Elevated serum macrophage migration inhibitory factor levels correlate with benign paroxysmal positional vertigo and recurrence events

Objective: We aimed to assess the possible relations between serum levels of macrophage migration inhibitory factor (MIF), a central cytokine of the innate immunity and inflammatory response, and benign paroxysmal positional vertigo (BPPV) risk and BPPV recurrence events. Methods: In the present study, 154 patients with BPPV, and 100 age-and sex-matched control subjects were enrolled in the study. All the patients and controls underwent a complete audio‐vestibular test battery including the Dix–Hallpike maneuver and supine roll test. In the BPPV group, measurements of MIF levels were repeated 1 month after the vertigo attack. The patients were also divided into the recurrence group and the nonrecurrence group in the 1-year follow-up. Results: The serum levels of MIF in patients with BPPV were higher than in those controls (13.9[interquartile range {IQR}, 8.9–18.4] ng/ml vs. 9.8[7.8–11.8]; P<0.001). As a continuous variable, MIF was associated with increased risk of BPPV (odds ratio [OR] 1.21, 95% confidence interval [CI]: 1.11–1.39; P=0.004) in multiple regression analyses. Recurrent attacks of BPPV were reported in 35 patients, and those patients had higher levels of MIF than those patients were not recurrence (18.0[IQR, 13.6–22.2] ng/ml vs. 12.6[9.3–16.8] ng/ml). In multivariate models comparing the second (Q2), third (Q3) and fourth(Q4) quartiles against the first (Q1) quartile of MIF, levels of MIF in Q4 were associated with recurrent BPPV, and the odds were increased by approximately 305% (OR = 4.05; 95%CI: 1.65–15.44; P=0.009). Conclusions: Elevated MIF is positively correlated with BPPV risk and BPPV recurrence events, requiring further efforts to clarify the exact mechanism.