Platelet Transfusion Therapy

National Institutes of Health (US). Office for Medical Applications of Research

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National Institutes of Health (US). Office for Medical Applications of Research. NIH Consensus Statements [Internet]. Bethesda (MD): National Institutes of Health (US); 1977-2002.

This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

NIH Consensus Statements [Internet].

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59Platelet Transfusion Therapy

National Institutes of Health Consensus Development Conference Statement October 6-8, 1986

Introduction

In the past, patients with chronic thrombocytopenia died of hemorrhage with distressingly predictable frequency. The increased use of platelet transfusions during the past 15 years has prevented most such deaths. Furthermore, this therapy has made it possible to treat patients with drugs who have otherwise fatal disorders that temporarily suppress platelet production. With this great benefit, however, have come complex problems. Transfused platelets can transmit fatal diseases and can elicit an immune response in recipients, so that further transfusions are no longer effective. Although platelet therapy has contributed greatly to the management of patients with many diseases such as acute leukemia and aplastic anemia, serious questions have emerged regarding its use in patients undergoing cardiac surgery and in other circumstances. The prophylactic administration of platelets is also controversial, and there is uncertainty as to the platelet levels that predispose thrombocytopenic patients to hemorrhage and as to the effectiveness of modalities other than platelets in the prevention of bleeding. The relative merits of the various methods for obtaining and storing platelets remain unclear. The advantages and disadvantages of platelets obtained from multiple and single donors require evaluation.

To resolve these issues, the National Heart, Lung, and Blood Institute, National Institutes of Health (NIH), the Center for Drugs and Biologics of the Food and Drug Administration, and the NIH Office of Medical Applications of Research convened a Consensus Development Conference on Platelet Transfusion Therapy on October 6-8, 1986. At a 1 1/2-day series of presentations by experts in the field, a consensus panel drawn from the medical professions, blood banking organizations, and the general public considered the evidence. The panel agreed on answers to the following key questions:

What are the appropriate indications for platelet transfusion?
What products are available, and what are their relative merits?
What are the risks associated with platelet transfusion?
What are the most important directions for future research?

What Are the Appropriate Indications for Platelet Transfusion?

Despite the obvious advantages of platelet transfusion therapy, there is concern that platelets are sometimes given to patients who do not really need them, are given too often to patients who do need them, and occasionally are given in insufficient quantities when treatment is urgently required. Clinical decisions regarding platelet transfusion are hampered by an insufficient number of properly controlled trials, by imprecise methods of evaluating clinical need, and by uncertain methods for measuring effects.

The platelet levels that predispose thrombocytopenic patients to hemorrhage and the efficacy of therapeutic modalities other than transfusion are not well defined. It is apparent that factors other than the platelet count must also be considered in deciding when to transfuse. The efficacy of transfused platelets may be altered by other abnormalities in the recipient such as uremia, concomitant coagulation disorders, or medications. The rate and direction of change in platelet count must also be considered.

Active Bleeding

Patients with thrombocytopenia or an abnormality of platelet function or both who have significant bleeding should receive platelets if the platelet disorder is likely to be causing or contributing to the bleeding. It is sometimes difficult to make this judgment clinically. It is unlikely that a patient with a platelet count of 50,000 per microliter or higher will benefit from a platelet transfusion if thrombocytopenia is the sole abnormality. If the disorder is one of function, reliance must be placed on some test of platelet function, such as the template bleeding time. A bleeding time of less than twice the upper limit of normal is usually not an indication for transfusion of platelets, unless there are other conditions that interfere with hemostasis. Patients with thrombocytopenia resulting from platelet destruction or splenic pooling may require more intensive transfusion therapy than those with marrow hypoplasia.

