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Thrombotic manifestations are a hallmark of many auto-immune diseases (AID), specially of warm autoimmune hemolytic anemia (wAIHA), as 15 to 33% of adults with wAIHA experience venous thromboembolic events (VTE). However, beyond the presence of positive antiphospholipid antibodies and splenectomy, risk factors for developing a VTE during wAIHA have not been clearly identified. The aim of this retrospective study was to characterize VTEs during wAIHA and to identify risk factors for VTE. Forty-eight patients with wAIHA were included, among whom 26 (54%) had secondary wAIHA. Eleven (23%) patients presented at least one VTE, that occurred during an active phase of the disease for 10/11 patients (90%). The frequency of VTE was not different between primary and secondary AIHA (23.7 vs. 19.2%; p = 0.5). The Padua prediction score based on traditional risk factors was not different between patients with and without VTE. On multivariate analysis, total bilirubin ≥ 40 μmol/L [odds ratio (OR) = 7.4; p = 0.02] and leucocyte count above 7x109/L (OR = 15.7; p = 0.02) were significantly associated with a higher risk of thrombosis. Antiphospholipid antibodies were screened in 9 out the 11 patients who presented a VTE and were negative. Thus, the frequency of VTE is high (23%) during wAIHA and VTE preferentially occur within the first weeks of diagnosis. As no clinically relevant predictive factors of VTE could be identified, the systematic use of a prophylactic anticoagulation should be recommended in case of active hemolysis and its maintenance after hospital discharge should be considered. The benefit of a systematic screening for VTE and its procedure remain to be determined. [ABSTRACT FROM AUTHOR]

Calreticulin (CALR) mutations have recently been reported in 70–84% of JAK2V617F-negative myeloproliferative neoplasms (MPN), and this detection has become necessary to improve the diagnosis of MPN. In a large single-centre cohort of 298 patients suffering from Essential Thrombocythemia (ET), the JAK2V617F, CALR and MPL mutations were noted in 179 (60%), 56 (18.5%) and 13 (4.5%) respectively. For the detection of the CALR mutations, three methods were compared in parallel: high-resolution melting-curve analysis (HRM), product-sizing analysis and Sanger sequencing. The sensitivity for the HRM, product-sizing analysis and Sanger sequencing was 96.4%, 98.2% and 89.3% respectively, whereas the specificity was 96.3%, 100% and 100%. In our cohort, the product-sizing analysis was the most sensitive method and was the easiest to interpret, while the HRM was sometimes difficult to interpret. In contrast, when large series of samples were tested, HRM provided results more quickly than did the other methods, which required more time. Finally, the sequencing method, which is the reference method, had the lowest sensitivity but can be used to describe the type of mutation precisely. Altogether, our results suggest that in routine laboratory practice, product-sizing analysis is globally similar to HRM for the detection of CALR mutations, and that both may be used as first-line screening tests. If the results are positive, Sanger sequencing can be used to confirm the mutation and to determine its type. Product-sizing analysis provides sensitive and specific results, moreover, with the quantitative measurement of CALR, which might be useful to monitor specific treatments. [ABSTRACT FROM AUTHOR]