Three group O sera manifesting prozone in reverse ABO tests are reported. All were implicated in erroneous blood typing results. One sample failed to react with A1 red cells (RBCs) in immediate-spin (IS) tests, had anti-A and -B titers of 8192 and 2048, respectively, by indirect antiglobulin technique (IAT), and was from a diabetic patient; the parenteral administration of A substance present in porcine insulin is a possible cause of hyperimmunity in this case. The second sample was from the recipient of a single unit of group B fresh-frozen plasma; the serum anti-A and -B titers were 10,240 by IAT, but only weak reactions with A1 and B RBCs were noted in routine IS reverse typing tests; the hyperimmunity in the patient concerned was likely due to crossreacting anti-A, B stimulated by B-active glycoproteins and/or glycolipids in the transfused plasma. The third serum also had anti-A and anti-B IAT titers of 10,240 but did not react with A1 and B RBCs by IS; the hyperimmunity in this case may be related to sepsis from intestinal flora carrying A- and/or B-like antigens. These antibodies lysed A1 and/or B RBCs in tests incubated at room temperature (RT) and strongly agglutinated those RBCs by IS when diluted 10-fold with saline. The absence of the prozone phenomenon in tests with RBCs suspended in diluents containing EDTA is consistent with the previously published mechanism for anti-A prozone: namely, the steric hindrance of agglutination by the C1 component of human complement.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Background: This article describes standard operating procedures (SOPs) for a computer crossmatch to replace the immediate-spin crossmatch for ABO incompatibility between patient blood samples submitted for pretransfusion testing and the blood component selected for transfusion. These SOPs were developed following recent changes to the Standards for Blood Banks and Transfusion Services of the American Association of Blood Banks (AABB). Study Design and Methods: SOPs were developed, utilizing currently available software, for pretransfusion testing. The SOP for donor unit processing entails bar code entry of the unit number, component name, and ABO/Rh type; computer entry and interpretation of serologic reactions; warning of discrepancies between bar code-entered blood type and result interpretation; and quarantine of the donor unit in such instances. The SOP for patient sample testing requires bar code entry of specimen accession number, which accesses patient demographics; computer entry and interpretation of ABO/Rh tests; repeat blood typing at the time of crossmatch if only one patient blood type is on record; and warning if there are nonconcordant current and historical blood types. The computer crossmatch SOP requires bar code entry of specimen accession and donor unit numbers; release of group O red cells pending resolution of discrepancies; and immediate-spin crossmatch during computer downtime. Tables validated on- site prompt warning messages and prevent both computer crossmatch and release if blood components of the wrong ABO type are selected. Results: These SOPs meet the requirements of the 15th edition of the AABB Standards. Projected annual time savings at this institution are > 100,000 workload recording units. Further benefits include reduced patient sample volume requirements, less handling of biohazardous material, and elimination of unwanted positive or negative reactions associated with the immediate-spin crossmatch. Release of incompatible blood components when the wrong patient blood type is on record is addressed by requiring the use of group O red cells in the absence of two concordant blood types, one of which must be from a current sample. Conclusion: A combination of existing computer programs and carefully developed SOPs can provide a safe and efficient means of detecting donor-recipient incompatibility without performance of serologic crossmatch. 相似文献
Purpose: To examine (1) the patterns of service use and costs associated with language impairment in a community cohort of children from ages 4–9 years and (2) the relationship between language impairment and health service utilisation.
Method: Participants were children and caregivers of six local government areas in Melbourne participating in the community-based Early Language in Victoria Study (ELVS). Health service use was reported by parents. Costs were valued in Australian dollars in 2014, from the government and family perspectives. Depending on age, the Australian adapted Clinical Evaluation of Language Fundamentals – Pre-school, 2nd Edition (CELF-P2) or the CELF, 4th Edition (CELF4) was used to assess expressive and receptive language.
Result: At 5, 7 and 9 years respectively 21%, 11% and 8% of families reported using services for speech and/or language concerns. The annual costs associated with using services averaged A$612 (A$255 to government, A$357 to family) at 5 years and A$992 (A$317 to government, A$675 to family) at 7 years. Children with persistent language impairment had significantly higher service costs than those with typical language.
