In-process cell counts during preparation of platelet concentrates from buffy coats.

To ensure the quality of platelet concentrates (PCs), we studied in-process recoveries of blood cell counts in pooled PCs derived from four or five buffy coats (BCs) from Biopack Compoflex Systems in Bern (PC-BC/4 or PC-BC/5) and from five BCs from Optipac (Baxter) in Zurich (PC-BC/5). BCs were pooled employing a sterile connecting device and flushing them with 300 mL of platelet additive solution. The pools were centrifuged for 12 min at 500 g at 20 degrees C and filtered with PALL's Auto-Stop BC-leukocyte removal filter.

[The extent of transfusion-associated HIV infections in Switzerland until 1994: an updated estimate].

Objective: The first report on transfusion-associated HIV infections was published in the USA in 1982. The first case reports in Switzerland were published in 1986. So far there has never been a methodologically sound answer to the question of how many persons were infected with HIV by receiving transfusions in Switzerland before the introduction of universal HIV blood donor screening.

[Significance of hepatitis C virus antibodies in asymptomatic blood donors].

The aim of the study was to determine the frequency and course of hepatitis C viremia in clinically healthy, anti-HCV positive test subjects, and to ascertain whether the HCV antibodies of the IgM type differed between viremia and immunity. In 21 anti-HCV positive blood donors (test subjects) with normal transaminase activity, two serum samples, taken at an interval of 25 +/- 10 months, have been investigated for HCV-RNA and HCV-IgM antibodies. In a total of 16 test subjects (76%) HCV-RNA was found during the first test and/or the follow-up: 14 of them were positive on both occasions, and one test subject each was HCV-RNA positive exclusively at the first test and the follow-up respectively.

[Positive direct antiglobulin test (DAGT) using the gel system].

In the gel test system the direct antiglobulin test (DAGT) shows a considerably higher sensitivity than in the tube test. Some 40% of gel test positive DAGTs prove to be negative when tested in the tube system. Most of the (auto-)antibodies detected by gel test DAGT appear to be bound integrally to the patient's own red cells and therefore are of questionable importance in view of future blood transfusions.

[Transfusion-associated HIV infections in Switzerland 1982-1989].

Up to summer 1987, 19 patients who had acquired HIV infection by blood transfusion had been recorded in Switzerland. In the subsequent period, up to 1989, a further 15 patients with transfusion-associated HIV infection were recorded. In December 1989, 7 of these patients were asymptomatic, 4 had ARC, 5 Aids and 11 had died of Aids.

[Blood component therapy after conversion to erythrocyte concentrate with added solutions].

Increased national quality requirements for blood products have led to the replacement of the conventional double-bag system with CPDA-1 anticoagulant by a 4-bag system with additive solution, buffy-coat free. Simultaneously the production of fresh blood was stopped for logistical reasons. Acceptance and possible drawbacks of these important changes in blood supply were analyzed in a postmarketing surveillance study involving some 30 hospitals.

[Transfusion-associated HIV infection].

In this paper an attempt is made to characterize different phases of HIV exposition by blood transfusion. In Europe, most transfusion associated (TA) HIV-infections have occurred between 1982, when AIDS started to spread and 1985, when Anti-HIV-testing was introduced in blood transfusion services. Figures of TA HIV infection in Switzerland are presented and the attitude regarding retrospective programs in this country is discussed.

[HIV transmission via blood transfusions: a study by the Swiss Red Cross blood bank service].

An inquiry amongst blood transfusion services served to establish at 19 the number of known transfusion associated HIV infections in Switzerland. In 12 cases the transfusion of an anti-HIV positive blood unit could be proven retrospectively, while in 7 cases an HIV-infected blood donor could not be found but the association of the infection with blood transfusion is highly probable by exclusion of other risk factors. All these infections occurred before introduction of anti-HIV screening in Switzerland in November 1985.

[Post-transfusion hepatitis in the Zürich region].

In the years 1979 to 1983 approximately 350,000 units of blood were transfused in the area of Zurich. During the same period 45 cases of posttransfusion hepatitis were reported. In 12 of these cases transfusion could be excluded as cause of the hepatitis.

[Transfusion-associated LAV/HTLV-III infections in Switzerland. Report of 2 cases].

Two patients developed signs of LAV/HTLV-III infection one and two years respectively after a blood transfusion. The leading symptom in one patient was generalized lymphadenopathy, while the other patient presented with Candida stomatitis. In both cases, blood transfusions administered in 1983 were found to be the only possible source of infection; one blood donor of each patient was anti-LAV/HTLV-III positive.

Blood units for patients with irregular blood group antibodies: frequency and supply.

Blood banks face significant problems supplying blood units compatible with erythrocyte antigens other than ABO and rhesus D. In this study the number of such units was evaluated between 1973 and 1982, and it was found that 1.5% of the total number of blood units were compatible with other antigens than ABO and rhesus D.

[Use of fresh frozen plasma in a Swiss hospital district].

The causes of a unexpected rise in the consumption of fresh frozen plasma (FFP) in the years 1977-1980 are analyzed. FFP appears to be used increasingly in the department of surgery, and more specifically cardiac surgery, in the University Hospital. No basic changes are registered regarding the type of operations performed or the indications for prescribing FFP.

[Hepatitis B virus epidemiology: degree of contamination and hyperreactors].

152 anti-HBs positive blood donors were observed for 2 to 9 years for persistence of this hepatitis-B marker. The results suggest an average persistence of anti-HBs-positive findings in the controlled carriers of at least 10 years. Some of the investigated blood donors belong to a special group of "hyperreactors" with long-lasting persistence of high-titred anti-HBs.

[Tetanus antibody screening in blood donors].

Two ELISA test methods for detection of tetanus antibodies are presented which are suitable for routine screening. Administration of the tests to blood donors shows good average immunization of the Swiss population against tetanus. Due to compulsory immunization during military service, men exhibit markedly higher antibody levels against tetanus than women.

[Anti-D hyperimmunoglobulin, a study of Swiss requirements].

Owing to the introduction of postpartum Rhesus prophylaxis with anti-D hyperimmunoglobulin, a very small number of Rh-negative women become sensitized against the Rhesus factor at birth. Accordingly, the number of naturally immunized women suitable for the collection of anti-D plasma is decreasing. Currently, the demand for anti-D plasma in Switzerland is covered by plasma donations of spontaneously immunized women.

[Pathogenesis of bone marrow necrosis in a patient with cancer].

Bone marrow necrosis was observed in a 23-year-old pregnant woman with severe anemia and thrombocytopenia due to bilateral ovarian carcinoma. After removal of the primary tumors, the hematological findings returned to normal, but the progression of the metastasis lead to respiratory insufficiency and death. The possible mechanisms leading to bone marrow necrosis are discussed.

[Erythrocyte concentrates as substitutes of whole blood; changes in transfusion methods in a regional hospital (author's transl)].

In Switzerland the amount of blood donations is determined by the demands for plasma; as a result there is a surplus of erythrocyte concentrates for which more uses should be found. Trials in a regional general hospital proved that these concentrates can be advantageously employed in the field of surgery and anasthesia: due to close cooperation between the clinical department and the blood donor sevice the demand for erythrocyte concentrates rose from 5 per cent to 80 per cent within 5 years.

[Hepatitis B antigen (HBSAG) in hospitalized children].

Blood samples of 1940 hospitalized children aged 0--18 years were investigated for presence of HBs-Ag by counter-electrophoresis, haemagglutination and radioimmunoassay, HBs-Ag was found in 1.34% of all patients, being distributed evenly amongst boys and girls. The incidence was 1.