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

Thrombopoietic factors potentially useful in the treatment of acute leukemia

Thrombocytopenia is a major cause of morbidity following intensive chemotherapy for acute leukemia. Over recent years, there has been an increasing use of platelet transfusions which, although generally efficacious to prevent severe hemorrhage, have associated risks of transmitting blood-borne disease and of alloimmunization. Therefore, there is a clinical requirement for a drug that will reliably alleviate the thrombocytopenia associated with leukemia therapy. The c-mpl ligand thrombopoietin is the most interesting factor for the treatment of thrombocytopenia because of its lineage specificity. Phase I and II studies confirm its biological efficacy to induce rise in platelet count in patients with solid tumors and acute leukemia. Several other pleiotropic hematopoietic growth factors are also currently in clinical trials. These include interleukin-6, interleukin-3, interleukin-11, PIXY321 and stem cell factor. The effects of these cytokines appear to be modest at most and, with the exception of interleukin-11, their side effects are likely to limit their clinical application. Combinations of factors may prove more efficacious approaches to enhance platelet recovery.

Preparations of synthetic phospholipids promote procoagulant activity on damaged vessels: studies under flow conditions

BACKGROUND

The possibility of developing synthetic platelet substitutes that could promote hemostasis with prolonged shelf-life and increased safety is an appealing one.

STUDY DESIGN AND METHODS

Preparations containing synthetic phospholipids were incorporated into blood samples (1.15 mg/mL) in which platelets and white cell counts had been experimentally reduced by a filtration procedure. Vesicles containing phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), phosphatidylinositol (PI), or combinations of PC and PE and of PC and PS were tested in this system. Blood was recirculated (10 min; shear rate, 250/sec) through a perfusion chamber containing vascular segments. The ability of the various phospholipid preparations to promote fibrin formation on the damaged subendothelium was evaluated morphometrically and expressed as the percentage of fibrin coverage. Generation of thrombin in the system was monitored through the measurement of prothrombin fragments 1 and 2.

RESULTS

Vesicles containing PC, PI, PE:PC (1:1), or PS:PC (1:3) increased fibrin deposition on the subendothelium (64.5 +/- 9.8%, 32.7 +/- 6.3%, 58.3 +/- 6.5%, and 46.6 +/- 15.2%, respectively; p < 0.01 vs. 11.5 +/- 1.2% in thrombocytopenic blood). Vesicles containing PE, PS, or PS:PC (3:1) did not show procoagulant effect.

CONCLUSION

Synthetic phospholipid preparations promote a local procoagulant activity at sites of vascular damage when they are incorporated into thrombocytopenic blood maintained under flow conditions.

Insulin-like growth factor-1 (IGF-1) has a costimulatory effect on proliferation of committed progenitors derived from human umbilical cord CD34+ cells

The effects of insulin-like growth factor-1 (IGF-1) on highly enriched human umbilical cord CD34+ cells were investigated in vitro. CD34+ cells were cultured in serum-free medium containing stem cell factor (SCF), GM-CSF, and interleukin-3 (IL-3). Culture of CD34+ cells for one week in the presence of these cytokines resulted in a dose-dependent increase in total cell number. Addition of G-CSF together with SCF+IL-3+GM-CSF increased the proliferation of myelopoietic cells as determined by the number of cells expressing the myelomonocytic marker CD64 and the granulocytic marker CD15 without significantly altering the number of CD34+ cells in the cultures. In the presence of G-CSF, IGF-1 induced a dose-dependent increase in the total cell number and a moderate but significant increase in the percentages of CD15+, CD64+ cells with sustained CD34+ cell proliferation. We conclude that IGF-1 can enhance the in vitro proliferation of committed progenitor cells derived from umbilical cord CD34+ cells.

A Risk Model for Thrombocytopenia Requiring Platelet Transfusion After Cytotoxic Chemotherapy

Severe thrombocytopenia is a rare but life-threatening side effect of cytotoxic chemotherapy for which risk factors are not well known. Our objective was to delineate a risk model for chemotherapy-induced thrombocytopenia requiring platelet transfusions in cancer patients. Univariate and multivariate analysis of risk factors for chemotherapy-induced thrombocytopenia requiring platelet transfusions were performed on the cohort of the 1,051 patients (CLB 1996) treated with chemotherapy in the Department of Medicine of the Centre Léon Bérard (CLB) in 1996. In univariate analysis, performance status (PS) greater than 1, platelet count less than 150,000/μL at day 1 (d1) before the initiation of chemotherapy, d1 lymphocyte count ≤700/μL, d1 polymorphonuclear leukocyte count less than 1,500/μL, and the type of chemotherapy (high risk v others) were significantly associated (P < .01) with an increased risk of severe thrombocytopenia requiring platelet transfusions. Using logistic regression, d1 platelet count less than 150,000/μL (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.9 to 9.6), d1 lymphocyte counts ≤700/μL (OR, 3.37; 95% CI, 1.77 to 6.4), the type of chemotherapy (OR, 3.38; 95% CI, 1.77 to 6.4), and PS greater than 1 (OR, 2.23; 95% CI, 1.22 to 4.1) were identified as independent risk factors for platelet transfusions. The observed incidences of platelet transfusions were 45%, 13%, 7%, and 1.5% for patients with ≥3, 2, 1, or 0 risk factors, respectively. This model was then tested in 3 groups of patients treated with chemotherapy used as validation samples: (1) the series of 340 patients treated in the CLB in the first 6 months of 1997, (2) the prospective multicentric cohort of 321 patients of the ELYPSE 1 study, and (3) the series of 149 patients with non-Hodgkin's lymphoma treated in the CLB within prospective phase III trials (1987 to 1995). In these 3 groups, the observed incidences of platelet transfusions in the above-defined risk groups did not differ significantly (P > .1) from those calculated in the model. This risk index could be useful to identify patients at high risk for chemotherapy-induced thrombocytopenia requiring platelet transfusions.

