Service des Explorations Fonctionnelles

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Service des Explorations Fonctionnelles

Paris, France
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Piketty M.-L.,Service des Explorations Fonctionnelles | Polak M.,Service dEndocrinologie | Flechtner I.,Service dEndocrinologie | Gonzales-Briceno L.,Service dEndocrinologie | Souberbielle J.-C.,Service des Explorations Fonctionnelles
Clinical Chemistry and Laboratory Medicine | Year: 2017

Immunoassays are now commonly used for hormone measurement, in high throughput analytical platforms. Immunoassays are generally robust to interference. However, endogenous analytical error may occur in some patients; this may be encountered in biotin supplementation or in the presence of anti-streptavidin antibody, in immunoassays involving streptavidin-biotin interaction. In these cases, the interference may induce both false positive and false negative results, and simulate a seemingly coherent hormonal profile. It is to be feared that this type of errors will be more frequently observed. This review underlines the importance of keeping close interactions between biologists and clinicians to be able to correlate the hormonal assay results with the clinical picture. © 2017 Walter de Gruyter GmbH, Berlin/Boston.


Souberbielle J.-C.,Service des Explorations Fonctionnelles | Courbebaisse M.,Service des Explorations Fonctionnelles | Cormier C.,Service de Rhumatologie A | Pierrot-Deseilligny C.,Service de Neurologie 1 | And 2 more authors.
Scandinavian Journal of Clinical and Laboratory Investigation | Year: 2012

The many recently published data on vitamin D have raised much interest in the medical community. One of the consequences has been a great increase in the prescription of vitamin D concentration measurements in clinical practice. It must be reminded that only the measurement of 25-hydroxyvitamin D (25(OH)D) concentration is indicated to evaluate vitamin D status. Furthermore, since vitamin D insufficiency is so common, since treatment is inexpensive and has a large safety margin, and since we already have much data suggesting that besides its classic effects on bone and mineral metabolism, vitamin D may potentially be helpful for the prevention/management of several diseases, perhaps should it be prescribed to everyone without prior testing? In our opinion, there are however groups of patients in whom estimation of vitamin D status is legitimate and may be recommended. This includes patients in whom a "reasonably" evidence-based target concentration (i.e., based on randomized clinical trials when possible) should be achieved and/or maintained such as patients with rickets/osteomalacia, osteoporosis, chronic kidney disease and kidney transplant recipients, malabsorption, primary hyperparathyroidism, granulomatous disease, and those receiving treatments potentially inducing bone loss. Other patients in whom vitamin D concentration may be measured are those with symptoms compatible with a severe vitamin D deficiency or excess persisting without explanation such as those with diffuse pain, or elderly individuals who fall, or those receiving treatments which modify vitamin D metabolism such as some anti-convulsants. Measurement of Vitamin D concentrations should also be part of any exploration of calcium/phosphorus metabolism which includes measurement of serum calcium, phosphate and PTH. © 2012 Informa Healthcare.


Coupaye M.,University Paris Diderot | Castel B.,University Paris Diderot | Bogard C.,Service de Biochimie | Bogard C.,University Paris Diderot | And 6 more authors.
Obesity Surgery | Year: 2014

Sleeve gastrectomy (SG) is supposed to induce fewer nutritional deficiencies than gastric bypass (GBP). However, few studies have compared nutritional status after these two procedures, and the difference in weight loss (WL) between procedures may alter the results. Thus, our aim was to compare nutritional status after SG and GBP in subjects matched for postoperative weight. Forty-three subjects who underwent SG were matched for age, gender, and 6-month postoperative weight with 43 subjects who underwent GBP. Dietary intakes (DI), metabolic (MP), and nutritional parameters (NP) were recorded before and at 6 and 12 months after both procedures. Multivitamin supplements were systematically prescribed after surgery. Before surgery, BMI, DI, MP, and NP were similar between both groups. After surgery, LDL cholesterol, serum prealbumin, vitamin B12, urinary calcium, and vitamin D concentrations were lower after GBP than after SG, whereas WL and DI were similar after both procedures. However, the total number of deficiencies did not increase after surgery regardless of the procedure. In addition, we found a significant increase in liver enzymes and a greater decrease in C-reactive protein after GBP. In conclusion, during the first year after surgery, in patients with the same WL and following the same strategy of vitamin supplementation, global nutritional status was only slightly impaired after SG and GBP. However, some nutritional parameters were specifically altered after GBP, which could be related to malabsorption or other mechanisms, such as alterations in liver metabolism. © 2013 Springer Science+Business Media New York.


