Annales de biologie clinique最新文献

The proinsulin molecule results from the cleavage of pre-pro-insulin, produced in pancreatic beta cells. Its subsequent -cleavage allows the release of insulin, the key hormone of glycemia regulation and C-peptide in equimolar proportions. During fasting trial, insulinoma diagnosis relies on inadequately high insulin and C-peptide serum levels concomitant with an hypoglycemia. In this context, proinsulin assay can be interesting in the cases of discrepancy between the two parameters. In diabetes, endoplasmic reticulum stress and beta cells inflammation, lead to the secretion of misfolded proinsulin molecules. Thus, in type 2 diabetes, proinsulin/insulin ratio increases with the degree of insulin resistance. In type 1 diabetes, proinsulin/C-peptide ratio could predict the onset of diabetes in relatives. In our practice, serum pro-insulin determined using an Elisa immunoassay (Millipore®) during fasting trial can be complementary to C-peptide and insulin assays in relation to glycemia to label an hypoglycemia. In case of glucose intolerance and diabetes, proinsulin could thus be measured.

The detection of erythrocyte morphological abnormalities is a valuable and sometimes overlooked element in the diagnostic management of anemias. The aim of this article is to evaluate the clinical performance of the different detection thresholds tested by our laboratory using the Cellavision RBC Advanced module, after manual reclassification by an experienced operator, and comparing them to the guidelines by the ICSH (International Council for Standardization in Haematology). We arbitrarily set thresholds at 1% for "critical" abnormalities (tear drop cells, target cells, schizocytes and spherocytes) except for sickle cells (threshold set at 0.01%). Our data show excellent sensitivity of 100% for the cut-offs defined by the investigation for tear drop cells and sickle cells, but low specificity for detection of associated clinical pathology compared with ICSH cut-offs, varying from 4% for teardrop cells (detection of myelofibrosis), 26% for target cells (detection of martial deficiency) to 55% for schizyocytes (presence of hemolytic anemia). Our results show a better specificity of the thresholds established by ICSH than our studied thresholds for the detection of the pathologies of concern, suggesting a better clinical relevance.

Iron deficiency is the leading cause of anemia worldwide, affecting approximately 600 million individuals. Once established, it typically manifests as a hypochromic microcytic anemia, the severity of which varies depending on the degree of deficiency. This anemia is frequently associated with thrombocytosis, but the presence of associated thrombocytopenia is much rarer. Here, we report a case of severe iron deficiency with an atypical presentation of bicytopenia, involving both severe anemia and profound thrombocytopenia, which rapidly resolved following iron supplementation. We then discuss the hypotheses that exist to explain the link between iron deficiency and regulation of thrombopoiesis.

Inflammatory biological parameters are altered in patients with COVID-19 depending on its severity. The objective of our study is to find a score to assess the prognosis of patients with severe COVID-19. This is a retrospective study of patients with severe COVID-19 hospitalized in the intensive care units of Ibn Sina Hospital in Rabat. The study involves a total of 197 patients. The biological parameters were collected and evaluated in order to recognize the factors of poor prognosis of severe COVID-19. In our cohort, 133 patients died (67.51%) and had a higher average age (p < 0.001). A statistically significant correlation was found in this group of patients for procalcitonin (p = 0.005), lactate dehydrogenase (p = 0.02) and ferritin (p = 0.017). The lactate dehydrogenase/lymphocyte ratio (LLR) had the highest accuracy among the calculated combined scores. The LLR AUC was 0.628 (95% CI: 0.549-0.708) and the optimal cut-off value was 341, which gave a sensitivity of 91 % and a specificity of 84 %. The LLR is a good predictor of the poor prognosis of patients with severe COVID-19.

We present a case of a 48-year-old woman with a fortuitous discovery of macrocytic anemia and thrombocytopenia. Serum folate and vitamin B12 levels were normal. However, due to the presence of indirect signs of cobalamin deficiency, such as elevated homocysteine and methylmalonic acid, and signs of dyserythropoiesis on the bone marrow aspirate, pernicious anemia was suspected. Vitamin B12 dosage was repeated finding fluctuating but always normal results. Anti-intrinsic factor antibodies were present at a very high level, explaining the fluctuations and the interference found on the assay using competitive binding chemiluminescence (CBLA). Serum vitamin B12 dosage by electrochemiluminescence, a method described as not interfering with intrinsic factor antibodies, showed a collapsed vitamin B12 level. Measurement of vitamin B12 with CBLA after adsorption of immunoglobulins in the sample using protein G SepharoseTM, confirmed the interference of the cobalamin assay with autoantibodies. This case illustrates the difficulties regarding the analysis and standardization of the vitamin B12 assay for the diagnosis of pernicious anemia.

The ordering of clinical haemostasis tests is increasing in Burkina Faso due to the newly emergence of cardiovascular and metabolic diseases. However, appropriate local reference values (RV) are lacking. Our study aimed to establish RV for prothrombin time (PT), activated partial thromboplastin time (aPTT) and fibrinogen assays. In 2020, we carried out a cross-sectional study at the transfusion centre of Ouagadougou and included 280 healthy blood donors (140 males and 140 females) as reference subjects (RS) according to CLSI guidelines (C28 A3). From each RS a 5 mL blood sample had been withdrawn in citrated tubes. We performed PT, aPTT and fibrinogen assays using the Sysmex™ CA660 coagulometer and Siemens™ reagents. RV were calculated using the "central 95 percentile" method. Reference values of PT, aPTT and Fibrinogen were respectively [73.84%-117.50%], [20,01-29.45] seconds and [2.04-3.83] g/L for females and [58.81%-112,31%] seconds, [20,9-29,98] seconds and [1.58-3.35] g/L for males. We report for the first time locally appropriate haemostasis RV for the Burkina Faso adult's population. They will be of clinical use to our health care professionals.