A Risk Model for Thrombocytopenia Requiring Platelet Transfusion After Cytotoxic Chemotherapy

Severe thrombocytopenia is a rare but life-threatening side effect of cytotoxic chemotherapy for which risk factors are not well known. Our objective was to delineate a risk model for chemotherapy-induced thrombocytopenia requiring platelet transfusions in cancer patients. Univariate and multivariate analysis of risk factors for chemotherapy-induced thrombocytopenia requiring platelet transfusions were performed on the cohort of the 1,051 patients (CLB 1996) treated with chemotherapy in the Department of Medicine of the Centre Léon Bérard (CLB) in 1996. In univariate analysis, performance status (PS) greater than 1, platelet count less than 150,000/μL at day 1 (d1) before the initiation of chemotherapy, d1 lymphocyte count ≤700/μL, d1 polymorphonuclear leukocyte count less than 1,500/μL, and the type of chemotherapy (high risk v others) were significantly associated (P &lt; .01) with an increased risk of severe thrombocytopenia requiring platelet transfusions. Using logistic regression, d1 platelet count less than 150,000/μL (odds ratio [OR], 4.3; 95% confidence interval [CI], 1.9 to 9.6), d1 lymphocyte counts ≤700/μL (OR, 3.37; 95% CI, 1.77 to 6.4), the type of chemotherapy (OR, 3.38; 95% CI, 1.77 to 6.4), and PS greater than 1 (OR, 2.23; 95% CI, 1.22 to 4.1) were identified as independent risk factors for platelet transfusions. The observed incidences of platelet transfusions were 45%, 13%, 7%, and 1.5% for patients with ≥3, 2, 1, or 0 risk factors, respectively. This model was then tested in 3 groups of patients treated with chemotherapy used as validation samples: (1) the series of 340 patients treated in the CLB in the first 6 months of 1997, (2) the prospective multicentric cohort of 321 patients of the ELYPSE 1 study, and (3) the series of 149 patients with non-Hodgkin's lymphoma treated in the CLB within prospective phase III trials (1987 to 1995). In these 3 groups, the observed incidences of platelet transfusions in the above-defined risk groups did not differ significantly (P &gt; .1) from those calculated in the model. This risk index could be useful to identify patients at high risk for chemotherapy-induced thrombocytopenia requiring platelet transfusions.

Safety and Cost Effectiveness of a 10 × 109/L Trigger for Prophylactic Platelet Transfusions Compared With the Traditional 20 × 109/L Trigger: A Prospective Comparative Trial in 105 Patients With Acute Myeloid Leukemia

In 105 consecutive patients with de novo acute myeloid leukemia (French-American-British M3 excluded), we compared prospectively the risk of bleeding complications, the number of platelet and red blood cell transfusions administered, and the costs of transfusions using two different prophylactic platelet transfusion protocols. Two hundred sixteen cycles of induction or consolidation chemotherapy and 3,843 days of thrombocytopenia less than 25 × 109/L were evaluated. At the start of the study, each of the 17 participating centers decided whether they would use a 10 × 109/L prophylactic platelet transfusion trigger (group A/8 centers) or a 20 × 109/L trigger (group B/9 centers). Bleeding complications (World Health Organization grade 2-4) during treatment cycles were comparable in the two groups: 20 of 110 (18%) in group A and 18 of 106 (17%) in group B (P = .8). Serious bleeding events (grade 3-4) were generally not related to the patient's platelet count but were the consequence of local lesions and plasma coagulation factor deficiencies due to sepsis. Eighty-six percent of the serious bleeding episodes occurred during induction chemotherapy. No patient died of a bleeding complication. There were no significant differences in the number of red blood cell transfusions administered between the two groups, but there were significant differences in the number of platelet transfusions administered per treatment cycle: pooled random donor platelet concentrates averaged 15.4 versus 25.4 (P < .01) and apheresis platelets averaged 3.0 versus 4.8 (P < .05) for group A versus group B, respectively. This resulted in the cost of platelet therapy being one third lower in group A compared with group B without any associated increase in bleeding risk.

Safety and Cost Effectiveness of a 10 × 109/L Trigger for Prophylactic Platelet Transfusions Compared With the Traditional 20 × 109/L Trigger: A Prospective Comparative Trial in 105 Patients With Acute Myeloid Leukemia

In 105 consecutive patients with de novo acute myeloid leukemia (French-American-British M3 excluded), we compared prospectively the risk of bleeding complications, the number of platelet and red blood cell transfusions administered, and the costs of transfusions using two different prophylactic platelet transfusion protocols. Two hundred sixteen cycles of induction or consolidation chemotherapy and 3,843 days of thrombocytopenia less than 25 × 109/L were evaluated. At the start of the study, each of the 17 participating centers decided whether they would use a 10 × 109/L prophylactic platelet transfusion trigger (group A/8 centers) or a 20 × 109/L trigger (group B/9 centers). Bleeding complications (World Health Organization grade 2-4) during treatment cycles were comparable in the two groups: 20 of 110 (18%) in group A and 18 of 106 (17%) in group B (P = .8). Serious bleeding events (grade 3-4) were generally not related to the patient's platelet count but were the consequence of local lesions and plasma coagulation factor deficiencies due to sepsis. Eighty-six percent of the serious bleeding episodes occurred during induction chemotherapy. No patient died of a bleeding complication. There were no significant differences in the number of red blood cell transfusions administered between the two groups, but there were significant differences in the number of platelet transfusions administered per treatment cycle: pooled random donor platelet concentrates averaged 15.4 versus 25.4 (P < .01) and apheresis platelets averaged 3.0 versus 4.8 (P < .05) for group A versus group B, respectively. This resulted in the cost of platelet therapy being one third lower in group A compared with group B without any associated increase in bleeding risk.

