Our informal observations suggested that some patients with acute
sensorineural hearing loss (ASNHL) have subnormal serum
immunoglobulin (Ig) levels. We evaluated 28 consecutive adults (18 men, 10 women) at ASNHL diagnosis using:
antibodies to 68 kD
protein, 30 kD
protein, and
type II collagen; and serum total
IgG,
IgG subclasses, total
IgA, and
IgM. Reference ranges for Ig levels were mean ± 2 SD. We compared prevalences of subnormal
IgG subclasses to those in 275 healthy European adults in previous reports. We also reviewed charts of consecutive adult index patients with primary Ig deficiency (35
common variable immunodeficiency, 406
IgG subclass deficiency) to identify other patients with probable ASHNL.
RESULTS: Mean age was 53 ± 10 (SD) y. Six patients (21.4%) had other autoimmunity manifestations.
Antibodies to 68 kD
protein, 30 kD
protein, and
type II collagen were detected in 21.4% (6/28), 21.1% (4/19) and 18.8% (3/16), respectively. Three patients (10.7%) had subnormal
IgG1, six (21.4%) had subnormal
IgG3, and four (14.3%) had subnormal
IgG1 and
IgG3. Some had subnormal
IgG2,
IgG4,
IgA, and
IgM (n = 1, 2, 3, and 1, respectively). Prevalences of subnormal
IgG1 or
IgG3 were greater in ASNHL patients (25.0% and 35.7%) than 275 controls (2.1% and 3.3%), respectively (p < 0.0001, each comparison). Relative risks of subnormal
IgG1 and
IgG3 in ASNHL were 11.5 [95% CI: 4.1, 31.7] and 10.9 [4.8, 25.6], respectively. Hearing improved after initial
therapy in 17 patients (60.7%). Multiple regressions on Ig levels revealed no significant associations with other available variables. Logistic regressions on initial
therapy response revealed a positive association with men (p = 0.0392) and a negative association with
IgA (p = 0.0274). Our estimated prevalence of probable ASNHL in 35 patients with
common variable immunodeficiency during a follow-up interval of 8 ± 4 y was 0% [95% CI: 0, 12.3]). Prevalence of probable ASNHL in 406 patients with
IgG subclass deficiency during the same interval was 0.74% [0.19, 2.33].
CONCLUSIONS: