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A young adult African American female presented with normocytic microangiopathic haemolytic anaemia, elevated lactate dehydrogenase and thrombocytopenia. The patient responded to therapeutic plasma exchanges (TPE) for presumed thrombotic microangiopathy caused by thrombotic thrombocytopenic purpura (TTP). After relapsing, the patient was found to have pancytopenia, megaloblastic bone marrow and low vitamin B12 consistent with pernicious anaemia, which improved with intramuscular B12 and discontinuation of TPE. B12-deficient macrocytosis was not seen at presentation due to concomitant alpha-thalassaemia. Initial clinical/laboratory improvement is attributed to B12 present in TPE plasma. B12 deficiency can mimic TTP. Vigilance is needed regarding atypical presentations of pernicious anaemia., (© 2024 The Author(s). British Journal of Haematology published by British Society for Haematology and John Wiley & Sons Ltd.)

COVID-19 infection is still a mystery in terms of its long-term effect on health and its consequences on hematological disorders. Prior studies including ours have shown the abnormal changes in hematopoietic cells in COVID-19 patients. In this article, we are presenting 2 cases of pediatric B-lymphoblastic leukemia (B-ALL) with a previous history of COVID-19 infection. The first case describes a 22-month-old boy presenting with lymphadenopathy, neutropenia, and anemia with concurrent COVID-19 infection without any evidence of a hematolymphoid neoplasm as per bone marrow and lymph node biopsy. However, he presented after 2 months with bone marrow biopsy confirming B-ALL. The second case is that of a 4-year-old girl presenting with B-ALL who has had asymptomatic COVID-19 infection 5 months before this current presentation. Both the cases had complete resolution of COVID-19 infection during the time of presentation with acute leukemia. There were notably 2 rare findings along the course of the patients' illnesses. First, the unusual plasmacytosis in the marrow during active COVID-19 infection in the first patient and the second, is predilection of development of B-ALL following COVID-19. In both the cases the fluorescence in situ hybridization (FISH) studies showed pathologic alteration of the RUNX1 gene. Overall, there are no literature to support a causal association between acute B-ALL and COVID-19. The diagnosis of B-ALL in these patients after COVID-19 infection may be totally unrelated. However, if we consider Greaves proposed 2-hit model for childhood acute leukemia, that an infectious agent can precipitate development of B-ALL in a genetically susceptible individual. Alteration of the RUNX1 gene in both the patients, opens a door for further exploration of the "second-hit" hypothesis regarding an infectious agent precipitating development of B-ALL in a genetically susceptible individual., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2024.)

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a clinical thrombotic microangiopathy (TMA) syndrome defined by the pentad of symptoms. Therapeutic plasma exchange with plasma replacement is an ASFA Category I modality that can reduce morbidity and mortality if initiated early. We describe a 14-year review of patients referred for plasma exchange with a suspected diagnosis of TTP., Methods: For 70 patients referred for urgent plasma exchange, clinical, therapeutic, and laboratory data were retrospectively analyzed, and the diagnosis was determined., Results: Fifteen of the patients were diagnosed with TTP based upon ADAMTS-13 activity with the other 51 patients having other non-TTP TMA diagnoses. The mortality rate was significant for both TTP and non-TTP TMAs. PLASMIC scores were also calculated retrospectively and were noted to have limited value. TMA is a diagnostic challenge and encompasses different syndromes with similar presentations., Conclusion: Determining an accurate diagnosis, including prompt ADAMTS-13 testing, makes it possible to initiate appropriate therapy for the multiple different TMAs that can be seen in clinical practice., (© 2022 International Society for Apheresis and Japanese Society for Apheresis.)

Objective: To verify the manufacturer performance claims of the TEG5000 with traditional laboratory methods., Materials and Methods: Samples were concurrently measured using the TEG5000 analyzer and either PT, APTT, fibrinogen, factor activities, platelet count, or platelet function testing using whole blood or platelet-rich plasma methods., Results: Within-run imprecision yielded coefficient of variation (CV) of <5%. There was no correlation of PT or APTT with R time. Only Factor VIII and factor XII activity significantly correlated with R time. There was significant correlation between k and angle with FBG, PLT count, and factor levels. There was weak inverse correlation between angle results and measures of platelet function. All laboratory methods were significantly correlated with MA. There were significant differences between citrated whole blood and fresh citrated plasma for angle and MA, and between fresh and frozen plasma for R time and MA. We demonstrated a high % inhibition noted with normal, drug naïve donors, especially with ADP PLT mapping (50% inhibition), but less so with AA PLT mapping (20% inhibition). For TEG platelet mapping, 19/22 (86.3%) and 17/22 (77.3%) results were concordant with traditional aggregation results., Conclusion: We demonstrated both the lack of, and strong correlation between laboratory tests and the TEG parameters., (© 2016 John Wiley & Sons Ltd.)

