Role of intravenous immunoglobulin in severe steroid-dependent asthma.
BACKGROUND: Subgroups of asthma patients have extremely severe respiratory symptoms that require chronic use of steroids for disease control. These patients are at risk of significant side-effects from chronic exposure to high doses of oral steroids. Intravenous immunoglobulin (IVIG) has immunomodulatory properties as shown by its use in some immune disorders. A few trials have suggested a possible benefit in individuals with severe asthma. AIMS: To evaluate the role of IVIG as an adjunctive therapy in steroid-dependent asthma, monitoring the outcomes of lung function and measured reduction in oral steroid requirement. METHOD: Seven patients with severe steroid-dependent asthma were given IVIG at a dose of 1 g/kg each month for 6 months. Baseline pulmonary function tests and immunoglobulin levels were obtained. At the end of 6 months, the end-points observed were lung function and the degree of reduction in the dose of oral steroids. The number of hospital admissions during the 12 months following commencement of IVIG was compared with the preceding 12 months. RESULTS: There was a significant reduction in daily prednisolone dose from 56 +/- 31 mg to 39 +/- 35 mg (P=0.04, Wilcoxon rank sum test) and a decrease in the number of hospital admissions from 5.9 +/- 2.9 to 3.6 +/- 3.5 (P=0.04). No significant improvement occurred in lung function. CONCLUSION: IVIG provides a potentially important adjunctive therapy in severe steroid-dependent asthma, reducing steroid requirement and decreasing hospital admissions, but not improving lung function.