Prophylaxis

The patient with severe thrombocytopenia may benefit from prophylactic administration of platelets. This is particularly true of patients with a temporary thrombocytopenia consequent to myelosuppressive therapy. It is common practice to use a preselected level of thrombocytopenia to decide when to transfuse platelets prophylactically. The value of 20,000 platelets per microliter is often used. This figure is based on older studies with potential defects as judged by current knowledge. Recent evidence suggests that this number might safely be lower for some patients based on clinical judgment and close observation. A problem with selecting specific concentrations is the lack of reproducibility and the variability of platelet counts at low levels.

Patients with chronic thrombocytopenia caused by impaired platelet production (e.g., aplastic anemia, myelodysplastic disorders) generally do not require routine platelet transfusions. Patients with accelerated destruction but active production of platelets (e.g., idiopathic thrombocytopenic purpura) have relatively less bleeding at a given platelet count than patients with hypoplastic platelet disorders. Thus, platelet transfusions are rarely needed in these conditions. Other appropriate medical and surgical therapy is usually effective. Preparation for invasive procedures in thrombocytopenic or thrombocytopathic patients might include prophylactic administration of platelets. In many instances there are associated disorders of coagulation or platelet function that cannot be completely corrected, as is common in patients with advanced hepatic or renal insufficiency. In such patients, transfusion of platelets may be necessary, especially for procedures in which hemostasis cannot be assessed by direct observation. Transfusion of enough platelets to correct the bleeding time to the normal range is logical, but there are few, if any, pertinent studies. A similar approach may be justified for patients threatened with hemorrhage in the central nervous system or other sites in which a small amount of bleeding could be critical.

Massive Transfusion

Dilutional thrombocytopenia occurs in patients receiving multiple tranfusions to replace blood lost through hemorrhage and may lead to generalized microvascular bleeding. The degree of dilution is usually predictable. Following replacement of one blood volume, 35 to 40 percent of the platelets usually remain. Thrombocytopenia is accentuated in the presence of accelerated platelet destruction, which sometimes occurs in such patients, mandating performance of platelet counts as a guide to platelet therapy. The majority of patients who receive rapid replacement of one to two blood volumes do not develop microvascular bleeding as a result of thrombocytopenia. Therefore, platelets should not be administered in the absence of documented thrombocytopenia and clinically abnormal bleeding.

Cardiac Surgery

Controlled prospective studies examining postoperative blood loss and outcome have demonstrated no correlation between platelet counts and bleeding following cardiopulmonary bypass and no detectable benefit from the prophylactic administration of platelets to such patients. The vast majority of such patients have some degree of thrombocytopenia, prolongation of the bleeding time, and continued slow bleeding. With an expected pattern of bleeding, thrombocytopenia alone is not an indication for platelet transfusion. There is no justification for prophylactic platelet administration in patients undergoing open heart surgery.

Newborns

Because of the special nature of neonatal requirements for blood and blood products as well as dosages, these issues were not addressed specifically in this report. Nonetheless, efforts should be exerted to continue to avoid undue exposure to multiple donor sources.

What Products Are Available, and What Are Their Relative Merits?

Platelets can be harvested from single donors by plateletapheresis or separated from whole blood, with pooling of cells from multiple donors to achieve a therapeutic dose. Single-donor platelets¹ can be obtained from random donors or from donors selected on the basis of HLA compatibility. Local conditions and practices often influence the choice among these alternatives, but there are identifiable advantages and disadvantages of each product that should be considered. These include availability, potential for disease transmission, and potential for alloimmunization.

Products

Since each single-donor apheresis collection provides the equivalent of the platelets obtained from five to eight whole blood donations, this product exposes a patient to fewer donors and offers potential advantages over the multiple-donor product: less exposure to infectious agents and reduced likelihood of alloimmunization. However, there is no evidence that single-donor platelets are either more or less effective than multiple-donor concentrates in patients who have not become alloimmunized.

A major advantage of multiple-donor platelets is that they are in relatively plentiful supply, having been derived from conventional whole-blood donations. Moreover, they can be stored for 5 days, assuring a stable community resource. Storage time for single-donor platelets depends on the method used for harvesting; in some cases, the product must be used within 24 hours.

