[Hemolytic disorders and venous thrombosis: An update]. / Maladies hémolytiques et thrombose veineuse : mise au point.

Many factors can contribute to the risk of venous thrombosis observed in hemolytic diseases. Some mechanisms are related to hemolysis by itself, while others seem more specific to each disease. Despite recent advances in the quantification of this risk and in understanding its physiopathology, the association of hemolysis with venous thrombosis is often unknown. The purpose of this general review is to clarify the main pro-thrombotic mechanisms during hemolysis and to synthesize the clinical data currently available. We will focus on the main types of hemolytic pathologies encountered in current practice, namely paroxysmal nocturnal hemoglobinuria, hemoglobinopathies, auto-immune hemolytic anemia and thrombotic microangiopathies.

Venous thromboembolism related to warm autoimmune hemolytic anemia: a case-control study.

BACKGROUND: The risk of venous thromboembolism (VTE) during warm autoimmune hemolytic anemia (wAIHA) is apparent in several published series. Unlike proximate disorders (autoimmune thrombocytopenia, non-immune hemolytic diseases) little is known about the presentation and risk factors for VTE in this setting. OBJECTIVE: To determine the frequency, presentation and risk factors for VTE associated with wAIHA. METHODS: We performed a single center retrospective study of adult patients (>18years) followed for wAIHA between 2009 and 2013. VTE risk factors were systematically assessed. The characteristics of patients with or without VTE were compared. VTE presentation and precipitating factors were analyzed. The Padua VTE risk score was calculated in each case. RESULTS: Forty patients were included. wAIHA was idiopathic in 24 patients (60%). Twelve patients (30%) had Evans syndrome. Mean lowest hemoglobin level was 6.6g/dl [3.7-11.5]. Eight patients (20%) presented VTE after the appearance of wAIHA, at a mean age of 52.5years. All patients had pulmonary embolus, associated with a deep venous thrombosis in 4 cases. At the time of VTE 7/8 patients had frank hemolysis (median hemoglobin level: 7g/dL) and 6/8 were outpatients with a low Padua VTE risk score. The frequency of usual VTE risk factor was similar in cases and controls. By contrast, lowest hemoglobin level was significantly lower in patients that experienced VTE (5.3 vs 7.2g/dL, p=0.016). During the first episode of wAIHA, patients with concurrent VTE had a more pronounced anemia (5.3 vs 7.4g/dL, p=0.026). At the time of VTE, anemia was more severe when no other precipitating factor was present (6 vs 8.9g.dL, p=0.04). CONCLUSION: In our cohort, 20% of patients with wAIHA presented VTE. The vast majority of VTE occurred during severe hemolytic flares and were not attributable to usual VTE risk factors. VTE prophylaxis is advisable in any patient admitted for wAIHA, irrespective of Padua VTE risk score. Prophylaxis also seems reasonable for outpatients with marked hemolysis.

[Unilateral isolated Raynaud's phenomenon leading to diagnosis of multifocal giant-cell arteritis complicated with renal ischemia]. / Phénomène de Raynaud unilatéral isolé révélateur d'une artérite à cellules géantes multifocale (maladie de Horton) compliquée d'ischémie rénale.

We report a case of a 76-year-old woman with isolated unilateral Raynaud phenomenon revealing giant-cell arteritis with diffuse arterial lesions and bilateral renal artery stenosis. Doppler ultrasonography showed bilateral stenosis of the subclavian and axillary arteries. Angio-CT PET enlightened diffuse arterial lesions, mainly involving the aorta and the brachial and femoral arteries as well as bilateral renal ostial stenosis with right kidney ischemia. Diagnosis of giant-cell arteritis was made on the temporal artery biopsy. Corticosteroid therapy led to rapid clinical and radiological improvement. Clinical manifestations of giant-cell arteritis may be atypical. Diffuse arterial disease may exist in the absence of cephalic symptoms or significant inflammatory biological features. Ostial renal artery stenosis may induce potentially threatening renal ischemia.