Response to hydroxychloroquine in Japanese patients with systemic lupus erythematosus using the cutaneous lupus erythematosus disease area and severity index (CLASI).

We evaluated the cutaneous lupus erythematosus disease area and severity index (CLASI) in Japanese patients with systemic lupus erythematosus (SLE) in order to design a clinical trial of hydroxychloroquine (HCQ) in Japan. Our prospective cohort study consisted of seven SLE patients with active skin disease who started HCQ at Tokyo Metropolitan Tama Medical Center. The therapeutic responses were assessed at 4 months. Patients were categorized as responders (improved) or non-responders (unchanged or worsened) using the criteria of a 4-point or 20% decrease in the CLASI activity score. We also assessed joint pain determined by patient visual analog scale (VAS), malaise (VAS), patient global assessment of SLE (VAS), and constitutional and musculoskeletal symptoms according to the British Isles Lupus Assessment Group (BILAG) disease activity index. Six patients (86%) were categorized as responders. The median (range) CLASI activity score of all patients at assessment had changed from 8.0 (2-22) to 4 (2-10). All five patients with joint pain and all five patients with malaise showed improvement in patient VAS but the BILAG findings failed to capture these improvements. In conclusion, the cutaneous aspects of SLE can be measured by the CLASI. The CLASI activity score may be a reasonable primary endpoint when performing a clinical trial of HCQ.