Cone and platelet analyser (CPA): a new test for the prediction of bleeding among thrombocytopenic patients

The risk of bleeding among thrombocytopenic patients was evaluated using our new cone and platelet analyser (CPA) test. Using this test, adherence of platelets was quantitated on extracellular matrix and expressed as percent of surface coverage (SC) and the average size (AS) of aggregates. 42 thrombocytopenic patients with ITP (n=23), post chemotherapy (n= 12) and others (n= 7) were tested over a total of 82 visits. On each visit, complete blood count and CPA tests were performed and patients were evaluated for evidence of bleeding (found in 40 visits). Bleeding patients had significantly lower platelet counts (27.4 +/- 22.0 v 47.1 +/- 21.0 x 10(9)/l), lower haematocrit values (30.2 +/- 8.1 v 35.2 +/- 6.6%), lower MPV (6.83 +/-1.89 v 8.98 +/- 1.13 fl), and lower SC (4.87 +/- 3.95 v 10.33 +/-5.48%) and AS (33.99 +/- 14.94 v 52.9 +/- 24.34 microm2). Univariate analysis yielded platelet count < or =20.0 x 10(9)/l, MPV < or =8 fl, haematocrit <35%, SC <5%, AS< or =40 microm2 as significantly associated with bleeding, whereas only MPV and SC were associated with bleeding (OR 6.95, CI 2.25-21.46 and OR 4.27, CI 1.29-14.16, respectively) by multivariate analysis. When taken together, 21/22 of patients (95%) with both low SC (<5%) and low MPV (<8.0 fl) had bleeding symptoms, whereas only 9/43 (21%) patients with both these parameters above these values experienced bleeding symptoms. We conclude that the CPA test and the parameter SC (<5%) together with MPV (< or =8 fl) might be used as independent predictors of bleeding in the management of thrombocytopenic patients.

Transfusion Therapy with Platelet Concentrates

At the end of 1960, the concept that platelet transfusion could reduce the death rate due to hemorrhage was confirmed by the reduction of life-threatening bleeding and prolonged survival in thrombocytopenic patients affected with acute leukemia and aplastic anemia. Thrombocytopenia is the result of an imbalance between platelet production and destruction: usually no bleeding problem will occur until circulating platelets fall below 20000/μl and even a platelet count of 5000/μl may be present in many patients without bleeding. Because of the high risk of alloimmunization in multiply transfused thrombocytopenic patients with random platelet concentrates, the main dilemma is the choice of strategy: “prophylactic”versus “therapeutic” treatment with platelet concentrates of cancer patients and the platelet count selected as the “transfusion trigger” for platelet support in patients without active bleeding. We describe our experience of 367 retrospective non-randomized leukemic patients transfused with platelet concentrates. A total of 225 patients (61.3%) received support therapy: the transfusions were administered prophylactically at a platelet count below 20000/μl in the group of patients with acute lymphoblastic leukemia (35% transfused) and acute myeloblastic leukemia (78% transfused). Only14 hemorrhagic episodes were observed in 148 patients receiving prophylactic platelets (9%), while 21 severe hemorrhages (27%) were documented in patients treated with therapeutic platelet concentrates. Several studies have concluded that maintaining the platelet count above 20000/μl was not justified in the majority of cancer patients. In the absence of more definitive data, a “transfusion trigger” of 10000/μl is selected for platelet transfusion support in leukemic non-bleeding patients receiving chemotherapy.

A Multicenter Study of Platelet Recovery and Utilization in Patients After Myeloablative Therapy and Hematopoietic Stem Cell Transplantation

An observational study was conducted at 18 transplant centers in the United States and Canada to characterize the platelet recovery of patients receiving myeloablative therapy and stem cell transplantation and to determine the clinical variables influencing recovery, determine platelet utilization and cost, and incidence of hemorrhagic events. The study included 789 evaluable patients transplanted in 1995. Clinical, laboratory, and outcome data were obtained from the medical records. Variables associated with accelerated recovery in multivariate models included (1) higher CD34 count; (2) higher platelet count at the start of myeloablative therapy; (3) graft from an HLA-identical sibling donor; and (4) prior stem cell transplant. Variables associated with delayed recovery were (1) prior radiation therapy; (2) posttransplant fever; (3) hepatic veno-occlusive disease; and (4) use of posttransplant growth factors. Disease type also influenced recovery. Recipients of peripheral blood stem cells (PBSC) had faster recovery and fewer platelet transfusion days than recipients of bone marrow (BM). The estimated average 60-day platelet transfusion cost per patient was $4,000 for autologous PBSC and $11,000 for allogeneic BM transplants. It was found that 11% of all patients had a significant hemorrhagic event during the first 60 days posttransplant, contributing to death in 2% of patients. In conclusion, clinical variables influencing platelet recovery should be considered in the design and interpretation of clinical strategies to accelerate recovery. Enhancing platelet recovery is not likely to have a significant impact on 60-day mortality but could significantly decrease health care costs and potentially improve patient quality of life.

