β2 Microglobulin as A Marker of Early Renal Damage In Patients With Sickle Cell Nephropathy

Abstract

Introduction: Sickle cell nephropathy is a cause of significant morbidity and mortality in patients with sickle cell disease. Traditional creatinine based assay for evaluating renal function has several limitations. Hence, the need for more sensitive markers such as β2 microglobulin (β2M). This study seeks to compare β2M with creatinine as a marker of renal damage in patients with sickle cell disease. Method: This is a cross sectional study conducted at the University of Benin Teaching Hospital, Benin City, Nigeria. Serum creatinine and β2M levels were determine using kinetic Jaffe method and β2M ELISA assay (Quantikine kit) respectively in 83 sickle cell disease patients and 40 age and sex match controls. Estimated glomerular filtration rate (eGFR) was calculated using Cockcroft-Gault formular for eGFRCr estimation. Data was analyzed with SPSS version 16. Result: β2M in the SCD patients and controls were 25.0±3.9% versus 45.6±5.8% (p = 0.001), 17.4±7.5mg/dl versus 24.0±8.0mg/dl (0.001), 0.7±0.3mg/dl versus 0.9±0.3mg/dl (p = 0.003), 3.3±1.0 versus 2.3±0.7 (p = 0.001) respectively. The eGFR-Cr was higher in SCD patients than in controls (128.9±8.4ml/min/1.73m 2 versus 113.6±11.0ml/min/1.73m 2 ) but the difference was not statistically significant P = 0.316. β2M has a positive correlation with urea, creatinine and a weak negative correlation with eGFRCr. Conclusion: β2M is superior to creatinine as a marker of sickle cell nephropathy.However, caution should be applied in patients with haematological malignancies and chronic inflammatory diseases.