PubMed | Service de rhumatologie, Service de nephrologie pediatrique, Service des explorations fonctionnelles, Center hospitalier Lyon Sud and 2 more.
Type: Journal Article | Journal: Annales de biologie clinique | Year: 2016

The 25-hydroxyvitamin D (25OHD) serum concentration should not be measured to everybody but recommendations for this measurement in several clinical situations are available from numerous guidelines and expert positions. It can be proposed to measure 25OHD in diseases where a target range of 25OHD concentrations associated with better outcomes is defined with a sufficient level of evidence, and when this target concentration is difficult to reach without previous measurement (or may be exceeded in case of too large doses are provided). Many National and International Medical Societies recommend to measure 25OHD at least in any situation of bone fragility (defined by a low bone mineral density and/or a low energy fracture), in malabsorptions, in chronic kidney disease, in any phosphocalcic pathology, in patients with clinical signs of profound vitamin D deficiency or excess, and, more generally in any biological exploration of calcium/phosphorus metabolism that includes the measurement of PTH. Although these recommandations may seem discordant with the recent French restriction in the reimbursment of 25OHD measurement, they may still be reimbursed.


Piketty M.-L.,Service des Explorations Fonctionnelles | Prie D.,Service des Explorations Fonctionnelles | Sedel F.,MedDAY Pharmaceuticals | Bernard D.,MedDAY Pharmaceuticals | And 4 more authors.
Clinical Chemistry and Laboratory Medicine | Year: 2017

High-dose biotin therapy is beneficial in progressive multiple sclerosis (MS) and is expected to be adopted by a large number of patients. Biotin therapy leads to analytical interference in many immunoassays that utilize streptavidin-biotin capture techniques, yielding skewed results that can mimic various endocrine disorders. We aimed at exploring this interference, to be able to remove biotin and avoid misleading results. We measured free triiodothyronine (fT3), free thyroxine (fT4), thyroid-stimulating hormone (TSH), parathyroid homrone (PTH), 25-hydroxyVitamin D (25OHD), follicle-stimulating hormone (FSH), luteinizing hormone (LH), prolactin, C-peptide, cortisol (Roche Diagnostics assays), biotin and its main metabolites (liquid chromatography tandem mass spectrometry) in 23 plasmas from MS patients and healthy volunteers receiving high-dose biotin, and in 39 biotin-unsupplemented patients, before and after a simple procedure (designated N5) designed to remove biotin by means of streptavidin-coated microparticles. We also assayed fT4, TSH and PTH in the 23 high-biotin plasmas using assays not employing streptavidin-biotin binding. The biotin concentration ranged from 31.7 to 1160 μg/L in the 23 high-biotin plasmas samples. After the N5 protocol, the biotin concentration was below the detection limit in all but two samples (8.3 and 27.6 μg/L). Most hormones results were abnormal, but normalized after N5. All results with the alternative methods were normal except two slight PTH elevations. In the 39 biotin-unsupplemented patients, the N5 protocol did not affect the results for any of the hormones, apart from an 8.4% decrease in PTH. We confirm that most streptavidin-biotin hormone immunoassays are affected by high biotin concentrations, leading to a risk of misdiagnosis. Our simple neutralization method efficiently suppresses biotin interference. © 2017 Walter de Gruyter GmbH, Berlin/Boston.


