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BACKGROUND Alloimmunization through blood transfusion, transplantation, or circulating fetal cells during pregnancy is a significant concern. Some exposed individuals make alloantibodies while others do not, implying variation in genetic risk factors. STUDY DESIGN AND METHODS We conducted a genomewide association study (GWAS) of 9,427,497 single-nucleotide polymorphisms (SNPs) to identify genetic variants for HLA alloimmunization in previously pregnant blood donors with (n = 752) and without (n = 753) HLA Class I or II alloantibodies. RESULTS A SNP in the neurexophilin 2 (NXPH2) gene surpassed genome-wide significance (p = 2.06 × 10-8 ), with multiple adjacent markers p

BACKGROUND Prevalence estimates of the serious hazards of transfusion vary widely. We hypothesized that the current reporting infrastructure in the United States fails to capture many transfusion reactions and undertook a multicenter study using active surveillance, data review, and adjudication to test this hypothesis. STUDY DESIGN AND METHODS A retrospective record review was completed for a random sample of 17% of all inpatient transfusion episodes over 6 months at four academic tertiary care hospitals, with an episode defined as all blood products released to a patient in 6 hours. Data were recorded by trained clinical research nurses, and serious reactions were adjudicated by a panel of transfusion medicine experts. RESULTS Of 4857 transfusion episodes investigated, 1.1% were associated with a serious reaction. Transfusion-associated circulatory overload was the most frequent serious reaction noted, being identified in 1% of transfusion episodes. Despite clinical notes describing a potential transfusion association in 59% of these cases, only 5.1% were reported to the transfusion service. Suspected transfusion-related acute lung injury/possible transfusion-related acute lung injury, anaphylactic, and hypotensive reactions were noted in 0.08, 0.02, and 0.02% of transfusion episodes, respectively. Minor reactions, including febrile nonhemolytic and allergic, were noted in 0.62 and 0.29% of transfusion episodes, respectively, with 30 and 50% reported to the transfusion service. CONCLUSION Underreporting of cardiopulmonary transfusion reactions is striking among academic, tertiary care hospitals. Complete and accurate reporting is essential to identify, define, establish pathogenesis, and mitigate/treat transfusion reactions. A better understanding of the failure to report may improve the accuracy of passive reporting systems.

Alloimmunization through blood transfusion, transplantation, or circulating fetal cells during pregnancy is a significant concern. Some exposed individuals make alloantibodies while others do not, implying variation in genetic risk factors.We conducted a genomewide association study (GWAS) of 9,427,497 single-nucleotide polymorphisms (SNPs) to identify genetic variants for HLA alloimmunization in previously pregnant blood donors with (n = 752) and without (n = 753) HLA Class I or II alloantibodies.A SNP in the neurexophilin 2 (NXPH2) gene surpassed genome-wide significance (p = 2.06 × 10Further work to extend the GWAS approach and to characterize variants in NXPH2 and E2F7 in the context of alloantibody formation is warranted.

Background and Objectives Human neutrophil antibodies (HNA) have been associated with severe transfusion-related acute lung injury (TRALI). We identified HNA antibodies in a blood donor population and performed an observational lookback on patients who received products from these donors to determine whether TRALI was associated with these transfusions. Materials and Methods Human neutrophil antibodies were determined in 1171 blood donors (388 non-transfused males, 390 human leucocyte antigen (HLA) antibody–negative females and 393 HLA antibody–positive females) for IgG and IgM antibodies using a flow cytometric assay. Selected positive samples had a monoclonal antibody immobilization of granulocyte antigen (MAIGA) and neutrophil genotyping performed to confirm specificity. Lookback was performed on patients receiving blood from donors with positive samples by extracting recipient data from hospital medical records. An expert panel of three pulmonary critical care physicians reviewed the summarized data and assigned a diagnosis of TRALI, possible TRALI, cannot distinguish between TRALI and TACO, TACO and other. Results Eight donors had HNA antibodies of which five contributed to this lookback (3-HNA-specific antibodies, 2-HNA non-specific antibodies). Seventy-six blood products were transfused from these donors into individual patients. One patient developed TRALI that was associated with a donor with a non-specific HNA antibody as well as class-I and class-II HLA antibodies. Conclusion The incidence of TRALI in this lookback was low and combined with low frequency of HNA antibodies in the donor population suggests not screening donors for HNA antibodies at this time is acceptable.

