Background: Infections that are caused by Candida albicans play a growing role in morbidity and mortality of paediatric patients who are immunocompromised or undergo intensive therapy. We investigated the role of Candida opsonisation by IgM-enriched intravenous immunoglobulin (IVIG) preparation in superoxide (O2) production of polymorphonuclear leukocytes (PMN).

Subject: Anticoagulated whole blood from healthy adult volunteers.

Methods: Superoxide dismutase inhibitable O2 -production by granulocytes in whole blood during Candida phagocytosis was measured according to the method of Bellavite et al. (1983 Eur J Clin Invest 13:363). Candida particles in different concentrations(3,125→100,000 particles/μl) were opsonized by IgM-enriched IVIG(5→30%, Pentaglobin, Biotest) and/or human serum (10%) for 30 min at 37°C. Statistical analysis: Kruskal-Wallis one-way ANOVA followed by Dunnett-test.

Results: Candida in 12,500 and 25,000 particles/μl concentrations induced the highest O2 -release. At 12,500Candida particles/μl, opsonisation with 5 and 10% IVIG significantly (p < 0.05) increased the O2 -production (13.62± 1.24 and 11.24 ± 0.66 nmol O2/15 min/106 PMN, respectively) compared to the non-opsonized particles (9.27 ± 0.44), while higher concentrations did not result in significant change. IVIG-opsonisation caused similar changes at 25,000 particles/μl concentration. Presence of 10% human serum during opsonisation did not influence O2 -release.

Conclusion: IgM-enriched IVIG increases PMN O2 -release during Candida phagocytosis.