Haemolysis after treatment with intravenous immunoglobulin due to anti-A

Intravenous immunoglobulin (IVIG) is used to treat an increasing number of conditions. IVIG contains immunoglobulin G (IgG) directed against many targets, including red blood cell (RBC) antigens.

We report on three patients identified within a 7-month period in a single institution who developed haemolysis because of passively transferred anti-A.

The patients were a 34-year-old A (non-A1) D-positive male with aplastic anaemia, a 61-year-old A1 D-negative female with myasthenia gravis and a 57-year-old AB D-positive female lung transplant recipient. The haemoglobin decreased from 11.1 to 5.3 g dL(-1) over 2 days, 12.8 to 7.8 g dL(-1) over 6 days and 7.8 to 6.0 g dL(-1) over several hours, respectively. All three patients had a negative antibody screen, positive direct antiglobulin test for IgG only and an elution containing anti-A1 reactivity. The patients were transfused with O RBC with an appropriate rise in haemoglobin.

These cases illustrate the potential severity of haemolysis after IVIG because of passively transferred antibodies to blood group antigens. Lack of recognition of IVIG as a cause for haemolysis by clinicians may be further confounded if routine testing fails to detect the passively transferred ABO blood group antibodies.