BACKGROUND: The importance of adverse reactions in terms of donor safety recently has received significant attention, but their role in subsequent donation behavior has not been thoroughly investigated. STUDY DESIGN AND METHODS: Six REDS-II blood centers provided data for this analysis. Summary minor and major adverse reaction categories were created. The influence of adverse reactions on donation was examined in two ways: Kaplan-Meier curves were generated to determine the cumulative pattern of first return, and adjusted odds ratios (AORs) for demographic and other factors positively and negatively associated with return were estimated using multivariable logistic regression. RESULTS: Donors who had major reactions had longer times to return than donors with minor or no reactions. The AOR of returning for donors with major reactions was 0.32 (95% confidence interval [CI], 0.28-0.37) and with minor reactions 0.59 (95% CI, 0.56-0.62) when compared to donors who did not have reactions. Conversely, the most important factors positively associated with return were the number of donations in the previous year and increasing age. Subsequent return, whether a major, minor, or no reaction occurred, varied by blood center. Factors that are associated with the risk of having adverse reactions were not substantial influences on the return after adverse reactions. CONCLUSION: Having an adverse reaction leads to significantly lower odds of subsequent donation irrespective of previous donation history. Factors that have been associated with a greater risk of adverse reactions were not important positive or negative predictors of return after a reaction.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related deaths in the United States. Thirty-five percent of the deaths reported to the US Food and Drug Administration in the federal fiscal year 2008 were attributed to TRALI;1 this percentage decreased to 30% in the federal fiscal years 2009.2 The AABB issued an association bulletin on TRALI mitigation in November 2006 recommending that member blood centers minimize the preparation of high-plasma-volume components from donors known to be white blood cell (WBC) alloimmunized or at increased risk for WBC alloimmunization.3 In response to these recommendations, many blood collection agencies have restricted the distribution of plasma for transfusion to plasma that is derived from male donors as much as possible, with diversion of plasma from female donors to recovered plasma for use in manufacturing derivatives. While this approach is practical for blood group A and O plasma products, it might be more difficult to collect sufficient group B and AB plasma products exclusively from male donors to support the need for transfusable plasma. The AABB also recommended mitigation steps for apheresis platelet (PLT) components. However, there is no excess of apheresis PLT products from male donors; therefore, TRALI mitigation steps must consider alternative approaches for TRALI reduction than simply the use of male-only donors. In response to the need for data on the prevalence of WBC alloimmunization in blood donors, the National Institutes of Health–funded Retrovirus Epidemiology Donor Study-II (REDS-II) initiated an investigation of the prevalence of antibodies to human leukocyte antigens (HLA) and/or human neutrophil antigens (HNA) among blood donors from six geographically dispersed US blood collection centers. The REDS-II Leukocyte Antibody Prevalence Study-I (LAPS-I) reported that the prevalence of HLA Class I and/or HLA Class II antibodies was similar in nontransfused (1.0%) versus transfused men (1.7%) and that 24.4% of female donors with a history of a previous pregnancy had HLA antibodies.4 This study estimates the prevalence of WBC alloimmunization according to the pregnancy and transfusion history of allogeneic blood donors at each of the REDS-II blood centers. These data, together with the data from the LAPS-I study,4 were used to compare the impact of the implementation of the AABB TRALI mitigation strategies among six different blood centers.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. Blood centers are implementing TRALI risk reduction strategies based on screening apheresis donors for antibodies to human leukocyte antigens (HLA). STUDY DESIGN AND METHODS: HLA antibody screening was performed on 7920 blood donors from the Leukocyte Antibody Prevalence Study (LAPS) using Luminex-based normalized background (NBG) cutoff ratios of 10.8 (Class I) and 6.9 (Class II). Single antigen bead (SAB) assay cutoffs of 2500 median fluorescence intensity units (Class I) and 1500 (Class II) were established based on results of two subpopulations of LAPS donors. Antibody frequencies against HLA A, B, C, DR, DQ, and DP antigens were determined for screen-reactive donors with prior pregnancies. RESULTS: SAB reactivity for samples above our multiantigen bead NBG cutoffs was 78% for Class I and 79% for Class II. The SAB-positive rate increased among women with zero to four or more pregnancies (0.3%-15.6% Class I and 0.4%-18% Class II; p

