Thrombotic Thrombocytopenic Purpura due to Checkpoint Inhibitors.

Ipilimumab is a monoclonal antibody that enhances the efficacy of the immune system by targeting a cytotoxic T-lymphocyte-associated protein 4 (CTLA-4), which is a protein receptor that downregulates the immune system. Nivolumab is also a humanized monoclonal antibody that targets another protein receptor that prevents activated T cells from attacking the cancer; this receptor is called programmed cell death 1 (PD-1). The FDA approved ipilimumab combined with nivolumab as a frontline therapy for patients with metastatic melanoma or renal cell carcinoma and as a second-line therapy for patients with microsatellite instability-high (MSI-H) metastatic colon cancer.

Therapeutic apheresis: when things go wrong.

Therapeutic apheresis medicine requires in-depth knowledge of physiology, disease mechanisms as well as a thorough understanding of the parameters that can be adjusted in the instrument that are used. We report two cases where critical decision making was crucial during management of patients being treated with therapeutic apheresis. Case 1 involves an adult patient with severe circulating cryoglobulins and Case 2 describes a patient with Waldenström's macroglobulinemia and hyperviscosity.

Use of plasma exchange in patients with heparin-induced thrombocytopenia: a report of two cases and a review of the literature.

Heparin-induced thrombocytopenia (HIT), which is characterized by thrombocytopenia and potentially serious thromboses, may develop in patients exposed to heparin anticoagulation. HIT is caused by antibodies to the heparin/platelet factor 4 (PF4) complex. Management of HIT involves discontinuation of heparin and anticoagulation with a nonheparin alternative such as a direct thrombin inhibitor (DTI).