ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249043.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: Polyethylene glycol (PEG) has been shown to potentiate antigen‐antibody reactions.STUDY DESIGN AND METHODS: To investigate the utility of PEG in pretransfusion testing, a blinded comparison study of PEG and a low‐ionic‐strength additive solution (LISS) was conducted. A total of 500 patient samples were tested in parallel with reagent antibody‐detection cells using blind‐coded PEG and LISS potentiators.RESULTS: In 34 (34%) of 100 samples with known antibodies in the Rh, Kell, Duffy, Kidd, and MNS systems, PEG antiglobulin reactions were stronger (total score, 382) than LISS antiglobulin reactions (total score, 216), and in 66 cases (66%), they were equal to those of LISS. Of 400 samples without detectable antibodies, 384 were negative with PEG and LISS, and 16 were positive in PEG tests and negative in LISS. Seven of the 16 were clinically important antibodies (D, 1; E, 3; Fya, 1; Jka; 1; Jkb, 1), and four were clinically benign antibodies (Le(a), 2; McCc, 1; Sda, 1). Five of the 16 demonstrated inconclusive PEG reactions, for a false‐positive rate of 5 in 400 (1.3%). Of the 500 samples, none was negative in PEG tests and positive in LISS (0% false‐negative rate).CONCLUSION: Although PEG demonstrates a relatively high false‐positive rate, PEG is more sensitive than LISS in detecting clinically signifi

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249044.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: In December 1991, the United States Food and Drug Administration received reports of blood donations with unconfirmed reactivity on screening tests for antibodies to human immunodeficiency virus, human T‐lymphotropic virus type I, and hepatitis C virus (HCV). Of 91 donors with these test results, 57 (63%) reported a recent influenza vaccination.STUDY DESIGN AND METHODS: To determine the extent of unconfirmed reactivity, the time at which it began, and its association or nonassociation with specific manufacturers' tests, a nationwide survey of blood centers was conducted. A case‐donation was defined as a blood donation that was repeatedly reactive, but not confirmed positive, on at least two of the three tests from May 1990 through December 1991.RESULTS: Among 14 million donations screened by 110 centers, 582 case‐donations were identified. An increase in case‐ donations was evident in the fall of 1990 (2.8/100,000 donations). In 1991, rates increased from 0.9 per 100,000 donations in the first quarter to 1.3, 3.2, and 19.7 in subsequent quarters. A significantly higher rate of case‐donations was observed among donations tested with one of the two available anti‐HCV screening tests (8.0 vs. 1.2/100,000 donations; risk ratio = 6.8; 95% CI = 5.4–8.5).CONCLUSION: Although unconfirmed reactivity on multiple screening tests appeared to be seasonal, its documentation prior to the availability of influenza vaccine in 1991 and higher rates among donations tested with one manufacturer's anti‐HCV test indicated that test‐specific factors w

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249045.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: Most enzyme immunoassay‐reactive specimens producing indeterminate Western blot results belong to individuals who are not infected with human immunodeficiency virus type 1 (HIV‐1). However, a small percentage may correspond to early seroconversion or advanced disease, at which stage partial reactivity on Western blot may be observed.STUDY DESIGN AND METHODS: To determine the utility of HIV‐1 p24 antigen and cell‐free RNA detection for the resolution of Western blot‐indeterminate serologic results, several types of enzyme immunoassay‐positive, sero‐indeterminate specimens were analyzed. Samples were obtained from infected individuals at the time of seroconversion (n = 20), from patients with AIDS (n = 2), as specimens from clinical samples obtained for diagnostic testing (n = 57), from blood donors producing persistent indeterminate results (n = 47), and from random blood donors (n = 72).RESULTS: HIV‐1 p24 antigen was detected in 10 of 20 specimens collected from 9 of 12 individuals who seroconverted and in 2 of 2 AIDS patients. HIV‐1 plasma RNA was positive in 22 of 22 samples from those 14 individuals. All of 57 diagnostic specimens and 47 samples obtained from persistently indeterminate donors were negative for HIV‐1 p24 antigen and plasma HIV‐ 1 RNA. One of 72 blood donor specimens was positive for HIV‐1 plasma RNA and had borderline reactivity for p24 antigen.CONCLUSION: The detection of plasma RNA appears to be sensitive and specific; negative test results may be used to identify false‐positive serologic reactions. The detection of p24 antigen and plasma RNA can also be used to confirm HIV‐1 infection in persons with indeterminate serologic results associated with early seroconve

