IVIG Induced Hemolytic Anemia
Intravenous immunoglobulin (IVIG) is derived from donated plasma used to treat immune deficiency, autoimmune, and inflammatory disorders. Adverse effects occur in 5-15% of patients with hemolytic anemia being a delayed reaction. Risk factors for hemolysis are high-dose infusions (1-2g/kg/day or >100g/day), female sex, and non-O blood group. Our case involves a 69-year old male presetting with bilateral lower extremity weakness for 1 year after sustaining a fall, affecting his ability to ambulate with no bowel or urinary incontinence. MRI revealed spondylotic changes of the lumbar spine. EMG showed severe bilateral lumbosacral polyradiculopathy with ongoing denervation and severe sensorimotor peripheral polyneuropathy with axonal loss. He was diagnosed with chronic inflammatory demyelinating polyneuropathy and started on high-dose IVIG (0.4mg/kg; 77.6mg) therapy for 5 days. 48 hours after IVIG completion, patient developed acute drop in hemoglobin (9.1 g/dL to 7.0 g/dL) that continued to down-trend (5.7 g/dL). Type and screen was AB positive. Labs were significant for elevated absolute reticulocyte count (141.5 K/uL), reticulocyte percentage (6.1%), and LDH (321 IU/L) while haptoglobin was low (<30.0 mg/dL), consistent with hemolytic anemia. Direct antiglobulin anti-IgG coombs test was positive and anti-complement negative, consistent with immunohemolytic anemia. He was supported with blood transfusion and continued on high-dose Prednisone (1mg/kg/day) for 3 months. Antibodies present in IVIG product react with RBC antigens predominantly of the ABO blood group, causing intravascular hemolysis. Although IVIG induced hemolysis is typically mild and self-limiting, it can often go undetected and prescribers should be aware.