We report an accurate method to count red blood cells, platelets, and white blood cells, as well as to determine hemoglobin in the blood of humans, horses, dogs, cats, and cows. Red and white blood cell counts can also be performed on human body fluids such as cerebrospinal fluid, synovial fluid, and peritoneal fluid. The approach consists of using a compact, custom-built microscope to record large field-of-view, bright-field, and fluorescence images of samples that are stained with a single dye and using automatic algorithms to count blood cells and detect hemoglobin. The total process takes about 15 min, including 5 min for sample preparation, and 10 min for data collection and analysis. The minimum volume of blood needed for the test is 0.5 μL, which allows for minimally invasive sample collection such as using a finger prick rather than a venous draw. Blood counts were compared to gold-standard automated clinical instruments, with excellent agreement between the two methods as determined by a Bland-Altman analysis. Accuracy of counts on body fluids was consistent with hand counting by a trained clinical lab scientist, where our instrument demonstrated an approximately 100-fold lower limit of detection compared to current automated methods. The combination of a compact, custom-built instrument, simple sample collection and preparation, and automated analysis demonstrates that this approach could benefit global health through use in low-resource settings where central hematology laboratories are not accessible.

Macrocytic anemia, defined as a mean cell volume (MCV) ≥100 fL in adults, has a narrow differential diagnosis that requires evaluation of the peripheral blood smear as well as additional laboratory testing taken in conjunction with clinical information that includes patient history and physical examination findings. This review is an update on the approach to a patient with macrocytic anemia with attention paid to the differentiation of megaloblastic and non-megaloblastic macrocytic anemias. Critical to the determination of the diagnosis is the judicious use of laboratory testing and the evaluation of those findings in conjunction with the patient medical, surgical, and medication history., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Introduction: Current recommendations for coagulation testing storage and thawing are based on historical studies that were performed using unbuffered 3.8% sodium citrate. We sought to measure the effects of freezing and thawing conditions 3.2% buffered sodium citrate plasma samples that have been stored in vials with either snap or sealed screw tops, frozen in -70 °C freezer or dry ice and thawed either capped or uncapped., Methods: Shed blood samples were pooled and then aliquoted into four snap top and four screw tops vials. Half the vials were stored in a -70 °C freezer, and half on dry ice for at least 16 h. Afterwards, half the frozen samples were thawed in 37 °C waterbath capped, and other half were thawed capped. After thawing cycles, samples were tested for PT, activated partial thromboplastin time (APTT), fibrinogen, D-dimer, factor assays, von Willebrand factor activity, plasminogen, antithrombin, protein C and lupus anticoagulant., Results: Prothrombin time, APTT, factor X, and lupus anticoagulant testing were affected by all vials, freezing and thawing conditions, whereas fibrinogen, D-dimer, von Willebrand activity or protein C were not affected by any vial, freezing or storage condition., Conclusions: Storage vials, freezing and thawing condition affect coagulation testing, although these differences may not be clinically significant., (© 2015 John Wiley & Sons Ltd.)

Patients with BCR-ABL1 positive hematologic malignancies and Philadelphia-like B-lymphoblastic leukemia (B-ALL) are potential candidates for targeted therapy with tyrosine kinase inhibitors (TKI). Before TKIs, patients with B-ALL had a much worse prognosis and current treatments with targeted TKI therapy have improved outcomes. Thus, the detection of BCR-ABL1 is crucial and a false negative BCR-ABL1 result may adversely affect patient care. We report a case of a 76-year-old male with a new diagnosis of B-ALL who was initially found to be BCR-ABL1 negative by quantitative polymerase chain reaction (PCR). A concurrent qualitative PCR was performed which detected a positive BCR-ABL1 result that was confirmed by a next generation sequencing (NGS) based assay and identified as the rare fusion variant e1a3 of p190(BCR-ABL). Based on this result, the patient was placed on dasatinib as a targeted therapy. In the era of molecular diagnostic medicine and targeted therapy, it is essential to have an understanding of the limitations of molecular assays and to follow a comprehensive diagnostic approach in order to detect common abnormalities and rare variants. Incorporating NGS methods in an algorithmic manner into the standard diagnostic PCR-based approach for BCR-ABL1 will aid in minimizing false negative results.

Most myelodysplastic syndromes (MDS) present with loss or gain of chromosomal material and less commonly show translocations as a sole abnormality. In addition, certain translocations are more commonly seen in MDS than others, but to our knowledge, the presence of t(6;15) has not been reported in MDS, specifically therapy-related MDS (t-MDS) cases. Patients with t-MDS, a group of heterogeneous stem cell related disorders resulting as a latent complication of cytotoxic and/or radiation therapy, generally tend to have a poorer prognosis than de novo MDS. We present a unique case of a patient who initially presented with acute myeloid leukemia (AML) with a normal karyotype and FLT3-ITD and NPM1 mutations. The patient was successfully treated with chemotherapy and an autologous bone marrow transplant but subsequently developed a new FLT3-ITD negative t-MDS with a unique translocation, t(6;15)(q12;q15), three years after transplant. To our knowledge, this unique sole translocation has never been reported in MDS or t-MDS and given her successful response to treatment and remission, presence of this translocation may have some prognostic value.

Current flow-based blood counting devices require significant medical infrastructure and are not appropriate for field use. In this article we report on the development of a sample preparation, measurement, and analysis method that permits automated and accurate counting of red blood cells (RBCs), white blood cells (WBCs), and platelets, as well as allowing a 3-part differential of the WBCs to be performed on extremely small volumes of whole blood. This method is compatible with portable instrumentation that can be deployed in the field. The method consists of serially diluting blood samples first with sodium dodecyl sulfate dissolved in phosphate buffered saline, then in acridine orange dissolved in phosphate buffered saline, followed by fluorescence and dark field imaging with low magnification objectives. Image analysis is performed to extract cell counts and differentials. We performed a paired analysis of 20 volunteers with complete blood count values both within and beyond the normal reference range using a commercial automated hematology analyzer and the image-based method, with the new method achieving accuracies comparable to that of the commercial system. Because the sample preparation and imaging are simple and inexpensive to implement, this method has applications for pediatrics, clinician offices, and global health in regions that do not have access to central hematology laboratories.

Background: Clinicians managing patients receiving the direct thrombin inhibitor dabigatran may benefit in being able to determine the amount of drug present in selected situations. This may include assessment of accumulation, concurrent drug interactions, or adequate removal from circulation. The ability to estimate the amount of dabigatran present using the chromogenic ecarin assay (ECA) requires further clarification., Objective: To describe the reliability of dabigatran measurements using a chromogenic ECA., Methods: This was an evaluation of the ECA method that incorporated assessment of imprecision, linearity, accuracy, carryover, and lower limits of detection or blank. Pooled normal plasma enriched with dabigatran at concentrations of 0, 25, 50, 75, 100, 125, 150, 200, 300, 400, and 500 ng/mL were sent blinded to 3 laboratories in the United States to compare our ECA results with those of laboratories reporting dilute thrombin time methods (HEMOCLOT thrombin inhibitor assay) for measuring dabigatran. Trough and peak levels from 35 patients were also compared with mass spectrophotometry for assessing ECA accuracy., Results: The within-run or day-to-day imprecision was less than 10%, with high linearity (R (2) = 0.989) and high degree of accuracy (R (2) = 0.985; slope = 0.908) for levels ranging between 18 and 470 ng/mL and no carryover at 0 ng/mL noted. The ECA approach appeared to be more reliable at lower dabigatran concentrations., Conclusions: The chromogenic ECA appears to be an effective approach to determine the amount of dabigatran present. Further insights are necessary to determine how it can be used to reduce thromboembolic or bleeding complications in patients receiving dabigatran.

Orbital involvement in nonendemic Burkitt lymphoma is rare. The authors report a unique case of a patient who sought treatment for extraocular muscle enlargement without a concurrent orbital mass, which subsequently led to the diagnoses of Burkitt lymphoma and acquired immune deficiency syndrome in an adult patient. The case report adhered to the principles of the Declaration of Helsinki and Health Insurance Portability and Accountability Act compliance. This single case report was institutional review board exempt, given that it does not meet the definition of human subjects' research.

Background: Use of liquid plasma (LP) has been reported as early as the mid 1930s. Unlike fresh-frozen plasma (FFP), LP is maintained at 1 to 6°C for up to 40 days after collection and processing. Despite its approved use by the US Food and Drug Administration, the coagulation profile of LP is incompletely described. In this study we evaluate the coagulation profile of LP stored up to 30 days., Study Design and Methods: LP was prepared by removing plasma from nonleukoreduced whole blood within 24 hours of collection. Three LP units from each ABO group were collected and stored at 1 to 6°C. Plasma aliquots were obtained at Postcollection Days 1 to 5, 10, 15, 20, 25, and 30 and then stored at -70°C. Each aliquot was tested for prothrombin time, activated partial thromboplastin time, and other coagulation and fibrinolytic factors., Results: There was a significant decrease in Factor (F)V, FVII, FVIII, von Willebrand factor (VWF), protein S (PS) activity, and endogenous thrombin potential on Day 15 compared with Day 1. No significant difference was observed for PS antigen, D-dimer, or thrombin-antithrombin complex. At least 50% activity of all measured factors was noted on Day 15, compared to Day 1. Considerable heterogeneity was observed between the different blood groups for FVII, FVIII, and VWF., Conclusion: These data demonstrate that LP maintains at least 50% of factor activity and thrombin-generating capacity up to 15 days of refrigerated storage. It may be more appropriate to limit LP storage and supplement with FFP when used for management of massively bleeding patients., (© 2012 American Association of Blood Banks.)