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249046.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: As clinical diagnosis of heparin‐associated thrombocytopenia (HAT) is often difficult, confirmation by sensitive laboratory assays is desirable.STUDY DESIGN AND METHODS: The sensitivity of the heparin‐induced platelet activation (HIPA) test and the platelet aggregation test (PAT) was prospectively compared by using the sera of 209 patients with the putative diagnosis of HAT. Both assays were performed concomitantly with platelets of the same four donors using a different combination of donors from day to day. Further, all sera were assessed with a platelet factor 4 (PF4)/heparin enzyme‐linked immunosorbent assay (ELISA).RESULTS: Positive results were obtained with 33 percent of sera in the PF4/heparin ELISA, with 33.5 percent of sera in the HIPA test, and with 11.5 percent of sera in the PAT. The PF4/heparin ELISA and the HIPA test showed no difference in sensitivity (p = 0.27 by McNemar's test) and were more sensitive than PAT (p<10(‐8) by McNemar's test). However, they recognized different patient cohorts. Nine HIPA‐indeterminate and 12 HIPA‐negative sera were positive in the PF4/heparin ELISA. Eight of the nine indeterminate sera caused platelet activation with high heparin concentrations in the HIPA test. Eleven of the 12 negative sera contained no IgG, but 9 contained IgM and 2 contained IgA HAT antibodies. Four sera that were indeterminate in the PF4/heparin ELISA and 18 sera that were negative were positive in the HIPA test. None of the sera that were positive in the PAT was missed in the HIPA test, but two of those were negative in the PF4/heparin ELISA. All sera were assessed with four low‐molecular‐weight heparins and a low‐molecular‐ weight heparinoid in the HIPA test with platelets from the same four donors. Low‐molecular‐weight heparin caused platelet activation with positive sera in 98 percent of tests, and the heparinoid did so in 10 percent; in a further 12.8 percent, crossreactivity to the low‐ molecular‐weight heparinoid could not be excluded.CONCLUSION: The majority of HAT antibodies react with a PF4/heparin complex, but there is strong evidence that other antigens are involved in some patients. The HIPA test and the PF4/heparin ELISA are sensitive for diagnosing HAT, and

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249047.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: Concern about the transmission of human immunodeficiency virus via blood has substantially increased the public's anxiety about the safety of the blood supply and has encouraged practices to minimize risks deriving from transfusions.STUDY DESIGN AND METHODS: To assess changes in transfusion practices in elective surgery as awareness of transfusion‐transmitted human immunodeficiency virus emerged, 80 randomly selected patients per year undergoing elective total hip replacement in five calendar years between 1977 and 1989 at a large university teaching hospital were studied.RESULTS: Total blood use decreased significantly from an average of 3.3 units per patient in 1977 to 2.1 units per patient in 1989 (p = 0.0003). Autologous blood use increased from essentially zero in 1977 to 82 percent of total blood use in 1989 (p<0.0001). The threshold hematocrit for postoperative transfusion of allogeneic blood (defined by use of logistic regression models) decreased from 30.1 percent (0.30) in 1977 to 26.7 percent (0.27) in 1989 (p = 0.01). As a result of these changes, the proportion of patients exposed to allogeneic blood decreased from 90 to 16 percent across the study period (p<0.0001). The dramatic decrease in the use of allogeneic blood in elective total hip replacement surgery during the study period was due to decreased demand for blood during and after the operation and to a striking shift in the blood supply from allogeneic to autologous sources.CONCLUSION: These findings demonstrate that physicians can appropriately alter practices when there are perceived health risk

