A novel 22bp deletion in a Tunisian phenylketonuria family.

Phenylketonuria (PKU) is an autosomal recessive metabolic disorder caused by a deficiency of phenylalanine hydroxylase. To date, more than 530 mutations in the PAH gene have been reported. In Tunisia, this disease seems to be the result of point mutations, few studies have been published about molecular defects of PKU in our country. In this study, we report a novel deletion in exon 6 of two brothers in a Tunisian family after DHPLC analysis and sequencing of the exon 6 of the PAH gene.

[Guidelines relative to the collection and handling management of biological samples]. / Recommandations pour la maîtrise de l'étape de prélèvement des échantillons biologiques.

Guidelines relative to the management of samples collection and handling for common tests are proposed with a list of websites to improve knowledge concerning the practices of biological sampling. Then, methodology is given for the creation of an electronic primary sample collection manual for medical laboratory tests. A list containing the medical laboratory tests for which the information and/or particular documents are needed either for the request or interpretation is presented. Another list for some specific laboratory tests with special individual requirements is proposed. We give also items allowing a standardized description of laboratory tests to help to create a personalized list of the available examinations, facilitating the information of professionals.

[Guidelines concerning sample reception and request recording of laboratory tests]. / Recommandations concernant l'accueil et l'enregistrement des échantillons de biologie médicale.

The process is described to help to achieve the requirements of the ISO 15189 standard. The precautions to be respected for a correct recording of the request are specified. The criteria for traceability are formalized. A logogram illustrates the propositions of attitude to be followed when occurs nonconformities. Then, we propose guidelines for the treatment of the identification uncertainties of the primary sample. An algorithm is proposed to formalize the process and treat the situations which can be met with an irreplaceable or critical sample.

[Management of pre-analytical nonconformities]. / Outils pour la gestion et la maîtrise des non-conformités pré-analytiques.

The main nonconformities enumerated to facilitate consensual codification. In each case, an action is defined: refusal to realize the examination with request of a new sample, request of information or correction, results cancellation, nurse or physician information. A traceability of the curative, corrective and preventive actions is needed. Then, methodology and indicators are proposed to assess nonconformity and to follow the quality improvements. The laboratory information system can be used instead of dedicated software. Tools for the follow-up of nonconformities scores are proposed. Finally, we propose an organization and some tools allowing the management and control of the nonconformities occurring during the pre-examination phase.

[Guidelines concerning stat laboratory process]. / Recommandations concernant le processus des examens urgents.

After a definition of the various emergency situations, vital or organizational, the paper describes the process of urgent laboratory tests requests from the medical prescription until the return of the interpreted results to the clinician. The intervention options of the various professionals to optimize and assure the control of the process 24 hours a day and 7 days/7 are presented. Then, a list of validated available stat tests is proposed. It recovers the main disciplines which have a direct link to bring the help to the clinical teams in responsibilities of critical situations. These propositions must be adapted to the conditions of laboratory local environment.

[Self assesment grid for pre-examination phase]. / Proposition de grille d'auto-évaluation de la phase pré-analytique.

This document is a proposal of questionnaire for self-assessment of pre-analytical phase referring to the different steps described in the document SG1-01. The questions are aimed at verifying that what is examined fulfills ISO 15189 standard requirements or in general tends towards client satisfaction. This questionnaire has been elaborated using 5 M risk assessment tool for exhaustiveness purpose. This document may be useful to develop internal audit grids.

[Reliability of immunoturbidimetric urine albumin determination for normal and moderately high values]. / Fiabilité du dosage immunoturbidimétrique de l'albumine urinaire pour les valeurs normales ou modérément élevées.