Conclusion: Language impairment in 4–9-year-old children is associated with higher use of services and costs to both families and government compared to typical language. 相似文献
Red cells preserved in extended-storage media are the standard product dispensed by many regional blood centers. When the red cells are intended for neonatal transfusion, concern exists about the safety of the relatively high quantities of additives present in these media. Definitive studies to address these concerns are not available. Therefore, to estimate the effects of additives and to delineate circumstances in which they might be harmful, the quantities transfused in defined clinical settings were calculated, and the following recommendations are offered for transfusing infants less than 4 months of age. First, red cells preserved in extended-storage media should present no substantive risks when used for small-volume (approximately 10 mL/kg) transfusions of premature infants and can be used without additional processing. Second, the risks of the most premature neonatal patients or those with severe renal and/or hepatic insufficiency cannot be defined clearly, and, because data are not available to ensure safety for these infants, removal of the additive medium and resuspension of the red cells in saline or albumin solution immediately before transfusion are recommended. Third, following a similar rationale, it seems prudent to avoid using entire units of red cells preserved in extended-storage media in massive transfusion settings (e.g., exchange transfusion, cardiac surgery, and extracorporeal membrane oxygenation). In these settings, the preservative medium should be removed and the red cells resuspended in the fluid that is most appropriate for the procedure that is planned. It must be emphasized that these recommendations are based on calculations and hypothetical settings, not actual data. Accordingly, they are tentative and should be altered as definitive information becomes available. 相似文献
The need to detect antibodies that agglutinate and/or hemolyze red cells (RBCs) directly at 37 degrees C, but do not react in subsequently performed indirect antiglobulin tests (IATs), is of concern relative to the streamlining and automation of antibody detection methods. To determine incidence and significance of such reactions, data from 87,480 tests, which used low-ionic-strength saline, 10-minute incubation at 37 degrees C, and anti-IgG, were analyzed for unexpected antibodies. There were 3590 positive tests, of which 475 showed reactions at 37 degrees C but not in subsequently performed IATs (37 + IAT-). Of these, 196 reactions were due to autoantibodies or other factors usually considered insignificant with respect to the survival of transfused incompatible RBCs, 176 were due to alloantibodies of questionable clinical significance (M, Lea, P1, etc.), and 103 were associated with alloantibodies of potential clinical significance (63 E, 27 K, 5 Jka, 4 D, 3 cE, and 1 C). This latter reaction was seen in 72 patients, with two 37 + IAT-antibodies occurring in each of 3 patients. Of the 75 potentially significant 37 + IAT-antibodies, 57 were seen in patients recently exposed to homologous RBCs, 13 in patients with a history of transfusion and/or pregnancy, and 5 in patients with no known exposure to homologous RBCs. IAT reactivity was observed in subsequent samples with 27 of these antibodies. The predictive value of a 37 + IAT-test was 21.7 percent for a potentially significant antibody. The incidence was 0.12 percent of all tests for unexpected antibodies.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
Percutaneous umbilical blood samples (PUBS), obtained under ultrasound guidance, are used for prenatal diagnosis and management of hemolytic disease of the newborn (HDN) and other fetal disorders. Rapid testing at the time of sampling is vital to distinguish fetal from maternal blood. Blood typing was performed by slide technique in the treatment room during 38 procedures on 25 patients. Anti-I was used to test 50 presumed PUBS; venous I-positive maternal blood was tested in parallel. Because anti-I cannot detect fetal blood after umbilical vein transfusion (UVT) of I-positive donor blood, ABO and Rh blood typing reagents were used to test 29 samples when maternal and fetal or donor blood groups differed. Monoclonal reagents were used for optimal detection of weak AB antigens in fetal blood. Avid, chemically modified anti-D was used for Rh typing. Blood typing showed 27 (34%) of 79 samples to be maternal blood. Fetal blood was obtained in 8 of 10 cases investigated for fetal disorder and in 16 cases of potential HDN (anti-D, 5; -CD, 5; -cE, 2; -K, 2; -c; -E). The absence of HDN (antigen-negative fetus) was determined in 4 cases. UVT afforded live birth of 9 of 10 infants with HDN and was not indicated in two cases. 相似文献