Evaluation of hearing in pediatric familial Mediterranean fever patients during attack period and attack-free period.

Objectives: Familial Mediterranean fever (FMF) is the most common monogenic autoinflammatory disease worldwide. It usually has a childhood onset and is characterized with recurrent attacks with irregular intervals. Few studies have been performed to investigate hearing in FMF patients ran with various tests and showed different results. In this study, first time in the literature, we aimed to evaluate and compare auditory functions in pediatric FMF patients during the attack periods and attack-free periods to see the possible effects of autoinflammation that was caused by FMF attacks.

Methods: 40 pediatric FMF patients (80 ears) enrolled in the study as study group and 21 matching (42 ears) healthy children as a control group. Blood samples were taken from patients who presented clinical attack symptoms. Control group and FMF patients that were in attack period underwent audiometric evaluation including pure tone audiometry (0.25, 0.5, 1, 2, 4, 8 kHz) and Distortion product otoaoustic emission (DPOAE) (1, 1.4, 2, 2.8, 4 kHz) test. The tests were repeated in attackfree period. Correlations between hearing results and C-reactive protein, erythrocyte sedimentation rate levels, duration of disease, age at disease onset, colchicine usage time, cumulative dosage of colchicine and the number of attacks in the last six months were studied.

Results: Hearing thresholds of FMF patients, compared to control group, were found to be increased at most frequencies. Lower signal/noise ratios (SNR) were detected at most frequencies in the DPAOE test. In the attack period compared to attack-free period, hearing thresholds in the audiometry were found to be increased at some frequencies (p < 0.05). However, this was not supported by the DPOAE test. In correlation analysis, increased colchicine usage time and colchicine cumulative dosage were associated with decreased thresholds in audiogram and increased SNR values in DPOAE. Detailed statistical analyses of all parameters were included in the study.

Conclusion: Results demonstrated cochlear involvement in FMF patients. Acute changes in hearing thresholds in the attack period may be suggesting the effect of acute inflammation on cochlea. The difference between the audiometry and otoacoustic emission test results of FMF patients and healthy controls suggests the cumulative effect of recurrent inflammation attacks on cochlea. Positive affect of treatment of the disease with long term colchicine in hearing were also demonstrated.