Certain organizational and logistical considerations influence the choice of platelets from random or HLA-matched single donors. Donation of platelets by apheresis requires a greater donor commitment than does whole-blood donation, as well as sophisticated equipment and highly trained personnel. Even where enough donors are available, the complexity of the procedure as currently employed can make its routine use infeasible. However, HLA-matched single-donor products are currently the most effective therapy for patients who have become refractory to unselected single-donor or multiple-donor platelets.

Storage

Platelets are normally stored at 20° C to 24° C, with constant agitation for up to 5 days. Although platelets stored at 4° C are a licensed product, they are now rarely used because of their reduced survival and function after transfusion.

Platelets can be frozen to extend their storage period. Since patients who have become refractory to platelet transfusions during one course of chemotherapy will usually be difficult to treat during subsequent periods of chemotherapy-induced hypoplasia, their anticipated need can be met by the cryopreservation of autologous platelets obtained by apheresis during a remission. The low yield and high cost of cryopreserved platelets have limited their use in other conditions.

Dosage

The therapeutic dose of platelets is affected by the patient's pretransfusion platelet count and blood volume, as well as by associated clinical conditions. The common practice of transfusing multiple-donor platelets at a dose of 1 unit per 10 kg body weight, or of transfusing a concentrate obtained from one apheresis donor, is a reasonable starting point for platelet therapy in the adult patient. The effect of a transfusion should be judged by the clinical result and the platelet count obtained 1 hour later. These measures plus later platelet counts as indicated can also provide guidance for further treatment.

A standard 170 micron filter is recommended for the administration of platelets. Filters of smaller pore size are not indicated.

Adjunctive Therapies

Several agents have been used in addition to, or in place of, platelets in the treatment of thrombocytopenia resulting from impaired production or platelet dysfunction. Epsilon-aminocaproic acid (EACA) and prednisone have been considered useful for the treatment of these conditions by some clinicians, but there are no satisfactory studies that support their regular use. In uremia, bleeding responds in many cases to treatment with cryoprecipitate or desmopressin (DDAVP), and platelet transfusions can be avoided.

What Are the Risks Associated With Platelet Transfusion Therapy?

The major risks associated with platelet transfusion are alloimmunization and infection. Rarely, platelet transfusions cause graft-versus-host disease.

Alloimmunization and the Refractory State

When platelet-reactive antibodies are induced by transfusion, platelets subsequently administered often fail to produce a therapeutic benefit. A poor response to transfused platelets also can be caused by splenomegaly, fever, sepsis, disseminated intravascular coagulation, nonviable platelets, and other conditions. Alloimmunization to platelet antigens is common in patients who have received repeated transfusions. However, an appreciable number of patients fail to form platelet-reactive antibodies for reasons that are not clear. There is no well-defined relationship between the number of donor exposures and the extent of antibody formation, although one study suggests a lower incidence of alloimmunization in patients exposed to platelets derived by apheresis from fewer donors. Alloimmunization to the HLA-A and HLA-B antigens is encountered most frequently. Evidence indicates that leukocytes, present in routinely prepared platelet concentrates, provoke HLA-antibody formation more readily than platelets.

The failure of HLA-matched platelets to elevate the platelet count after transfusion to some alloimmunized patients suggests that antibodies reactive with non-HLA, platelet-specific antigens can cause destruction of transfused platelets. Circulating immune complexes have also been implicated. ABO compatibility between donor and recipient is of minor importance in platelet transfusion therapy in most adults. Administration of ABO incompatible platelets is an acceptable transfusion practice. The possibility of Rh immunization by red cells contained in platelet concentrates should be considered in female recipients.

Various strategies have been proposed to cope with the therapeutic problems presented by alloimmunized, thrombocytopenic patients. Administration of leukocyte-poor blood products to patients likely to require continuing transfusion support has been advocated to reduce the frequency of alloimmunization, but the feasibility and effectiveness of this strategy have not been conclusively demonstrated. The same is true of the prospective use of platelets from single donors. New approaches to this problem, still in an experimental stage, are treatment of platelet concentrates with ultraviolet light to abolish the immunogenicity of contaminating leukocytes and the transfusion of soluble, class I HLA antigens to induce active tolerance.