Objective: We sought to develop a murine model to examine the antithrombotic and antiinflammatory functions of human thrombomodulin in vivo., Methods and Results: Knock-in mice that express human thrombomodulin from the murine thrombomodulin gene locus were generated. Compared with wild-type mice, human thrombomodulin knock-in mice exhibited decreased protein C activation in the aorta (P<0.01) and lung (P<0.001). Activation of endogenous protein C following infusion of thrombin was decreased by 90% in knock-in mice compared with wild-type mice (P<0.05). Carotid artery thrombosis induced by photochemical injury occurred more rapidly in knock-in mice (12±3 minutes) than in wild-type mice (31±6 minutes; P<0.05). No differences in serum cytokine levels were detected between knock-in and wild-type mice after injection of endotoxin. When crossed with apolipoprotein E-deficient mice and fed a Western diet, knock-in mice had a further decrease in protein C activation but did not exhibit increased atherosclerosis., Conclusion: Expression of human thrombomodulin in place of murine thrombomodulin produces viable mice with a prothrombotic phenotype but unaltered responses to systemic inflammatory or atherogenic stimuli. This humanized animal model will be useful for investigating the function of human thrombomodulin under pathophysiological conditions in vivo.

Introduction: Hemoglobin variants are a result of genetic changes resulting in abnormal or dys-synchronous hemoglobin chain production (thalassemia) or the generation of hemoglobin chain variants such as hemoglobin S. Automated high-pressure liquid chromatography (HPLC) systems have become the method of choice for the evaluation of patients suspected with hemoglobinopathies., Methods: In this study, we evaluated the performance of two HPLC methods used in the detection of common hemoglobin variants: Variant and Ultra2., Results: There were 377 samples tested, 26% (99/377) with HbS, 8.5% (32/377) with HbC, 20.7% (78/377) with other hemoglobin variant or thalassemia, and 2.9% with increased hemoglobin A(1) c. The interpretations of each chromatograph were compared. There were no differences noted for hemoglobins A(0), S, or C. There were significant differences between HPLC methods for hemoglobins F, A(2), and A(1) c. However, there was good concordance between normal and abnormal interpretations (97.9% and 96.2%, respectively)., Conclusion: Both Variant and Ultra2 HPLC methods were able to detect most common hemoglobin variants. There was better discrimination for fast hemoglobins, between hemoglobins E and A(2), and between hemoglobins S and F using the Ultra2 HPLC method., (© 2010 Blackwell Publishing Ltd.)

In this paper we report the development of two attachments to a commercial cell phone that transform the phone's integrated lens and image sensor into a 350x microscope and visible-light spectrometer. The microscope is capable of transmission and polarized microscopy modes and is shown to have 1.5 micron resolution and a usable field-of-view of 150 x 50 with no image processing, and approximately 350 x 350 when post-processing is applied. The spectrometer has a 300 nm bandwidth with a limiting spectral resolution of close to 5 nm. We show applications of the devices to medically relevant problems. In the case of the microscope, we image both stained and unstained blood-smears showing the ability to acquire images of similar quality to commercial microscope platforms, thus allowing diagnosis of clinical pathologies. With the spectrometer we demonstrate acquisition of a white-light transmission spectrum through diffuse tissue as well as the acquisition of a fluorescence spectrum. We also envision the devices to have immediate relevance in the educational field.

In the past, transfusion-transmitted virus (TTV) infections were not uncommon. In recent years with advanced technologies and improved donor screening, the risk of viral transfusion transmission has been markedly reduced. Hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) have all shown marked reduction in transmission rates. However, the newer technologies, including nucleic acid technology (NAT) testing, have affected the residual rates differently for these virally transmitted diseases. Zero risk, which has been the goal, has yet to be achieved. False negatives still persist, and transmissions of these viruses still occur, although rarely. It is known that HBV serological testing misses some infected units; likewise, HBV NAT-negative units have also been known to transmit the virus. Similarly, HIV minipool NAT-negative units have transmitted HIV, as recently as 2007; likely, these transmissions would have been prevented with single-unit NAT testing. Newer technologies, such as pathogen inactivation (PI), will (ideally) eliminate these falsely test negative components, regardless of the original testing method used for detecting the viruses., (© 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.)

