Annales de biologie clinique最新文献

Medical laboratories in France have always adapted to technical and medical progress, as well as to the regulations imposed by the supervisory authorities. However, over the last ten years, this evolution has been so important that biologists are witnessing a revolution in their mode of practice. The supervisory authorities wanted to increase and harmonize the quality of laboratory results. But the new legislation, sometimes misused, as well as the fear and the cost of accreditation, are at the origin of the excessive acceleration of the financialization of medical biology laboratories. We will see how the hegemony of financial groups can be detrimental to the quality of service provided to patients and to the independence of the medical biologist.

ISO published the draft for final approval of the revision of ISO 15189 standard. Following ISO directives, ISO 15189 must be aligned with ISO/IEC 17025:2017 and should be less prescriptive. Draft ISO/DIS 15189 deviates in some points from ISO 17025 and the ISO indications to limit prescriptiveness: equipment, uncertainty, quality control. This do not seem to be justified by medical specificities and could complicate the understanding of the new requirements in medical laboratories.

Background: 25-Hydroxyvitamin D 24-hydroxylase (CYP24A1) deficiency is a rare cause of autosomal recessive infantile hypercalcemia due to vitamine D hypersensitivity.

Case presentation: We report the case of a 2-year-old boy who presented with severe hypercalcemia-hypercalciuria and a bilateral nephrocalcinosis. Laboratory investigations detected a collapsed parathormone and a highly elevated 1α,25-dihydroxycholecalciferol along with an increased phosphate excretion (hypophosphatemia and hyperphosphaturia). An adapted management with two courses of palmidronic acid and an eviction of vitamin D and calcium allowed to stabilize him. A homozygous p.Leu409Ser pathogenic variant on CYP24A1 gene resulting in a collapsed 25-Hydroxyvitamin D24-hydroxylase activity was found. A normal development is possible with a meticulous clinical, biological and nutritional management and monitoring.

Conclusions: Vitamin D hypersensitivity is challenging during childhood, especially due to the need to avoid vitamin D while requiring a close nutritional monitoring to maintain a normal growth. Biomarkers such as vitamin D metabolite ratio and 24,25(OH)2D3 along with ionized calcium and nutritional management can contribute to properly follow patients with vitamin D hypersensitivity.

The diagnosis of hemoglobinopathy is based on a range of arguments: clinic, results of a blood count, the haemoglobin study and possibly a genetic study of the globin chains. The interpretation of these profiles can be complicated, especially in newborns due to the ontogenesis of globin genes. The clinical impact can range from simple microcytosis without anemia to severe anemia requiring iterative transfusions and various clinical symptoms depending on the number and type of chains produced. Knowledge of a hemoglobin pathology remains essential because of the possible transmission and combination of these anomalies to offspring.

Anti-mitochondrial antibodies (AMA) represent serological markers of primary biliary cholangitis (PBC). Investigation of these autoantibodies can be performed by indirect immunofluorescence (IIF) on tissue sections or immunodot using M2 and M2-3E antigens. We aimed to evaluate the concordance of these immunological tests and their performance in PBC diagnosis. We reviewed sera which were tested for autoimmune liver disease anti-bodies by IIF (EUROIMMUN®) and immunodot (EUROIMMUN®). Results of IIF (AMA) and immunodot (anti-M2 and anti-M2-3E) were analyzed. A focus was given on positive results for AMA and/or anti-M2 and/or anti-M2-3E. According to available clinical data, patients were divided into two groups "PBC" and "Non PBC". Three-hundred-nineteen sera were tested by both techniques. Results of AMA, anti-M2 and anti-M2-3E were concordant in 296 cases (92.8%). Indeed, the three biomarkers were negative in 237 cases (74.3%) and positive in 59 cases (18.5%). Eighty-two sera were tested positive for AMA and/or anti-M2 and/or anti-M2-3E. Clinical data were available for 30 patients. In "PBC" group (n = 15), AMA, anti-M2 and anti-M2-3E antibodies were positive in 14/15 cases. PBC diagnosis was made in 12/15 patients without requiring liver biopsy. In "non PBC" group (n = 15), AMA, anti-M2 and antiM2-3E antibodies were positive in 9/15 cases. However, PBC diagnosis was not reached in the absence of other diagnostic criteria. IIF represents a first-line technique for AMA detection while immunodot is useful to confirm antigenic specificity in IIF-AMA positive cases. Anti-M2 and/or anti-M2-3E can be detected in some IIF-AMA negative cases. Interpretation of these tests'results relays mainly on clinical context.

Neurofilaments (Nf) are proteins selectively expressed in the cytoskeleton of neurons, and their increase is a marker of neuronal damage. The potential utility of neurofilament light chain (NfL) has recently increased considerably, well beyond neurodegenerative diseases, due to analytical advances that allow measurement of their concentrations (even low ones) in cerebrospinal fluid and blood. This article completes the first part, in which we presented the interest of NfL in the context of neurodegenerative diseases. Here we focus our review on other clinical contexts of neurological injury (such as traumatic brain injury, multiple sclerosis, stroke, and cancer) and present the potential value of NfL assay in the management of these patients, for both diagnosis and prognosis. We also discuss the added value of the NfL assay compared to other biomarkers commonly used in the described clinical situations.

A 65-year-old female was admitted to the Emergency Department for a fall. Upon admission, a blood sample was drawn for routine laboratory tests. Blood glucose measurement using the hexokinase method was made impossible due to a high lipemia index measured by the instrument despite a clear plasma specimen. It is well known that hemolysis, icterus, and lipemia interferences disrupt spectrophotometric quantifications. However, in this case, the absence of lipemia was confirmed by plasma triglycerides measurement in the normal reference range. Protein electrophoresis along with an immunofixation were carried out to characterize a monoclonal gammopathy since the presence of a monoclonal gammopathy in very high concentrations generates turbidity and interferes with spectrophotometric assays. A gamma peak evoking a monoclonal gammopathy was found on the serum electrophoresis and the immunofixation was positive for a monoclonal IgM kappa. Myelogram showed plasmocytes, lymphoplasmacytic cells and mast cells infiltration which led to the diagnosis of Waldenstrom macroglobulinemia. Based on this case, we propose a course of action to be taken in the case of a high lipemia index and clear plasma.