Background/Purpose: Relapsing polychondritis (RP) is a multisystem disorder of cartilaginous tissues. We previously found that, in a Japanese cohort study, RP patients with airway involvement and RP patients with external ear involvement were mutually exclusive in the clinical characteristics, suggesting an inverse relationship between airway involvement and ear involvement (Arthritis Rheumatol. 2018; 70: 148–9.). Here, we divided the patients into two subgroups by the patterns of clinical manifestations, namely a subgroup of patients with airway involvement (A subgroup) and those with ear involvement (E subgroup) and investigated the clinical and laboratory characteristics of each subgroup.

Methods: After categorizing 239 Japanese patients into two (A and E) subgroups, we compared patients’ profiles, clinical features, laboratory findings, medicines, and prognosis using dummy variables and the Student’s t-test. The presence and absence of these clinical and laboratory parameters formed dummy variables, 1 and 0, respectively. We measured serum matrix metalloproteinase-3 (MMP3) concentrations and anti-type II collagen antibody titers, disease-related biomarkers, of 26 samples obtained from 22 newly recruited RP patients.

Results: In Japanese RP patients, 47 patients (19.7%) and 118 patients (49.4%) were allocated to the A and E subgroups, respectively. In a comparison of the clinical data between the two subgroups, saddle nose deformity and progressive disease course were observed frequently in the A subgroup. Joint, eye, and CNS involvement were observed frequently in the E subgroup. The remaining RP patients formed the third subgroup (75 patients, 31.4%) and had both airway and ear involvement (termed as B subgroup). Disease duration of the B subgroup (5.70 ± 0.64 years) was significantly longer than that of the E subgroup (4.12 ± 0.45 years). We found that cardiovascular involvement was more predominant in the B subgroup than in the A and E subgroups. High concentrations of serum MMP3 were observed frequently in the B subgroup compared with A and E subgroups. In a new cohort of 26 serum samples, MMP3 concentrations were significantly higher in the B subgroup (n=10) than those in the A subgroup (n=6) and E subgroup (n=10).

Conclusion: RP patients in the A and E subgroups exhibited different characteristics from each other. Progressive disease course and CNS involvement were observed frequently in the A and E subgroups, respectively, in Japanese patients with RP. We did not observed cardiovascular involvement in the A subgroup of the RP patients.

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/japanese-relapsing-polychondritis-patients-with-airway-involvement-were-mutually-exclusive-with-those-with-ear-involvement-in-the-clinical-characteristics/