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249048.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: The provision of a safe and sufficient supply of blood is critical to patient care.STUDY DESIGN AND METHODS: A survey was conducted of the blood collection activity of the 189 community blood centers operating in the United States from 1988 through 1992. Data were analyzed by source of the donation (allogeneic or autologous), by center's collection volume, and by geographic region. Total collection figures were compared to historical blood collection activity since 1970.RESULTS: A total of 12.31 million units of blood were collected in 1992, an increase of 2.6 percent over the total number of units collected in 1988. For the 5‐year period (1988–1992), total collections increased at a compound annual growth rate of 0.6 percent. The collection of allogeneic blood units declined by 0.2 percent annually, while that of autologous units increased by 23.2 percent annually. Autologous blood units accounted for 5.7 percent of total collections in 1992. Nationally, 48 units were collected per 1000 people in 1992, although substantial geographic variation (range, 38–64 units/1000) was observed across nine US census regions.CONCLUSION: The data from this study provide evidence that the total supply of blood grew more slowly from 1988 through 1992 than in the years before

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249049.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: A transfusion threshold of 7 g per dL (70 g/L) of hemoglobin has been proposed for patients, although scant human data are available to support this recommendation.STUDY DESIGN AND METHODS: The medical community's experience with Jehovah's Witnesses was examined, in order to assess the lowest tolerable hemoglobin concentration and the lower transfusion threshold of 7 g per dL (70 g/L) of hemoglobin. A MEDLINE search was conducted to capture medical and surgical reports involving Jehovah's Witnesses from 1970 through early 1993.RESULTS: Sixty‐one reports of untransfused Jehovah's Witnesses with hemoglobin concentrations

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249050.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: Expensive devices have been developed for the collection and transfusion of blood salvaged after hip or knee arthroplasty.STUDY DESIGN AND METHODS: The volume of salvaged red cells was measured for the first 6 hours after operation. This volume was compared to total red cell loss during hospitalization and to the volume of allogeneic red cells transfused.RESULTS: Mean postoperative red cell loss in 31 patients following hip replacement was 55 ± 29 mL and that in 20 patients following knee replacement was 121 ± 50 mL. The 6‐hour wound drainage represented 8.7 and 16.8 percent of overall red cell loss during hospitalization for hip and knee replacement, respectively. The transfusion of postoperatively salvaged red cells would have supplanted transfusion of less than one‐third of a unit of allogenic blood after hip replacement and two‐thirds of a unit after knee replacement. Only three patients (5.9%) lost red cell volume in the drainage equivalent to or in excess of 1 unit of red cells (180 mL). The volume of red cells salvaged postoperatively bore no relationship to perioperative red cell losses as a whole.CONCLUSION: The relatively small red cell loss in the postoperative period in most arthroplasty patients does not appear to justify the routine use of this technique for the recovery of autologou

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249051.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY

摘要:

BACKGROUND: Platelet concentrates (PCs) for premature infants may be subjected to filtration, centrifugation, and various storage conditions before transfusion.STUDY DESIGN AND METHODS: As there are few data on the cumulative effect of these procedures on PCs, platelet properties (including biochemical and functional in vitro assays) were evaluated after the processing of single units of PCs through a 1‐unit‐capacity high‐efficiency white cell (WBC)‐reduction filter followed by syringe storage at either 22 or 37 degrees C for 6 hours. Two‐ and 5‐day‐old PCs, volume‐reduced PCs, and prestorage WBC‐reduced PCs were evaluated.RESULTS: WBC filtration consistently resulted in a 3 to 4 log10 reduction in WBCs, with less than 15‐percent platelet loss. No adverse effects of platelet function or evidence of increased platelet activation as determined by the percentage of P‐selectin positivity were noted. A decrease in pH associated with increased lactate production and consumption of glucose was observed following syringe storage under all conditions tested. Such changes were most pronounced, however, with volume‐reduced PCs stored at 37 degrees C (pH 6.31 ± 0.15, lactate 23.0 ± 3.06 mmol/L). All pH levels at the end of storage were above the minimum Food and Drug Administration requirement (pH 6.0).CONCLUSION: The in vitro data suggest that single units of PCs can undergo WBC filtration followed by syringe storage for up to 6 hours and still maintain acceptable storage characteristics. The practice of maintaining volume‐reduced PCs in syringes for 6 hours at 37 degrees C in isolettes during transfusion

ISSN:0041-1132    

DOI:10.1046/j.1537-2995.1994.34594249052.x

出版商:Blackwell Science Ltd    

年代:1994

数据来源: WILEY