Automatic laboratory-initiated reflex testing to identify patients with autoimmune hemolytic anemia

The clinical usefulness of automatic laboratory-initiated testing of patients with recent-onset normocytic anemia to diagnose autoimmune hemolytic anemia (AIHA) is uncertain. During a 28-month period, we performed 784,185 CBC counts. Patients without a history of anemia had reticulocyte count testing if hemoglobin values were less than 10 g/dL (< 100 g/L) and mean corpuscular volume was 80 pm 3 (80fL) or more. A direct antiglobulin test (DAT) was performed if the uncorrected reticulocyte count was 2% or more of the RBCs (>= 0.02). Of 784,185 CBC counts, 3,841 (0.49%) revealed recent-onset normocytic anemia, 424 (11.04%) with reticulocyte counts of 2% (0.02) or more. Of those with elevated reticulocytes counts, 52 (12.3%) had positive DAT results. Patient information was available for 40 patients. Physicians were unaware of the existence of AIHA in 33 (83%) of them. Of the 40 patients, 11 (28%) were treated with steroids and 6 (15%) were hospitalized; in 2 patients (5%), medications were stopped because they were suspected to have caused the hemolytic anemia. Automatic laboratory testing for patients with recent-onset normocytic anemia ensures recommended practices, probably saves physician visits, and, for some patients, results in more timely diagnosis and appropriate treatment.