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We describe a flow-cytometric method for estimating residual white blood cells (WBC) counts in WBC depleted blood components, namely units of packed red cells. The method uses fluorescent staining of nuclear ADN with ethidium bromide. WBC nuclei are discriminated from background events using fluorescence ratio (585 nm versus 650 nm). A facultative procedure of concentration is described, in order to get better sensitivity at very low WBC counts. Main steps of validation are dilution assays and correlation with hemocytometer counts. The method can be used to explore very low concentrations (less than 100 WBC/ml) and should be useful in quality control of blood products.

It is difficult for blood transfusion centers to validate the link blood products-receiver because of two reasons: most of transfusional acts are performed outside of transfusion centers; information feed-back is not perfect: data processing is completed by someone who has not carried out the transfusion. Therefore, the error risk is higher and it is impossible to enter data on transfusion reactions. The solution is the direct data storage just before transfusion and the computerized transmission to the system containing transfusion index cards. The necessary computerization is not constraining for the users: the portable computer is perfectly autonomous, not very cumbersome, light and reliable. The use of bar codes optimizes the security of the process making is possible to get a line donor-donation-analysis-blood products-receiver and to follow the trace of blood products.

The first case is provided by a french women (KK, husband k/k) who delivered a first healthy full term infant in 1970 and received one blood unit at this time. In 1972 and 1975, his second and fourth pregnancies ended by spontaneous abortion. In 1974 and 1976, she delivered stillborn infants with hydrops fetalis during the sixth month. In serum, anti-k antibody reacted by the indirect antiglobulin test with a titer of 4 096. In the second case, french women delivered a first full term female infant who had a strongly positive direct antiglobulin test. The mother had received one blood unit ten years before during nephrectomy. Her red blood cell were KK and her husband was kk. She had a anti-Cellano in serum reactive in the indirect antiglobulin test with a titer of 16. The infant developed a mild hyperbilirubinemia and recovered without treatment these two cases confirm the variable effect of maternal anti-k antibody evidenced by few other published cases.

11 blood and seric group markers were studied in a case of 46,XX,del(8)(qter yields p22 :) in order to contribute to the exclusion map. MNSs and Jk are informative and could be excluded from the region. The proband is also definitly heterozygous for immunoglobulin Gm groups which were tentatively assigned to the short arm of chromosome 8 or 12.

Routine examination in pre-operative patients revealed the presence of anti-erythrocyte antibodies in 1.23 per cent of cases. Such examination made it possible to avoid, despite strict compability in ABO Rhesus groups, a transfusional immunological conflict in 0.45 per cent of cases, i.e. 7 patients in one year. This provides preventive cover wihich would seem, in surgical context, to be the easiest ti undertake, the most reliable and, in fact, the most economical: widened application of examinations for anti-erythrocyte antibodies together with the avoidance of all unnecessary transfusions.