Hemolytic anemia following high dose intravenous immunoglobulin in patients with chronic neurological disorders.

BACKGROUND AND PURPOSE: High dose intravenous immunoglobulin (IVIG) is an established treatment for various neuromuscular disorders. Recently, cases of hemolytic anemia following IVIG have been observed. The objective of this study was to determine the extent of anemia and hemolysis after IVIG and its relationship to the AB0 blood type system.

METHODS: In a prospective study 34 de novo treated patients were given 2.0 g/kg bodyweight of Privigen and 50 patients received either Privigen [n = 28; 1.53 ± 0.4 g/kg (mean ± SD)] or Kiovig (n = 22; 1.7 ± 0.4 g/kg) as maintenance therapy. The de novo patients all had a post-polio syndrome, whereas the remaining patients received maintenance therapy for the neuromuscular disorders chronic inflammatory demyelinating polyradiculoneuropathy and multifocal motor neuropathy. Blood sampling was performed before and 2 weeks after infusion of IVIG.

RESULTS: Following IVIG treatment blood hemoglobin declined from 8.6 ± 0.9 to 8.0 ± 1.2 mM, P < 0.001. Reticulocyte counts and levels of bilirubin and lactate dehydrogenase were increased and haptoglobin levels decreased. The decline of hemoglobin was 0.9 ± 1.2 mM after de novo therapy versus 0.4 ± 0.8 mM after maintenance therapy with Privigen (P = 0.05) and 0.2 ± 0.3 mM after maintenance therapy with Kiovig (P = 0.47). In de novo patients compared with patients on maintenance therapy reticulocyte count and lactate dehydrogenase level increased whereas haptoglobin level decreased. Anemia correlated with the AB0 blood type system with a significant difference between type 0 (n = 17; +0.3 ± 0.4 mM) and type A, B and AB (n = 48; -1.0 ± 1.0 mM), anemia being most pronounced in type AB.

CONCLUSION: Moderate hemolytic anemia is a concomitant complication of high dose IVIG in subjects with blood types A, B and AB.