Abstract
            Introduction: Patients with chronic kidney disease (CKD) have increasingly been diagnosed  with cognitive impairment. Glycogen synthase kinase 3β (GSK3β) is directly causing both  phosphorylated tau (pTau) and amyloid β (Aβ) accumulation in Alzheimer’s disease (AD). GSK3β  expression is more abundant in human platelets than in other blood cells. Recombinant human  erythropoietin (rHuEPO) is a common medicine for treating anemia in patients with CKD, as well  as a neuroprotective agent.  
  Objectives: The goal of this research is to find out how platelet GSK3β regulates plasma Aβ, total  Tau and tau phosphorylated at threonine 181 (p-tau181) levels in CKD patients with cognitive  dysfunction and also the efficacy of rHuEPO treatment.  
  Patients and Methods: The study included 60 participants, which consist of 30 CKD without  cognitive dysfunction and 30 CKD with cognitive dysfunction based on the neuropsychological  examination. The expression of GSK3β in platelets was evaluated using a western blot and plasma  Aβ, total Tau, pTau 181 levels were quantified by ELISA. The data were compared statistically  (P< 0.05) to AD, normocytic normochromic anemic and healthy patients.  
  Results: In CKD with cognitive dysfunction subjects, platelet GSK3β expression and plasma Aβ, total  Tau and pTau181 levels were significantly (P< 0.05) altered like AD when compared to normocytic  normochromic anemic, healthy and CKD without cognitive dysfunction subjects. In post rHuEPO  (100 IU/kg, weekly twice, six months) treatment, the altered protein abnormalities were retrieved  significantly (P<0.05) compared to pre-treatment.  
  Conclusion: This study established that platelet GSK3β expression and plasma Aβ, total Tau,  pTau181 are the candidate biomarkers for cognitive dysfunction in CKD patients. The clinical  utility of rHuEPO as a GSK3β inhibitor and therapeutic agent for cognitive dysfunction in CKD  has been determined.