Abstract
Introduction: IgA nephropathy (IgAN) is known as the most prevalent primary chronic glomerulopathy. Hence, it is of critical importance to identify the aggravating factors impacting the disease progress, and to predict disease-specific therapy.
Objectives: The aim of our investigation was to determine whether C4d deposits in glomeruli had any correlation with various immunopathologic variables of Oxford classification in IgAN.
Patients and Methods: The characterization of IgAN requires the presence of diffuse and global IgA deposits which were graded ≥2+ with weak C1q deposition. C4d immunohistochemical (IHC) staining was conducted retrospectively on 29 renal biopsies of patients with IgAN, who were selected randomly from all biopsies. C4d IHC staining was performed on 3-μm deparaffinized and rehydrated sections of formaldehyde-fixed, paraffin-embedded (FFPE) renal tissues.
Results: In this study, a significant correlation of C4d deposits with interstitial fibrosis/tubular atrophy (IFTA; T) (r = 0.58, P = 0.001) was obsereved. An analysis regarding the association of C4d deposits with other deposited antibodies and complement fragments showed that only C3 had a significant negative correlation with C4d deposits ( r = -0.42, P = 0.02).
Conclusion: The results show that C4d deposits correlate with IFTA or T variable of Oxford classification of IgAN. There is no significant correlation of C4d deposits with other morphological variables of Oxford classification. C4d deposits showed a negative correlation with C3 deposits. These results need further studies to confirm the relationship of glomerular C4d deposits with immunopathological variables in cases of IgAN.