The association between ear involvement and clinical features and prognosis in ANCA-associated vasculitis

The concept of otitis media with ANCA-associated vasculitis (OMAAV) was recently proposed by the study group of the Japan Otological Society. However, little is known about the effect of ear involvement on the clinical features and prognosis of AAV. We investigate this issue in this study.

We retrospectively examined 36 patients diagnosed with OMAAV and 44 patients diagnosed with AAV without ear involvement (non-OMAAV) at Ehime University Hospital from 2013 to 2018. We collected serological findings including ANCA type and titer, C-reactive protein (CRP), serum creatinine level, organ involved at initial diagnosis, treatment, remission, disease relapse, and mortality from medical records. We investigated whether clinical features and outcomes differed between the OMAAV and non-OMAAV groups.

Age, ANCA titer, and CRP at initial diagnosis were not significantly different between the two groups, and the rate of intravenous cyclophosphamide (IVCY) use also did not differ. The proportions of patients with concurrent eye involvement, facial palsy (FP), and hypertrophic pachymeningitis (HCP) were significantly higher in the OMAAV than in the non-OMAAV group (p = 0.005, 0.005 and 0.049, respectively), while both renal and peripheral nerve involvement were significantly less common in OMAAV patients (p = 0.04). Among the 30 patients with renal involvement, serum creatinine level at diagnosis was significantly lower in the OMAAV group (p = 0.04). The mortality rate was 8.3% in OMAAV and 6.8% in non-OMAAV cases, but this difference was not significant. The rate of relapse was 33.3% in OMAAV and 13.6% in non-OMAAV cases; this difference was significant (p = 0.04).

Serological measurements of disease activity did not differ between the groups. Eye involvement, FP, and HCP, however, were significantly more common in AAV with ear involvement. In addition, renal involvement was less common and renal impairment was milder in AAV with ear involvement. These findings can be considered clinical features. The relapse rate was significantly higher in AAV with ear involvement.