Evaluation of serum soluble klotho protein in patients with different degrees of chronic kidney disease

Objectives The aim of this study was to investigate serum α-klotho as a new biomarker for the diagnosis of chronic kidney disease (CKD), especially in its early stages. Background α-Klotho is a novel antiaging protein that was identified as a regulator of calcium and phosphate homeostasis, which is highly expressed in the kidney. The soluble form of klotho acts as an endocrine substance that exerts multiple actions including the modulation of renal solute transport and protection of the kidney. Methods A case–control study was conducted at the Clinical Pathology Department, Menoufia University Hospitals, Faculty of Medicine, during the period from January 2015 to November 2016. Sixty-eight patients suffering from CKD who were admitted to the hospital during the period from January 2015 to November 2016 were included in this study. In addition, 10 apparently healthy subjects with matching age and gender formed the control group. Routine laboratory investigations performed were: hemoglobin, urea, creatinine, uric acid, calcium (Ca2), phosphate (PO4), and albumin and the estimated glomerular filtration rate were measured and the α-klotho protein level was measured by ELISA. Results Serum soluble α-klotho protein levels were significantly lower in CKD patients compared with normal controls. Besides, α-klotho protein levels were positively correlated with estimated glomerular filtration rate, hemoglobin and were negatively correlated with renal function tests and phosphate. Conclusion Soluble α-klotho levels are significantly decreased in CKD not only in the advanced stages but also in the early stages.