Blood donation and transfusion practices: the 1990 American Association of Blood Banks Institutional Membership Questionnaire.

Responses to the 1990 American Association of Blood Banks (AABB) Institutional Membership Questionnaire were submitted by 2126 regional blood centers, hospital-based blood banks, and transfusion facilities. Data from 2117 of these facilities were considered to be valid. The questionnaire included information on blood donor demographics, number of units collected, and collection procedures; services performed; usage of blood components; and transfusion-transmitted diseases reported during 1989. Institutional members collected 7.4 million whole blood units, of which 90.8 percent were donated for allogeneic use, 6.0 percent were donated for autologous use, and 3.2 percent were donated for directed use. Approximately 630,546 allogeneic and directed-use blood donors were deferred, most often for low hemoglobin or hematocrit values. Approximately 225,205 full allogeneic and directed-donor units were discarded, primarily for elevated alanine aminotransferase levels or the presence of hepatitis B core antibody. The 14.3 million transfused components included 56.7 percent red cell-containing components, 27.4 percent platelets, 11 percent fresh-frozen plasma, and 4.8 percent cryoprecipitate. Institutional members reported 1397 cases of transfusion-associated hepatitis. In this group, 921 patients were tested for hepatitis B surface antigen after the transfusion; 339 (36.8%) were found to be hepatitis B surface antigen positive. The AABB Institutional Questionnaire results provide recent data on blood donor and transfusion-related activities that are vital to the evaluation of current transfusion medicine practices.

Transfusion-transmitted diseases other than AIDS and hepatitis.

Although the major diseases transmitted by transfusion today are AIDS and hepatitis, many others also are known. These include CMV, syphilis, Chagas disease, babesiosis, parvovirus B19, malaria, Epstein-Barr infection, and many others that have been reported only once or twice. Reducing the risk of transfusion-transmitted diseases is a problem for donor centers where donor screening and laboratory testing for possible carriers is undertaken. Physicians should be aware that the potential for disease transmission is always present when transfusions are administered.

Testing in the years ahead: new pressures and new concerns.

In the past, testing by blood banks was intended primarily to ensure product quality or donor safety or to meet existing regulations. As a result of recent pressures, especially the AIDS epidemic, additional reasons to test have become evident. Although some of these reasons are not easy to accept, it is appropriate to review them and to evaluate a new approach to reaching blood bank decisions that have public policy implications. It is suggested that The Institute of Medicine of the National Academy of Sciences sponsor a new and permanent structure for this purpose.

Transfusion-associated hepatitis and AIDS. What is the risk?

Infectious complications have been, and will continue to be, a problem in recipients of blood transfusions. Steps to exclude high-risk donors and to test for antibody to HIV, antibody to hepatitis B core antigen, and alanine aminotransferase almost surely have a beneficial effect on the blood supply. The risk of transfusion-transmitted infectious disease will never be nonexistent, and each transfusion will always have to be considered in terms of benefit versus risk. Patients and physicians need to understand that an absolutely safe blood supply is an unattainable goal, but that current approaches to donor selection and testing are highly effective in minimizing the risk of transfusion-transmitted infection.

A review of recent events related to surrogate testing of blood to prevent non-A, non-B posttransfusion hepatitis.

A workshop sponsored by the Food and Drug Administration was held recently during which available data were reviewed concerning surrogate testing of blood donated for transfusion in order to reduce the risks of posttransfusion non-A, non-B hepatitis. Clinical studies from which the efficacy of testing for alanine aminotransferase and antibody to hepatitis B core antigen (anti-HBc) could be predicted indicated such testing would be useful, although several studies using tests for anti-HBc developed recently questioned their effectiveness. Different approaches to establishing the cut-off values for the screening tests were presented and difficulties regarding test standardization were discussed. The legal, ethical, and medical implications for donors of surrogate screening programs in the United States also were considered. A meeting sponsored by the private sector that included representatives of the major blood banking organizations and was convened to discuss the workshop proceedings and nationwide screening of the blood supply also is summarized.

Look-back: preliminary experience of AABB members. American Association of Blood Banks.