Plateletapheresis with the New Baxter-Amicus Blood Cell Separator: An Italian Multicenter Study

The efficiency and quality of platelet (PLT) collection were evaluated in a preliminary study using a new cell separator: Baxter-Amicus. The new fully automated blood cell separator combines centrifugation with elutration to obtain higher PLT efficiency with a lower white blood cell (WBC) contamination. We compared procedures performed with the first software version 2.13 and the more recent 2.37 version, then with and without plasma collection. Data from 262 plateletapheresis procedures were analyzed. The mean value of the PLT yield was 4.5±1.0x1011, collection efficiency: 69.4±12%; WBC contamination: 0.8±2.x106; and procedure time: 73± 19 minutes. The use of the new software vs the former permitted the collection of a higher number of platelets: 4.9± 1.1 vs. 4.5± 1.9 x1011 (=ns), with a lower WBC contamination: 0.6± 1.0 vs 0.7± 1.2 x106 (p=ns), in less time: 63± 10 vs 73± 19 minutes (p=0.002). The efficiency of platelet harvesting with simultaneous plasma collection was higher than the standard procedure: 73± 13 vs. 67± 10% (p=0.003).

A Multicenter Study of Platelet Recovery and Utilization in Patients After Myeloablative Therapy and Hematopoietic Stem Cell Transplantation

An observational study was conducted at 18 transplant centers in the United States and Canada to characterize the platelet recovery of patients receiving myeloablative therapy and stem cell transplantation and to determine the clinical variables influencing recovery, determine platelet utilization and cost, and incidence of hemorrhagic events. The study included 789 evaluable patients transplanted in 1995. Clinical, laboratory, and outcome data were obtained from the medical records. Variables associated with accelerated recovery in multivariate models included (1) higher CD34 count; (2) higher platelet count at the start of myeloablative therapy; (3) graft from an HLA-identical sibling donor; and (4) prior stem cell transplant. Variables associated with delayed recovery were (1) prior radiation therapy; (2) posttransplant fever; (3) hepatic veno-occlusive disease; and (4) use of posttransplant growth factors. Disease type also influenced recovery. Recipients of peripheral blood stem cells (PBSC) had faster recovery and fewer platelet transfusion days than recipients of bone marrow (BM). The estimated average 60-day platelet transfusion cost per patient was $4,000 for autologous PBSC and $11,000 for allogeneic BM transplants. It was found that 11% of all patients had a significant hemorrhagic event during the first 60 days posttransplant, contributing to death in 2% of patients. In conclusion, clinical variables influencing platelet recovery should be considered in the design and interpretation of clinical strategies to accelerate recovery. Enhancing platelet recovery is not likely to have a significant impact on 60-day mortality but could significantly decrease health care costs and potentially improve patient quality of life.

Acute Bleeding After Bone Marrow Transplantation (BMT)— Incidence and Effect on Survival. A Quantitative Analysis in 1,402 Patients

Acute bleeding after bone marrow transplantation (BMT) was investigated in 1,402 patients receiving transplants at Johns Hopkins Hospital between January 1, 1986 and June 30, 1995. Bleeding categorization was based on daily scores of intensity used by the blood transfusion service. Moderate and severe episodes were analyzed for bleeding sites. Analysis of the cause of death and the interval of the bleeding episode to outcome endpoints was recorded. Survival estimates were computed for 1,353 BMT patients. The overall incidence was 34%. Minor bleeding was seen in 10.6%, moderate bleeding was seen in 11.3%, and severe bleeding was seen in 12% of all patients. Fourteen percent of patients had moderate or severe gastrointestinal hemorrhage, 6.4% had moderate or severe hemorrhagic cystitis, 2.8% had pulmonary hemorrhage, and 2% had intracranial hemorrhage. Sixty-one percent had 1 bleeding site and 34.4% had more than 1 site. Moderate and severe bleeding was more prevalent in allogeneic (31%) and unrelated patients (62.5%) compared with autologous patients (18.5%). Significant distribution of incidence was found among the different diagnoses, but not by disease status in acute myeloid leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, Hodgkin's disease, and non-Hodgkin's lymphoma. Bleeding was associated with significantly reduced survival in allogeneic, autologous, and unrelated BMT and in each disease category except multiple myeloma. Survival was correlated with the bleeding intensity, bleeding site, and the number of sites. Although close temporal association was evident to mortality, bleeding was recorded as the cause of death in only the minority of cases compared with other toxicities after BMT (graft-versus-host disease, infections, and preparative regimen toxicity). Acute bleeding is a common complication after BMT that is profoundly associated with morbidity and mortality. Although bleeding was not a direct cause of death in the majority of cases, it has a potential prognostic implication as a predictor of poor outcome in clinical assessment of patients after BMT.

Thrombocytopenia-Platelet Support or Growth Factors?

The prevention and treatment of hemorrhage in patients with severe thrombocytopenia following cytotoxic chemotherapy and/or radiotherapy remain important issues in the supportive care of these patients. Platelet transfusions have been available for this purpose for over 30 years, and there have been recent initiatives to refine the way in which they are used and to improve their safety. An alternative to platelet transfusions is the enhancement of platelet recovery through the use of hemopoietic growth factors, and the recent identification of thrombopoietin and its potential for clinical use are exciting developments. Further work is needed to ensure its safety, and to define the appropriate indications for its use. Another alternative to platelet transfusions is the use of platelet substitutes, and a number of products are being developed. The clinical use of hemopoietic growth factors and platelet substitutes raises the prospect of reducing the current high demand for platelet concentrates. However, it remains to be seen whether their potential will be fully realised, and platelet transfusions will continue to be needed for the forseeable future.

