Fewer subsequent relapses and lower levels of IL-17 in Takayasu arteritis developed after the age of 40 years

BACKGROUND The clinical characteristics of Takayasu arteritis (TAK) developing in individuals older than 40 years (TAK >40) are little-known. METHOD We retrospectively analyzed 43 patients with TAK treated at three hospitals in Japan from April 2000 to March 2016. From medical records we collected baseline variables at diagnosis including clinical symptoms, laboratory data, and subsequent relapses. We compared these indices in the patients with TAK onset at >40 years of age (TAK >40) to those with TAK onset ≤40 years (TAK ≤40). Multiplex cytokine/chemokine bead assays were performed using preserved serum supernatants from 24 patients with TAK and 40 healthy donors. RESULTS Of the 43 patients, 20 had TAK >40; this group had significantly fewer instances of orthostatic hypotension (2 (10%) vs. 10 (43%), p = 0.019), carotid bruit (7 (35%) vs. 16 (70%), p = 0.034), and chest pain (0 (0%) vs. 6 (26%), p = 0.023) compared to patients with TAK ≤40 (n = 23). The initial prednisolone dose was significantly lower in TAK >40 (median 30 mg vs. 40 mg per day, p = 0.024). Assessed by the log-rank test, the relapse-free survival rate after remission was significantly higher in the patients with TAK >40 (p = 0.029). The interleukin 17 levels were significantly lower in patients with TAK >40 compared to patients with TAK ≤40 and healthy donors. CONCLUSION Compared to TAK ≤40, TAK >40 could be treated by lower initial doses of prednisolone to achieve remission, and with fewer relapses. These differences might be due to the difference of T helper 17 (Th17) activity suggested by the cytokine profiles.