Cytarabine-based induction immunochemotherapy in the front-line treatment of older patients with mantle cell lymphoma

The role of cytarabine-based induction and autologous stem cell transplantation (ASCT) in front-line treatment of younger patients with mantle cell lymphoma (MCL) is well established, however the utility of intensive approaches in older patients remains unclear. This retrospective study compared first line treatment outcomes in patients aged 60 years or more, treated at six tertiary centres between 2000-2015. 70 patients included had a median age of 69 (60-91) and most (94%) demonstrated advanced stage disease. Treatment regimens included: R-CHOP-like (n = 39), alternating R-CHOP/R-DHAC (n = 10), R-HyperCVAD/R-MA (n = 7), R-CHOP/Cytarabine (Nordic Protocol) (n = 10) and other (n = 4). 16 patients underwent an ASCT. The median follow-up for surviving patients was 37 months. Compared to R-CHOP-like therapies, cytarabine-based regimens were associated with an improved overall response rate (ORR) of 70% vs 33% (p < 0.001) and overall survival (OS) (HR 0.541, [0.292-1.001], p = 0.05). No difference in efficacy between different cytarabine-based regimens was detected, but R-HyperCVAD/R-MA was associated with increased hospitalisation and transfusion requirements. Patients undergoing ASCT demonstrated an improved median OS (HR 0.108 [0.015-0.796], p = 0.029) but were significantly younger. These results reaffirm the use of cytarabine in MCL for selected patients aged over 60. Such regimens should be strongly considered for this population in frontline therapy.

Atraumatic splenic rupture following IVIg for parvovirus B19 pure red cell aplasia post renal transplant

Parvovirus B19 (PB19) associated pure red cell aplasia (PRCA) is an uncommon but well described complication of immunosuppression post solid organ transplantation. We report a unique case of a renal transplant patient with PB19 associated PRCA who developed a spontaneous splenic rupture after receiving IVIg for persistent anemia. He subsequently required splenectomy. Within the spleen we subsequently identified PB19 affected cells.

Abstract 532: Shear-induced Release of Platelet Receptors Contributes to Bleeding Outcomes in Patients With Lvads or Exposed to Ecmo

Despite advances in design and materials, as well as pharmacological prophylaxis, hemostatic complications continue to plague device recipients. Ventricular assist devices (VADs) and extracorporeal membrane oxygenation (ECMO) are associated with bleeding that is not fully explained by anticoagulant or antiplatelet use. Exposure of platelets to elevated shear in vitro leads to increased shedding. We examined blood samples from patients with heart failure or in receipt of high fluid shear mechanocirculatory support to assess whether loss of platelet receptors occurs in vivo , and the relationship with acquired von Willebrand syndrome (AVWS) and changes in inflammatory cytokines. Platelet counts, levels of inflammatory cytokines IL-1β, IL-6, TNFα, MCP-1, IL-17A and IFNγ, coagulation tests and von Willebrand factor (VWF) analyses were performed on samples from 13 continuous flow VAD (CF-VAD), 14 ECMO, and 24 heart failure patients. Levels of platelet receptors were measured by flow cytometry or ELISA. The loss of high molecular weight VWF multimers was observed in 12 of 13 CF-VAD and 7 of 14 ECMO patients, consistent with AVWS. Platelet receptor shedding was demonstrated by elevated soluble glycoprotein (GP) VI levels in plasma and significantly reduced surface GPIbα and GPVI levels in CF-VAD and ECMO patients as compared with healthy donors. Platelet receptor levels were also significantly reduced in heart failure patients. Significant differences in levels of inflammatory cytokines monocyte-chemoattractant protein and tissue necrosis factor-a in a subset of patients with decompensated HF. These data link AVWS and increased platelet receptor shedding in patients with CFVADs or ECMO. Loss of the platelet surface receptors GPIbα and GPVI in heart failure, CFVAD and ECMO patients may be linked with extent of inflammation and may contribute to ablated platelet adhesion/activation, and limit thrombus formation under high/pathologic shear conditions.

Mechanisms of Platelet Dysfunction in Patients with Implantable Devices

As treatment options in modern medicine continue to expand, physicians globally have witnessed a veritable explosion in the utility of therapeutic devices. Particularly within the spheres of cardiology and critical care medicine, a plethora of devices are now available with an ever-increasing range of clinical indications. Additionally, the advent of transcatheter-mounted devices has enabled patients unsuitable for more invasive procedures to benefit from intervention, thereby greatly expanding the cohort of device-eligible patients. However, despite advances in design and materials, as well as pharmacological prophylaxis, hemostatic complications continue to plague device recipients, contributing to morbidity and mortality. Elucidating the complex interplay between components of the hemostatic system and cardiac devices has been the subject of much recent research, with greater focus on the coagulation cascade and device-induced perturbations. However, less is known about impact of mechanical surfaces on platelets and the resultant clinical complications, both hemorrhagic and thrombotic. This review will focus on exploring the pathobiology of platelet-surface interactions, contextualized within the wider hemostatic system, with a focus on the increasingly utilized technologies of transcatheter aortic-valve implantation, ventricular assist devices, and extracorporeal membrane oxygenation.