Renal tubular dysfunction in children with sickle cell haemoglobinopathy

Children with sickle cell disease (SCD) are remarkably more prone than others to renal dysfunction. The kidneys, as one of the systemic long-term hazards in SCD, may be affected by both the haemodynamic changes of chronic anaemia as well as by the consequences of vaso-occlusion. The aim of this study was to evaluate the proximal tubular function in a group of Saudi children with established SCD.

This study was conducted in Al-Khafji Joint Operations (KJO) Hospital, in Saudi Arabia during the period from June 2011 to August 2012. Thirty-four children: Group I (18 males and 16 females) with SCD (HBSS) and 27 children: Group II (17 males and 10 females) with sickle cell trait (HBAS) were evaluated for urinary excretion of retinol binding protein (RBP) and - Beta 2 microglobulin (β2 MG).

Group I patients showed a significantly impaired urinary concentrating ability compared to that of Group II (417 ± 94 mOsm/kg vs 581 ± 165 mOsm/kg). The urinary excretions of RBP and β2-microglobulin were significantly higher in Group I than in Group II. The values were 762.01 ± 124.20 μg/L and 841.84 ± 389.02 μg/L versus 198.12 ± 42.24 μg/L and 298.3 ± 38.11 μg/L, respectively.

Significant proximal tubular dysfunction was a feature in the SCD group, indicated by high urinary RBP and β2-microglobulin excretion. Assessing the urinary excretion of these low molecular weight proteins in children with sickle cell disease at different points of diagnosis may add key clinical information to the follow up of renal tubular function in patients with SCD.