Assessment of renal function in long-term surviving children after hematopoietic cell transplantation

Background Hematopoietic stem cell transplantation (HSCT) is the standard therapy for many disorders, however long-term complications post-HSCT in pediatrics remain a significant concern, where a pre-existent subclinical kidney damage, the use of nephrotoxic medications, or consequences of primary disease carry the hazard of acute kidney injury (AKI) and chronic kidney disease (CKD), which could be devastating complications, therefore identification of risk factors, prompt diagnosis, and treatment of CKD is vital for secure HSCT. So, we aimed to assess the kidney function to detect the development of CKD in our pediatric patient, using different formulas to measure the estimated glomerular filtration rate (eGFR). Patients and methods A prospective cross-sectional study was conducted at the Bone Marrow Transplantation Unit, Faculty of Medicine, Ain Shams University, Cairo, Egypt, where we included all available HSCT long-term survivors, who underwent HSCT during the period between 2011 and 2018. A detailed medical history and complications were collected from patient’s medical records, while clinical examination with measurement of serum creatinine, and Cystatin C (CysC) were done to determine eGFR, and hence CKD, using different methods; bedside Schwartz and Cockcroft Gault formulas (according to the age), serum CysC, and Chronic Kidney Disease in Children (CKiD) Creatinine-Cystatin C-based CKiD equation (CKiD-eGFR CysC formula). Results We included 23 pediatric HSCT survivors, with a mean (±SD) age of 14.35 (±5.27) years. Most of our patients were diagnosed with aplastic anemia (43.5%) and beta-thalassemia major (26.1%), where HSCT, 87% was allogeneic, 4.3% cord blood; meanwhile 8.7% was autologous. The most common reported complications were AKI (56.5%), and acute Graft-versus-host disease (43.5%), meanwhile, CKD was reported in 4/23 (17.4%) according to serum creatinine bases formulas, and one (4.3%) patient according to serum cystatin C, and two (8.6%) patients based on CKiD-eGFR CysC formula. CKD was linked to the conditioning regimen by Cyclophosphamide and antithymocyte globulin, the use of vancomycin and aminoglycoside, and the history of AKI. Conclusion CKD is not uncommon complications post-transplantation, and is strongly correlated to the previous conditioning regimen, antimicrobials, and history of AKI. The accuracy and early diagnosis of CKD necessitated the use of combined equations of eGFR calculation. CKD Controllable measures are needed to prevent renal insult in children post-transplantation.