The threshold for prophylactic platelet transfusions in adults with acute myeloid leukemia. Gruppo Italiano Malattie Ematologiche Maligne dell'Adulto

BACKGROUND

Prophylactic platelet transfusions are usually administered to patients receiving myelotoxic chemotherapy when their platelet count falls below 20,000 per cubic millimeter. Some observations suggest that lower platelet counts can be appropriate in patients in stable condition, but the safety of lower thresholds is uncertain.

METHODS

We evaluated 255 adolescents and adults (age, 16 to 70 years) with newly diagnosed acute myeloid leukemia (but not acute promyelocytic leukemia), who were treated in 21 centers. One hundred thirty-five patients were randomly assigned to receive a transfusion when their platelet count fell below 10,000 per cubic millimeter (or 10,000 to 20,000 per cubic millimeter in those with a temperature above 38 degrees C, with active bleeding, or a need for invasive procedures), and 120 patients were assigned to receive a transfusion when their platelet count was less than 20,000 per cubic millimeter.

RESULTS

Patients in the group with a threshold of 10,000 platelets per cubic millimeter received 21.5 percent fewer platelet transfusions than the patients in the group with a threshold of 20,000 platelets per cubic millimeter (P=0.001). The numbers of red-cell units transfused were not significantly different between groups. Major bleeding (defined as any bleeding more than petechiae or mucosal or retinal bleeding) occurred in 21.5 and 20 percent of patients, respectively (P=0.41), and on 3.1 and 2.0 percent of the days of hospitalization. One episode of fatal cerebral hemorrhage occurred in the group with a threshold of 10,000 platelets per cubic millimeter; none occurred in the other group (P= 0.95). Actuarial estimates of survival during induction chemotherapy, actuarial estimates of the absence of major bleeding, and the length of hospital stay were not significantly different in the two groups.

CONCLUSIONS

The risk of major bleeding during induction chemotherapy in adolescents and adults with acute myeloid leukemia (except acute promyelocytic leukemia, which we did not study) was similar with platelet-transfusion thresholds of 20,000 per cubic millimeter and 10,000 per cubic millimeter (or 10,000 to 20,000 per cubic millimeter when body temperature exceeded 38 degrees C, there was active bleeding, or invasive procedures were needed). Use of the lower threshold reduced platelet use by 21.5 percent.

When less is more: cost-containment in transfusion medicine

The drive to contain the rising cost of medical care provides numerous challenges to blood bankers. Not the least of these is the opportunity to improve quality of care while reducing the cost thereof. This paper explores various cost-reduction strategies, focusing primarily on those applicable to small and medium-sized transfusion services, and demonstrates methods by which they can be implemented to yield improved patient care.

Audit of practice in platelet refractoriness

OBJECTIVES

A significant number of patients become refractory to platelet transfusion and prompt investigation of the cause will encourage appropriate selection of platelet products.

METHODS

We surveyed haematologists to assess perceived practice concerning platelet refractoriness because of the high cost and limited availability of HLA-compatible platelets. Some 56 of 58 consultant haematologists participated.

RESULTS

Clinicians differed on their definition of platelet refractoriness, and non-immune factors were not considered as important as immune causes of platelet refractoriness. A working group, including an invited moderator, was established to produce guidelines on recommended practice for the management of platelet refractoriness. Re-audit after implementation of the guidelines showed that more patients receiving HLA-compatible platelets had been tested for HLA antibodies. There was a mean 50.9% reduction in the use of HLA-compatible platelets.

CONCLUSIONS

Increased testing for leucocyte and platelet antibodies resulted in reduced demand for and more selective use of HLA-compatible platelets, with no apparent increase in haemorrhagic complications.

Clinician's overview of platelet support

In a period of 2 years, 48 patients over age 55 were treated for acute myeloblastic leukaemia or myelodysplastic syndrome with greater than 10% blasts. 15 patients were treated with intestine chemotherapy, requiring a mean of 48 units of platelets per course. 33 patients were treated by supportive care alone of whom 19 required a mean of 380 units of platelets each. Long term supportive care is a feasible option in elderly leukaemia. Because of dysplasia some patients bleed at a higher threshold than younger patients. A further hazard is the use of i.v. hydrocortisone to suppress transfusion reactions. Such unintentional use of steroids in patients with dysplastic neutrophils and monocytes may predispose to fungal infections.

Index of pretreatment intensity predicts outcome of high-dose chemotherapy and autologous progenitor cell transplantation in chemosensitive relapse of Hodgkin's disease

PURPOSE

To identify prognostic factors in patients with chemosensitive relapsed Hodgkin's disease treated by high-dose chemotherapy with autologous progenitor cell transplantation (HDC) and to compare the duration of treatment-free remission prior to HDC with the progression-free survival after HDC in individual patients.

PATIENTS AND METHODS

Forty-five consecutive patients were analyzed retrospectively. We devised an index of pretreatment intensity (IPTI) based number of different chemo- and radiotherapy regimens given between diagnosis and HDC and on the duration of disease.

