Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by the persistent positivity of antiphospholipid antibodies (aPLA) together with thrombosis or obstetrical complications. Despite their recognized predominant role, aPLA are not sufficient to induce the development of thrombosis and a second hit has been proposed to be necessary. The mainstay of treatment of APS is anticoagulant therapy. However, its optimal intensity in different presentations of the disease remains undefined. Moreover, decision on which patients with aPLA would benefit from an antithrombotic prophylaxis and its optimal intensity are challenging because of the lack of stratification tools for the risk of thrombosis. Finally, decision on the optimal type of anticoagulant drug is also complex because the central pathway responsible for the development of thrombosis is so far unknown and should be carried out on an individual basis after a careful evaluation of the clinical and laboratory features of the patient. This review addresses the epidemiology, physiopathology, diagnosis and management of thrombosis and obstetrical complications in APS, with a special focus on the role of direct oral anticoagulants.

Autoimmune hemolytic anemias are rare and heterogeneous disorders characterized by hemolysis, which is a well-recognized risk factor for thrombosis. The most common immune-mediated anemias are represented by autoimmune hemolytic anemia and paroxysmal nocturnal hemoglobinuria, both associated with a high rate of thrombosis. Multiple pathophysiological mechanisms for thrombosis have been proposed, involving hemolysis itself and additional effects of the immune system. Despite the increasing awareness of the thrombotic risk in these conditions, evidence-based guidance on prevention and management of thrombotic events is lacking. We herein report available evidence on epidemiological data on thrombosis and thrombophilia in immune-mediated hemolysis, together with possible underlying pathophysiological mechanisms. In addition, we summarize current recommendations for treatment of thrombosis in immune-mediated hemolysis. In particular, we address the issue of thrombotic complications treatment and prophylaxis by proposing a therapeutic algorithm, focusing on specific situations such as splenectomy and pregnancy.

Venous thrombosis rarely occurs at unusual sites such as cerebral, splanchnic, upper-extremity, renal, ovarian, or retinal veins. Clinical features, symptoms, and risk factors of rare thrombotic manifestations are heterogeneous and in large part differ from those typical of the commonest manifestations of venous thrombosis at the lower extremities. The therapeutic approach also varies widely according to the affected site, whether cerebral, abdominal, or extraabdominal. To date, anticoagulant therapy for thrombosis at unusual sites is generally accepted, but the optimal therapeutic approach remains challenging. This review is focused on the treatment of unusual thrombotic manifestations as reported in the most recent guidelines and according to the updated scientific literature.

Diagnostic boundaries between immune thrombocytopenia (ITP) and other thrombocytopenic states, such as thrombocytopenic myelodysplastic syndromes, may be difficult to establish, and the detection of somatic mutations by next-generation sequencing (NGS) may be of aid. Here, we aimed at characterizing the prevalence and clinical significance of clonal hematopoiesis in ITP. In this multicentric retrospective observational study, we enrolled 167 adult patients with ITP, followed at 13 centers in Italy, United Kingdom, and the United States. Patients underwent NGS evaluation after a median of 3.6 years from ITP onset, and 83% had received at least 1 therapy line, for a median of 2 lines (range, 0-9); 51 of 167 patients (30%) had at least 1 mutation. After exclusion of germ line variants and polymorphisms, 31 of 167 (18.5%) were defined as having clonal hemopoiesis. Most commonly mutated genes were TET2, DNMT3A, SRSF2, and ASXL1 (median variant allele frequency, 29%); 19 of 31 patients (68%) had high-risk variants, and 8 had multiple mutations. Mutated patients were more frequently older males and showed a shorter time from first to second-line therapy, particularly with thrombopoietin receptor agonist (TPO-RA). Additionally, clonal hematopoiesis was associated with increased thrombotic risk (26% vs 8% in NGS-negative cases; P = .01), independently from TPO-RA exposure, though with an age effect. These data demonstrated the prevalence of clonal hematopoiesis in 18% of adult patients with ITP, which is associated with older age, relapsed/refractory disease, and high risk of thrombotic complications.

Key Points. Azathioprine is effective in achieving durable ADAMTS13 remission in 48% of iTTP patients in clinical remission with ADAMTS13 activity < 20%Azath

Since their license in 2008, studies on thrombopoietin receptor agonists (TPO-RAs) are proceeding at a fast pace. Their favorable efficacy and safety profile makes them good candidates for the management of thrombocytopenia in different settings, even beyond their current indications. In the last 10 years, we faced patients with refractory thrombocytopenia that required treatment with off-label TPO-RA, despite the paucity of data in the literature and the possible risks, particularly that of thrombosis. We hereby report our 10-year real-life single-center experience of TPO-RA used off-label. Fourteen patients were divided into three groups according to the etiology of thrombocytopenia: myelodysplastic syndromes, post-transplantation, and lymphoproliferative diseases. Clinical features and results are reported within each group. Overall, TPO-RA proved effective in all these conditions achieving responses also in heavily pretreated patients. The overall response rate (ORR) was 100% in patients with thrombocytopenia after transplantation and in those with lymphoproliferative diseases and 75% in patients with myelodysplastic syndromes. The median duration of therapy was 285 days (range 93–1,513 days). Four patients (29%) discontinued treatment because of lack of response (n=2) or a sustained response (n=2). No grade 3–4 adverse events occurred, particularly no thrombosis. In our real-life experience, TPO-RAs were effective and safe and proved of value in the challenging management of patients with refractory thrombocytopenia associated with different conditions.