Are you Benoit Soudan?

Claim your profile

Publications (5)18.53 Total impact

  • Article: Phenotype-genotype correlation and follow-up in adult patients with hypokalaemia of renal origin suggesting Gitelman syndrome.
    [show abstract] [hide abstract]
    ABSTRACT: Gitelman syndrome (GS) is a tubulopathy caused by SLC12A3 gene mutations, which lead to hypokalaemic alkalosis, secondary hyperaldosteronism, hypomagnesaemia and hypocalciuria. The aim of this study was to assess the prevalence of SLC12A3 gene mutations in adult hypokalaemic patients; to compare the phenotype of homozygous, heterozygous and non-mutated patients; and to determine the efficiency of treatment. Clinical, biological and genetic data were recorded in 26 patients. Screening for the SLC12A3 gene detected two mutations in 15 patients (six homozygous and nine compound heterozygous), one mutation in six patients and no mutation in five patients. There was no statistical difference in clinical symptoms at diagnosis between the three groups. Systolic blood pressure tended to be lower in patients with two mutations (P=0.16). Hypertension was unexpectedly detected in four patients. Five patients with two mutated alleles and two with heterozygosity had severe manifestations of GS. Significant differences were observed between the three groups in blood potassium, chloride, magnesium, supine aldosterone, 24 h urine chloride and magnesium levels and in modification of the diet in renal disease. Mean blood potassium levels increased from 2.8 ± 0.3, 3.5 ± 0.5 and 3.2 ± 0.3 before treatment to 3.2 ± 0.5, 3.7 ± 0.6 and 3.7 ± 0.3 mmol/l with treatment in groups with two (P=0.003), one and no mutated alleles respectively. In adult patients referred for renal hypokalaemia, we confirmed the presence of mutations of the SLC12A3 gene in 80% of cases. GS was more severe in patients with two mutated alleles than in those with one or no mutated alleles. High blood pressure should not rule out the diagnosis, especially in older patients.
    European Journal of Endocrinology 07/2011; 165(4):665-73. · 3.42 Impact Factor
  • Article: 25-hydroxy vitamin D deficiency causes parathyroid incidentalomas.
    [show abstract] [hide abstract]
    ABSTRACT: 25-OH D3 (D3) deficiency causes secondary hyperparathyroidism. Asymmetric gland hypertrophy may also lead to unnecessary parathyroid gland resection by mistaking these glands for parathyroid incidentalomas. We tested the hypothesis that D3 deficiency causes parathyroid gland hypertrophy. This is a prospective study of 100 consecutive patients undergoing total thyroidectomy. Pre-operative D3 measurement was made at first presentation and on the day after surgery. During thyroidectomy, the parathyroid glands were searched for and measured. Using an ellipsoid volume calculator, the gland volume was calculated. This was correlated with D3 and other possible confounding factors. Normal parathyroid volume is 25.1 mm(3). Parathyroid gland size correlated with D3 levels, p < 0.001. There is a greater asymmetry in gland volume in those patients with the lowest levels of D3 (Spearman's rank correlation coefficient r = -0.51). There was a significant difference in individual gland volume between D3 levels >30 ng/ml and those <30 ng/ml. However, there was no difference in mean gland volume between these groups. There was no difference in correlation according to pathology or thyroid specimen weight. There is a significant difference in both individual gland volume and variation in parathyroid gland volume according to D3 levels. Patients with a D3 level <30 ng/ml have a more asymmetrical hyperplasia corresponding with parathyroid incidentalomas. D3 levels should be measured pre-operatively in all patients undergoing total thyroidectomy to avoid unnecessary parathyroid resection.
    Langenbeck s Archives of Surgery 09/2010; 395(7):919-24. · 1.81 Impact Factor
  • Source
    Article: Quantitative in vivo islet potency assay in normoglycemic nude mice correlates with primary graft function after clinical transplantation.
    [show abstract] [hide abstract]
    ABSTRACT: Reliable assays are critically needed to monitor graft potency in islet transplantation (IT). We tested a quantitative in vivo islet potency assay (QIVIPA) based on human C-peptide (hCP) measurements in normoglycemic nude mice after IT under the kidney capsule. QIVIPA was initially tested by transplanting incremental doses of human islets. hCP levels in mice were correlated with the number of transplanted islet equivalents (r(2) = 0.6, P<0.01). We subsequently evaluated QIVIPA in eight islet preparations transplanted in type 1 diabetic patients. Conversely to standard criteria including islet mass, viability, purity, adenosine triphosphate content, or glucose stimulated insulin secretion, hCP in mice receiving 1% of the final islet product was correlated to primary graft function (hCP increase) after IT (r(2)=0.85, P<0.01). QIVIPA appears as a reliable test to monitor islet graft potency, applicable to validate new methods to produce primary islets or other human insulin secreting cells.