RESULTS

With a median follow-up of 47 months the post-transplant event-free survival (EFS) was 44% and the overall survival (OAS) was 62% at four years. The IPTI allowed to discriminate between a low and a high-risk group with a four-year post-transplant EFS of 66% and 11% and a OAS of 87% and 28%, respectively (P = 0.0001). Of the 39 patients with sufficient follow-up after HDC, post-transplant EFS lasted on average > or = 18.5 months longer than the pretransplant treatment-free remission.

CONCLUSIONS

HDC with the CBV regimen confers significant benefit to patients with chemosensitive relapsed Hodgkin's disease. The IPTI may help to select patients with a good response to HDC and to identify poor prognosis patients suitable for experimental protocols or palliative care only.

Thrombocytopenia

Determining the true cause of thrombocytopenia is a difficult and challenging clinical problem. Thrombocytopenia results from various causes, but ultimately occurs when platelets are destroyed, sequestered in the body, or not produced. The differential diagnosis of thrombocytopenia is extensive and complex, and there is a significant overlap among disorders. The advanced practice nurse must take a holistic approach to the patient, eliciting a detailed history and performing a comprehensive physical examination with special emphasis on the skin, abdominal, lymph node and neurologic consideration.

Acute profound thrombocytopenia after C7E3 Fab (abciximab) therapy

BACKGROUND

Platelets play a crucial role in the ischemic complications of percutaneous coronary procedures. The recent availability of c7E3 Fab (abciximab; ReoPro), a chimeric monoclonal antibody Fab fragment directed against the platelet glycoprotein IIb/IIIa receptor, has reduced abrupt closure and other adverse clinical events and lessened the need for revascularization procedures. As experience accrues, rare cases of acute profound thrombocytopenia have been revealed.

METHODS AND RESULTS

From November 1991 to July 1996, patients at Duke University Medical Center who underwent percutaneous coronary revascularization and received their first exposure to c7E3 Fab were evaluated for the development of acute profound thrombocytopenia, defined as a platelet count < 20 x 10(9)/L occurring within 24 hours of initial treatment. Four patients (0.5%) developed acute profound thrombocytopenia within 11 to 21 hours of receiving the c7E3 Fab bolus. Nadir platelet counts ranged from 1 to 16 x 10(9)/L and occurred within 11 to 26 hours. No patient developed a significant hemorrhagic complication, and each patient's platelet count responded to platelet transfusion. Platelet counts remained depressed for at least 3 days but returned to baseline within 2 weeks.

CONCLUSIONS

Acute profound thrombocytopenia can occur after c7E3 Fab administration. Its development was not predictable, and it requires consideration in every patient treated. A platelet count 2 to 4 hours after the bolus would likely have detected these four cases. When indicated, platelet transfusion will raise the platelet count to safer levels without adverse effects. The differential diagnosis (including heparin-induced thrombocytopenia), a plan for management, and postulates as to the mechanism are discussed.

Transfusion and stem cell support in cancer treatment

Intensification of therapeutic regimens, improved patient survival, and advances in cytokine and cellular therapies have led to increasingly complex requirements for transfusion and stem cell support in cancer treatment. This article focuses on current and evolving issues in red blood cell, platelet, and granulocyte transfusion support, as well as measures to avoid increasingly important complications of transfusion therapy, such as alloimmunization, graft-versus-host disease, cytomegalovirus infection, and immunomodulation. Issues concerning current applications of hematopoietic stem cell transplantation and future prospects also are discussed.

Coagulation disorders in cancer

Coagulation disorders are common in cancer patients. This article reviews the coagulation laboratory findings in these patients and the thromboembolic and hemorrhagic manifestations of malignancy. Among the many topics addressed are Trousseau's syndrome, disseminated intravascular coagulation, and acquired von Willebrand disease. Pathogenesis of the coagulation disorders and recommendations for treatment of various syndromes are discussed.

Clinical and laboratory factors underlying refractoriness to platelet transfusions

Of the spectrum of clinical and laboratory factors responsible for refractoriness to platelet transfusions, some are amenable to intervention, some to circumvention, and others only to acceptance and support for complications. Identification of the likely reason for refractoriness in a given individual patient is critical to determine the optimum management strategy. The blood bank or transfusion service can and perhaps should play a direct role in that strategy through the provision of single donor platelets collected by apheresis. Single donor platelets offer a number of real and theoretical advantages over random donor platelets, including the potential for crossmatching, reduction in net donor exposures, maintenance of ABO-compatibility, improved inventory management, and perhaps diminished rate of alloimmunization. The sole perceived benefits of random donor platelets are cost and availability. The cost differential, however, needs to take into account a variety of factors beyond the immediate concern of platelet collection and distribution, including many highly dependent upon local factors. The optimum management of the platelet refractory patient requires more appropriate use of single donor apheresis platelets coupled with platelet crossmatching when necessary. Data from outcomes studies presented indicates that increased reliance upon single donor apheresis platelets at the expense of pooled random donor units can improve the overall quality of transfusion practice by decreasing platelet utilization, resource consumption, donor exposures, and platelet wastage.

