Warm autoimmune hemolytic anemia: experience from a single referral center in Mexico City

BACKGROUND Autoimmune hemolytic anemia (AIHA) is characterized by an autoimmune-mediated destruction of red blood cells. Warm AIHA (wAIHA) represents 60% of AIHA cases and is associated with the positive detection of IgG and C3d in the direct antiglobulin test (DAT). This study aimed to assess the clinical and laboratorial differences between primary and secondary wAIHA patients from a referral center in Mexico City. METHODS All patients diagnosed with wAIHA in our institution from January 1992 to December 2015 were included and received corticosteroids as the first-line treatment. We analyzed the response to the first-line treatment, relapse-free survival, and time to splenectomy. RESULTS Eighty-nine patients were included. Secondary wAIHA represented 55.1% of the cases. At diagnosis, secondary wAIHA patients showed a DAT mixed pattern more frequently than primary wAIHA patients (36.7 vs. 17.5%, P<0.001). In the survival analysis, patients with secondary wAIHA had a lower time to response (18 vs. 37 days, P=0.05), median disease-free survival (28.51 vs. 50.95 weeks, P=0.018), and time to splenectomy (43.5 vs. 61 wks, P=0.029) than those with primary wAIHA. Due to economic constraints, rituximab was considered as the third-line treatment in only two patients. CONCLUSION Secondary wAIHA may benefit from a longer low-dose steroid maintenance period mainly due to its shorter time to relapse and time to splenectomy than primary wAIHA.