Background: The incidence of hemolytic disease of the fetus and newborn (HDFN) has decreased since the introduction of Rh immunoglobulin prophylaxis in Rh(D)-negative pregnant women. Thus, the relative incidence of rare alloantibody-related HDFN has increased. The lack of available maternally matched red blood cells for transfusion in these cases may create management difficulties., Case: We report a case of anti-Kp(b) HDFN. Severe fetal anemia required intrauterine transfusion. Difficulty in obtaining Kp(b)-negative blood necessitated using the mother's donated RBCs., Conclusion: Severe HDFN with rare antibodies can be managed successfully using maternal blood., (Copyright © 2010 Elsevier Ltd. All rights reserved.)

Purpose: The purpose of this study was to evaluate the effect of 20-gauge (20-G) and 25-gauge (25-G) vitrectomy on cell viability and diagnostic yield (surface marker expression) using flow cytometry and human lymphoma cells in culture., Methods: Cultured human Burkitt lymphoma cells (Raji B-cell lymphoma line) were allocated into five study groups in Roswell Park Memorial Institute media. By using manual aspiration, cells were then processed by aspiration alone, by 20-G vitrectomy at 600 cuts per minute (cpm) and 1,500 cpm, or by 25-G vitrectomy at both 600 and 1,500 cpm. To assess cell viability and cell surface marker expression, samples underwent standard flow cytometry analysis for suspected lymphoma using 7-amino-actinomycin D and antibodies against CD45, CD19, lambda, and kappa light chains., Results: Twenty-five samples were processed after being divided into four vitrectomy groups and one nonvitrectomy group (control). The mean cell viability was 98.5 for both the nonvitrectomized and vitrectomized specimens. The percentage of cells positive for CD45 or kappa light chain was the same in the nonvitrectomized and vitrectomized groups. In addition, the level of expression of these molecules was not significantly different in all five groups. Similarly, no difference was seen for these markers between 20-G and 25-G vitrectomy at either a cut rate of 600 or 1,500 cpm. The percentage positive for CD19 was significantly lower for the 20-G vitrectomy at 1,500 cpm compared with the 25-G vitrectomy at both 600 and 1,500 cpm. Percentage of CD19 cells was greater for the 25-G vitrectomy at 600 cpm than the nonvitrectomy group., Conclusion: Compared with simple aspiration, both 20-G and 25-G vitrectomy seem to have no significant effect on cell viability or diagnostic yield for B-cell lymphoma cells (Raji cell line) in suspension based on flow cytometry. Further studies need to be conducted to study and compare 20-G versus 25-G vitrectomy on lymphoma cells in human vitreous or in an animal model.

Background and Objectives: Emergency situations often elicit a generous response from the public. This occurred after attacks on the US on September 11, 2001 when many new blood donors lined up to donate. This study was performed to compare return rates for first time donors (FTD) after September 11th, 2001 to FTD during a comparable period in 2000., Materials and Methods: A total of 3315 allogeneic whole blood donations from FTD at a regional blood centre were collected between September 11th and 30th, 2001. Subsequent donations by the FTD before March 31, 2002 were reviewed. This (test) group was compared to 1279 FTD (control group) donating during the same time period in September 2000 and to their return rate in the subsequent 6 months., Results: Following September 11, 2001, 1087/3315 (32.8%) FTD returned by March 31, 2002. This return rate was similar to the control group [427/1279 (33.4%)]. The deferral rate during the donor screening process for the control group was significantly higher than the deferral rate for the September 11-30, 2001 group (P < 0.01). The odds of an individual FTD returning increased with age, and the chance of a female donor returning was 1.13 times higher than a male (P = 0.06). There was a carryover effect after September 11, 2001 too., Conclusion: A national emergency, September 11, 2001, inspired people to donate blood for the first time. However, the proportion of return donations amongst them was not increased. Females and males in certain age groups were more likely to become repeat donors due to the residual effect of September 11, 2001. Additional efforts are needed to retain eligible FTD in donor pools.