Various techniques have been used to improve the effectiveness of platelets in alloimmunized patients. The most feasible of these is the transfusion of HLA-matched platelets from family members or unrelated persons. If not available locally, matched platelets can sometimes be obtained from regional blood centers with access to large panels of HLA-typed donors. Only about two-thirds of HLA-matched platelet transfusions given to alloimmunized patients are effective. Newer immunologic techniques appear capable of predicting transfusion response in such patients with an 80 percent to 90 percent certainty. These assays are available in only a few centers and are not yet applicable to standard transfusion practice. High-dose intravenous immunoglobulin therapy, splenectomy, and removal of alloantibodies by plasmapheresis may be of marginal benefit but cannot be recommended for routine use.

Infection

Infections transmitted by platelet transfusions are similar to those associated with other blood components. These are of special concern because platelet transfusions often are prepared by pooling concentrates from multiple donors and are given in large numbers to immunocompromised patients. With agents infrequently present in donated blood such as the human immunodeficiency virus (HIV), the risk of infection is roughly proportional to the number of donor exposures. As with other blood products, agents causing most of the serious infections are the non-A, non-B hepatitis virus(es), hepatitis B virus, cytomegalovirus, and HIV. The risk of disease transmission with blood transfusion varies geographically and among donor populations but appears to be decreasing nationally because of newly implemented test methods and donor screening policies.

An unusual, but sometimes fatal, complication of platelet transfusion is infusion of bacteria that have proliferated in concentrates stored at 20° C to 24° C. Physicians should be aware of this complication and be prepared to administer antibiotics and supportive measures. Attempts should be made to identify the source of the contamination in all such cases.

Graft-Versus-Host Disease

Graft-versus-host disease is a rare complication of platelet transfusions that can be prevented by gamma irradiation of concentrates prior to transfusion to patients who have undergone bone marrow transplantation or have other forms of immunodeficiency.

What Are the Most Important Directions for Future Research?

Research should be directed toward the following²:

Recipient-Related Issues

Development of a practical test that predicts the likelihood of clinically significant platelet-related bleeding.
Controlled clinical trials to evaluate strategies for prophylactic use of platelets in patients with disorders of platelet production.
Evaluation of pharmacologic approaches designed to reduce platelet requirements.

Product-Related Issues

Development of better techniques to harvest platelets with minimal contamination with other blood components.
Better methods of platelet preservation.
Practical means for detecting ineffective units and bacterial contamination prior to transfusion.
Better characterization of platelet alloantigens and the development of practical methods to detect platelet alloantibodies and select compatible donors.
Effective means to prevent alloimmunization and to manage the alloimmunized patient.
Development of methods and strategies to lessen the incidence of transfusion-transmitted diseases.
Monitoring of the patterns of platelet use.

Donor-Related Issues

Assessment of the long-term effects of repeated plateletapheresis.
Identification of factors leading to successful recruitment of plateletapheresis donors.

Platelet use is controlled locally and determined largely by existing practice. Attempts to alter platelet use frequently have been ineffective. The most successful attempts can be attributed to a strong local proponent of appropriate transfusion practices. Ongoing collaborative efforts, including component therapy workshops involving clinicians, blood bank directors, and members of hospital transfusion committees, can do much to alter existing practices. Increased attention to the risks and benefits of component therapy in medical schools and teaching hospitals also may change the use of platelet concentrates. When appropriate, information regarding potential risks and benefits of platelets and other blood products should be made available to patients who receive those products. Monitoring the patterns of platelet use on a continuing basis will provide a means for evaluating the impact of those strategies and a basis for suggesting additional or alternative approaches.

