To Study Renal Dysfunction In Children And Adolescents With Thalassemia Major

Abstract

Introduction: β-Thalassemia major is an autosomal recessive disease that leads to a severe haemolytic anaemia in early infancy. Affected children are dependent on repeated packed red cell transfusions and iron chelating therapy. Anemia may reduce systemic vascular resistance, by determining a hyperdynamic circulation, that increases renal plasma flow and GFR, eventually leading to endothelial and epithelial injury and reduced GFR. Also, iron overload and chelation therapy have adverse effects on renal functions. The present study was aimed to investigate renal functions in paediatric patients with transfusion dependent β-Thalassemia major on iron chelation. Aims and Objectives: To study the clinico-demographic profile, impact of iron overload and chelation therapy on renal functions in children and adolescents with Thalassemia major. Methodology: A consecutive consenting sample of 93 patients with Thalassemia Major between the age group of 5-18 years undergoing regular packed red cell transfusion and on iron chelation (Deferasirox/Deferiprone/Deferoxamine/Combination of these) for a minimum period of two years,attending the Thalassemia Day Care Centre were recruited in this cross-sectional, observational study. All patients were subjected to renal function tests and DTPA scan (Diethylenetriaminepentaacetic acid scan), the results were correlated with demographic profile, iron overload status and chelation therapy. Results: None of the patients in our study cohort had any symptoms pertaining to the renal system like loin pain, edema, hematuria, polyuria or any other urinary complaints. The blood urea nitrogen (BUN) and serum creatinine levels of all patients were within normal range. Of our 93 study subjects, twenty-two (23.7%) patients had metabolic acidosis and two (2.2%) had metabolic alkalosis. Ultrasonography evaluation suggests that there was no medico renal disease or any altered echotexture of the kidney. As per the criteria of renal dysfunction (GFR <90ml/min/1.73m2), 17(18.3%) patients had a GFR less than 90, while hyperfiltration i.e. GFR more than 120ml/min/1.73m2 was seen in 54(58%) of the patients. There is no statistically significant correlation between Glomerular Filtration Rate and age and gender of the study subjects. We found that there was no association between the degree of iron overload and renal dysfunction. Also, no statistically significant correlation was noted between the type of iron chelator and degree of renal dysfunction. Conclusion: Hyperfiltration was observed in 58% of patients which is seen in initial stages of renal dysfunction. This is significant, considering the fact of missing subclinical cases. However, more studies similar to ours with a large sample size are required to validate the annual screening of patients with the help of DTPA scan.