Neutrophil Gelatinase Associated Lipocalin: A Possible Role in β Thalassemia Syndromes

Abstract

Abstract Background Beta Thalassemia is a group of inherited blood disorders that caused by reduced or absent synthesis of the beta chains of hemoglobin resulting in variable outcomes ranging from severe anaemia to clinically asymptomatic individuals. Neutrophil gelatinase-associated lipocalin (NGAL), is a protein which is encoded by the LCN2 gene. NGAL is involved in innate immunity by sequestrating iron that in turn limits bacterial growth. It is expressed in neutrophils and in low levels in the kidney, prostate, and epithelia of the respiratory and the alimentary tracts. It also plays a key role in the physiology and pathophysiology of red blood cells, particularly in anemia. Aim of the Work The aim of the present work is to assess plasma level of NGAL in Beta thalassemia syndromes and correlate with laboratory hematological data and iron profile. Patients and Methods A Case-Control study conducted on Beta Thalassemia patients of both sexes attending the outpatient clinic of Ain Shams University Hospitals, this Pilot study of 50 previously diagnosed Beta Thalassemia patients and 30 sex and age matched healthy control subjects. Results The results were correlated with clinical and laboratory parameters. Comparative analysis of the results showed that all groups were homogeneous in terms of size and demographic characteristics. This can explain our results that shows that there is a highly statistically significant difference (p-value < 0.001) between the cases subgroups regarding the inter-transfusion interval with longer intervals among the thalassemia intermedia subgroup. While by comparing the Hb electrophoresis parameter between the 2 groups HbA% levels were higher is the group of serum ferritin <1000 ng/ml and HbF% where higher in group of serum ferritin >1000 ng/ml with (p-value < 0.05) for both of them. On conducting a linear regression analysis we found that the intertransfusion interval was the only independent parameter to have an effect on NGAL level on our patient group with regression coefficient -5.78 and this complies with our results of correlation between NGAL and those parameters mentioned and discussed previously. Conclusion The relationship between NGAL and iron level in Egyptian β-TM patients proved in our results has confirmed the proposed regulatory role played by NGAL on erythropoiesis and iron metabolism in β-thalassemia, NGAL at a cutoff value of > 100 proved to be an efficient predictor of increased serum ferritin > 1000 ng/ml. we believe that incorporating NGAL testing in the work up of β-TM patients in the early phases of iron transfusion dependency would provide a promising sensitive and predictive tool for early iron accumulation. We recommend further studies β-TM patients with larger samples size to clarify the co-regulatory role of erythropoiesis and iron metabolism played by NGAL.