    Transplantation 07/2008; 86(2):360-3. · 4.00 Impact Factor
  • Article: Accuracy of intra-operative PTH measurement during subtotal parathyroidectomy for tertiary hyperparathyroidism after renal transplantation.
    [show abstract] [hide abstract]
    ABSTRACT: Intra-operative parathyroid hormone (IOPTH) results are not known in the setting of tertiary hyperparathyroidism (HPT) after renal transplantation. A retrospective analysis of 35 tertiary HPT patients who all underwent subtotal parathyroidectomy and IOPTH monitoring was conducted. The mean follow-up time was 2.2+/-1.4 years. Thirty-four patients were cured; one patient (2.8%) had a persistent disease and was cured after reoperation. Median parathyroid hormone (PTH) (median percent decrease from highest) at baseline and at 5, 10, 20, and 30 min were 244, 78 (69%), 63 (75%), 53 (79%), and 49 pg/ml (83%), respectively. Four patients who were cured had a decrease of <50% at 5 min and two of them had a decrease of <50% at 10 min. The patient with persistent disease had a decrease of >50% at 10 min. The sensitivity of the test was 94% at 10 min using the Miami criteria. This study shows that IOPTH in tertiary hyperparathyroidism has a high sensitivity. However, because of the low risk of persistent hyperparathyroidism when a subtotal parathyroidectomy is performed, its potential impact on the overall success rate is very small. We therefore do not recommend the routine use of IOPTH in tertiary hyperparathyroidism.
    Langenbeck s Archives of Surgery 12/2006; 391(6):561-5. · 1.81 Impact Factor
  • Article: Surgical management of primary hyperparathyroidism: the case for giving up quick intraoperative PTH assay in favor of routine PTH measurement the morning after.
    [show abstract] [hide abstract]
    ABSTRACT: To analyze the utility of quick intraoperative parathyroid hormone (PTH) measurement in the surgical management of primary hyperparathyroidism. The use of intraoperative PTH monitoring is well established in the surgery of primary hyperparathyroidism. However, some false-negative predictions lead to unnecessary explorations; furthermore, surgeons are becoming increasingly dependent on hormone measurement for intraoperative decisions, which raises concerns about the cost-effectiveness of the method. A retrospective analysis of 268 neck explorations performed for primary hyperparathyroidism using intraoperative PTH monitoring from April 2001 to February 2003 was done. We used the criterion of "biologic recovery" of hyperfunctioning tissue, defined as a more than 50% decrease in PTH level from baseline value at 5 minutes after excision to predict the outcome of successful parathyroidectomy documented by normal postoperative serum calcium level. Additionally, we also sampled PTH at 10 minutes, 30 minutes, and the morning after surgery to compare the predictive value of delayed sampling. Patients were classified according to the prediction being concordant or discordant with the outcome. The data were analyzed using a 2 x 2 table construct for each of the sampling times, therefore providing sequential sensitivity, specificity, positive and negative predictive values, and overall accuracy of the predictions. Concordance or overall accuracy of prediction (true positives and negatives) was obtained in 229 cases (85.4%), and discordance or failure of prediction (false positives and negatives) was obtained in 34 cases (12.7%) at T5. On analyzing the iPTH prediction at T10, T30, and D1 among the group of 33 false negatives, we found that 28 (10.4%) patients reached the concordance at 30 minutes, while by the first day 32 patients (12.3%) had achieved concordance. Thus, there was a progressive increase in sensitivity and overall accuracy, but more importantly, in the negative predictive value reaching 88.9% on the day after surgery. The method of sampling PTH intraoperatively at 5 minutes has a high positive predictive value (99.5%) but a low negative predictive value (19.5%), which can lead to unnecessary explorations and a delay in the operative procedure. The negative predictive value increases substantially at 30 minutes and is best on the day after surgery. We suggest giving up the intraoperative measurement of PTH to adopt the first day postoperative measurement of PTH as a predictor of successful parathyroidectomy.
    Annals of Surgery 01/2005; 240(6):949-53; discussion 953-4. · 7.49 Impact Factor