Background and Objectives: Thrombotic thrombocytopenic purpura (TTP) is a clinical diagnosis that can be difficult to establish in severely ill patients. We report a case of fulminant TTP in a woman who died before receiving plasma exchange. An autopsy plasma sample was analyzed for ADAMTS13 activity and inhibitor for correlation with the diagnosis of TTP. Recognizing that hemolysis in postmortem blood samples could interfere with ADAMTS13 activity, plasma samples from four additional decedents not suspected of having TTP were analyzed and correlated with their autopsy results. The purpose of this study was to assess whether testing postmortem samples for ADAMTS13 is useful in the postmortem diagnosis of TTP., Material and Methods: Plasma samples from the index case and four non-TTP decedents were analyzed for ADAMTS13 activity, ADAMTS13 inhibitor levels, and plasma free hemoglobin (PFH). Autopsy tissues were evaluated for evidence of platelet microthrombi in all five cases., Results: The ADAMTS13 activity level in the index patient was <4%, and the inhibitor level was 1.0 inhibitor unit. Microthrombi were prominent in the heart, kidneys, pancreas, and adrenal glands, consistent with the clinical diagnosis of TTP. ADAMTS13 activity levels in the four non-TTP decedents ranged from 4 to 82% (3/4 < or = 26%), and inhibitor was present in two of the four samples. Postmortem PFH levels in the four non-TTP decedents ranged from 64 to 3,917 mg/dL. No microthrombi were observed., Conclusion: Low postmortem ADAMTS13 activity and evidence of inhibitor can occur in decedents without clinical or histologic evidence of TTP. Postmortem ADAMTS13 activity levels may not be valid in establishing a diagnosis of TTP, and high inhibitor levels in this setting may be related to elevated PFH. Caution must be used in the interpretation of ADAMTS13 testing in the presence of hemolysis.

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare complication of transfusion of cellular blood components producing a graft-versus-host clinical picture with concomitant bone marrow aplasia. The disease is fulminant and rapidly fatal in the majority of patients. TA-GvHD is caused by transfused blood-derived, alloreactive T lymphocytes that attack host tissue, including bone marrow with resultant bone marrow failure. Human leucocyte antigen similarity between the transfused lymphocytes and the host, often in conjunction with host immunosuppression, allows tolerance of the grafted lymphocytes to survive the host immunological response. Any blood component containing viable T lymphocytes can cause TA-GvHD, with fresher components more likely to have intact cells and, thus, able to cause disease. Treatment is generally not helpful, while prevention, usually via irradiation of blood components given to susceptible recipients, is the key to obviating TA-GvHD. Newer methods, such as pathogen inactivation, may play an important role in the future.

Transfusion-related acute lung injury (TRALI) is a life-threatening complication of blood transfusion. The epidemiology and pathogenesis of TRALI are not well established. A Medline literature search shows only rare reports of recurrent TRALI, all occurring soon after the first episodes. We report a case of recurrent TRALI after a 2-year interval. A patient developed TRALI after transfusion of 4 units of fresh frozen plasma for gastrointestinal bleeding due to oesophageal varices in September 2002. The patient required mechanical ventilation but recovered completely. Two years later, in October 2004, the patient experienced a second episode of TRALI during liver transplantation for hepatitis C virus /alcoholic cirrhosis. Again, the patient recovered after ventilator support. Laboratory investigation of the first TRALI episode (2002) showed antibodies against class II human leukocyte antigens (HLA) in three female donors. Laboratory investigation of the second episode (2004) showed anti-DR52 (HLA class II) antibodies in one female donor matching the DR-52 HLA class II antigen in the recipient. TRALI can rarely recur. Consideration of future blood needs for patients experiencing recurrent TRALI should include preventive measures against further TRALI reactions, such as blood from male donors or blood less than 14 days old.

Blood banks require a sensitive, specific, and efficient method to detect clinically significant RBC antibodies. Solid phase antibody screening methods are popular due to high sensitivity and automation. However, the high degree of reactivity detects "false positive" antibodies of questionable clinical significance leading to additional testing. We studied positive rates of Capture-R vs. PEG methods and categorized RBC antibodies identified by initial test results of 33,564 consecutive samples by Capture-R method. Capture-R was positive in 1,084/33,564 (3.2%) of samples. Using PEG as our "gold standard", PEG confirmed true positivity (i.e., > or = 1 cell reacting) in 710 Capture-R positive samples (65.5%); 374 Capture-R positive samples (34.5%) did not react in PEG (i.e., false positives). Of the 710 samples with true positivity, only 510 showed clinically significant alloantibodies. Using PEG as our "gold standard", only 2/3 of reactions by Capture-R were considered true positives. Because of ease and automation, Capture-R is popular as a screening test, but a more specific method may be helpful in order to identify truly significant alloantibodies.

The Protein C pathway plays a crucial role in the regulation of thrombosis and inflammation. One of the tools that researchers presently use to elucidate mechanisms of action of activated protein C (APC) is the use of transgenic or gene deletion murine models. To correlate observations in these murine models with the APC levels, there is a need for a sensitive and specific assay for circulating murine APC in plasma. We developed an immunological assay to measure the physiological and pharmacologic levels of circulating murine APC. The sandwich ELISA uses an anti-murine anti-protein C antibody capture antibody and human protein C inhibitor (PCI) as a detection reagent, taking advantage of the facts that the mouse lacks plasma PCI and that human PCI forms a 1/1 stable complex with mouse APC. The amount of complex APC:PCI is detected with an anti-human PCI monoclonal antibody. The assay shows improved sensitivity versus enzyme immunocapture assays commonly used to detect human APC and considerably reduces the processing time.