BACKGROUND: HLA antibody testing of previously transfused or pregnant donors may help reduce the risk of transfusion-related acute lung injury (TRALI). However, the prevalence of HLA antibodies in transfused donors has not been well characterized. STUDY DESIGN AND METHODS: Transfusion and pregnancy history was obtained from consenting donors. HLA Class I and II antibody testing was performed by multiantigen bead Luminex platform. Cutoff values for Class I and II antibodies used normalized background ratios of 10.8 and 6.9, respectively. Linear probability models were used to evaluate potential associations between HLA alloimmunization and donor characteristics. RESULTS: A total of 7920 donors (2086 males and 5834 females) were tested. HLA antibody prevalence did not significantly differ between 895 transfused (1.7%) and 1138 nontransfused males (1.0%; odds ratio [OR], 1.75; 95% confidence interval [CI], 0.80-3.82]. Prevalence in 45 transfused nulliparous females (4.4%; 95% CI, 0.1%-11.8%) was not different from the 1.6% prevalence in 1732 nontransfused nulliparous females (OR, 2.94; 95% CI, 0.68-12.74). Transfused parous females had higher prevalence than nontransfused counterparts (p = 0.004; OR, 1.39; 95% CI, 1.07-1.80). In a linear probability model, the estimated additive risk of transfusion-induced alloimmunization was only 0.8% (95% CI, −0.2% to 1.8%; p = 0.10). Donor transfusion history showed that 58% of transfusions occurred more than 10 years previously. CONCLUSION: Transfused volunteer blood donors do not appear to have a significantly higher prevalence of HLA antibodies than their nontransfused counterparts. Thus, in an effort to reduce TRALI risk, ascertaining past history of transfusion and testing these donors for HLA antibodies is not necessary.

BACKGROUND: Antibodies to human leukocyte antigens (HLA) in donated blood have been implicated as a cause of transfusion-related acute lung injury (TRALI). A potential measure to reduce the risk of TRALI includes screening plateletpheresis donors for HLA antibodies. The prevalence of HLA antibodies and their relationship to previous transfusion or pregnancy in blood donors was determined. STUDY DESIGN AND METHODS: A total of 8171 volunteer blood donors were prospectively recruited by six US blood centers from December 2006 to May 2007. Donors provided a detailed history of pregnancy and transfusion and a sample for HLA Class I and II antibody testing by multiantigen bead flow analysis. RESULTS: A total of 8171 donors were enrolled; 7920 (96.9%) had valid HLA antibody test results and 7841 (99%) of those had complete pregnancy and transfusion information. The prevalence of any HLA antibody was similar in nontransfused (n = 1138) and transfused (n = 895) men, 1.0% versus 1.7% (p = 0.16). HLA antibodies were detected in 17.3% of all female donors (n = 5834) and in 24.4% of those with a history of previous pregnancy (n = 3992). The prevalence of HLA antibodies increased in women with greater numbers of pregnancy: 1.7% (zero), 11.2% (one), 22.5% (two), 27.5% (three), and 32.2% (four or more pregnancies; p < 0.0001). CONCLUSION: HLA Class I and Class II antibodies are detectable at low prevalence in male donors regardless of transfusion and in female donors without known immunizing events. The prevalence of HLA antibodies increases significantly with more pregnancies. These data will allow blood centers to estimate the impact of HLA antibody testing as a potential TRALI risk reduction measure.

BACKGROUND: Primary care physicians commonly care for patients whose disabilities caused by cardiovascular diseases result in difficulty driving an automobile. Patients often seek their physician's advice as to whether they can continue to drive safely. METHODS: A MEDLINE literature search was performed from 1966 to 2000, using the query terms "automobile driving" and "automobile driving and cardiac." Selected articles were reviewed, as well as additional articles found through review of the references. In some cases articles were found by searching the Internet using the above key words and new query terms guided by the results of the original search. RESULTS AND CONCLUSIONS: The most important factor determining eligibility is whether the patient reports manifestations of cerebral hypoxia. Laboratory procedures are available for patients in whom the decision is difficult. Sometimes a referral to a specialist is needed. Many patients with a known cardiovascular disorder can continue to drive safely. Some conditions require a waiting period before driving can be resumed, while others call for a complete cessation of driving. Several guidelines from the literature are listed that can be helpful to primary care physicians when dealing with questions from their patients on this important topic. Language: en

The role of physicians in deciding whether a patient should continue to drive is purely advisory. However, physicians have a moral and, in some states, a legal obligation to report patients who are no longer fit to drive. The most authoritative test to predict safe driving in the elderly is an on-road evaluation conducted by the state driver's licensing authority, which has ultimate responsibility for deciding a patient's fitness to drive. Patients with mild dementia are generally considered safe drivers, although specialized testing, such as an on-road test, may be indicated. Those with moderate dementia can be further evaluated by the on-road test, since psychological testing to distinguish moderate from mild dementia is imprecise. Severe dementia is generally considered a contraindication to driving. When a patient is deemed unfit to drive, the physician can provide counseling and support to help ease the transition away from driving.

A 24-year old female, gravida ΠI, para ΠI, delivered a full-term infant by cesarean section. A maternal blood sample at the time of admission showed antibody in her serum that had apparent anti-e specificity and that her RBCs were e+. Further studies determined that the antibody was anti-hrs. Cord RBCs had a negative DAT and a normal Hb level. There was no clinical evidence for increased hemolysis in the infant. We describe an hrs+ infant with no evidence of HDN due to anti-hr5.

