Safety of stringent prophylactic platelet transfusion policy for patients with acute leukaemia

Thrombocytopenia. Issues in diagnosis and therapy

Thrombocytopenia is defined by clinical characteristics and pathophysiologic mechanisms. The patient with thrombocytopenia often presents diagnostic and management challenges simultaneously. The differential diagnosis is broad because the disorders leading to thrombocytopenia are diverse, with failed production at one extreme and accelerated destruction at the other. Reviewed in terms of diagnosis and therapy are pseudothrombocytopenia, dilutional thrombocytopenia, and the three major mechanisms: decreased production, altered distribution, and increased destruction.

Factors associated with transfusion requirements during treatment for acute myelogenous leukemia

Supportive care is a prerequisite for intensive chemotherapy in leukemic patients. Little has been published about quantitative aspects of red blood cell and platelet transfusions. We evaluated transfusion requirements and factors associated with observed differences in 206 patients undergoing initial induction consolidation chemotherapy for newly diagnosed acute myelogenous leukemia. All patients were treated during a 5-year period in 12 hospitals on a common protocol of the Swiss Study Group for Clinical Cancer Research (SAKK). Protocol 30/85 comprises a double induction and one course of consolidation. Of 206 registered patients, 199 were evaluable; 118 of 199 (59%) patients entered completed all three cycles of chemotherapy. These 118 patients received a median (range) of 18 (3-44) units of red blood cells and 12 (2-61) platelet transfusions during 112 (70-129) days of hospitalization. Patients with a hemoglobin > 10 g/l, platelets > 100 x 10(9)/l, and white blood cell counts < 5 x 10(9)/l at diagnosis received fewer transfusions than patients with less favorable blood counts during the first cycle of chemotherapy (p < 0.05). Patients with FAB subtype M3 received more platelet transfusions during the first cycle. Female patients received more platelet transfusions than male patients. In multivariate analyses the participating center was the most important single factor associated with the number of red cell and platelet concentrates given per patient and cycle (p < 0.05), the number of days in hospital (p < 0.05), and the risk of premature withdrawal from the study. These data define factors associated with transfusion requirements in patients treated for newly diagnosed AML. They include severity and subtype of disease at diagnosis, age and sex of the patients, and the participating institution. Results suggest that medical decision-making varies from center to center. The participating institution is strongly associated with differences in transfusion requirements, hospitalization time, and premature withdrawal from study. Leukemia trials tend to focus on the prospective evaluation of chemotherapy or growth factors. Our results suggest that other variables, such as management strategies, should be included for prospective analysis.

The Role of Hemapheresis Technology in Allogeneic Bone Marrow Transplantation

In this paper the impact of hemapheresis technology on 238 allogeneic bone marrow transplants performed in Pescara from 1982 through 1993 is described. Granulocyte transfusions were limited to patients with neutrophil level <0.2x109/L. An average of 4 units of packed red blood cells were required to maintain adequate hemoglobin levels. Patients with major ABO incompatibility showed an increased requirement of red blood cell support as compared to patients ABO-matched and ABO minor mismatched. For platelet support single-donor platelets collected on a blood-cell separator were given. A total of 1548 platelet transfusions were examined. The median number of platelet transfusions for each patient was 5. Platelet refractoriness occurred in 44% of patients. The hemorrhage related mortality was 0.9%.

The advancement made in the field of hemapheresis technology, as well as the improved transplant technique, have contributed to increase the post-transplant survival from 17% in the early experience (1976-1982) to 88% in the recent years (1992-1993).

Guidelines for platelet transfusions. British Committee for Standards in Haematology, Working Party of the Blood Transfusion Task Force

Recommendations for the optimal transfusion support of patients likely to receive repeated platelet transfusions. 1. Determine policy for prophylactic platelet support, and select the platelet count below which platelet transfusions will be used. 2. Consider using leucocyte depletion of red cell and platelet concentrates to prevent HLA alloimmunization from the outset. 3. Type patients for HLA-A and B antigens at an early stage. 4. Use random donor platelet concentrates for initial platelet support (either single or multiple donor, depending on availability). 5. If refractoriness occurs, determine whether clinical factors, which may be associated with non-immune consumption of platelets, are present and test the patient's serum for HLA antibodies. 6. Use HLA-matched platelet transfusions if HLA alloimmunization is the most likely cause of refractoriness. 7. If there is no improvement with HLA-matched transfusions, platelet crossmatching may identify the cause of the problem and help with the selection of compatible donors. 8. Discontinue prophylactic platelet support if a compatible donor cannot be found. Use platelet transfusions from random donors to control bleeding and increase the dose, if necessary.

Blood transfusion in marrow graft recipients

Of 182 consecutive patients undergoing allogeneic bone marrow transplantation (BMT), the relative numbers of those who received red blood cells (RBC), platelets (PLT), and granulocytes were 82%, 96%, and 26%, respectively. The transfused patients received an average of 1.26 (SD +/- 2.0) RBC units, 9.41 (SD +/- 13.2) PLT transfusions, and 0.33 (SD +/- 1.1) granulocyte concentrates per week per 50 kg body wt. in the period starting on the day of bone marrow transplantation (BMT) up to 60 days post BMT. The total number of units per transfused patient was 7.7 (range 1-63) RBC, 55.2 (range 2-394) PLT and 6.2 (range 1-36) granulocytes in the same period. Patients with grades II-IV acute graft-versus-host disease (GVHD) needed more RBC and PLT (p less than 0.001) than patients with grades 0-I acute GVHD. Patients with late engraftment required more granulocyte and PLT transfusion than those with early engraftment (p less than 0.05). Patients with high-risk malignancy had greater need for RBC and PLT than "low-risk patients" (p less than 0.02 and p less than 0.01), respectively). Patients with major ABO-incompatible donors showed a greater need for RBC than patients with minor ABO incompatibility (p = 0.02) or ABO identical donors (p = 0.01). Patients with relatively poor estimated survival required the most RBC and PLT.