Duval X.,Center dInvestigation Clinique | Duval X.,University Paris Diderot | Iung B.,Service de Cardiologie | Iung B.,University Paris Diderot | And 15 more authors.
Annals of Internal Medicine | Year: 2010

Background: Neurologic complications of endocarditis can influence diagnosis, therapeutic plans, and prognosis. Objective: To describe how early cerebral magnetic resonance imaging (MRI) affects the diagnosis and management of endocarditis in hospitalized adults. Design: Single-center prospective study between June 2005 and October 2008. (ClinicalTrials.gov registration number: NCT00144885) Setting: Tertiary care university hospital in France. Patients: 130 patients with endocarditis. Intervention: Cerebral MRI with angiography performed up to 7 days after admission and before any surgical intervention. Measurements: 2 experts jointly established the endocarditis diagnostic classification (according to Duke-modified criteria) and therapeutic plans just before and after MRI and then compared them. Results: Endocarditis was initially classified as definite in 77 patients and possible in 50 and was excluded in 3. Sixteen patients (12%) had acute neurologic symptoms. Cerebral lesions were detected by MRI in 106 patients (82% [95% CI, 75% to 89%]), including ischemic lesions in 68, microhemorrhages in 74, and silent aneurysms in 10. Solely on the basis of MRI results and excluding microhemorrhages, diagnostic classification of 17 of 53 (32%) cases of nondefinite endocarditis was upgraded to either definite (14 patients) or possible (3 patients). Endocarditis therapeutic plans were modified for 24 (18%) of the 130 patients, including surgical plan modifications for 18 (14%). Overall, early MRI led to modifications of diagnosis or therapeutic plan in 36 patients (28% [CI, 20% to 36%]). Limitation: Investigators did not assess whether the MRI-related changes in diagnosis and therapeutic plans improved patient outcomes or led to unnecessary procedures and increased costs. Conclusion: Cerebral lesions were identified by MRI in many patients with endocarditis but no neurologic symptoms. The MRI findings affected both diagnostic classifications and clinical management plans. Primary Funding Source: French Ministry of Health. © 2010 American College of Physicians.


PubMed | Annaba University, EHS duro nephrologie Daksi, University of Mentouri Constantine and Service des explorations fonctionnelles
Type: Journal Article | Journal: Progres en urologie : journal de l'Association francaise d'urologie et de la Societe francaise d'urologie | Year: 2016

Determine stones composition of the upper urinary tract in the eastern region of Algeria.Our study focuses on a set of 359 stones of the upper urinary tract collected between January 2007 and December 2012 at hospitals in the eastern region of Algeria and analyzed by Fourier transform infrared spectroscopy.The male/female ratio was only 1.32. Calcium oxalate prevailed in 68.5% of stones and 49.3% of nuclei, mainly as whewellite (51.8% of stones and 37.9% of nuclei vs 16.7% and 11.4% respectively for weddellite). Carbapatite prevailed in 15% of stones and 29.8% of nuclei. The struvite, identified in 11.1% of calculi, prevailed in 3.9% of stones and 3.1% of nuclei. Among purines, uric acid prevailed with frequencies quite close to 8.9% and 7% respectively in the stone and in the nucleus while the ammonium urate prevailed in only 0.3% of stones and 3.3% of nuclei. The cystine frequency was 3.6% in both stone and nucleus. The frequency of stone with umbilication was 26.2%. Whewellite was the main component of umbilicated stones with Randalls plaque.Our results suggest that stones of the urinary tract in the Algerian east region resemble those observed in industrialized countries. Some features such as stones location, the whewellite prevalence, the frequencies of main components in both the stone and the nucleus as well as the formation of stones on renal papilla confirm this trend.4.


