Correlation between serum ferritin level and immature reticulocyte fraction (IRF) in children with beta thalassemia major

Blood transfusion is the primary therapeutic approach for patients diagnosed with beta thalassemia major. However, this treatment can lead to the accumulation of toxic iron in various organs such as the liver, heart, endocrine system, and bone marrow, causing tissue damage. Damage to the bone marrow results in the suppression of erythropoiesis. The serum ferritin level is an unreliable indicator of total body iron levels since it is a positive acute phase protein which limits its use for diagnosis. Moreover, examining serum ferritin levels can be costly and not widely available. In contrast to serum ferritin levels, Immature Reticulocyte Fraction (IRF) is an early indicator of erythropoiesis activity that reduces iron overload and does not react significantly during acute-phase responses. Additionally, IRF parameters are already present in hematology analyzers, however their optimization has been limited by lack of investigation into their utility for examination purposes. Therefore, this study aims to investigate the correlation between serum ferritin levels and IRF values among children diagnosed with beta thalassemia major. The study design was a cross-sectional approach. Subjects consisted of 55 cases of children with beta thalassemia major who came to the Hemato-Oncology Outpatient Clinic in the Pediatric Department of one of the hospitals in Surabaya, East Java, Indonesia. Levels of serum ferritin were measured using ECLIA (Electrochemiluminescence immunoassay) methods, while IRF was measured via flowcytometry. The results were statistically analyzed using Spearman correlation test. In children with beta thalassemia major, levels of serum ferritin ranged from 358ng/mL to 5696ng/mL, with an average value of 2542.760ng/mL and a standard deviation of 1279.850ng/mL being recorded. Immature Reticulocyte Fraction (IRF) varied from 1.600% to 34.300%, having an average value of 15.240% and a standard deviation amounting to 6.228%. Correlations were shown between serum ferritin levels and IRF with a correlation coefficient (r) of - 0.369 and a p value of 0.006. There was a negative correlation between serum ferritin levels and IRF. It was found that the higher serum ferritin levels, the lower the IRF.