The role of serum immunoglobulin e in patients with immunoglobulin А-nephropathy

THE AIM. To determine the frequency of elevated serum immunoglobulin E (IgE) levels in patients with immunoglobulin A nephropathy (IGAN) and to establish its relation to clinical and morphological, laboratory manifestations and disease course. PATIENTS AND METHODS. The study enrolled 47 patients with primary IGAN, age 32 (27 ÷ 39) years. Daily proteinuria (PU), hematuria, serum creatinine, degree of arterial hypertension (AH) and glomerular filtration rate (GFR) were analyzed. Blood concentration of total IgE was determined by enzyme immunoassay, and allergen-specific IgE antibodies to 57 allergens (domestic, epidermal, fungal, vegetable, food) using a commercial kit "EUROLINE Atopy Screen (IgE)" ("Euroimmun", Germany). RESULTS . In patients with IGAN, serum total IgE was found to exceed the normal value in 55 % of cases, with a concentration of 89.4 (47.5 ÷ 198.7) IU/ml and correlation with GFR (R=0.32, p=0.02) and creatinine (R=-0.40, p=0.01) was detected. Patients with elevated IgE levels showed a reduced incidence of AH (p=0.01), tubular atrophy and interstitial fibrosis (T1) (p=0.03). A correlation analysis revealed that the severity of endothelial proliferation decreased with increasing IgE concentration (R=– 0.40, p=0.02). The highest prevalence among allergens was shown for specific IgE to domestic mites Dermatophagoides farinae (42,1 %), specific activity of 31,4 (1,7 ÷ 71,3) u.u. was noted to Dermatophagoides pteronyssinus. There was a correlation between IgE concentration to Dermatophagoides pteronyssinus and PU (R=-0.51, p=0.01) and between the amount of IgE to Dermatophagoides farinae and the percentage of half moon (R=-0.55, p=0.01). The five-year event-free survival rate was 67 ± 19 % in the IgE group within normal limits and 100 % in the IgE group above normal limits (p=0.008). CONCLUSION. The presence of elevated concentrations of total and specific IgE indicated a more favourable course of IGAN.