Refractory heparin induced thrombocytopenia with thrombosis (HITT) treated with therapeutic plasma exchange and rituximab as adjuvant therapy.

We report a case of refractory heparin-induced thrombocytopenia with thrombosis (HITT) with prolonged thrombocytopenia and multiple thrombotic complications that failed to improve despite aggressive treatment. A 60 year old female with a prior history of venous thromboembolism was admitted with an acute pulmonary embolism, and developed HITT after several days on heparin therapy. She suffered multiple complications including bilateral venous limb gangrene, acute renal failure, and refractory thrombocytopenia, leading us to use multimodality therapy including therapeutic plasma exchange (TPE) and rituximab immunosuppression. The patient had transient improvements in her thrombocytopenia with TPE, and rituximab was added in an attempt to reduce antibody production. She eventually required bilateral limb amputation, and only after removal of the gangrenous limbs did her platelet count show sustained improvement. We discuss the possible contribution of infection to her prolonged course.