MO276TOTAL AND SPECIFIC IGE IN PATIENTS WITH IGA NEPHROPATHY

Abstract

Abstract Background and Aims IgA nephropathy (IgAN) is the most common form of primary glomerulonephritis characterized by impaired immunological tolerance. One of possible trigger factors for IgAN initiation and development are allergens which have been described to form IgA complexes deposited in the mesangium. Previous studies reported that serum immunoglobulin class E (IgE) levels are elevated and suggested as a prognostic indicator in glomerular diseases. However, mechanisms of IgE/IgG4-mediated allergic reactions involvement in IgAN as well as specific allergens and their clinical significance have poorly been investigated. The aim of the study was to assess the total serum IgE and IgG4 level and to determine the allergoprofile in IgAN patients. Method The peripheral blood was obtained from 21 IgAN patients (aged of 32.0 (27.0 ÷ 36.0) y.o., male/female ratio as 14/7) and 18 donors (aged of 38.0 (30.0 ÷ 46.0) y.o., male/female ratio as 10/8). IgAN diagnosis was confirmed in patients’ biopsy materials according to the Oxford classification (MEST-C score). The concentrations of total IgE and IgG4 were determined using «IgE total-ELISA-BEST» kit («Vector-Best», RF) and «Human IgG4 Platinum ELISA» kit («eBioscience», Austria)». Allergen-specific IgE to 55 inhalation (domestic, epidermal, fungal, plant) or food allergens were measured using «EUROLINE Atopy Screen IgE» immunoblot kit («Euroimmun», Germany). Statistical analysis was done in Statistica 8.0. Results The increased level of total IgE (in 47,4% of cases) but not IgG4 was established in sera of IgAN patients as compared to donors (p=0.004). Moreover, proteinuria was lower in IgAN patients with a high IgE level as compared to normal one (610 (220 ÷ 910) mg/day vs 1545 (600 ÷ 2200) mg/day, p=0.01) as well as there were no any crescent formation. The investigation of allergen-specific IgE in IgAN patients revealed a strong positive reaction to dust mite allergens of Dermatophagoides pter. (22,75 (16,72 ÷ 35,69) IU/ml – in 29% of cases) and Dermatophagoides farinae (38,24 (12,19 ÷ 65,88) IU/ml – in 43% of cases) correlated with the total IgE (R=0,57, p=0,03) and IgM (R=0,54, p=0,04). The more concentration of specific IgE to dust mite allergens was the lower the severity of segmental glomerulosclerosis (R= -0.55, p=0.04), crescent formation (R= -0.56, p=0.03), proteinuria (R= -0.65, p=0.01) and haematuria (R = -0.55, p = 0.04) were reported. A weak positive reaction was established to other domestic (house dust, honey bee venom, common wasp venom, cockroach), epidermal (cat), plant (sweet vernal grass, orchard grass, timothy grass, cultivated rye, alder, birch, hazel, oak, common ragweed, mugwort, plantain) and food (carrot, sesame, hazelnut, apple) allergens in 9–18% of IgAN patients. Conclusion The prevailing of specific IgE to dust mite allergens of Dermatophagoides pter. and Dermatophagoides farinae but not to food or plant allergens was determined in IgAN patients. The obtained data demonstrated that IgAN pathogenesis in patients with latent sensibilization to dust mite allergens is characterized by a milder disease course what allows to identify this cohort as possible secondary form of IgAN.