~ 467 ~ The Pharma Innovation Journal 2017; 6(11): 467-470 ISSN (E): 2277- 7695 ISSN (P): 2349-8242 NAAS Rating 2017: 5.03 TPI 2017; 6(11): 467-470 © 2017 TPI www.thepharmajournal.com Received: 04-09-2017 Accepted: 05-10-2017 Kailash Kumar Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, NDVSU, Jabalpur, Madhya Pradesh, India Aditya Mishra Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, NDVSU, Jabalpur, Madhya Pradesh, India Amir Amin Sheikh Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, NDVSU, Jabalpur, Madhya Pradesh, India Pragati Patel Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, NDVSU, Jabalpur, Madhya Pradesh, India Rakshanda Bhagat Department of Veterinary Medicine, International Institute of Veterinary Research and Education (IIVER), Rohtak, Haryana, India Uttarani Maibam Department of Veterinary Physiology and Biochemistry, International Institute of Veterinary Research and Education (IIVER), Rohtak, Haryana, India Correspondence Amir Amin Sheikh Department of Veterinary Physiology and Biochemistry, College of Veterinary Science and Animal Husbandry, NDVSU, Jabalpur, Madhya Pradesh, India Cystatin C as a marker and its clinical importance Kailash Kumar, Aditya Mishra, Amir Amin Sheikh, Pragati Patel, Rakshanda Bhagat and Uttarani Maibam Abstract Cystatin C is a non glycosylated neuroendocrine protein having isoelectric pH of 9.3, encoded by CST3 gene. It is a low molecular weight protein approximately 13.3 kilodaltons consisting 120 amino acids and is removed from the bloodstream by glomerular filtration in the kidneys which can be used as a biochemical marker for proximal tubular damage superior to serum creatinine (sCr). Increased levels of CysC are linked with the risk of death, several types of cardiovascular disease and healthy aging. sCysC is a better glomerular filtration rate marker than sCr for its early detection in incipient diabetic nephropathy. Concentration of cystatin C is increased in patients with hypothyroidism and decreased in patients with hyperthyroidism with treatment. Individuals with untreated carcinomas and leukaemia had significantly higher sCysC concentrations compared to treated patients due to its antitumor effect. CysC regulates certain aspects of immune function because interleukin-10 controls CysC synthesis in response to inflammation. Keywords: Cystatin C, diabetes, hypothyroidism, hyperthyroidism, leukaemia Introduction The livestock sector of India is one of the largest populations in the world and contributes the largest economy to the India. Different systemic diseases like kidney diseases, neuronal diseases and cardiovascular diseases are being emerged widely not only in medical but also in veterinary field. Proper diagnosis is the major problem to combat these diseases in animal. Chronic kidney disease (CKD) is an important emerging disease not only in human but also in animals [1] . So early detection and treatment of this disease is very important which increases the survival rate by preventing the additional renal damage [2] . Evaluation of kidney function is done by direct measurement of Glomerular Filtration rate (GFR), but it is very labour intensive and time consuming [3] . Indirect markers of GFR i.e. serum Creatinine (sCr) and blood Urea Nitrogen (BUN) can be easily measured but the only disadvantage is that they are influenced by non-renal factors, such as age, diet, hydration status and muscle mass [4] . To overcome this problem, an ideal endogenous marker should be evaluated to assay the kidney function. Use of serum Cystatin C (CysC) as a marker of GFR is well documented and some authors have suggested that it may be more accurate than sCr for this purpose [5] . CysC has a stable production rate and is removed from the blood circulation by glomerular filtration. In healthy individuals, CysC is completely reabsorbed and degraded in the tubules. A normal value for CysC in serum ranges from 0.8 to 1.2 mg/L and in patients with renal tubular disorders may be raised as high as 2 to 5 times as the normal values. CysC is an endogenous renal marker and is not affected by age, sex, nutrition and other factors. Serum CysC is considered to be a more sensitive marker than Cr in patients with moderate decrease in GFR [6] . CysC, having many properties like constant production and plasma concentration in the absence of GFR variation, low intra individual variability, no plasma protein binding, no tubular secretion, no tubular reabsorption without catabolism and renal clearance make it a suitable endogenous GFR marker [6] . Cystatin C, a low molecular weight protein approximately 13.3 kilodaltons, is removed from the bloodstream by glomerular filtration in the kidneys that can be used as a biochemical marker for proximal tubular damage superior to sCr. This can be used as new biological tool for other diseases like neuronal, cardiovascular and also different metabolic diseases in livestock sector. In human, the variation of CysC due to different biological factors (age, sex, body weight) was extensively studied but contradictory results were reported regarding the effect of age and body weight on sCysC in dogs. Plasma CysC was shown to be lower in adult dogs compared with younger and older dogs and lower in dogs with body weight <15 Kg