Background: Thrombotic microangiopathies (TMA) are systemic vasoocclusive disorders associated with significant morbidity and mortality. Rapid and reliable diagnosis of TMA is critical. The diagnosis is complicated by a lack of objective and sensitive laboratory testing as well as multiple concurrent diseases, including infectious processes., Case Study: We report two cases of disseminated histoplasmosis associated with TMA manifestations in renal transplant recipients, including one patient with histologically documented renal microthrombi; both patients were referred for plasma exchange. After the diagnosis of histoplasmosis, the treatment plan was changed to antifungal medications, reduced immuno-suppression, and supportive care, with progressive resolution of TMA manifestations., Conclusion: TMA occurs in transplant populations in association with infections, medications, and other factors. Appropriate management includes recognition and treatment of possible etiological factors. Disseminated histoplasmosis should be considered in transplant patients presenting with TMA.

Transfusion-related acute lung injury (TRALI) is a rare transfusion reaction presenting as respiratory distress during or after transfusion of blood products. TRALI varies in severity, and mortality is not uncommon. TRALI reactions have equal gender distributions and can occur in all age groups. All blood products, except albumin, have been implicated in TRALI reactions. TRALI presents as acute respiratory compromise occurring in temporal proximity to a transfusion of a blood product. Other causes of acute lung injury should be excluded in order to definitively diagnose TRALI. Clinically and pathologically, TRALI mimics acute respiratory distress syndrome (ARDS), with neutrophil-derived inflammatory chemokines and cytokines believed to be involved in the pathogenesis of both entities. Anti-HLA and anti-neutrophil antibodies have been implicated in some cases of TRALI. Treatment for TRALI is supportive; prevention is important. It is suspected that TRALI is both underdiagnosed and underreported. One of the difficulties in the evaluation of potential TRALI reactions is, until recently, the lack of diagnostic criteria. A group of transfusion medicine experts, the American-European Consensus Conference (AECC), recently met and developed diagnostic criteria of TRALI, as well as recommendations for management of donors to prevent future TRALI reactions. In light of the AECC consensus recommendations, we report an incident of TRALI in an oncology patient as an example of the potential severity of the lung disease and the clinical and laboratory evaluation of the patient. We also review the literature on this important complication of blood transfusion that internists may encounter.

New developments in the understanding of thrombotic thrombocytopenic purpura (TTP) provide opportunities for improved patient care. A widely held historical model of TTP microvascular thrombosis implicated circulating ultra large von Willebrand factor (ULVWF) in causing spontaneous platelet (PLT) aggregation. From this pathogenic model, concerns about ULVWF in fresh-frozen plasma (FFP) used to treat patients led to widespread use of cryopoor plasma (CPP) as an alternative. There is scant evidence, however, that circulating ULVWF contributes to microvascular thrombosis in TTP. New evidence suggests that the formation of PLT aggregates in TTP may be mediated by VWF in the process of being released from endothelium. Moreover, clinical studies do not demonstrate superior efficacy of CPP compared to FFP in the treatment of TTP. Because CPP may have reduced concentrations of factors important in the treatment of TTP, including ADAMTS13 metalloprotease, a reappraisal of the use of CPP in the treatment of TTP is warranted.

In a previous report [Z. Török, G. Satpathy, M. Banerjee, R. Bali, E. Little, R. Novaes, H. Van Ly, D. Dwyre, A. Kheirolomoom, F. Tablin, J.H. Crowe, N.M. Tsvetkova, Preservation of trehalose loaded red blood cells by lyophilization, Cell Preservation Technol. 3 (2005) 96-111.], we presented a method for preserving human red blood cells (RBCs) by loading them with trehalose and then freeze-drying. We have now improved that method, based on the discovery that addition of phospholipid vesicles to the lyophilization buffer substantially reduces hemolysis of freeze-dried RBCs after rehydration. The surviving cells synthesize 2,3-DPG, have low levels of methemoglobin, and have preserved morphology. Among the lipid species we studied, unsaturated PCs were found to be most effective in suppressing hemoglobin leakage. RBC-vesicle interactions depend on vesicle size and structure; unilamellar liposomes with average diameter of less than 300 nm were more effective in reducing the hemolysis than multilamellar vesicles. Trehalose loaded RBCs demonstrated high survival and low levels of methemoglobin during 10 weeks of storage at 4 degrees C in the dry state when lyophilized in the presence of liposomes.

