Correlation of immunostaining findings with demographic data and variables of Oxford classification in IgA nephropathy

J Nephropathol. 2013 Jul;2(3):190-5. doi: 10.12860/JNP.2013.30. Epub 2013 Jul 1.

Abstract

Background: Oxford classification for IgA nephropathy (IgAN) did not include pattern of immunostaining in the analysis.

Objective: The aim of this study is to determine the potential correlation between the immunostaining data and morphologic variables of Oxford classification (MEST) and various clinical and demographic data of patients with IgAN.

Patients and methods: The pathologic diagnosis of IgAN requires the demonstration of IgA-dominant mesangial or mesangio-capillary immune deposits through immunofluorescence (IF) microscopy. The immune deposits were semiquantitatively assessed as 0 to 3+ positive bright. These were correlated with various clinical, demographic and histological variables of Oxford classification.

Results: A total of 114 biopsies were enrolled to the study (70.2% were male). Mean age of the patients was 37.7 ± 13.6 years. This study showed that, only C3 deposits had a significant correlation with serum creatinine. Other antibodies (IgA, IgM and IgG) had no significant association with serum creatinine. This study also showed that IgA deposition score had significant positive association with endocapillary proliferation (E) and segmental glomerulosclerosis (S) variables of Oxford classification. Moreover, IgM deposition score had positive association with S variable. There was no significant association of IgG deposition score with four morphologic variables of Oxford classification. There was significant association of C3 deposition score with S and E variables too.

Conclusions: The significant relationships of IgA and C3 deposits with some of the Oxford variables need more attention. We propose to further investigate this aspect of IgAN disease.

Keywords: Deposition; Immune deposits; Immunofluorescence; Immunoglobulin A nephropathy; Immunoglobulins; Immunostaining.