Thrombocytopenia is independently associated with poor outcome in patients hospitalized for COVID-19 Thrombocytopenia (defined by platelet count <150 9 10 9 / l) has been observed in up to 36% of patients with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19). 1 In this setting, thrombocytopenia is usually mild, caused by platelet activation and consumption. 2,3 In a recent paper published in the British Journal of Haematology, Jiang et al 4 conducted a meta-analysis of 31 studies involving 7613 participants and found a significant association between thrombocytopenia and patients hospitalized Correspondence e276

Autoimmune hemolytic anemia (AIHA) is characterized by the destruction of red blood cells by warm or cold autoantibodies. Its epidemiology is not well known. The incidence rate of AIHA has been estimated at 1.77 per 100 000 person-years between 2008 and 2016 in Denmark. 1 However, these results need to be confirmed and variations by age and sex are not known. The main causes of secondary AIHA E292 CORRESPONDENCE Maquet conducted the statistical analyses. Julien Maquet, Margaux Lafaurie and Guillaume Moulis wrote the paper; all other authors critically reviewed the manuscript and gave final approval for publication.

We aimed to assess the risk factors of venous thrombosis (VT) and arterial thrombosis (AT) in adults with primary immune thrombocytopenia (ITP), particularly in relation to treatments. The population comprised all incident primary ITP adults in France between 2009 and 2017 (FAITH cohort; NCT03429660) built in the national health database. Outcomes were the first hospitalisation for VT and AT. Multivariable Cox regression models included baseline risk factors, time-varying exposure to ITP drugs, splenectomy and to cardiovascular drugs. The cohort included 10 039 patients. A higher risk of hospitalisation for VT was observed with older age, history of VT, history of cancer, splenectomy [hazard ratio (HR) 3Á23, 95% confidence interval (CI) 2Á26-4Á61], exposure to corticosteroids (HR 3Á55, 95% CI 2Á74-4Á58), thrombopoietin-receptor agonists (TPO-RAs; HR 2Á28, 95% CI 1Á59-3Á26) and intravenous immunoglobulin (IVIg; HR 2Á10, 95% CI 1Á43-3Á06). A higher risk of hospitalisation for AT was observed with older age, male sex, a history of cardiovascular disease, splenectomy (HR 1Á50, 95% CI 1Á12-2Á03), exposure to IVIg (HR 1Á85, 95% CI 1Á36-2Á52) and TPO-RAs (HR 1Á64, 95% CI 1Á26-2Á13). Rituximab was not associated with an increased risk. These findings help to estimate the risk of thrombosis in adult patients with ITP and to select treatment.

Data about the presentation and the management of primary immune thrombocytopenia (ITP) in very elderly patients (VEPs; aged ≥80 years) are lacking. The aim of the present study was to describe ITP in this subgroup. The data source was the prospective CARMEN-France registry. Patients included between 2013 and 2018 were selected. ITP presentation and management in VEPs was compared to elderly patients (EPs; aged 65-79 years). We assessed factors associated with bleeding at ITP onset in VEPs. Of 541 patients, 184 were included: 87 in the VEP group and 97 in the EP group. The mean age was 85Á7 years in the VEP group. Comorbidities were more frequent in the VEP group (67Á4% vs. 47Á9%). The median platelet count at ITP onset was similar but severe bleeding tended to be more frequent in VEPs (10Á3% vs. 4Á1%, P = 0Á1) as well as mortality. Exposure to ITP drugs, response to first-line treatment, need of second-line treatment, evolution towards persistency, occurrence of bleeding, infection and thrombosis did not differ between groups. In VEPs, factors associated to bleeding were female sex [odds ratio (OR) 4Á75, 95% confidence interval (CI) 1Á31-17Á32] and platelet count of <20 9 10 9 /l (OR 10Á05, 95% CI 4Á83-67Á39). Exposure to anticoagulants was strongly associated with severe bleeding (OR 7Á61, 95% CI 1Á77-32Á83).

Vaso-occlusive episodes (VOEs) are a major concern in patients with sickle cell disease (SCD). Exposure to systemic corticosteroids has been suspected to increase the occurrence of VOEs in case reports or series. No comparative study has been conducted to investigate this risk, which is still debated. Several clinical trials demonstrated the effectiveness of corticosteroids for the treatment of VOEs, but with increased rates of readmission. The aim of the study was to assess the risk of hospitalization for VOE associated with exposure to systemic corticosteroids in patients with SCD. We used a case-case-time control design in a nationwide population-based cohort built in the French national health insurance database between 2010 and 2018. The population included all patients with SCD with at least one hospitalization for VOE. Corticosteroids were identified using out-of-hospital dispensing data. The outcome was the first hospitalization for VOE. The case-case-time-control design induces self-adjustment for time-invariant confounders, including genotype. Analyses were adjusted for time-dependent confounders (infections, red blood transfusions) and stratified by exposure to hydroxyurea. Overall, 5,151 patients were included in the main analysis. Corticosteroid exposure was significantly associated with the occurrence of hospitalizations for VOEs: adjusted Odds Ratio (aOR): 3.8 (95% Confidence Interval - CI: 2.4-5.6). In patients exposed to hydroxyurea, the aOR was 2.6 (95% CI: 1.1-6.4); it was 4.0 (95% CI: 2.5-6.3) in unexposed patients. These results were consistent in children and adults. In conclusion, systemic corticosteroids were associated to an increased risk of hospitalization for VOE and should be limited in patients with SCD.