[Gordon syndrome: The importance of measuring blood pressure in children]. / Syndrome de Gordon : de l'importance de mesurer la pression artérielle chez l'enfant.

Gordon's syndrome, or type II pseudo-hypoaldosteronism, is a rare cause of arterial hypertension in children. However, it is important to diagnose this syndrome because of the spectacular efficacy of thiazide diuretics. The typical clinical picture of Gordon syndrome includes, apart from arterial hypertension and dyskaliemia, hyperchloremia metabolic acidosis, hypercalciuria, a low rate of renin, and most frequently, a normal or high rate of aldosterone. Dental abnormalities and growth retardation can also be associated. In most cases, it is inherited in an autosomal dominant pattern. We report on a 7-year-old girl who was discovered with arterial hypertension during a consultation for chronic diarrhea. The association of growth retardation, hyperkaliemia, and metabolic acidosis oriented the diagnosis. Starting a thiazide diuretic helped control the arterial hypertension and the kaliemia in a spectacular manner. The genetic analysis proved the existence of a splice mutation on exon 9 of the CUL3 gene coding for cullin 3. This mutation is de novo.

Trichodysplasia spinulosa: a polyomavirus infection specifically targeting follicular keratinocytes in immunocompromised patients.

Trichodysplasia spinulosa (TS) is a rare skin disease, caused by a specific polyomavirus, occurring in immunocompromised patients. The pathophysiological mechanisms of TS are not yet fully understood. By using polymerase chain reaction and skin biopsy immunostaining we report evidence, in a paediatric case, of follicular keratinocytes being the primary target of trichodysplasia spinulosa-associated polyomavirus.

Development of a Bayesian estimator for the therapeutic drug monitoring of mycophenolate mofetil in children with idiopathic nephrotic syndrome.

The use of mycophenolate mofetil (MMF) in children with idiopathic nephrotic syndrome (INS) is increasing. However, the clinical benefit of its monitoring has been scarcely studied, and little is known about its pharmacokinetics in this context. The objectives of the present study were: (i) to study and model the pharmacokinetics of mycophenolic acid (MPA; the active moiety of MMF) in paediatric patients with INS given MMF, at all stages of the disease; (ii) to develop a Bayesian estimator (MAP-BE) for individual inter-dose area under the concentration-time curve (AUC) prediction in this population, using a limited blood sampling strategy (LSS). Full-pharmacokinetic (PK) profiles of MPA collected in paediatric inpatients with INS already treated with a maintenance immunosuppressive therapy based on MMF (with no calcineurin inhibitors; CNI) were studied. A classical iterative two-stage (ITS) method was applied to model the data and develop MAP-BEs using a one-compartment open model where the absorption is described by a double gamma law allowing the description of a potential enterohepatic recirculation. The performance of the MAP-BE developed for individual exposure assessment was evaluated by the bias and precision of predicted AUCs with respect to measured, trapezoidal AUCs (reference value), and by the proportion of predicted AUCs with absolute error >20%. These PK tools were tested in an independent group of patients. Sixty PK profiles of MPA from children receiving MMF in association to corticosteroids or given alone were included in the study. Forty-five of these PK profiles were used to develop a PK model and a MAP-BE, and 15 for their validation. In the building group, the PK model fitted accurately the PK profiles of MPA: mean residual error of modelled vs. reference AUC was m±SD=-0.015±0.092 (range: -0.153 to 0.204). The MAP-BE which allowed the estimation of MPA AUC on the basis of a 20 min-60 min-180 min LSS was then developed. In the independent group of patients, its mean residual error vs. reference AUCs was m±SD=-0.036±0.145 (range: -0.205 to 0.189). Thus, a PK model and its derived MAP-BE for MMF (without any associated CNI) when given to children with INS have been developed. Clinical trials using these PK tools could test the potential impact of the therapeutic drug monitoring of MMF based on the AUC on the clinical evolution of INS.