Platelet transfusion and alternatives to transfusion in patients with malignancy

Platelet transfusions have long had an important role in the treatment of patients with thrombocytopenia due to disease or myelotoxic treatment or in patients with reduced platelet function. However, platelet transfusions are associated with numerous risks, both immunologic (e.g., transfusion reactions, alloimmunization, immunosuppression) and infectious (e.g., viral, bacterial). In addition, several laboratory and clinical factors can influence post-transfusion platelet recovery. Recent technological advances have introduced the potential for using alternatives to platelet transfusions, such as cytokines or platelet substitutes, which may avoid the risks of transfusion. Platelet development from megakaryocytes is a process that is highly regulated by cytokines and animal research suggests that selected cytokines involved in this process may be useful in the treatment of thrombocytopenia. Newer developments, including the utilization of recombinant cytokines with relatively selective stimulation of platelet production (e.g., interleukin 6 [IL-6]) and the recent discovery of a megakaryocyte colony stimulating factor (thrombopoietin), represent major therapeutic opportunities in the treatment of thrombocytopenia. Platelet substitutes, e.g., thromboerythrocytes, also show promise in the management of platelet deficiencies.

Collection and transfusion of blood and blood components in the United States, 1992

BACKGROUND

Studies were conducted to measure the state of the United States' national blood resource in 1992 and changes therein from 1989.

STUDY DESIGN AND METHODS

With data supplied by the American Red Cross and the American Association of Blood Banks, as well as data from a stratified random-sample survey of 3350 non-American Association of Blood Banks hospitals, statistical methods were applied to estimate national blood activities in 1992.

RESULTS

The total US blood supply in 1992 was 13,794,000 units, a decrease of 3.1 percent from 1989. Some 11,307,000 red cell units were transfused to 3,772,000 patients, an average of 3.0 units per transfused patient. Preoperative autologous blood deposits totaled 1,117,000 units, a 70-percent increase over 1989. Of this number, 566,000 units (50.7%) were transfused, 5,000 (4.4%) transferred to the allogeneic supply, and 546,000 (48.9%) discarded. Of 436,000 directed-donation units, 136,000 (31.2%) were transfused, 57,000 (13.1%) transferred to allogeneic supply, and 243,000 (55.7%) discarded. The total allogeneic blood supply, including imports, decreased by 7.4 percent from 1989, and allogeneic blood transfusions, including those to children, decreased by 8.6 percent. Over 8,300,000 platelet units were transfused; of these, some 3,600,000 were apheresis platelets. In addition, 2,255,000 units of plasma and 939,000 units of cryoprecipitate were transfused.

CONCLUSION

While the US blood supply was adequate for transfusion needs in 1992, blood collections and red cell transfusions had decreased substantially since 1989.

Autologous platelet transfusion in alloimmunized patients with acute leukemia

Seventy-eight transfusions of autologous platelets were given to eight alloimmunized patients receiving curative chemotherapy for acute leukemia. Platelets were collected at regeneration of hematopoiesis after a chemotherapy cycle, cryopreserved with 5% dimethylsulfoxide in liquid nitrogen, and retransfused during bone marrow aplasia following the next treatment cycle. The in vitro platelet recovery after freezing, thawing, and washing was 85 +/- 4%. The in vivo corrected count increment 1 h after autologous platelet transfusions was 11 +/- 5 x 10(9)/l. With the exception of moderate urticaria and slight nausea each after one transfusion, no immediate or chronic side effects occurred. The bleeding time was shortened and hemorrhage during bone marrow aplasia was prevented in all alloimmunized patients by autologous platelet transfusions.

A controlled trial of tranexamic acid therapy for the reduction of bleeding during treatment of acute myeloid leukemia

In order to determine the efficacy of the antifibrinolytic agent tranexamic acid (TA) in reducing bleeding and platelet transfusions during the treatment of acute myeloid leukemia (AML), we conducted a randomized placebo-controlled double-blind study. Patients with AML undergoing induction or postremission consolidation chemotherapy were randomized into TA or placebo groups. Patients were not given platelet transfusions prophylactically but only when bleeding occurred. The severity of any bleeding event was scored. Thirty eight patients were randomized during induction. There were no significant differences between the two groups in the number of bleeding events and their severity or in the number of platelet transfusions given. Eighteen patients were studied during consolidation. In contrast, to the induction period, during consolidation there was a significantly less severe bleeding tendency in the TA group resulting in a lower platelet transfusion requirement [3.7 +/- 4.1 vs. 9.3 +/- 3.3 platelet units (p < .05)]. TA was well tolerated and no side effects were seen and no specific thromboembolic events were noticed. We conclude that giving TA during the thrombocytopenic period of AML patients undergoing consolidation chemotherapy is beneficial and safely reduces platelet transfusions.

Short-term weekly chemotherapy followed by high-dose therapy with autologous bone marrow transplantation for lymphoblastic and Burkitt's lymphomas in adult patients

BACKGROUND

Type and duration of treatment for highly aggressive non-Hodgkin's lymphoma has been a matter of debate over the past decade. To determine the therapeutic efficacy of an abbreviated treatment regimen, 26 patients with newly-diagnosed highly aggressive lymphomas, 17 of them belonging to the International Working Formulation (IWF) group I and 9 with Burkitt's lymphoma (IWF J), were entered in a study using short-term weekly chemotherapy followed by high-dose therapy and autologous bone marrow transplantation.

PATIENTS AND METHODS

Besides histology, requirements for entry into to the study were age between 16 and 60 years, stage 1 bulky disease and elevated LDH or stage II to IV disease with or without bulk or elevated LDH, and an absence of HIV infection or CNS involvement at diagnosis. The treatment plan was 12 weeks of MACOP-B or VACOP-B chemotherapy followed by high dose therapy and autologous bone marrow transplantation in first complete remission.