Conclusions

In this document, the panel has made a number of observations and recommendations based on information presented at this conference relating to the indications for platelet transfusion, products available, and associated risks. We believe platelets are overused in some conditions. An example is the prophylactic use of platelets in open heart surgery, a practice the panel believes is unwarranted. Some of the uncertainty surrounding platelet transfusion practices is related to the lack of methods for predicting which patients are at risk to bleed and the effectiveness of various platelet preparations. We recommend research initiatives to provide better guidelines for transfusion practice.

More basic research to elucidate the role of platelets in hemostasis is needed. In addition, better information on current platelet transfusion practices, obtained through a surveillance system at a national level, would be of great benefit as an educational tool. Efforts to overcome the problems associated with alloimmunization to platelets are imperative. A major step in this regard would be the establishment of a national network to facilitate transfusion of HLA-matched platelets to selected patients. Infections transmitted by platelet transfusions remain a major concern. Elimination of bacterial growth in platelet concentrates stored at room temperatures warrants special attention.

Consensus Development Panel

Richard H. Aster, M.D.
Panel Chairperson
President
Blood Center of Southeastern Wisconsin
Clinical Professor of Medicine and Pathology
Medical College of Wisconsin
Milwaukee, Wisconsin

Alfred A. Bartolucci, Ph.D.
Professor and Chairman
Department of Biostatistics and Biomathematics
University of Alabama at Birmingham
Birmingham, Alabama

John A. Collins, M.D.
Professor and Chairman
Department of Surgery
Stanford University School of Medicine
Stanford University Medical Center
Stanford, California

Theodore Colton, Sc.D.
Professor of Public Health
Boston University School of Public Health
Boston, Massachusetts

Arlan J. Gottlieb, M.D.
Professor of Medicine
Chief of Hematology
Department of Medicine
State University of New York Health Center at
Syracuse
Syracuse, New York

Tibor J. Greenwalt, M.D.
Director
Hoxworth Blood Center
Emeritus Professor of Internal Medicine and
Pathology
University of Cincinnati
Cincinnati, Ohio

Leon W. Hoyer, M.D.
Associate Vice President
Biomedical Research and Development
American Red Cross
Bethesda, Maryland

Robert McMillan, M.D.
Director
Weingart Center for Bone Marrow Transplantation
Member, Department of Basic and Clinical Research
Scripps Clinic and Research Foundation
La Jolla, California

Jane Allyn Piliavin, Ph.D.
Professor and Director of Graduate Studies
Department of Sociology
University of Wisconsin
Madison, Wisconsin

Jane E. Russell
Deputy Director
Quality Control Center
Dana-Farber Cancer Institute
Boston, Massachusetts

Jacob N. Shanberge, M.D.
Chief
Hemostasiology Laboratory
Department of Clinical Pathology
William Beaumont Hospital
Royal Oak, Michigan
and
Clinical Professor of Medicine
University of Michigan

Ernest R. Simon, M.D.
Executive Vice President for Medical Affairs
Blood Systems, Inc.
Scottsdale, Arizona
and
Clinical Professor of Medicine
University of New Mexico

Linda Stehling, M.D.
Professor of Anesthesiology and Pediatrics
State University of New York Health Center at
Syracuse
Syracuse, New York

Speakers

Ernest Beutler, M.D.
"Prophylactic Platelet Transfusions"
Chairman
Department of Basic and Clinical Research
Scripps Clinic and Research Foundation
La Jolla, California

Joseph R. Bove, M.D.
"Infectious Complications of Blood Transfusion"
Professor of Laboratory Medicine
Yale University School of Medicine
Director
Blood Bank
Yale-New Haven Hospital
New Haven, Connecticut

Hayden G. Braine, M.D.
"Bacterial Contamination of Platelet Concentrates"
Associate Professor of Oncology and Medicine
Johns Hopkins Oncology Center
Baltimore, Maryland

