Search

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: 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.

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.

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.

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.

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.

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.