Biochemistry

The biochemistry department performs both emergency and routine biochemistry analyses for inpatients and outpatients at the University Hospital, as well as for external laboratories. It also offers a range of specialized biochemistry analyses for which it is a leading provider in Normandy.

Routine and emergency activities

The general biochemistry department provides 24/7 emergency services. Routine parameters represent nearly 90% of our activity and are primarily measured on an automated platform: PURR · ABC  .

• Blood gas
• Colorimetric techniques, potentiometrics: ionograms, renal and hepatic functions, lipids…
• Immuno-enzymatic techniques: cardiac markers, tumor markers, hormone analysis…
• Nephelometric techniques: inflammatory proteins, malnutrition markers, apolipoproteins…
• Electrophoresis: serum and urinary proteins using capillary technique, lipid profile on gel,
• Glycated hemoglobin by HPLC

Delocalized biology

This involves carrying out analyses as close as possible to the patient while maintaining the integration of data into the biological file: blood gases, cardiac troponin.

Analyses of this sector are carried out mainly at the separation platform.

Vitamins and trace elements:

• Study of nutritional deficiencies:
  • Trace elements by ICP-MS technique: selenium, zinc, iodine…
  • water- and fat-soluble vitamins by liquid chromatography techniques HPLC, HPLC-MSMS (B1, B6, C, PP, A, E, K) or immuno-analysis (D, B9 and B12).
• ICP-MS analysis of toxic metals
• study of copper pathologies: serum, urinary and hepatic copper, ceruloplasmin.

Catecholamines and their metabolites; serotonin metabolite:

• Adrenaline, noradrenaline, dopamine, metanephrines, vanylmandelic acid, hormovanilic acid, 5-hydroxyindoleacetic acid: HPLC-MSMS

Analyses in this sector are carried out on the specialized biology platform or on the separation platform.

Endocrine disorders:

• Automated immunoassay techniques: GH and IGF1, ostase (bone alkaline phosphatases), renin, 1-25 OH vit D, chromogranin.
• RIA technique (approval for the use of radioactive isotopes for in vitro diagnostic purposes) : T3L, TSH receptor antibody (TSI), C-peptide, free β subunit hCG, ultrasensitive estradiol, histamine.
• Monitoring of congenital hypothyroidism on blotting paper up to the age of 2 years.
• LC MS/MS: steroid profile (aldosterone, testosterone, 17-hydroxyprogesterone, delta 4-androstenedione, DHEA sulfate, 11-desoxicortisol).

Fetal biochemistry:

• Detection of the presence of acetylcholine esterase in amniotic fluid by electrophoresis.
• Study of digestive enzymes in amniotic fluid.
• Renal function markers (β2 microglobulin on fetal and maternal blood).
• Nominal approval of the biologists (Dr Frédérique Grandhomme and Prof Stéphane Allouche).

Neurological diseases:

• Measurement of serum anti-ganglioside antibodies in multifocal motor neuropathies by ELISA (anti-GM1, GD1a, GD1b, GM2, GT1b and GQ1b).
• Measurement in cerebrospinal fluid of Alzheimer's disease markers (tau, phospho-tau, beta-amyloid protein) by chemiluminescence immunoassay.
• Search for oligoclonal bands in cerebrospinal fluid for the diagnosis of multiple sclerosis by IEF.
• Determination of the converting enzyme in the CSF (neurosarcoidosis) by spectrofluorimetry.

The analyses in this sector are carried out on the genomic, separation and specialized biology platform.

Hereditary metabolic diseases

Dosages used:

• Blood: metabolic explorations: REDOX balance (ammonium, lactic acid, pyruvic acid, beta-hydroxybutyric acid, acetoacetic acid, free fatty acids), amino acids, phenylalanine, total homocysteine, leucine, 7-dehydrocholesterol, acylcarnitines, carnitine, 25OH-vitamin D3/24,25 (OH) 2-vitamin D3 ratio.
• Urine: metabolic investigations: amino acids, organic acids, orotic acid, mevalonic acid, cystine.
• CSF: lactic acid, pyruvic acid, amino acids.

Techniques:

Liquid or gas chromatography, colorimetry and mass spectrometry detection (GC-MS and LC MS/MS).