Nguyen M.T.,University of Paris 13 | Cosson E.,University of Paris 13 | Valensi P.,University of Paris 13 | Poignard P.,Service des explorations fonctionnelles | And 3 more authors.
Diabetes and Metabolism | Year: 2011

Aims: This study aimed to assess, on routine echocardiography, cardiac left ventricular (LV) disorders, their determinants and their role in the screening process of silent myocardial ischaemia (SMI) in asymptomatic diabetic patients. Methods: A total of 586 asymptomatic diabetic patients with one or more additional cardiovascular risk factors, but no history of heart failure or myocardial infarction, prospectively underwent rest echocardiography and myocardial scintigraphy. Those with SMI (abnormal scintigraphy) were subsequently screened for angiographic coronary artery disease (CAD). Results: LV hypertrophy, LV dilatation, systolic dysfunction and hypokinesia were found in 33.6, 8.6, 3.2 and 6.1%, respectively, of the study population. SMI was found in 156 (26.6%) patients, 55 of whom had silent CAD. On multivariate analysis, age (OR: 1.03 [1.00-1.05], P=0.02), microalbuminuria (OR: 2.2 [1.4-3.2], P<0.0001) and silent CAD (OR: 2.4 [1.3-4.6], P=0.007) were predictive of LV hypertrophy. Creatinine clearance (OR: 0.97 [0.96-0.99], P=0.002) and silent CAD (OR: 3.7 [1.3-10.0]) were associated with LV dilatation. LV systolic dysfunction was associated with microalbuminuria (OR: 3.8 [1.3-11.4], P=0.02) and silent CAD (OR: 3.8 [1.1-12.6], P=0.03). Hypokinesia was associated with retinopathy (OR: 2.4 [1.1-5.4], P=0.04), microalbuminuria (OR: 2.3 [1.1-5.0], P=0.04) and LV dilatation (OR: 3.0 [1.1-8.1], P=0.03). In patients with SMI, the positive predictive value of LV hypertrophy associated with another echocardiographic abnormality (n=19) for CAD was 63.2%. Conclusion: LV hypertrophy was found in one-third of asymptomatic diabetic patients, while LV dilatation, systolic dysfunction or hypokinesia was seen in < 10%. The main predictors of LV abnormalities were microalbuminuria and silent CAD. The presence of LV hypertrophy with another abnormality should raise the possibility of the presence of silent CAD. © 2011 Elsevier Masson SAS.


Daudon M.,Service des Explorations Fonctionnelles
Progres en Urologie - FMC | Year: 2012

Morphoconstitutional analysis of calculi is often very useful for identifying the cause of urolithiasis while the clinical signs and the past history of the patient are not contributive. Stone morhology, in addition to crystalline composition may be of a valuable help for the early detection of severe lithogenic conditions such as primary hyperoxaluria, adenine phosphoribosyltransferase deficiency or acquired distal tubular acidosis. © 2012 Elsevier Masson SAS. Tous droits reserves.


Daudon M.,Service des explorations fonctionnelles
Nephrologie et Therapeutique | Year: 2015

Abstract Crystalluria is the presence of crystals in urine. It results from excessive supersaturation and may induce kidney problems such as nephrolithiasis, nephrocalcinosis and sometimes acute or chronic kidney impairment able to result in end stage renal failure. Crystalluria is not, per se, a marker of a pathologic condition. For distinguishing between physiologic and pathologic crystalluria, various criteria may be considered (1) either related to the sample such as urine pH, crystal identity, crystal habit, abundance of the crystals, aggregation and also the occurrence of crystalluria judged on serial samples, (2) or related to the clinical context such as nephrolithiasis, nephrocalcinosis or renal failure. The choice of the sample and the pre-analytical conditions are critical to validate the results from a clinical point of view. In our experience, the first morning urine sample is often the best one to assess, through the crystalluria analysis, the main metabolic factors involved in the crystal and stone formation. The storage of urine sample should be less than two hours at room temperature following the voiding. Crystalluria examination allows identifying simply monogenic crystallogenetic pathologies, providing explanation for acute renal failure related to drug intake, helping the physician for identifying the main metabolic disorders involved in stone formation and assessing the efficacy of preventive measures proposed to avoid stone recurrence in stone former patients. Crystalluria study is by far the best marker for predicting stone recurrence during the follow-up of stone formers, offering the opportunity to adjust dietary advices or drug management and thus to prevent stone formation. In conclusion, crystalluria examination is a major tool for the diagnosis and the management of most lithogenetic diseases and pathologic conditions responsible for intratubular crystal formation and renal impairment. © 2015 Association Société de néphrologie.

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