Effective use of rituximab for acquired amegakaryocytic thrombocytopenia

Abstract

Between 1981 and 2010, we have treated 40 patients requiring chronic transfusion with periodic manual erythrocyte exchange and autologous plasma rescue (MEEX). Here, we present retrospective, long-term (median 22, range 14-29 years) follow-up data for a subset of seven patients with sickle cell syndromes who did not respond to hydroxyurea (HU). Patient characteristics are listed in Supporting Information, Tables I and II. MEEX was accomplished by using a single venous access and infusing 500 ml of isotonic solution (for adults) and removing 500 ml blood (range 400-600 ml according to the patient's weight and the physician's discretion). The rescue process involves centrifugation of the collected blood product and reinfusion of autologous plasma. This is followed by another 500 ml phlebotomy and the infusion of 2-3 units of packed Rh-matched, leuko-filtered, plasma-depleted red cells, with the aim of lowering HbS levels to around 40%. For pediatric patients, the bleeding volume is smaller (5-10 cc/Kg) and the volumes of infused saline and packed Rhmatched, leuko-filtered, plasma-depleted red cells are equal to the phlebotomy volumes, without plasma rescue.The interval between each MEEX procedure for these seven patients ranged from 45 to 90 days to maintain at all times HbS concentrations below 60-70% and the median number of procedures was 133 (range 85-204). None of the seven patients experienced acute complications of sickle cell disease (SCD), such as acute chest syndrome, splenic sequestration, stroke, bone necrosis, or priapism, or long-term complications such as renal failure, cerebrovascular or retinal damage, or pseudoxanthoma-like manifestations. None of the seven patients experienced alloimmunization and all but one patient had normal liver iron concentrations [assessed by superconducting quantum interference device, magnetic iron detector, magnetic resonance imaging (MRI), or biopsy]. This patient, who started the program at the age of 26 years with iron overload due to previous transfusions, required regular iron chelation therapy. Cardiac function tests indicated that all subjects had a left ventricular ejection fraction of >60% and cardiac T 2 * > 20 mms (measured by MRI). There was no evidence of pulmonary arterial hypertension on echocardiography.During the observation period, five patients required hospitalization (four with acute cholecystitis and one due to venous occlusive crisis). Only one patient requires chronic analgesia (to relieve pain caused by pre-existing femur head necrosis).Automated EEX (AEEX) ensures lower postprocedural HbS levels (30% HbS vs. 40% with our MEEX protocol) because it makes use of two distal ports to increase the volume of red cells removed. However, the larger number of transfused units in AEEX exposes the patient to a higher transfusional risk. In addition, the automated procedure is significantly more expensive than the manual one, as indicated in Table I.Previous studies have indicated that EEX is a safe and efficacious alternative to both HU and simple transfu...

Acquired Amegakaryocytic Thrombocytopenia in a Child: A Very Rare Case

“…Our patient was treated with cyclosporine and steroids with platelet transfusion. In few published literature patients were treated with ATG, Danazol, myeloablative chemotherapy, cyclophosphamide, IVIG, blood and marrow stem cell transplantation [7][8][9][10]. So, far cyclosporine has shown to be the best therapeutic intervention.…”

“Almost Bleeding to Death”: The Conundrum of Acquired Amegakaryocytic Thrombocytopenia

“…Patients can achieve a durable remission, develop a long relapsing and remitting course, progress to aplastic anemia, or require a bone marrow transplantation to achieve remission [8–10]. AAT may be associated with other hematologic and rheumatologic conditions, including MDS, aplastic anemia, acute myeloid leukemia, and systemic lupus erythematosus [11, 12]. The exact mechanism has not been elucidated; however, the presence of antithrombopoietin IgG antibodies in patients with AAT suggests a dysregulated humoral immunity [13].…”

Amegakaryocytic Thrombocytopenia and Subsequent Aplastic Anemia Associated with Apparent Epstein-Barr Virus Infection

“…Biological therapies, e.g., rituximab or recombinant interleukin-11, were used in a few cases [2,21], while attempts to stimulate thrombopoiesis with TPO receptor agonists have also been reported [1,4,5,18]. Finally, bone marrow transplantation, which is the treatment of choice in congenital amegakaryocytic thrombocytopenia, has also been performed in a few cases with the acquired form [1,2,4].…”