The value of albuminuria determination is commonly accepted in the monitoring of renal function, particularly in diabetic patients. This may be achieved in different ways and using different assay kits. The aim of this study was to assess the reliability of immunoturbidimetric measurements by comparing the results obtained by two different methods in our laboratory. Therefore we measured albuminuria of 54 patients monitored for their diabetes, with normal to moderately high albuminuria, according to two methods: Microalbumin reagent (Beckman Coulter) on a Unicel DxC 600 (Beckman Coulter) and Albumin Turbiquant reagent (Dade Behring, Siemens) on a Turbitimer system (Dade Behring, Siemens). It was then possible to study the correlation between the two techniques. Our results suggest that although this correlation is excellent, the values differ significantly: the results observed with the Siemens method are higher by about 10%. It seems legitimate to think that a correction should be applied, depending on the used method. In addition, it appears that standardization is necessary, concerning analytical stage but although urine collection, pre-analytical stage or reporting and interpretation of results.

[Prematurity and neonatal screening]. / Prématurité et dépistage néonatal.

Neonatal screening for metabolic and endocrine diseases has clear benefits for full-term infants by providing early diagnosis and treatment to prevent or limit the severe adverse outcomes which occur in untreated infants. The situation of preterm infants is more complicated, with an increased risk of false-positive as well as false-negative screening results. The aim of this work was to evaluate the impact of prematurity in screening strategies in order to answer practical questions: is there a need or not to adjust cut-off values in accord to gestational parameters? Is there a need or not to repeat screening tests at a later age?

First ISNS Reference Preparation for Neonatal Screening for thyrotropin, phenylalanine and 17alpha-hydroxyprogesterone in blood spots.

BACKGROUND: Neonatal screening for congenital disorders like phenylketonuria (PKU), congenital hypothyroidism (CH) and congenital adrenal hyperplasia (CAH) is generally performed in dried blood spots on filter paper. The analytes of interest for testing for PKU, CH and CAH are phenylalanine, thyrotropin (TSH) and 17alpha-hydroxyprogesterone (17OHP), respectively. The International Society for Neonatal Screening (ISNS) decided to prepare a combined reference preparation for the three analytes on filter paper Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545. This 'First ISNS Reference Preparation for Neonatal Screening for TSH, phenylalanine and 17OHP in blood spots' (1st ISNS-RPNS) has been prepared by the RIVM (Bilthoven). METHOD: The number of filter paper cards prepared, each with two sets of six blood spot calibrators, was 480, 42 and 69 for Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545, respectively. The volume of blood dispensed was 50 microl. The range of concentrations for TSH was 1-121 mIU/L blood, for phenylalanine 65-865 micromol/L blood and for 17OHP 2.2-302 nmol/L blood. RESULTS: The linearity of the blood spot calibrators and the homogeneity of the batch (only tested for Schleicher & Schuell) were good. The differences between the three filter papers were small: i.e. the potency of the ISNS-RPNS on Whatman and Toyo Roshi in terms of Schleicher & Schuell was between 0.98 and 1.09 for the three analytes. CONCLUSION: The 1st ISNS-RPNS for TSH, phenylalanine and 17OHP can be said to be suitable as formal reference preparation and as a source for (re)calibrating kit calibrators.

[Interest of Prom-Test in the follow-up of premature rupture of membranes]. / Place du Prom-Test dans la prise en charge de la rupture prématurée des membranes.

The follow-up of premature rupture of membranes requires an hospitalization. The aim of this work was to evaluate the interest of the Prom-Test in the action to be taken in the case of a suspicion of premature rupture of membranes, a negative result allowing to not hospitalize the patient. 105 tests have been carried out producing 73 negative results, 23 positive and 9 doubtful. The childbirth, started or not, occurred much more quickly when the test is positive. Only 13 of the 73 negative tests resulted in a hospitalization including 11 for beginning of delivery. A correct use of the test can prevent unnecessary days of hospitalization.

[Hyperhomocysteinaemia and type 2 diabetes]. / Hyperhomocystéinémie et diabète de type 2.

