Renal tubular function in children with beta-thalassemia minor.
BACKGROUND
beta-thalassemia minor is a common heterozygous haemoglobinopathy that is characterized by both microcytosis and hypochromia. It requires no treatment. It has been postulated that low-grade haemolysis, tubular iron deposition and toxins derived from erythrocytes might cause renal tubular damage in adult patients with beta-thalassemia minor. Our aim was to investigate the renal tubular functions in children with beta-thalassemia minor and to determine its possible harmful effects.


METHODS
The study was conducted on 32 children (14 female and 18 male) at the age of 5.8 +/- 3.1 years (range 2-14 years) with beta-thalassemia minor. The patients were classified as anaemic (haemoglobin (Hb) </= 11 g/dL) (Group 1, n = 14) and non-anaemic (Hb > 11 g/dL) (Group 2, n = 18). A control group was formed with 18 healthy children whose ages and sexes match those in other groups (Group 3, n = 18). Fractional excretion of sodium (FE(Na), %), fractional excretion of magnesium (FE(Mg), %), fractional excretion of uric acid (FE(UA), %) and tubular phosphorus reabsorption (TPR,%) were calculated with standard formulas. Urinary calcium excretion (mg/kg per 24 h), zinc (Zn) (microg/dL), glucosuria (mg/dL), beta-2 microglobulin (mg/dL) and N-acetyl-beta-D-glycosaminidase (NAG, U/mmol creatinine) levels were measured through biochemical methods.


RESULTS
There was no statistically significant difference among the three groups in terms of the results of FE(Na) (%), FE(Mg) (%), FE(UA) (%), TPR (%), calciuria (mg/kg per 24 h), NAG, urine Zn, proteinuria, glucosuria or urine beta- 2 microglobulin levels (P > 0.05).


CONCLUSIONS
On the contrary of children with beta-thalassemia major, renal tubular dysfunction has not been determined in children with beta-thalassemia minor in the present study.
Kalman
Süleyman
S
Division of Pediatric Nephrology, Gülhane Military Medical Faculty, Ankara, Turkey. suleymankalman@yahoo.com
Atay
A Avni
AA
Sakallioglu
Onur
O
Ozgürtaş
Taner
T
Gök
Faysal
F
Kurt
Ismail
I
Kürekçi
A Emin
AE
Ozcan
Okan
O
Gökçay
Erdal
E
D000118:Acetylglucosaminidase / Q000652:urine; D000293:Adolescent; D002118:Calcium / Q000652:urine; D002648:Child; D002675:Child, Preschool; D005260:Female; D006030:Glycosuria, Renal / Q000209:etiology / Q000652:urine; D006801:Humans; D007674:Kidney Diseases / Q000209:etiology* / Q000652:urine; D007684:Kidney Tubules / Q000502:physiology*; D008297:Male; D011507:Proteinuria / Q000209:etiology / Q000652:urine; D015032:Zinc / Q000652:urine; D001613:beta 2-Microglobulin / Q000652:urine; D017086:beta-Thalassemia / Q000150:complications* / Q000652:urine
D001613:beta 2-Microglobulin; D000118:Acetylglucosaminidase; D015032:Zinc; D002118:Calcium