By mid-fall of 1986 the "look-back" process conducted by blood banks belonging to the American Association of Blood Banks was about 50 percent complete. Over one-half of the traced recipients had died; 15 percent were alive and negative for antibodies to the human immunodeficiency virus and 16 percent alive but had seroconverted. In a small number of cases physicians or patients elected not to be tested. No major problems were reported.

Results of nationwide screening of blood and plasma for antibodies to human T-cell lymphotrophic III virus, type III.

From April 22 to July 28, and from October 7 to November 3, 1985 the American Red Cross, the Council of Community Blood Centers, the American Association of Blood Banks, and the American Blood Resources Association provided the Food and Drug Administration with data at 2-week intervals on human T-lymphotropic virus type III (HTLV-III) test kit results at blood and plasma collection centers. Reports were received from over 150 blood collection centers that screened 2,502,829 units of blood for antibody to HTLV-III by enzyme-linked immunosorbent assay (ELISA) during nine 2-week surveillance intervals. Of these, 25,324 or 1.01 percent were initially reactive and 8443 or 0.34 percent were repeatedly reactive. The repeatedly reactive rate for women was 0.33 percent and for men 0.30 percent. Data for source plasma was collected at 275 locations and tested at eight central laboratories showed that for 2,603,652 units screened (which may represent multiple collections from the same donor) 3978 or 0.15 percent were repeatedly reactive. Screening results from both blood and plasma collection centers varied over time and among kits.

The effect of storage on the ganglioside content of human platelets.

Gangliosides are glycolipids which contain sialic acid and are found in the membranes of mammalian cells. By analogy with recent studies of other cells, it is possible that gangliosides play a role in the membrane functions and in vivo survival of platelets. In order to determine if ganglioside destruction plays a role in the storage-induced loss of platelet viability and function (storage lesion), the ganglioside content of platelets was measured after 24 and 96 hours of storage. Samples were taken from platelet concentrates that were stored either on a flat-bed shaker (n = 6) or on a circular rotator (n = 6). Total ganglioside content was determined colorimetrically from the total lipid extracts of purified platelet pellets using the Svennerholm resorcinol method. Ganglioside GM3 content was determined by Folch partitioning, high performance thin-layer chromatography, and densitometric scanning. Ganglioside content, measured as microgram of lipid-bound sialic acid per 10(10) platelets, was significantly decreased (p less than 0.005) between 24 and 96 hours of storage, whether measured as total or GM3 ganglioside. The mean values +/- SEM at 24 and 96 hours of storage were 9.4 +/- 0.6 and 6.7 +/- 0.6, respectively (n = 12 for each). These data indicate that storage causes irreversible loss of membrane ganglioside, which may be detrimental to the function and in vivo survival of platelets.

Effect of hyperosmolality on control of blood flow and sweating.

To study the effect of hyperosmolality on thermoregulatory responses, five men [average maximal O2 consumption (VO2 max) = 48 ml X kg-1 X min-1] cycled at 65-75% VO2max for up to 30 min in a 30 degrees C, 40% relative humidity environment under three conditions. First, control tests (C) were performed where preexercise plasma volume (PV) and osmolality (Osm) averaged 3,800 ml and 282 mosmol X kg-1, respectively. Second, exercise tests (D) were performed following dehydration induced by fluid restriction and mild exercise (30% VO2max) in hot (40 degrees C) ambient conditions. Each subject then rested in cool surroundings 1 h before performing the exercise test. Preexercise PV and Osm averaged 3,606 ml and 293 mosmol X kg-1, respectively. Third, exercise tests (I) were performed following dehydration, but during the 1-h rest interval, 3% saline was infused so that PV was restored to 3,826 ml and Osm averaged 294 mosmol X kg-1 prior to exercise. During D, esophageal temperatures (Tes) were significantly higher than C, an avg 0.56 degrees C after 20 min exercise due to a 0.22 degrees C increase in Tes threshold for vasodilation, a 39% reduction in slope of the forearm blood flow (BF)-Tes relationship, a 32% average reduction in maximal exercise BF, and a 0.22 degrees C increase in Tes sweating threshold. During I, responses were similar to D, except the BF-Tes slope and the maximum BF were not significantly different from C. Thus hyperosmolality modifies thermoregulation by elevating thresholds for both vasodilation and sweating even without decreases in PV.