Anti-Ku seen in K0(Kell-null) individuals has previously been shown to cause severe hemolytic transfusion reactions. Maternal anti-Ku can cause none or moderate to severe hemolytic disease of the fetus and newborn (HDFN). In two of four previously described HDFN cases, intrauterine transfusions were required because of severe anemia. We report a case in which maternal anti-Ku did not cause HDFN. Standard serologic methods were used for RBC antibody screening and identification, adsorption and elution of RBC antibodies, and antigen typing. A gravida 3, para 3 (G3P3) woman was first evaluated in 2006 and was found to have an IgG RBC antibody that reacted against all panel RBCs in the anti-human globulin phase. A panel of RBCs treated with DTT did not react with the antibody. The antibody failed to react with one example of K0 RBCs. The patient’s RBCs typed negative for the following Kell blood group antigens: KEL1, KEL2, KEL3, KEL4, KEL6, KEL7, KEL11, KEL13, and KEL18. These results established the presence of anti-Ku in maternal serum. The newborn was group A, D+ and required phototherapy for hyperbilirubinemia, but did not require transfusion. The woman was seen again in January 2010 during the third trimester (G4P3). At this time, anti-Ku titer was 256. She delivered a healthy group O, D+ baby boy at 37 weeks’ gestation. Cord RBCs were 4+ for IgG by DAT. An eluate reacted with all RBCs tested, but did not react when tested against a panel of DTT-treated RBCs. K0phenotype is rare to begin with, and the maternal anti-Ku formation may require more than one pregnancy. Therefore, cases that can be evaluated for anti-Ku–related HDFN are rare. Our case contributes to serologic and clinical aspects of such rare cases. Immunohematology 2010;26:119–122.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. Blood centers are implementing TRALI risk reduction strategies based on screening apheresis donors for antibodies to human leukocyte antigens (HLA).HLA antibody screening was performed on 7920 blood donors from the Leukocyte Antibody Prevalence Study (LAPS) using Luminex-based normalized background (NBG) cutoff ratios of 10.8 (Class I) and 6.9 (Class II). Single antigen bead (SAB) assay cutoffs of 2500 median fluorescence intensity units (Class I) and 1500 (Class II) were established based on results of two subpopulations of LAPS donors. Antibody frequencies against HLA A, B, C, DR, DQ, and DP antigens were determined for screen-reactive donors with prior pregnancies.SAB reactivity for samples above our multiantigen bead NBG cutoffs was 78% for Class I and 79% for Class II. The SAB-positive rate increased among women with zero to four or more pregnancies (0.3%-15.6% Class I and 0.4%-18% Class II; p0.00001). The highest frequency antibodies were DR11 and B15 (4.4% of women with prior pregnancies). The majority of Class I positives contained more than five specificities. For Class II, antibody-positive women segregated into two groups: a single specificity or more than five specificities.Identification of HLA antigen specificities supports pregnancy associations previously found with screening assays. The significance of particular HLA specificities for inducing TRALI is currently being evaluated in a large lookback study of recipients of high-plasma-volume components from this donor cohort.

BACKGROUND: The Kell blood group system consists of 25 antigens that result from single-nucleotide polymorphisms. Most polymorphic Kell antigens reside on the N-terminal domain of Kell before the zinc-binding catalytic motif, which is the major site for endothelin-3–converting enzyme activity. Kell antigens are important in transfusion medicine owing to their strong immunogenicity, and the corresponding antibodies are clinically significant. Two probands were studied whose serum samples contained antibodies to different high-prevalence Kell antigens. STUDY DESIGN AND METHODS: Standard hemagglutination methods were used for serologic testing of Proband 1 and Proband 2. DNA was prepared from both probands and family members. The 19 exons and the intron-exon regions of KEL from both probands were amplified by polymerase chain reaction, and the sequences were compared with that of common KEL. The identified substitutions were located on a three-dimensional model of Kell generated based on the crystal structure of neutral endopeptidase, a homolog of Kell. RESULTS: In Proband 1, a homozygous 1988G>A mutation (Arg623Lys) in Exon 17 was present. One sibling of Proband 1 was homozygous for 1988G>A. In Proband 2, a homozygous 1033G>A mutation (Asp305Asn) in Exon 8 was present. Three siblings of Proband 2 were heterozygous for 1033G>A. CONCLUSION: The identified KEL mutations of the two probands are novel and inherited. The antigen absent from the red blood cells (RBCs) of Probands 1 and 2 are named KALT and KTIM, respectively. KALT is unique in that it is the only Kell antigen sensitive to treatment of RBCs by trypsin.

