Search

Survivors of immune-mediated thrombotic thrombocytopenic purpura (iTTP) are exposed to clinical relapses when a disintegrin and metalloproteinase with thrombospondin type 1 repeats, member 13 (ADAMTS13) activity decreases during follow-up. Although preemptive rituximab usually improves ADAMTS13 activity in this context, 15% of patients experience refractoriness or intolerance to rituximab and require alternative strategies. Here, we addressed whether cyclosporine A (CSA) could improve ADAMTS13 activity and prevent clinical relapses in this context. We treated preemptively with CSA 14 iTTP patients who were unresponsive (n = 11) or intolerant (n = 3) to rituximab. All patients had a severe ADAMTS13 deficiency (activity20%) and otherwise in clinical remission. ADAMTS13 activity normalized in almost all patients (n = 13, 93%), after a median time of 2.5 months [IQR 1-6] following initiation. Median duration of CSA treatment was 17.5 months [IQR 10-34]. ADAMTS13 activity further declined to undetectable values during follow-up in five patients, but retreatment with rituximab or CSA allowed a recovery in ADAMTS13 activity in three cases. CSA could be stopped durably in two patients, while two others experienced an ADAMTS13 relapse. Severe but reversible side effects requiring cessation of the treatment occurred in two patients. CSA provides high and sustained response rates in patients who are refractory or intolerant to rituximab, with acceptable adverse events.

Thrombotic thrombocytopenic purpura (TTP) has a devastating prognosis without adapted management. Sources of misdiagnosis need to be identified to avoid delayed treatment. We studied 84 patients with a final diagnosis of severe (

The standard four-rituximab infusions treatment in acquired thrombotic thrombocytopenic purpura (TTP) remains empirical. Peripheral B cell depletion is correlated with the decrease in serum concentrations of anti-ADAMTS13 and associated with clinical response. To assess the efficacy of a rituximab regimen based on B cell depletion, 24 TTP patients were enrolled in this prospective multicentre single arm phase II study and then compared to patients from a previous study. Patients with a suboptimal response to a plasma exchange-based regimen received two infusions of rituximab 375 mg/m2 within 4 days, and a third dose at day +15 of the first infusion if peripheral B cells were still detectable. Primary endpoint was the assessment of the time required to platelet count recovery from the first plasma exchange. Three patients died after the first rituximab administration. In the remaining patients, the B cell-driven treatment hastened remission and ADAMTS13 activity recovery as a result of rapid anti-ADAMTS13 depletion in a similar manner to the standard four-rituximab infusions schedule. The 1-year relapse-free survival was also comparable between both groups. A rituximab regimen based on B cell depletion is feasible and provides comparable results than with the four-rituximab infusions schedule. This regimen could represent a new standard in TTP. This trial was registered at www.clinicaltrials.gov (NCT00907751). This article is protected by copyright. All rights reserved.

Objective To assess the role of Toll-like receptors (TLRs) in antiphospholipid antibody (aPL)–mediated vascular abnormalities in patients with primary arterial antiphospholipid syndrome (APS). Methods Forty-eight subjects participated in the study. Arterial function and structure and TLR pathway activation were determined in patients with primary arterial APS and matched controls. The pathogenic effects of aPL isolated from patients were assessed in wild-type (WT) and TLR-knockout mice. Results APS patients had endothelial dysfunction, arterial stiffening, and hypertrophy, as evidenced by decreased brachial artery endothelium-dependent flow-mediated dilation (FMD) and increased aortic pulse wave velocity and carotid intima-media thickness (IMT), as compared with controls. Plasma samples from APS patients revealed decreased nitric oxide (NO) availability and a pro-oxidative, proinflammatory, and prothrombotic state illustrated by a decrease in nitrite and an increase in lipid peroxidation, tumor necrosis factor α levels, and tissue factor (TF) levels. Furthermore, TLR pathway activation was found in APS patients with increased TLR-2 and TLR-4 messenger RNA expression and increased protein levels of the activated TLR transduction protein interleukin-1 receptor–associated kinase 1 in peripheral blood mononuclear cells. Moreover, agonist-stimulated cell-surface expression of TLR-2 and TLR-4 in circulating monocytes was higher in APS patients than in controls. These changes were positively associated with IMT and negatively associated with FMD. Finally, aPL injection decreased mesenteric endothelium-dependent relaxation and increased TF expression in WT mice but not in TLR-2– or TLR-4–knockout mice. Conclusion This translational study supports the notion that TLR-2 and TLR-4 play a role in mediating vascular abnormalities in patients with primary arterial APS. TLRs thus constitute a promising pharmacologic target for preventing cardiovascular complications in APS.