Anneke Brand, M.D., Ph.D.
"Alloimmunization After Leukocyte-Depleted Multiple Random-Donor Platelet Concentrates"
Department of Immunohematology and Blood Bank
Academish Ziekenhuis Leiden
Rijnsburgerweg
NETHERLANDS

James B. Bussel, M.D.
"Use and Avoidance of Platelet Transfusion in Idiopathic Thrombocytopenic Purpura"
Assistant Professor of Pediatrics
Division of Pediatric Hematology/Oncology
New York Hospital-Cornell Medical Center
New York, New York

Richard B. Counts, M.D.
"Platelet Transfusions in Massively Transfused Patients"
Managing Director
Puget Sound Blood Center
Seattle, Washington

Jürg P. Gmür, M.D.
"Random Single-Donor Platelets Compared to Random Multiple-Donor Platelet Concentrates"
Chief of Transfusion Medicine
Department of Internal Medicine
University Hospital of Zurich
Zürich
SWITZERLAND

F. Carl Grumet, M.D.
"Prevention and Management of the Refractory State: Induction of Tolerance to Allogenic Platelet Transfusions"
Associate Professor of Pathology
Department of Pathology
Stanford University
Stanford Blood Center
Palo Alto, California

Thomas S. Kickler, M.D.
"Refractoriness to Platelet Transfusions"
Associate Professor of Medicine and Pathology
Johns Hopkins University School of Medicine
Baltimore, Maryland

Thomas J. Kunicki, Ph.D.
"The Platelet as an Immunologic Target"
Senior Investigator
Blood Center of Southeastern Wisconsin
Milwaukee, Wisconsin

Jack Levin, M.D.
"Use of Platelets in Open-Heart Surgery"
Professor of Laboratory Medicine and Medicine
Departments of Laboratory Medicine and Medicine
University of California at San Francisco School of Medicine
Chief
Hematology Laboratory/Blood Bank
Veterans Administration Medical Center
Clinical Pathology Service
San Francisco, California

Naomi L.C. Luban, M.D.
"Graft-Versus-Host Disease as a Consequence of Transfusion of Platelets"
Director
Blood Bank and Hematology
Children's Hospital National Medical Center
George Washington University Medical Center
Washington, D.C.

Scott Murphy, M.D.
"Preparation and Storage of Platelet Concentrates"
Professor of Medicine
Thomas Jefferson University
Philadelphia, Pennsylvania

Ralph L. Nachman, M.D.
"Role of Platelets in Hemostasis"
Professor of Medicine
Department of Medicine
Cornell University Medical College
New York, New York

A. Koneti Rao, M.D.
"Transfusions of Platelets to Patients With Disorders of Platelet Functions"
Associate Professor of Medicine and Thrombosis Research
Deputy Director for Clinical Research
Thrombosis Research Center
Temple University School of Medicine
Philadelphia, Pennsylvania

Wendell F. Rosse, M.D.
"Donor Selection in Platelet Transfusion"
Professor of Medicine
Florence McAlister Professor of Medicine
Duke University Medical Center
Durham, North Carolina

Charles A. Schiffer, M.D.
"Experience With Single-Donor Platelet Transfusion"
Professor and Chief
Division of Hematology
University of Maryland Cancer Center
University of Maryland School of Medicine
Baltimore, Maryland

Laurence A. Sherman, M.D.
"Prevention and Management of the Refractory State"
Chief
Medical Services
Missouri/Illinois Red Cross
Regional Blood Services
St. Louis, Missouri

N. Raphael Shulman, M.D.
"Historical Perspective"
Medical Director
Chief
Clinical Hematology Branch
National Institute of Diabetes and Digestive and Kidney Diseases
National Institutes of Health
Bethesda, Maryland

Toby L. Simon, M.D.
"Evaluation of the Effectiveness of Platelet Transfusion"
Medical Director
United Blood Services
Associate Professor of Pathology and Medicine
University of New Mexico School of Medicine
Albuquerque, New Mexico

