Renal function of children exposed to cyclosporin in utero

Background. The use of cyclosporin (CsA) has improved graft survival in tra nsplant (Tx) patients despite its potential nephrotoxicity. Children born t o transplanted women may present with intrauterine growth retardation (IUGR ). On the basis of potential reduced nephron mass both in IUGR and in newbo rn experimental animals exposed to CsA in utero, we investigated the renal function of children >1 year of age born to women under maintenance immunos uppression, including CsA. Methods. Fourteen children born to 12 Tx women (nine kidney, one pancreas-k idney, one heart, one liver) were investigated using inulin clearance (C-in ), paraaminohippuric acid clearance (C-PAH), microalbuminuria, and electrol yte reabsorption rate. Results. Gestational age of the 14 infants was 34 +/- 3 weeks and birth wei ght 2018 +/- 620 g. During pregnancy, CsA trough blood level was 234 +/- 11 5 mu g/l and plasma creatinine range was 96-136 mu mol/l. Two children were excluded from the study because renal investigation led to a diagnosis of hereditary nephritis (one Alport syndrome, one familial dominant focal segm ental glomerulosclerosis) that was retrospectively completed in the mother. Renal function tests were finally performed in 12 children at 2.6 +/- 1.8 years of age: BP 94 +/- 7/55 +/- 5 mmHg, C-in 117 +/- 28 ml/min/1.73 m(2), C-PAH 545 +/- 124 ml/min/1.73 m(2), filtration fraction 0.23 +/- 0.03, micr oalbuminuria 4.2 +/- 3.5mg/mmol. Electrolyte tubular reabsorption rates and urine concentrating capacity were normal. Conclusion. These results suggest that in children born to transplanted wom en taking CsA, renal function develops normally despite prolonged exposure in utero.