Transfusion and bone marrow transplantation

Prevalence of risk factors for platelet transfusion refractoriness in multitransfused hemato-oncological patients at tertiary care center in North India

Background:

This study was designed to determine the prevalence and assess the risk factors responsible for platelet transfusion refractoriness in hemato-oncological patients.

Materials and Methods:

The study included 30 patients. Twelve were clinically diagnosed as aplastic anemia and the 18 were of acute myeloid leukemia. A prospective 3 months follow-up was planned to monitor the response of platelet transfusion therapy, based on their posttransfusion corrected count increment at 1^st and 24^th h. Based on the observations, patients were categorized into refractory and nonrefractory groups. Common nonimmunological causes such as fever, sepsis, bleeding, disseminated intravascular coagulation, chemotherapy, splenomegaly, ABO mismatch, and antithymocyte globulin therapy were monitored. Among the immunological causes, presence of antihuman leukocyte antigen (HLA) class I antibodies and platelet glycoprotein antibodies in patient's serum were monitored.

Results:

During the study period, 17 (56.66%) patients did not show desired platelet count increment. Transfusion requirements of refractory group for both red cell and platelet product were significantly higher (P < 0.05) in comparison to nonrefractory group. Among immunological causes, anti HLA class I antibodies (P < 0.013), antihuman platelet antigen-5b antibodies (P < 0.033) were significantly associated with refractoriness. Among nonimmunological causes, bleeding (P < 0.019, odd ratio 8.7), fever (P < 0.08, odd ratio 5.2), and infection (P < 0.07, odd ratio 5.4) were found to associated with refractoriness.

Conclusion:

Platelet refractoriness should be suspected in multitransfused patients not showing expected increment in platelet counts and thoroughly investigated to frame further guidelines in order to ensure proper management of these kind of patients.

Epsilon aminocaproic acid reduces transfusion requirements in patients with thrombocytopenic hemorrhage

BACKGROUND

Epsilon aminocaproic acid (EACA) is an antifibrinolytic drug that has been used to control hemorrhage by stabilizing the thrombus. It has been used in thrombocytopenic patients largely on an empiric basis.

METHODS

Concerns regarding side effects have limited the use of this drug. The authors reviewed their experience with EACA at the Cleveland Clinic Foundation from 1997 to 2003.

RESULTS

Of 77 patients with thrombocytopenic hemorrhage, 51 (66%) patients achieved a complete response and 13 (17%) patients achieved a partial response, resulting in a decrease in platelet and red blood cell transfusions. Adverse effects were manageable in this set of patients with severe underlying disease.

CONCLUSIONS

Based on this experience, EACA may be a valuable adjunctive therapy in the treatment of patients with thrombocytopenic hemorrhage.

The availability of full match sibling donors and feasibility of allogeneic bone marrow transplantation in Brazil

The feasibility of allogeneic bone marrow transplantation (alloBMT) in a developing country has not yet been demonstrated. Many adverse factors including social and economic limitations may reduce the overall results of this complex and expensive procedure. Our objective was to characterize the most important clinical, social and economic features of candidates for transplantation and their potential donors as well as the influence of these factors on overall survival in a retrospective and exploratory analysis at a university hospital. From July 1993 to July 2001, candidates for BMT were referred to the Bone Marrow Transplantation Unit by Hematology and Oncology Centers from several regions of Brazil. A total of 1138 patients were referred to us as candidates for alloBMT. Median age was 25 years (range: 2 months-60 years), 684 (60.1%) were males and 454 (39.9%) were females. The clinical indications were severe aplastic anemia and hematological malignancies. From the total of 1138 patients, 923 had HLA-typing; 497/923 (53.8%) candidates had full match donors; 352/1138 (30.8%) were eligible for alloBMT. Only 235 of 352 (66.7%) were transplanted. Schooling was 1st to 8th grade for 123/235 (52.3%); monthly family income ranged from US$60 (7%) to more than US$400 (36%). Overall survival for patients with chronic myeloid leukemia, severe aplastic anemia and acute myeloid leukemia was 58, 60 and 30%, respectively. Thus, overall survival rates for the most frequent hematological diseases were similar to those reported in the International Registry, except for acute myeloid leukemia. This descriptive and exploratory analysis suggests the feasibility of alloBMT in a developing country like Brazil.

Bleeding risk and platelet transfusion refractoriness in patients with acute myelogenous leukemia who undergo autologous stem cell transplantation

Therapy for acute myelogenous leukemia can be complicated by alloimmunization to histocompatibility antigens (HLA), with resultant refractoriness to platelet transfusions. Autologous peripheral blood or bone marrow stem cell transplantation (referred here collectively as 'autoBMT') is emerging as a standard consolidative strategy in acute myelogenous leukemia (AML). We had noted life-threatening bleeding associated with platelet transfusion refractoriness following autoBMT; we therefore retrospectively analyzed 39 AML patients for this complication following BMT. All patients received high-dose chemoradiotherapy, followed by infusion of allogeneic sibling donor (n = 12, alloBMT) or autologous (n = 27, autoBMT) stem cells. HLA alloimmunization was assessed if patients were suspected of immune refractoriness to random donor platelet transfusions. Within 100 days of stem cell infusion, one of three alloBMT and six of 12 autoBMT recipients tested were HLA alloimmunized (not statistically significant, NS). Five of six HLA alloimmunized autoBMT patients experienced delayed bleeding, which contributed to their demise while still in remission (P < 0.001). Increased platelet requirements in HLA alloimmunized autoBMT recipients were observed between days 61 and 100 post-BMT, at a median of 211 platelet transfusions vs 0 in non-alloimmunized autoBMT patients (P < 0.01) and 17 in alloBMT patients. Our data suggest that platelet transfusion refractoriness, when associated with HLA alloimmunization, is a risk factor for increased platelet transfusion requirements, delayed bleeding, and poor outcome following autoBMT for AML.

Relative importance of immune and non-immune causes of platelet refractoriness

In this prospective study, 26 consecutive patients being treated for haematological malignancies receiving standard (i.e. non-leucocyte-depleted) blood components were observed for the development of refractoriness to platelet transfusions. One hundred and sixteen of the 266 (44%) platelet transfusions failed to produce a satisfactory response. In 102/116 (88%), the poor response was in the presence of non-immune factors known to be associated with platelet refractoriness. Non-immune factors were present alone in 78/116 (67%), and in combination with immune factors in a further 24/116 (21%). Immune factors (HLA and platelet-specific antibodies) were present during 29/116 (25%) of unsuccessful platelet transfusions. Statistical analysis confirmed that platelet refractoriness was significantly associated with the presence of non-immune factors. The non-immune factors associated with refractoriness were often multiple, most frequently a combination of fever, infection and antibiotic therapy. This study provides evidence that immune mechanisms were not the predominant cause of platelet refractoriness in the patient population studied. It also suggests that measures for the prevention of HLA alloimmunisation, such as leucocyte depletion, may have a limited impact in reducing the incidence of refractoriness to platelet transfusions.

Leukodepleted blood components

The use of leukodepleted blood components may reduce some adverse effects of transfusion in certain clinical situations. This review outlines the recognised effects of contaminating passenger leucocytes, the value of leukodepleted components in preventing some of these complications, methods of leukodepletion and the current recommendations for use of these components.