An immune complex mechanism for ceftriaxone sodium– induced severe autoimmune hemolytic anemia has previously been demonstrated using routine blood bank techniques. We describe herein a patient with severe hemolysis that subsided once the drug was discontinued. Serologic techniques demonstrated immune complex–mediated ceftriaxone-dependent red cell antibodies. These findings were further supported by the results of flow cytometry, in which a change in basal red cell autofluorescence was seen in the presence of the antibody and the drug. Our case illustrates the adjunctive value of flow cytometry in the diagnosis of ceftriaxone-dependent red cell antibody.

A survey of 19 large blood centers, each with an average annual collection of 158,889 units, was conducted to identify current practices of management of red cell units that contain unexpected red cell antibodies. The routine antibody identification, distribution, and charge for such units varied widely among the 19 centers. In addition, although use of these units was low, costs were considerable. This survey can serve as a basis for other studies to arrive at cost-effective ways to manage such units. Immunohematology 1994;10:99–101.

Tissue bankers, as well as those transplanting tissues, have been sensitized to the possibility of transmission of fatal infection via tissue transplants, particularly following recent reports of a few cases of AIDS or HIV infection from bone, semen, and skin grafts. It is beyond the scope of this review to describe the steps taken by tissue banks to enhance the safety of tissue transplants. Of note is the fact that a number of new donor screening tests, such as those for antibody to HIV, HBcAg, hepatitis C virus, and human T cell lymphotropic virus type I, have recently been implemented. In addition, rapid advances in the medical history screening of tissue donors and tissue procurement, processing, and preservation continue. Viral inactivation studies are also being undertaken. All these measures are being introduced to increase the safety of tissue transplants.

Background: Our blood center began routine screening of Single Donor Platelets, Pheresis (SDP) for bacteria on December 15, 2003 using aerobic culture bottles with the BacT Alert® 3D System. SDP units are held a minimum of 24 hours prior to sampling and then are labeled and released while the culture bottles are incubated for five days. Case Study: A 77-year old female donated a SDP and concurrent Plasma. Pre-donation platelet count was 328 x103/μL and hemoglobin level was 15.0 g/dL. Collection was uneventful with no error codes received from the equipment. Sample for was obtained on day-1, inoculated in an aerobic culture bottle, and incubated. The inoculated bottle showed growth of bacteria at 19.6 hours of the culture period. SDP had not been distributed and was recultured. Repeat culture was performed on day-2 and it also showed growth at 13.4 hours. The concurrent plasma was thawed and cultured and did not show any growth. A gram stain of the positive culture bottle revealed gram-positive cocci in chains that were later identified as Streptococcus viridans. The donor was notified of the culture results. The donor denied any skin rash or infection, sore throat, fractures, heart or lung conditions. She denied fever, chills or any acute illness. Her chronic conditions included hypertension treated with Lisinopril. She was also receiving thyroid replacement for hypothyroidism and Asiphex for gastro esophageal reflux disease (GERD). She denied any GI or GU symptoms. The culture results were mailed to the donor so that she could share them with her personal physician. The donor is a frequent apheresis donor and has donated 54 SDPs over the past seven years. Three previous donations immediately prior to the current donation were found to be negative after 5-day culture. On day 18, the donor felt weak and tired but without fever or other symptoms and she went to see her physician. The physician obtained a blood culture that grew bacteria the next day. Further testing identified the organism as Streptococcus salivarius, a viridans species. Donor was then hospitalized for five days to begin intravenous Ceftriaxone. Further antibiotic treatment was given at home via a peripherally inserted central (PIC) line. The donor had a three-year history of a benign heart murmur. The PIC line was removed with the completion of the antibiotic treatment on day 65. The donor remained asymptomatic throughout the treatment. Two trans-thoracic and two trans-esophageal echocardiograms were negative for bacterial endocarditis. However, mild idiopathic hypertrophic subaortic stenosis was discovered. The donor had dental work done two months prior to the time the bacteremia was found. However, she had one SDP donation that was culture negative after the dental work. The cause of the donor’s bacteremia remains obscure. Discussion: Although the screening of Platelets, Pheresis is for the protection of the patient who will receive the product, this case shows that the detection of the bacteria also may benefit the donor. In our case, aymptomatic Streptococcus viridans bacteremia would not have been recognized if it were not detected by culturing her SDP. The donor was grateful for the information that lead to the early detection of blood stream infection that resulted in successful treatment. The donor continues to ask that she be able to donate when eligible.

Reactivity of high-incidence antigens after glycine-EDTA treatment of red blood cells (RBCs) to prepare artificial Ko RBCs was investigated. The treatment had little or no effect on Yta, JMH, Yka, Kna, and McCa. Hy antigen-positive-treated RBCs reacted less well with anti-Hy when compared to nontreated cells. Glycine-EDTA treatment to prepare Ko RBCs offers an advantage over AET treatment because it preserves some high-frequency antigens that AET treatment does not.

