Efficacy and predictive factors of cyclosporine A in alopecia areata: a systematic review with meta-analysis.

Introduction: Drugs for alopecia areata (AA) can induce hair regrowth, but do not change the disease course. Dual properties of cyclosporine A (CsA) as hypetrichotic and immunosuppressive agent have encouraged use in AA. We aimed to determine the most meaningful efficacy of CsA and reveal features helping enhance its efficacy and reduce relapses.

Method: Efficacy of CsA and predictive factors were investigated. Cochrane, MEDLINE, Pubmed and Embase databases were searched.

Results: 2,189 papers were retrieved. Based on 344 patients, mean proportion of responders was 73%. CsA monotherapy showed proportion of hair regrowth of 66%, whereas CsA combined with systemic corticosteroids yielded 78%. Overall efficacy in studies with duration of CsA treatment <6 months was: 74% (53-88%), while in those with duration ≥6 months was: 73% (47-89%). Recurrence with CsA monotherapy was 55% (6-96%) whereas when CsA was combined with systemic corticosteroids it was 28% (6-72%).

Conclusion: CsA confers a favorable therapeutic effect and concomitant use of steroids slightly enhances efficacy, but it dramatically decreases relapses. Longer treatments seem to lead to less relapse likelihood, but daily dose does not influence recurrence. Optimal CsA dosage is 5 mg/kg/day in single therapy regimen, whereas it is 3 mg/kg/day in the steroid-associated regimen. KEY POINTS Most treatments for alopecia areata have not been critically evaluated. Current outcomes about the efficacy and relapse rate of cyclosporine A (CsA) are inconsistent and predictive factors about the clinical response are lacking. CsA confers a favorable therapeutic hair regrowth. Longer treatment seems to lead to less likelihood of relapse of AA, but the daily dose does not exert any effect on the recurrence of the disease. The concomitant use of corticosteroids broadly decreases relapses, and it also enhances efficacy. The combination with corticosteroids is the most predictive feature to prevent relapse of AA, followed by the duration of CsA therapy. The daily dose of CsA is the feature with the least or null impact on the clinical course of AA.