Sherrill J. Slichter, M.D.
"Transfusion of Platelets to Patients With Hypoplastic States"
Scientific Director
Puget Sound Blood Center
Professor of Medicine
University of Washington School of Medicine
Seattle, Washington

Douglas MacN. Surgenor, Ph.D.
"Usage Patterns and Trends"
President
Center for Blood Research
Visiting Professor of Pediatrics
Harvard Medical School
Boston, Massachusetts

Planning Committee

George J. Nemo, Ph.D.
Planning Committee Chairperson
Chief
Blood Resources Branch
Division of Blood Diseases and Resources
National Heart, Lung, and Blood Institute
National Institutes of Health
Bethesda, Maryland

Richard H. Aster, M.D.
President
Blood Center of Southeastern Wisconsin
Clinical Professor of Medicine and Pathology
Medical College of Wisconsin
Milwaukee, Wisconsin

Michael J. Bernstein
Director of Communications
Office of Medical Applications of Research
National Institutes of Health
Bethesda, Maryland

Susan M. Clark
Social Science Analyst
Office of Medical Applications of Research
National Institutes of Health
Bethesda, Maryland

Carol Florance
Public Affairs Specialist
National Heart, Lung, and Blood Institute
National Institutes of Health
Bethesda, Maryland

Joseph C. Fratantoni, M.D.
Chief
Laboratory of Cellular Components and Transfusion Medicine
Center for Drugs and Biologics
Food and Drug Administration
Bethesda, Maryland

Edwin W. Salzmann, M.D.
Professor of Surgery
Department of Surgery
Harvard Medical School
Beth Israel Hospital
Boston, Massachusetts

Charles A. Schiffer, M.D.
Professor and Chief
Division of Hematology
University of Maryland Cancer Center
University of Maryland School of Medicine
Baltimore, Maryland

Sherrill J. Slichter, M.D.
Scientific Director
Puget Sound Blood Center
Professor of Medicine
University of Washington School of Medicine
Seattle, Washington

Conference Sponsors

National Heart, Lung, and Blood Institute
Claude Lenfant, M.D. Director

Food and Drug Administration
Frank E. Young, M.D. Commissioner

NIH Office of Medical Applications of Research
Itzhak Jacoby, Ph.D. Acting Director

Supplemental Information for NIH Consensus Statement on Platelet Transfusion Therapy

Since the NIH Consensus Statement on Platelet Transfusion Therapy was issued, additional information has become available that supplements the original statement.

Recommendations included in the statement continue to be valid. However, it should be noted that the current frequencies of infectious virus transmission by single units of blood or blood components are lower than reported in the statement. For more recent information, see Schreiber GB. The risk of transfusion-transmitted viral infections. NEJM 1996;334:1685-1690. Also, "non-A, non-B hepatitis" is now known to be almost exclusively caused by hepatitis C virus (HCV). A test for HCV antibodies was developed several years ago, and a recently improved version is in universal use in the United States.

Footnotes

1: The term single-donor platelets is used to mean platelets obtained by apheresis from a single donor. The number of platelets obtained is approximately equal to the number of platelets obtained from five to eight whole-blood donations.
2: Priorities are not implied in this sequence.

: This statement was originally published as: Platelet Transfusion Therapy. NIH Consens Statement 1986 Oct 6-8;6(7):1-6.
: For making bibliographic reference to the statement in the electronic form displayed here, it is recommended that the following format be used: Platelet Transfusion Therapy. NIH Consens Statement Online 1986 Oct 6-8 [cited year month day];6(7):1-6. [PubMed: 3553903]
: NIH Consensus Statements are prepared by a nonadvocate, non-Federal panel of experts, based on (1) presentations by investigators working in areas relevant to the consensus questions during a 2-day public session; (2) questions and statements from conference attendees during open discussion periods that are part of the public session; and (3) closed deliberations by the panel during the remainder of the second day and morning of the third. This statement is an independent report of the consensus panel and is not a policy statement of the NIH or the Federal Government.

Bookshelf ID: NBK15140

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