C4d Deposition in Native Kidney Disease and Its Clinical Significance

Abstract

C4d is a well-known biomarker of the complement cascade. It is derived from cleavage of the labile thioester bond of C4b. This was a retrospective and prospective cross-sectional study, done at our tertiary care hospital. Methods: We evaluated 50 cases and 10 controls to adjudge the significance of C4d deposits in native renal diseases. Majority of the patients (44%) were in the age group of 10-20 years followed by 20% in the age group of 31-40 years. 62% of study population were male. Results: Majority of patients were diagnosed with FSGS (16%), followed by membranous nephropathy (14%), Lupus nephropathy (14%) and IgA nephropathy (12%). All patients diagnosed with Membranous nephropathy, IgA nephropathy and hypertensive nephropathy showed glomerular C4d deposits. All patients diagnosed with IgA Nephropathy, post infectious glomerulonephritis, Lupus Nephritis, minimal change disease, acute/ chronic tubulointerstitial nephritis, diabetic nephropathy, hypertensive nephropathy showed tubular C4d deposits. All patients diagnosed with Diabetic nephropathy and hypertensive nephropathy showed arterial C4d deposits. There was correlation of intensity expression of glomerular C4d deposits with presenting 24 hours urinary protein level at the time of biopsy ( p value=0.027) but no correlation with urea/creatinine. There was significant association (p value 0.019) of tubular C4d positivity with 24 hour protein at the time of biopsy. Tubular C4d deposits showed no significant presenting serum urea and creatinine at the time of biopsy. Conclusion: There was also no correlation noted between presenting 24 hours urinary protein and serum urea and creatinine levels with arterial C4d deposit in diabetic and hypertensive nephropathy patients.