The relationship between PTEN and stage 3 chronic kidney disease progression

INTRODUCTION Chronic Kidney Disease (CKD) is a structural and functional disorder of the kidneys persisting for three months or longer. Regardless of etiology, fibrosis is the main cause of CKD. It is known that Phosphatase and Tensin Homolog (PTEN), a lipid and protein phosphatase, plays a role in fibrosis, particularly through the PI3K/Akt pathway, and PTEN expression decreases in fibrotic conditions. In this study, the relationship between PTEN, recognized as a fibrosis biomarker, and disease progression in Stage 3 CKD was examined, and the role of PTEN in predicting CKD progression was evaluated. METHODS Between March 2023 and September 2023, 126 volunteers diagnosed with Stage 3 CKD (aged 18 and above, classified according to KDIGO stages with an eGFR of 30-60 ml/min/1.73 m2) who applied to the Pamukkale University Nephrology Clinic were included in this single-center prospective study. From these individuals, WBC, HB, PLT, urea, creatinine, Cystatin C, AST, ALT, LDH, uric acid, total protein, albumin, sodium, potassium, calcium, phosphorus, PTH, D vitamin, HbA1c, glucose, LDL, HDL, triglyceride, PTEN, and 24-hour urine analyses for protein, sodium, and potassium values were conducted at both 0. and 6. months. GFR was calculated using the three-variable equation used in the MDRD study, as updated in 2005; additionally, eGFRs were calculated using the 2021 CKD-EPI Creatinine-Cystatin C equation. Data were analyzed using SPSS Version 28.0, Inc., Chicago, IL, USA for statistical evaluation. RESULTS Among the 126 Stage 3 CKD patients included in our study, 60 were male (47.6%), and 66 were female (52.4%), with a 1.1 times higher prevalence in females compared to males. Statistically significant differences were observed between pre- and post-values for PTEN (p=0.004), GFR (p<0.001), eGFR (p<0.001), LDL (p<0.001), urea (p=0.010), Vitamin D (p<0.001), WBC (p=0.046), and PLT (p=0.004). A positive correlation was found between PTEN change at 0 and 6 months and the change in urinary sodium excretion (r=0.287, p=0.018). In diabetic patients among the Stage 3 CKD individuals included in our study (67 people, 53.2%), we could not detect a statistically significant association between PTEN values and eGFR progression (p>0.05). Significant differences were observed in eGFR 6-month values among PTEN 0-month groups. eGFR 6-month values were higher in the group with PTEN 0-month >6.38 (P=0.039). CONCLUSION In our study, eGFR values at 6 months were found to be higher in the group with PTEN 0.month >6.38. Additionally, a relationship was observed between PTEN and urinary sodium excretion. The study suggests that PTEN can be used as a predictor for Stage 3 CKD progression. However, multicenter and larger-scale studies are needed in this regard. Keywords: PTEN, Stage 3 CKD, fibrosis, urinary sodium excretion