Assessment of Subclinical Renal Glomerular and Tubular Dysfunction in Children with Beta Thalassemia Major

Renal Dysfunction in Pediatric Patients in Iraq With β-Thalassemia Major and Intermedia

Background

With optimum transfusion and chelation therapy, the survival of β-thalassemia patients and the incidence of various complications, including renal complications, have improved.

Objectives

To investigate renal involvement in β-thalassemia patients using serum and urinary biochemical markers of glomerular and tubular dysfunction.

Methods

This case-control study included 69 β-thalassemia major (β-TM) patients, 23 β-thalassemia intermedia (β-TI) patients, and 100 healthy controls, all ranging from 1 to 16 years in age. Blood urea nitrogen (BUN), serum ferritin, serum and urinary levels of creatinine (Cr), uric acid (UA), calcium (Ca), phosphorus (Ph), magnesium (Mg), sodium (Na), and potassium (K), and the urinary albumin/creatinine ratio were evaluated.

Results

The BUN level and the urinary Na/Cr, K/Cr, Ca/Cr, Mg/Cr, Ph/Cr, albumin/Cr, and UA/Cr ratios were significantly higher in the β-thalassemia patients than in the controls. In contrast, the serum Na, K, Ca, and Mg levels were significantly lower in the patients (P<0.05). An elevated urinary UA/Cr ratio was found in 61.9% of β-thalassemia patients, and an elevated urinary Ca/Cr, and urinary albumin/Cr ratio was found in 53.2%. An elevated Na/Cr ratio was found in 41.3%. The serum and urinary renal markers showed no significant differences between patients with β-TM and β-TI, except for microscopic hematuria, which was significantly higher in β-TI patients (34.8%) than in β-TM patients (13%), P>0.02. At an older age, high serum ferritin levels and deferoxamine therapy were associated with significant tubular and glomerular dysfunction in β-thalassemia patients.

Conclusions

Pediatric patients with β-thalassemia have significantly abnormal tubular and glomerular functions, necessitating early detection and monitoring to prevent/reverse renal function deterioration.

Comparative evaluation of cystatin C and neutrophil gelatinase-associated lipocalin in patients with thalassemia major versus thalassemia intermedia

Kidney disorders are long-term complications in thalassemia patients, especially with the high life expectancy of these patients. Proper evaluation of kidney impairment in β-thalassemia patients can be difficult due to higher intake of iron chelators, resulting in renal impairment. Early biomarkers of renal disease are used for the diagnosis of tubular and glomerular abnormalities. The current study was conducted on 88 individuals, 25 healthy people and 63 β-thalassemia patients. Circulating levels of urea, creatinine, cystatin C and neutrophil gelatinase-associated lipocalin were measured in all groups. Compared to healthy control, patients with thalassemia major and intermedia showed a significant increase in both cystatin C and NGAL levels, with no effects on creatinine levels. Furthermore, urea levels were markedly higher in patients with thalassemia major compared to control. As early renal dysfunction markers, cystatin C and NGAL should be routinely evaluated in thalassemia patients major and intermedia.