Association of Presence and Quantity of C4d with the Severity of Kidney Injury in Primary Membranous Nephropathy

OBJECTIVE: The aim of this study was to evaluate the correlation between glomerular C4d staining and the demographic, clinical and histopathological findings in patients with primary membranous nephropathy (MN). MATERIAL and METHODS: A total of 20 patients who underwent kidney biopsy and diagnosed as MN between 2005 and 2014 were included in this study. Patients were divided into two groups based on to C4d staining degrees and patterns. Those two groups were compared according to their demographical features, clinical follow-up, laboratory follow-up and histopathological findings. RESULTS: The percentage of segmental sclerosis (p=0.017), deposition of immunoglobulin A (p=0.044), and kappa and lambda proteins (p=0.029, p=0.049 respectively) were associated significantly with the negative-mild degree C4d staining group. Staining in a global pattern was statistically associated with intermediate-severe degree of C4d staining (p=0.001). The C4d staining patterns of the patients were then scored (segmental pattern one point, global pattern two point) and multiplied by the degree of C4d staining. The score of segmental/global pattern of staining factor was significantly higher within the intermediate-severe degree of C4d staining group (p<0.01). CONCLUSION: Association of the global pattern and intermediate-severe degree of C4d staining suggests that immune deposition is more prevalent within the global pattern in primary MN.