RESULTS

Twenty patients (76%), 16 (62%) of those on MACOP-B or VACOP-B, 1 who had received 2 cycles of ProMACE-CytaBOM prior to MACOP-B and 3 after a first salvage regimen, achieved complete remissions. Seventeen patients (65%) were transplanted in first remission, and 15 (58%) after induction treatment with only MACOP-B or VACOP-B. Reasons for not being given high dose therapy and autologous bone marrow transplantation (ABMT) were failure to achieve complete remission in 6 patients, early relapse in 2 and severe pulmonary toxicity associated with chemotherapy in 1. The median time of follow-up was 45 months. At 3 years, the estimated event-free survival was 31% (CI 14%-50%) and the overall survival 48% (CI 25%-67%). There were no deaths from toxic effects of treatment. Pretreatment factors associated with relapse were stage III or IV disease, age over 30 years and bone marrow involvement. Logrank analysis showed that age was the only factor significantly associated with poor event-free survival.

CONCLUSION

Short-term weekly chemotherapy followed by high-dose therapy with the CBV regimen in first remission is not a higly effective treatment for advanced lymphoblastic and Burkitt's lymphomas. The 30% rate of failure to achieve partial remission after 6 weeks and/or complete response after 12 weeks of MACOP-B or VACOP-B treatment, as well as the 42% failure rate to undergo ABMT in first remission, suggest that more aggressive chemotherapy should be used in the beginning.

Reliability of automated platelet counts: comparison with manual method and utility for prediction of clinical bleeding

The 20 x 10(9)/L (20,000/microliters) threshold for prophylactic platelet transfusion may be unnecessarily high. The widespread use of this threshold may reflect lack of confidence in the reliability of low platelet counts. We evaluated the performance of automated platelet counts and their relation to clinical bleeding. First, we prepared serial blood dilutions with "target" platelet counts from 2 to 40 x 10(9)/L. For the 48 measurements on 2 x 10(9)/L "target" dilutions, values of 1 or 2 x 10(9)/L were obtained with the Sysmex NE-8000 analyzer (mean 1.44 x 10(9)/L; SD 0.31 x 10(9)/L). Similarly, for 5 x 10(9)/L "target" counts, automated counts were 3-6 x 10(9)/L (mean 4.42 x 10(9)/L; SD 0.18 x 10(9)/L). Similar results were observed with all other "target" levels, with coefficients of variation (CV) from 6.39% to 7.71% with 10-40 x 10(9)/L "target" values. Secondly, we compared triplicate automated and manual platelet counts on thrombocytopenic patients with platelet counts from 4-30 x 10(9)/L. The triplicate automated platelet counts differed by no more than 5 x 10(9)/L among themselves, whereas the manual counts varied by as much as 30 x 10(9)/L. Mean platelet counts: automated, 14.40 x 10(9)/L (CV 10.12%); manual, 16.48 x 10(9)/L (CV 30.39%) (P = 0.038 for counts; P < 0.001 for CV). Finally, we prospectively evaluated bleeding in thrombocytopenic patients (1,809 patient-days of observation). Univariate and multivariate logistic regression analysis revealed highly significant correlations between the automated platelet count and major and minor bleeding manifestations. Thus, automated platelet counts are highly reliable and accurately predict clinical bleeding. The use of automated analyzers should facilitate improved prophylactic platelet transfusion protocols.

Unexpected high incidence of intracranial subdural haematoma during intensive chemotherapy for acute myeloid leukaemia with a monoblastic component

We report a high incidence of subacute, chronic and sometimes occult intracranial subdural haematoma (SDH) occurring during intensive chemotherapy for acute myeloid leukaemia (AML) with a monoblastic component. Between March 1990 and January 1993, 86 AML patients from our institution were randomized in the multicentric French AML 90 trial. Eight patients (9%) presented a grade > 2 haemorrhagic event, which was intracranial SDH in five of them. All these five SDH patients had hyperleucocytic AML4 or AML5 and had experienced at least one lumbar puncture (LP) before SDH diagnosis (with intrathecal chemotherapy in four cases). SDH diagnosis was assessed on a brain computed tomography scan which was performed 1-9 d after initial SDH symptoms (mainly mild headaches considered a result of prior LP). All these five patients recovered from this severe event after a specified therapy. SDH does not appear to be an uncommon complication of AML4 and AML5 therapy. Its incidence might be under-reported because of poor symptomatology. Lumbar punctures, known to cause exceptional SDH in nonleukaemic patients, might trigger these haemorrhagic events, eventually in combination with other predisposing factors such a haemostasis disorders or leukaemic CNS infiltration.

Disseminated intravascular coagulation (DIC) in adult patients with acute leukaemia

In 71 patients with acute leukaemia admitted for remission induction, disseminated intravascular coagulation (DIC) was looked for in 50 patients and diagnosed in 10 (20%). Of 10 patients with acute lymphoblastic leukaemia, 3 had DIC, and of 40 patients with acute myeloblastic leukaemia, 7 had DIC. The presence of DIC was related to bleeding manifestations within the first 2 weeks. A haemorrhagic diathesis was present in all DIC patients: 4 had minor and 6 had major bleeding, i.e. WHO grade > or = 2. In addition to blood product support, most DIC patients were treated with low doses of heparin and tranexamic acid. In all DIC patients the haemorrhagic symptoms preceded the heparin administration. Among 40 screened patients without DIC, 17 patients had minor and 3 had major haemorrhagic manifestations. Thus, the proportion of patients with major bleeding was significantly greater among the DIC patients (6/10 vs 3/40, p < 0.001). In conclusion, DIC at presentation was associated with a significantly increased risk for severe haemorrhagic complications and should be looked for in adults with acute leukaemia.