Lupus anticoagulant laboratory diagnosis by applying the 2020 ISTH-SSC guidelines.

BACKGROUND: The ISTH-SSC guidelines for lupus anticoagulant (LA) testing recommend using in-house determined cut-off values, pooled normal plasma (PNP) for ratio normalization, and a ratio for the mixing test interpretation. They strongly support the mixing step role in the diagnostic process. OBJECTIVES: To investigate and compare the LA testing results and interpretations obtained following the ISTH-SSC guidelines or the available alternatives. PATIENTS/METHODS: Blood samples for LA testing from 462 consecutive patients were evaluated for screening, mixing and confirmatory tests. The analysis focused on the interpretation differences between using (1) the in-house cut-off values versus the manufacturer's cut-off values, (2) a normalized ratio calculated using PNP at each run versus the mean of the reference interval, (3) a normalized ratio versus the index of circulating anticoagulant to interpret the mixing step, and (4) a two-step versus three-step procedure. RESULTS: LA testing outcomes were comparable when using the in-house and manufacturer's cut-off values. More positive dilute Russell's viper venom (DRVV) time results were obtained with the normalized ratio based on PNP than with the mean of the reference interval. Overall, the mixing test results obtained with the normalized ratio and the index of circulating anticoagulant showed a good agreement. Among the 97 DRVV Screen test-positive samples, 33 and 89 were classified as LA-positive with the 3-step and the 2-step procedure, respectively. CONCLUSIONS: The cut-off value used and the way to normalize ratios had a limited impact. Conversely, it is important to understand the mixing test characteristics to maximize its diagnostic potential.

[Fatal intracerebral hemorrhage in a patient with chronic neutrophilic leukemia: About one case and literature review]. / Hémorragie intracérébrale fatale chez un patient atteint d'une leucémie chronique à polynucléaires neutrophiles : à propos d'un cas et revue de la littérature.

INTRODUCTION: Chronic neutrophilic leukemia (CNL) is a rare myeloproliferative syndrome characterized by a significant increase in mature neutrophils. One of the most serious complications is the occurrence of bleeding events, which may sometimes lead to death. CASE REPORT: A 75-year-old patient presented with CNL, complicated by a severe bleeding phenotype. Biological investigations revealed platelet function defect and increase in neutrophil elastase. The follow-up was marked by an intracranial hemorrhage leading to the patient's death 7 months after diagnosis. CONCLUSION: This bleeding phenotype has been reported several times in patients with CNL. However, the pathophysiological mechanisms that cause bleeding are not yet fully understood.

[Diagnosis of iron deficiency: evaluation of the "soluble transferrin receptor/transferrin" ratio]. / Diagnostic de la carence en fer: évaluation du rapport "récepteur soluble de la transferrine/ferritine".

OBJECTIVE: This study was aimed at determining the diagnostic value of conventional laboratory tests regarding the iron status and serum transferrin receptor in hospitalized patients. METHODS: Patients who had to undergo bone marrow aspirate examination were included in this 8-month prospective study. Iron deficiency was defined as the absence of stainable iron on bone marrow examination. Patients with stainable iron were included in the control group. The higher value of diagnostic efficacy determined the cut-off value for each parameter of the iron status. RESULTS: Twenty-one patients (17 females, four males) (mean age: 52 years) with iron deficiency and 33 control subjects (20 females, 13 males) (mean age: 60 years) were included in the study. The ratio serum transferrin receptor/serum ferritin had the best diagnostic efficiency (78%) with a sensitivity of 81% and a specificity of 97%. Serum ferritin alone with a cut-off value of 60 micrograms/L had the same specificity (97%) but a lower sensitivity (76%). The diagnostic value of all other analyzed tests was below 66% (transferrin alone, mean corpuscular volume, transferrin saturation, iron, serum transferrin receptor alone, red cell distribution width). CONCLUSION: Among in-patients, ferritin remains the first intention test to diagnose iron deficiency, but the cut-off value should be increased (60 micrograms/L in this study). The ratio "serum transferrin receptor to serum ferritin" provides the highest specificity with a higher cost and should be used only in doubtful cases.