Evaluation of the Role of Interleukein-2 and Interleukein-4 in the Immunopathogenesis of Steroid Therapy Resistance in Iraqi Asthmatic Patients

Abstract

Interleukins (IL-2 and IL-4) are increased in asthmatics and were reported to induce resistance to steroid therapy in some patients who fail to get benefit from glucocorticoids when used in full dose and for long period of time. In this context, the present study was conducted on Iraqi patients to provide additional laboratory mean, beside the clinical diagnosis, for the decision whether the asthma is steroid sensitive or resistant by monitoring the level of immunoglobulins, complement proteins and interleukins among asthmatic patients (steroid sensitive or resistant) and the possible contribution of other factors like age, sex and environments in the development of steroid resistance. A total number of 55 asthmatics and 28 normal subjects were enrolled in the study. Patients were diagnosed clinically as steroid sensitive (SSA) and steroid resistant (SRA) and blood samples were taken from all subjects included in the study for the measurement of immunoglobulins (IgA, IgG, IgM and IgE), complement proteins (C3 and C4), interleukins (Il-2 and Il-4), and total and differential WBC counts.The results showed no age, sex and residence dependency of acquired steroid resistance, while smoking habit (and may be the atopic allergy) constitute marked predisposing factors. The level of IgA and IgE were high in both SRA and SSA, while IgG level was low in SRA. Complement proteins (C3 and C4) were not differ in asthmatic patients in comparison with control group. The interesting results were those concerning interleukins. The levels of IL-2 and IL-4 were very high in SRA than in SSA. These are parallel with high lymphocyte and neutrophil counts in blood samples of those patients.In conclusion, beside clinical diagnostic features concerning the dose and duration of therapy with glucocorticoids, monitoring the levels of IL-2 and IL-4 could provide additional laboratory diagnostic measures for the convincing decision that asthma is steroid resistant.

Key words: steroid resistant asthma, steroid sensitive asthma, IL-2, IL-4