الفهرس 
OVERVIEW ON b-THALASSEMIAOnly 14 pages are availabe for public view
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Abstract
The aim of this study was to assess renal functions in patients with β-thalassemia major and β-thalassemia intermedia in correlation with iron overload and type of chelator in order to detect early deterioration of renal function.
The study took place in the Pediatric Hematology Clinic, Children’s Hospital, Ain Shams University. It included 60 patients; 40 (66.7%) patients with β-thalassemia major and 20 (33.3%) patients with β- thalassemia intermedia.Thalassemia major patients were further subdivided into two groups according to the serum ferritin level; well chelated group of 30 patients (75%) with serum ferritin <2500 ng/ml and poorly chelated group of 10 patients (25%) with serum ferritin ≥2500ng/ml.
All the included patients were subjected to full medical history taking including age, age at first transfusion, type of chelator, duration of chelation, compliance to chelation therapy, transfusion index, mean pretransfusion hemoglobin, serum ferritin, platelet count, Liver functions, presence or absence of hepatitis and symptoms suggestive of diabetes mellitus.
Also, all cases were subjected to thorough clinical examination with stress on complications of iron overload, anthropometric measures, pubertal stage and skin hemosiserosis.
We assessed different parameters of kidney function for all patients with calculation of serum electrolytes, serum creatinine, urinary electrolytes, urinary protein/creatinine ratio, estimated GFR by Schwartz equation, fractional excretion of sodium (FENa%), fractional excretion of potassium (FEK%) and urinary 2 microglobulin.
Among our 60 patients, there were 22 patients in the pubertal stage; 17(77%) of them showed delayed puberty for age of which 53% were males and 47% were females. Also, 15(25%) of all our patients were splenectomized; 14(35%) belonged to TM group and only one (5%) in TI patients (P=0.00).
In addition, 17(42.5%) of our TM patients had skin hemosiderois compared to only 2(10%) TI patients (P=0.03).
50% of TI patients were not on iron chelation therapy compared to only 5% in TM patients. Deferiprone was the most prevalent iron chelator,it was used as a single chelator by 27.5% of TM patients and 25% of TI patients. 17.5% of TM patients and 15% of TI patients were treated by deferrioxamine only. 25% of TM patients were on combined deferiprone and deferrioxamine chelation therapy compared to only 10% 0f TI patients.The new oral iron chelator,deferasirox was used by 25% of TM patients while none of TI patients used deferasirox.
The mean level of serum creatinine in all our cases was within the normal range and comparable in both TM and TI groups (P>0.05).
The mean GFR (done by Schwartz equation) among our studied patients was higher than the normal range in both TM and TI groups indicating glomerular hyperfiltration.
Also, the mean urinary protein/creatinine ratio in our study was higher than the normal range.We found that 11 of all our studied patients(18.3%); 8 TM patients and 3 TI patients had protein/creatinine ratio higher than normal.
The mean level of urinary 2 microglobulin in our patients was within the normal range, where only 2 TM patients(3.3%) had slightly higher levels tha normal. Meanwhile, all TI patients included in the study showed normal urinary 2 microglobulin levels (P=0.00). The urinary 2 microglobulin in all the study patients was significantly and positively correlated to both transfusion index and serum ferritin level (P<0.05).
There was no significant difference in the tubular reabsorption of phosphorus(TRP) between TM and TI groups. A significant negative correlation was found between duration of chelation and TRP in TI patients (P=0.04).
Normal mean levels of fractional excretion of sodium (FENa%) and fractional excretion of potassium(FEK%) were found among TM and TI patients with also no significant difference between the two groups.
The mean serum potassium and serum sodium in all our cases was within the normal range but there was a significant difference regarding these mean levels between TM and TI groups, where the mean serum potassium was higher in TM patients than in TI patients (P=0.04) and the mean serum sodium was higher among TI patients than TM patients (P=0.01).
Our study showed that the mean serum phosphorus level in all the study patients was within the normal range, but 20 (33.3%) of our cases; 18 (30%) TM patients and 2 (3.3%) TI patients had high serum phosphorus levels.
On the other hand, the mean serum ferritin level was significantly higher in TM than in TI patients (P=0.00). There was a significant positive correlation between serum ferritin and transfusion index (P=0.00). Also, a significant negative correlation existed between serum ferritin and mean pretransfusion hemoglobin (P=0.03).
In the present study, the mean height as well as the height percentile were lower in poorly chelated group (serum ferritin≥2500 ng/ml) than well chelated group (seum ferritin<2500). We found also that splenectomy cases were more prevalent in the poorly chelated group; 4 cases(40%) when compared to the well chelated group; 10 cases (33.3%).In addition, the mean serum sodium and urinary protein/creatinine ratio were significantly higher in poorly chelated group than in well chelated group (P<0.05).