A pheresis procedure was devised to isolate young red cells by centrifugation using the Fenwal CS 3000 continuous flow cell separator. Young red cell enriched products were collected in a 2.5-3-hour procedure. Large numbers of white cells and platelets were collected with the red cells, but cryopreservation and subsequent washing removed 99% of the contaminating cells. At the completion of all processing a product yielding 70% of the total hemoglobin content of a standard frozen/deglycerolized red cell unit was produced. Autologous radiochromium survival of young red cells, measured in 12 normal donors, showed an average 24-hour recovery of 89.9% with a T50Cr of 40.8 days. In paired autologous studies (N = 4) there was a mean increase of 35% in the observed T50Cr of young red cells as compared to standard frozen red cells.

The influence of the size of the container on platelet concentrate storage at 20-24 degrees C was examined. Baseline studies were obtained with 50 platelet concentrates in 300-ml PL-146 plastic containers. Experimental studies included 6 platelet concentrates each in 300-, 600- and 2,000-ml containers made of PL-146 plastic. Platelet count, total platelets, pO2, pCO2, pH, glucose consumption, lactate production, platelet morphology and recovery by platelets to osmotic stress were monitored during storage. During storage, the best pH and morphology values were observed with 2,000-ml containers. The lowest glucose consumption and lactate production were also associated with the 2,000-ml containers. Intermediate improvement in these parameters was noted in 600-ml containers. Recovery from osmotic stress was better in 2,000- and 600-ml containers as compared to 300-ml containers. In addition, characteristic changes in pO2 and pCO2 during storage suggest that improved platelet preservation in larger containers is due to improved gas exchange conditions obtained with increased surface area available for gas exchange.

We employed four crossmatch techniques to select platelet donors for refractory patients. Forty-four donor-recipient pairs were studied in 32 patients. Analysis of effectiveness of platelet transfusions revealed that only 18 percent of transfusions gave a borderline response; the remainder were either effective or not effective at all. The corrected predictive values of three crossmatch tests were as follows: enzyme-linked immuno-specific assay, 81 percent; platelet immunofluorescence test, 73 percent; and lymphocytotoxicity, 70 percent (p greater than 0.05). The predictive value of these tests did not differ in HLA-matched versus unmatched platelet transfusions. Donor selection by lymphocytotoxicity compatibility did not appear to be useful if donors were selected by either of the other two methods. The fourth test, antiglobulin-modified lymphocytotoxicity, offered no advantage over lymphocytotoxicity. Our data suggest that platelet crossmatching assays are a useful adjunct to the selection process for the platelet donor in addition to ABO, Rh, and HLA matching.

A new blood container material (PL 1240 plastic) made of polyvinyl chloride containing a tri(2-ethylhexyl) trimellitate plasticizer was evaluated in three laboratories. When platelet concentrates (50–60 ml) were stored on a variety of agitators for 7 days at 22 ± 2°C, poststorage pH (mean ± SD) ranged from 7.29 ± 0.05 (6 rpm elliptical rotator) to 6.87 ± 0.8 (70 cycles per minute flatbed agitator). The platelet counts ranged from 1.51 ± 0.12 to 0.95 ± 0.36 × 106 per μ|. Morphology scores and hypotonic shock response values of platelets stored 7 days in PL 1240 plastic containers were better than those noted following 3-day storage of control platelets in PL 146 plastic containers. The percent discharge of lactic dehydrogenase from platelets stored 7 days in PL 1240 plastic containers for 3 days (p < 0.05). Mean platelet recoveries of 44 ± 15 percent (n = 11; 111Indium) and 39 ± 8 percent (n = 29; 51Chromium) were seen when autologous platelets were infused following 5-day storage in PL 1240 plastic bags. Platelet half-lives of 3.6 ± 0.4 (n = 9) 4.1 ± 0.4 (n = 20) days were reported in the two laboratories which used 51Cr labeling, while survival values of 7.0 ± 1.0, 2.8 ± 0.8, and 5.4 ± 1.9 days were seen when data from the 111Indium studies (n = 11) were analyzed using linear, exponential, and multiple hit programs, respectively. Platelets stored for 5 days also were administered to 13 thrombocytopenic oncology patients. In eight instances, a second (control) transfusion of platelets stored 2 to 5 days in PL 732 plastic containers was given to the recipient. There was no difference seen in postinfusion corrected platelet increments (15.6 ± 12.1 × 103/μ| versus 15.2 ± 10.4 × 103/μ| per m2/1011 platelets infused) for cells stored in PL 1240 and PL 732 plastic containers, respectively. Hemostatic efficacy was seen posttransfusion in all four bleeding recipients. We conclude that platelets stored in PL 1240 plastic containers for 5 days are safe and efficacious for use in clinical transfusion practice.

