=0.1).No signi.cant difference was detected between the mean age of idiopathic and non-idiopathic SNHL patients with positive AECAs in serum and perilymphatic .uids (PV=0.2 PV=0.2).

Discussion: Idiopathic SNHL was diagnosed in 47.5 % of studied cases. Idiopathic SNHL has a poor out come in children. In cases with idiopathic SNHL, .nding AECAs in perilymphatic .uids are more valuable than in the serum. We suggest that serum and perilymphatic .uids testing for AECAs would be helpful in management of idiopathic SNHL cases.

Speci.c immunosuppressive treatments for selected cases suffering from Idiopathic SNHL (only in those older than 5) might be successful in disease management. However, this theory should .rst be validated by randomized clinical trials.