European journal of molecular biology and biochemistry

CYSTATIN C IN CHRONIC KIDNEY DISEASE

*Chubalemla Longkumer, Sangeeta N, C Lalrindiki, Sungdirenla Jamir, Abhishek Dubey, Victoria Laishram, Soumyadip Sarma, N Sharat Kumar Singh, M.A Singh

dr.alemlanuken@yahoo.in

Cystatin C, chronic kidney disease, glomerular filtration rate marker.

Cystatin C has emerged as an alternative marker of kidney function. Because of its small size and basic isoelectric point, cystatin C is freely filtered by the glomerulus. It is not secreted, but is reabsorbed by tubular epithelial cells and subsequently catabolised so that it does not return to the blood flow. The use of serum cystatin C to estimate GFR is based on the same logic as the use of blood urea nitrogen and creatinine, but because it does not return to the blood stream and is not secreted by renal tubules, it has been suggested to be closer to the ideal endogenous marker. To determine the levels of serum cystatin C in patients with Chronic Kidney Disease (CKD). And to find out the correlation of serum cystatin C and serum creatinine with estimated Glomerular Filtration Rate in patients with CKD. A Cross-sectional study, carried out in the Department of Biochemistry in collaboration with Nephrology unit, Department of Medicine, Regional Institute of Medical Sciences (RIMS), Imphal, Manipur between October 2013 to September 2015. Sixty nine (69) chronic kidney disease patients fulfilling criteria of definition of chronic kidney disease recommended by Kidney Disease Improving Global Outcomes (KDIGO). Estimation of serum cystatin C was done using Arbor Assays human cystatin C ELISA kit. Estimation of serum creatinine was done by the photometric colorimetric method. Serum cystatin C level was higher (mean = 1976.5 ± 540.3) than normal value (590-910 ng/dl) in all the CKD cases ( 100%)., while serum creatinine was increased in only 97.1 % of cases ( mean=6.9 ± 4.4) as compared to normal value (0.6-1.6 mg/dl). Both cystatin C and creatinine had a good inverse correlation with GFR and statistically significant , (rs=-0.676) and (p<0.05). (rs=-0.973) and (p<0.05) respectively. This study suggest that both cystatin c and creatinine are good marker of renal function, these correlates well with GFR However, cystatin C was found to be a better marker as it was increased in 100% cases compared to creatinine which was increased only in 97.1% cases.