Regional blood centers frequently need to hold units of whole blood at 20 to 24 degrees C for several hours after phlebotomy so that sufficient platelet concentrates can be prepared to meet the increasing need. We have evaluated the in vivo viability and in vitro properties of platelets that were prepared from whole blood drawn into citrate-phosphate-dextrose-adenine (CPDA-1) either immediately after phlebotomy or after an 8-hour hold at 20 to 24 degrees C. Platelet concentrates were stored for 5 days at 20 to 24 degrees C in polyolefin containers (PL 732, Fenwal) with end-over-end tumbler agitation. The autologous in vivo recovery (mean +/- SD) and one-half disappearance of 51Cr-labeled platelets prepared immediately after phlebotomy were 44.4 +/- 9.4 percent and 4.0 +/- 0.5 days, respectively. Platelets prepared after the delay of 8 hours showed a recovery of 44.5 +/- 8.4 percent and a one-half disappearance of 4.1 +/- 0.4 days. After 5 days of storage, platelet concentrates showed a mean pH of 7.21 +/- 0.20 when prepared immediately after phlebotomy, and of 7.22 +/- 0.15 when prepared after an 8-hour delay. Mean morphology scores were 280 +/- 33 and 302 +/- 27 for platelets from units prepared immediately after phlebotomy or after a holding period of 8 hours, respectively. Platelets underwent synergistic aggregation after 5 days of storage, independent of the length of time that the units of whole blood were held prior to centrifugation. These studies indicate that platelet concentrates prepared from units of whole blood held initially for 8 hours can be stored for 5 days at 20 to 24 degrees C and survive satisfactorily in vivo and retain in vitro characteristics.

To determine the degree of platelet damage produced by different modes of agitation during storage of concentrates for 5 days in CLX blood bags, we studied pH, platelet counts, release of LDH and beta thromboglobulin, morphology and osmotic recovery. Platelets were maintained at 20-24 degrees C on elliptical, 6-rpm circular, 2-rpm circular and flat bed agitators. At 72-120 h platelet concentrates stored on the flat bed shaker had significantly lower pH values than units stored on the elliptical or on either of the circular rotators (p less than 0.05). The percent LDH discharged was highest for the units stored on the elliptical rotator (p less than 0.05). Remaining tests of platelet function were not significantly different for concentrates stored on any of the four agitators. Flat bed shakers were unable to resuspend the platelet 'button' which formed after the final preparative centrifugation. Based on our in vitro studies, we conclude that due to problems with low pH values, flat bed shakers may not be optimal for storing platelet concentrates in CLX blood bags and that some other form of agitation should be used.

Two preparations of fresh frozen plasma were studied. The plasma from CPDA-1 whole blood units was either frozen within 6 h (FFP-I) or 18-20 h (FFP-II) of phlebotomy. Average activity for factor VIII for FFP-I (n = 6) and FFP-II (n = 19) was 102% and 55%, respectively (p less than 0.01). Average activity for factor V and VII in both products was approximately 100%. Factor XI activity (n = 13) in FFP-II averaged 84%. We conclude that FFP-I and FFP-II are equivalent in terms of coagulation factor activity except for factor VIII.

In this report, a case of rifampin-induced immune thrombocytopenia with the following characteristics is described: (a) thrombocytopenia follows intermittent drug administration; (b) onset occurs within hours of drug ingestion; (c) IgG antirifampin antibody binds in vitro to normal platelets only in the presence of rifampin; (d) thrombocytopenia resolves quickly in the absence of rifampin; (e) using immunofluorescence microscopy, IgG binding to normal platelets was seen with the patient's serum only in the presence of rifampin, and (f) using fluorescence spectrofluorometry, an absence of rifampin binding to normal platelets was demonstrated. Although the serological studies are not definitive, the mechanism of thrombocytopenia in the patient can best be explained by the formation of immune complexes composed of rifampin-antirifampin antibody binding to platelets causing their rapid clearance from the circulation.

