RENAL FUNCTIONS AND ERYTHROPOIETIN STATUS OF BETA THALASSEMIA PATIENTS

Abstract

Background

Thalassemias are heterogeneous group of hereditary disorders resulting from mutations that impact the synthesis of globin chains of hemoglobin. Evidence of both glomerular and proximal tubular damage is observed in β-TM  patients. Erythropoietin (EPO) is one of the key regulators of erythropoiesis, promoting the proliferation of erythroid progenitor cells and increasing the production of red blood cells with recently discovered receptors in multiple organs. Inspired by studies proposing EPO as a part of the treatment in β-hemoglobinopathies and more studies with significant effects of EPO to reduce tubular dysfunction and glomerular injury, our study aimed to assess the tubular and glomerular renal functions of β-TM patients along with their EPO status.

Materials and methods

This prospective case-control study included a total of 71 TDT beta thalassemia patients and 22 healthy, age- and sex-matched controls. All patients were examined for their current weight and height, body mass index (BMI), z score, blood pressure, renal glomerular and tubular status and erythropoietin levels.

Results

There were 16 malnourished patients with VKI <18 and -2 SDS. Forty-eight patients (67,6% of patient group) had proteinuria and 16 (22,5%) had albuminuria. Twenty nine of β-TM (40,8%) patients had high fractional excretion of uric acid (FEUA). TmP/GFR was <2,8 in 22,5% (n=16) of patients demonstrating higher phosphate wasting. Thirty eight percent (n=27) of the patients showed hypercalciuria. Serum beta-2-microglobulin and urine β-2-MG were elevated in 80,3% (n=57) and 49,3% (n=35) of the patients respectively. Sixty four (90,1%) patients had elevated serum EPO.

Conclusion

Compared to healthy group, patient group had significantly higher levels of serum urea, proteinuria, albuminuria, hyperuricosuria, phosphaturia and significantly elevated eGFR, EPO, urine and serum β-2-MG. Both renal tubular and glomerular functions of a β-TM patient deteriorate beginning from childhood years. Routine follow-up of serum creatinine, eGFR, serum cystatin C, spot urine protein/creatinine, spot urine Ca/Cr, FENa and  FEUA could fail to detect early renal damage but still essential to analyze as they may be discovered impaired.