Case 1 Case 2 Hemoglobin, g/dl (lowest) 2.9 5.7 Reticulocytes (%) 2.8 5.6 Mean corpuscular volume (fL) 74 69 White blood cells (×106/L) 11.8 8.3 Platelets (×103/L) 196 224 Bilirubin, Total (mg/dL) 8.4 8.0 Bilirubin, Direct (mg/dL) 0.6 0.8 Coombs test, Direct Positive Positive Coombs test, Indirect Positive Positive Serum ferritin (ng/mL) 2123 435 Lactate dehydrogenase (U/L) 2874 834 Serum B12 and folate  Normal  Normal Electrolytes, blood sugar, blood urea nitrogen, and creatinine  Normal  Normal Anti-nuclear, anti-DNA, anti-smooth muscle, and anti-mitochondrial antibodies Negative Negative Cytomegalovirus and Epstein-Barr virus (IgM, IgG)a Negative Not done Mycoplasma antibodies Positive, titer 1:80 Weak positive, titer 1:40 Hepatitis B virus, hepatitis C virus, and human immunodeficiency virus (HIV) Negative Negative Blood type B Rh-positive with negative C, E, K, Fy(a), and S antigens B Rh-positive with anti-c antibodies Hemoglobinuria Positive Positive aIgM: immunoglobulin M; IgG: immunoglobulin G

Table 1: Laboratory workup of Cases 1 and 2.