Investigation of the Relationship Between Neutrophil/Lymphocyte, Platelet/Lymphocyte, IgA/C3, IgA/C4, and C3/C4 Ratios and Proteinuria in Patients With Immunoglobulin A (IgA) Nephropathy

Background Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease, characterized by IgA-containing immune complexes in the mesangium and mesangial cell proliferation. Proteinuria is a strong indicator of the progression of chronic kidney disease. This study aimed to evaluate the relationship between systemic inflammation markers, including the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), IgA/complement (C)3, IgA/C4, and C3/C4 ratios, and proteinuria in IgAN patients. Methods This retrospective study involved 38 patients diagnosed with IgAN between 2002 and 2011. We assessed various serum markers such as leukocyte count, NLR, PLR, C-reactive protein (CRP), C3, C4, IgA, and IgM, as well as proteinuria. The correlation between these markers and proteinuria was examined. Results The mean age of the patients was 37.8 ± 2 years, with 68.42% male. No significant correlation was found between the NLR and proteinuria (p=0.3) or CRP (p=0.3). However, a moderate positive correlation was observed between the NLR and sedimentation rate (R=0.38, p=0.07). Significant negative correlations were found between proteinuria and both urine pH (R=-0.5, p=0.002) and IgA/C4 ratio (R=-0.5, p=0.013). There were positive correlations between the PLR and C4 (R=0.45, p=0.02) and negative correlations between the PLR and IgA/C4 ratio (R=-0.56, p=0.003) and IgA/C4 and C3 (R=-0.48, p=0.008). No significant differences in proteinuria and leukocyte count were observed between the two sexes. Conclusion Although no significant relationship was found between the NLR, PLR, and proteinuria in IgAN, correlation between the IgA/C4 ratio and C4 warrants further investigations in larger studies.