OBJECTIVES: Hyperhomocysteinaemia is associated with cardiovascular events in nondiabetic individuals. The present study was aimed to explore the implication of hyperhomocysteinemia in development of cardiovascular events in patients with type 2 diabetes. DESIGN: A total of 185 patients with type 2 diabetes (115 women and 70 men, 30 to 93 years of age) have been included consecutively in the ambulatory unit at the Saint-Philibert Hospital. For each patient the concentration of homocysteine, cholesterol and triglyceride levels and HbA1c have been measured. In the studied population, 121 patients presented cardiovascular events (myocardial infarctus, peripheric arteriopathy, cerebrovascular accident). RESULTS: The patients with cardiovascular events were older, the concentration of homocysteine and creatinine were higher. The plasma homocysteine levels adjusted for age and creatinine levels were higher in patients with cardiovascular events than in patients without cardiovascular events (15.4 +/- 3.52 micromol/L and 13.13 +/- 2.26 micromol/L respectively; p = 2. 10(-5)). CONCLUSIONS: Hyperhomocysteinemia is an independant risk factor for cardiovascular events in type 2 diabetes, independent of age and renal function.

[Good practices for the study of hemoglobin]. / Bonnes pratiques de l'étude de l'hémoglobine.

Hemoglobinopathies have become a significant national health problem in France. The biologists have a pivotal role in the genetic diagnoses. Although sickle cell disease (SCD) is the most frequent abnormality found: not less than 200 new cases are observed each year at birth, many other globin gene variations are found in the various ethnic groups. Since 1995 a neonatal sickle cell screening program has been established for at risk newborns. This programme is supported by the "Association française de dépistage et prévention des handicaps de l'enfant" (AFDPHE). The characterization of hemoglobin genetic variations requires a comprehensive set of laboratory techniques for which we specify here main clinical and technical recommendations.

[Use of formulas for calculating serum osmolality]. / De l'usage des formules de calcul de l'osmolalité sérique.

Osmolality can be measured or calculated. More than ten formulas have been proposed for calculating serum osmolality from chemical concentrations. The aim of this work was to compare results obtained whith some of these formulas, those calculated in the laboratory using a multiple regression model and measurements with an osmometer. Scattered results for natremia and chloremia, depending on the automate, led us to define formulas adapted for each measurement system in order to reduce the risk of error in the evaluation of the " osmolar gap ".

[Usual values for 5-hydroxy-indol acetic acid and homovanillic acid in cerebrospinal fluid]. / Etablissement de valeurs usuelles pour les acides 5-hydroxyindolacétique et homovanilliquedans le liquide céphalorachidien.

The aim of this work was to reinvestiagte usual values of neurotransmitter catabolites (5-HIAA and HVA) in CSF, their determination being a current method for studying pathological processes and/or drug induced changes on CNS metabolism. 5-HIAA and HVA have been measured by reverse phase HPLC and electrochemical detection. Since many confounding factors have been identified to modify the concentration of both analytes in CSF, data from 1.480 patients have been revisited with strict exclusion and 323 have been selected. Age dependent variation and asymetric distributions were observed. Age-related usual values ranges were established after identification of outliers by non-parametric analysis. In a group of patients for which repeated CSF collection have been performed for the follow up of acute leukemia, wide and unpredictible individual variations (up to 400 %) of CSF 5-HIAA and HVA concentrations have been observed. These large interindividual and individual variations may explain the numerous discrepancies found in studies investigating the CNS monoamine metabolism, especially when small groups of patients are used. Such observation limits the interpretation of monoamine metabolic for diagnostic purposes without a strict selection of indication.

[Sickle cell disease neonatal screening. First evaluation]. / Dépistage néonatal de la drépanocytose au CHU de Dakar: premier bilan.

A neonatal screening allows a preclinical diagnosis of major sickle cell syndromes and an early management of the affected children. That would improve their life quality and expectancy. The preliminary program was set up on 518 senegalese newborn aged from 1 to 4 days, and coming from all the country ethnic groups. Isoelectrofocalisation is the test used on dried blood eluate and the positive control on citrate agar gel. 478 samples out of 518 (92.5%) have been analysed. Haemoglobinopathy have been found in 11.1% of cases, distributed as follow: heterozygoty FAS and FAC: 9%, double heterozygoty FSC: 0.2% and homozygoty FSS: 1.9%. Sickle cell neonatal screening should be imperatively implemented, with regards in economical considerations. It would be relevant to integrate it in a larger program including information, training and genetic counselling in order to avoid homozygotes birth and to lower the spread of this disease.