Mitochondrial diseases

Dosages used:

• Blood: Coenzyme Q10 measurement, sequencing.
• Muscle: Coenzyme Q10 assay, respiratory chain complex assay, search for mitochondrial DNA deletions/depletion, sequencing.
• Fibroblasts: Coenzyme Q10 assay, respiratory chain complex assay, mitochondrial respiration (oxygraphy), sequencing.
• Urine: sequencing.

Techniques:

Liquid chromatography and mass spectrometry detection (LC MS/MS), spectrophotometric assays, skin fibroblast culture, oxygraphic analyses, Sanger sequencing, high-throughput sequencing (DNA mitochondrial, PCR , Southern-blot, PCR/long-PCR.

Analyses in this sector are carried out on the separation and specialized biology.

Prenatal screening for Down syndrome

• Assessment of the risk of fetal trisomy 21 using maternal serum markers (markers from the 1st^and 2nd^trimester ).
• The service holds an authorization issued by theARS for the assessment of the risk of fetal trisomy 21 using maternal serum markers.
• Nominal approval of the biologists (Dr Anne Chocat, Dr Geneviève Lubac and Dr David Guénet).

E-mail

Newborn screening

The biochemistry department is integrated into the Regional Neonatal Screening Centre , which aims to detect and provide early care for 12 serious diseases in newborns.

In practice, this is a national health program; it involves collecting drops of blood placed on filter paper via a prick in the baby's heel. It is most often performed at the maternity ward and with parental consent. It is free of charge and is carried out as early as 48 hours after birth, ideally at 72 hours.

The filter papers are sent daily, either directly or by mail, to the CRDN. The analysis is carried out very quickly, allowing the child to be summoned promptly for a definitive diagnosis and the implementation of appropriate treatment in the event of an abnormal result.

Because treatment solutions exist, early detection is a real benefit for patients.

The national neonatal screening program is for all newborns in France. Its aim is to detect certain diseases as early as possible, even before any symptoms appear. Currently, this program covers 13 diseases:

• Phenylketonuria (phenylalanine level) : a genetic disorder linked to a deficiency of an enzyme which, without treatment, leads to intellectual disability. With a specific diet starting in the first weeks of life and continuing throughout life, the child's development will be normal.
• Congenital hypothyroidism (TSH level) : insufficient secretion of thyroid hormones by the thyroid gland, which can lead to intellectual disability and growth retardation. Treatment with thyroid hormone will allow the child to develop normally.
• Congenital adrenal hyperplasia (17-OHP level) : a genetic disorder characterized by the excessive development of the adrenal glands, which do not function normally; this can lead to severe dehydration and growth and genital development disorders. Appropriate hormonal treatment, starting in the neonatal period, can address these disorders and prevent their consequences.
• Sickle cell disease (hemoglobin electrophoresis) : a genetic blood disease that affects red blood cells (erythrocytes) and more specifically hemoglobin; this disease is more present in certain regions; these sickle-shaped red blood cells will have difficulty circulating in the blood, leading to painful crises or difficulties in vascularizing certain organs.
• Cystic fibrosis (immuno-reactive trypsin assay) : a hereditary genetic disease that primarily affects the respiratory and digestive systems. Medical care for children with cystic fibrosis must be tailored to slow the progression of the disease. Children with cystic fibrosis receive care at the Cystic Fibrosis Resource and Competence Center.
• MCAD a (Medium-Chain-Acyl-CoA Dehydrogenase; C8 assay) : hereditary disease that makes it difficult for the body to use fat as an energy source. Without treatment, the consequences can be serious when the child's energy needs exceed what their body can produce.
• Seven inborn errors of metabolism (homocystinuria, maple syrup urine disease, type I tyrosinemia, glutaric aciduria type I isovaleric aciduria, deficiency in long chain fatty acid 3-hydroxyacyl-coenzyme A dehydrogenase, primary carnitine deficiency) which are all genetic diseases that can have serious consequences for the body and whose treatment is based essentially on dietary measures.

Carrying out these screenings therefore makes it possible to know very quickly and almost exhaustively which babies are affected by one of these 12 diseases and to put in place effective treatment at a pre-symptomatic stage.

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