Warm autoimmune hemolytic anemia (w-AIHA) is an uncommon disease with heterogeneous response to treatment. Steroids are the standard treatment at diagnosis, whereas rituximab has recently been recommended as the second-line therapy of choice. Our main objective was to document the response to treatment in patients with newly diagnosed w-AIHA, including the effectiveness of low-dose rituximab as frontline treatment and for refractory disease.

Patients with w-AIHA from 2002 to 2017 were included. Relapse-free survival (RFS), probability of maintained response (MR), and time-to-response were analyzed using the Kaplan–Meier method. Response was classified as complete, partial, and no response.

We included 64 adults with w-AIHA (39 women and 25 men). The median age was 37 (16–77) years. Response rates to steroids alone were 76.7%, rituximab plus steroids, 100%; and cyclophosphamide, 80%. RFS with steroids at 6, 36, and 72 months was 86.3%, 65.1%, and 59.7%, respectively. Eighteen patients received rituximab at 100 mg/wk for 4 weeks plus high-dose dexamethasone as first-line therapy, with RFS at 6, 36, and 72 months of 92.3%, 58.7% and 44.1%, respectively. Eight patients refractory to several lines of therapy were treated with low-dose rituximab, and all achieved a response (three complete response and five partial response) at a median 16 days (95% confidence interval, 14.1–17.8), with a 75% probability of MR at 103 months; the mean MR was 81.93±18 months.

Outcomes of w-AIHA treatment were considerably heterogeneous. Low rituximab doses plus high dexamethasone doses were effective for refractory disease.