SummaryTwo recent reports have shown platelet patching/capping by concanavalin A (Con A). In these studies, Con A receptors were shown to mobilize from pseudopodia and lamellipodia to the central cell parts during platelet attachment and spreading. The molecular mechanism underlying Con A receptor capping was not examined in either study.Con a binds maximally to human platelet membrane glycoproteins IIb and IIIa. In order to test whether Con A-induced capping caused the capping of this membrane glycoprotein complex, we treated normal human platelets with unlabeled Con A. After fixation, platelets were further treated with mouse monoclonal antibodies against the membrane glycoprotein IIb/IIIa complex and stained with fluorescein isothiocyanate (FITC) tagged anti-mouse IgG. An average of 16% platelets manifested capping with one monoclonal antibody preparation (N = 2) and 12% with a second preparation (N = 2).Control studies showed that only 18% of normal human fresh platelets exhibit capping with FITC-Con A (N = 17). If platelets were first incubated with unlabeled Con A, followed by staining with FITC-labeled anti-Con A antibody, an average of 15% platelets manifested caps (N = 17). Capping was inhibited by methyl-alpha-D-mannopyranoside (a known inhibitor of Con A), at cold temperature and by pre-treatment of platelets with colchicine.Our studies confirm the earlier findings on Con A induced capping. Also, our findings suggest that the molecular mechanism for Con A receptor capping involves patching and capping of the platelet membrane glycoprotein IIb/IIIa complex. It is possible that glycoprotein Ilb/IIIa redistribution might be intimately involved during platelet attachment and spreading.

Platelets prepared by discontinuous flow centrifugation contain significant numbers of leukocytes and red cells. Platelet products often are centrifuged further to remove this cellular "contamination." A method is described by which platelet products obtained by cytapheresis were prepared using an additional slow centrifugation step (121 X g for 7.5 minutes). In a production environment, we removed an average of 97 percent of leukocytes and most of the contaminating red cells with this method, while retaining 89 percent of the platelets in the final product. This method is an improvement over methods described previously and was consistently effective in routine use.

The Antigen Society dealt with subtypic specificities of the antigen cluster “4c” (1). B5 was recognized in the 1967 Workshop; B18, B35 and Bw53 (formerly HR), were identified in 1972 (2,3). The B5 “splits,” B51 and Bw52, were recognized in the 1975 Workshop (4) but did not achieve official status until the 1977 Workshop (5), together with Bw53. An additional specificity, Bw70 (formerly Bu-Sv), and its two “splits” Bw71 and Bw72, all of them Bw6-associated, were included in the B5 CREG and are now officially established.

Assessment of venous hemoglobin (Hb), serum ferritin, and zinc protoporphyrin (ZPP) levels was carried out in women identified by CuSO4 screening as ineligible to donate blood. The correlation of log ferritin with ZPP was relatively poor (r = -0.580) but significant (p greater than 0.01). However, a ZPP level of 2.0 micrograms per g Hb or greater (upper limit of normal for first-time female donors) showed a predictive value of 0.85 for a ferritin level of 12 ng per ml or less in these donors. The correlation of hemoglobin concentration with ZPP level was significant (r = -0.667; p less than 0.001) in blood donors with ferritin levels at or below 12 ng per ml. ZPP level appears to be increased in iron-depleted (hypoferritinemic) blood donor in whom animals had developed or was developing (Hb less than 12.5 g/dl). Although direct measurements of venous hemoglobin and ferritin levels most accurately evaluate such blood donors, these tests are time-consuming and expensive and are currently not adaptable to bloodmobile operations. Copper sulfate screening has proved feasible in the bloodmobile setting, and the measurement of ZPP level has been used for mobile screening for lead poisoning. ZPP may be an inexpensive and useful screening test to determine a subset of donors who should receive supplemental iron or reduce their frequency of blood donation.

To determine the degree of damage induced by different modes of agitation during storage of platelets for 5 days in polyolefin (PL-732), we studied pH, platelet count, release of lactic dehydrogenase (LDH) and beta-thromboglobulin (beta-TG), morphology and osmotic recovery. Platelets were maintained at 20-24 degrees C on elliptical, 6 rpm circular, 2 rpm circular and flat bed agitators. Results showed that the most and least effective modes of agitation were the 2 rpm circular and the elliptical rotators, respectively. Elliptical rotators exhibited excessive release of LDH (46%) and beta-TG (51%) while the 2 rpm circular model produced significantly less discharge of these proteins (LDH 13%; beta-TG 30%; p less than 0.05). With elliptical units, by 120 h of storage, pH was often very alkaline (pH greater than 7.5) when platelet counts were under 1 x 10(9)/ml. Flat bed shakers and 6 rpm circular agitators were acceptable but flat bed units were unable to resuspend the platelet 'button' which forms after the final preparative centrifugation. The 2 rpm circular rotator showed significantly less LDH and beta-TG release than did the 6 rpm version (p less than 0.05) and permitted smooth resuspension of the platelet 'button'. Based on our in vitro studies, we conclude that elliptical rotators may not be suitable for storing PL-732 platelet concentrates and that some other form of agitation should be used.