A method for freeze-drying red blood cells (RBCs) while maintaining a high degree of viability has important implications in blood transfusion and clinical medicine. The disaccharide trehalose, found in animals capable of surviving dehydration can aid in this process. As a first step toward RBC preservation, we present a method for loading RBCs with trehalose. The method is based on the thermal properties of the RBC plasma membranes and provides efficient uptake of the sugar at 37 degrees C in a time span of 7 h. The data show that RBCs can be loaded with trehalose from the extracellular medium through a combination of osmotic imbalance and the phospholipid phase transition, resulting in intracellular trehalose concentrations of about 40 mM. During the loading period, the levels of ATP and 2,3-DPG are maintained close to the levels of fresh RBCs. Increasing the membrane fluidity through the use of a benzyl alcohol results in a higher concentration of intracellular trehalose, suggesting the importance of the membrane physical state for the uptake of the sugar. Osmotic fragility data show that trehalose exerts osmotic protection on RBCs. Flow cytometry data demonstrate that incubation of RBCs in a hypertonic trehalose solution results in a fraction of cells with different complexity and that it can be removed by washing and resuspending the RBCs in an iso-osmotic medium. The data provide an important first step in long-term preservation of RBCs.

Background: Uncommonly, antibodies that appear to exhibit antigenic specificity on red blood cell (RBC) panels fail to maintain specificity following alloadsorption (i.e., they mimic antigenic specificity). Understanding both the pitfalls and the proper pathways to establish the diagnosis and to interpret the clinical significance of these mimicking antibodies is important for patient management., Case Report: A 68-year-old woman was admitted with dyspnea, anemia, bilateral pulmonary emboli, and metastatic ovarian cancer. Blood bank evaluation identified anti-E reactivity in the patient's plasma sample and a positive direct antiglobulin test (DAT)., Results: The DAT was positive for immunoglobulin G and negative for C3b. An eluate of the RBCs showed E-antigen specificity on a RBC antibody panel. Repeat serologic testing with RBC antibody panels with adsorbed patient plasma showed removal of apparent anti-E reactivity with either E-antigen-positive or E-antigen-negative RBC stroma., Conclusion: A mimicking autoantibody with apparent E-antigen specificity was identified in the plasma sample of a woman with newly diagnosed ovarian cancer. Despite their relative low frequency, mimicking antibodies, whether auto- or alloantibodies, may interfere with the timely issuance of compatible blood products and may confuse laboratory and clinical staff. Determining the clinical significance of the antibody, by taking into account the RBC phenotype of the patient and the antigen prevalence in the general population, guides the extent of workup required to best utilize resources while assuring patient safety.

Background and Objectives: Platelet function abnormalities have been reported in blood donors who have not consumed aspirin. Our objective was to identify factors other than aspirin that may contribute to impaired platelet function in qualified volunteer blood donors., Materials and Methods: Blood samples were obtained from 24 donors following routine blood donation. Donors completed a study questionnaire that included questions about recent food consumption, medication and medical history. Platelet activation was measured using monoclonal antibodies and flow cytometry. CD62P expression and PAC-1 binding on platelets were used as indicators of platelet activation. Platelet function was measured on a platelet function analyser (PFA-100) using both collagen/epinephrine (cEPI) and collagen/ADP (cADP) cartridges., Results: Fifty-four per cent of donors (13 of 24) had normal platelet function. Thirty-eight per cent (nine of 24) had prolonged cEPI closure times, of whom four (17%) had no cEPI closure (> 300 seconds). No closure was associated with aspirin use (two donors) or chocolate consumption (two donors) before donation. Two donors (8%) had either a shortened cEPI or cADP closure time., Conclusions: Platelet dysfunction in qualified blood donors is underestimated. Platelet function screening can identify donors with diet-related platelet dysfunction or with poor recollection of aspirin use.

We evaluated six D-dimer methods to determine their sensitivity, specificity, and negative predictive values (NPV) in symptomatic patients suspected of deep vein thrombosis (DVT). In patients suspected of DVT a whole blood D-dimer test (SimpliRED, Agen) was performed, and then tested using enzyme-linked immunosorbent assay (VIDAS D-Dimer, BioMerieux; Asserachrome D-Di, Stago International; Dimertest Gold, Agen) and automated immunoturbidometric methods (Advanced D-Dimer, Dade Behring; MiniQuant, Biopool). Each D-dimer method was independently compared with radiographic results to determine sensitivity and NPV. There were 151 patients enrolled in the study. Thirty-five (23.2%) patients had a positive Doppler ultrasound, with 26 proximal, eight distal, and one patient with both proximal and distal thrombus. Two patients (1.3%) had inconclusive studies and were excluded from the analyses. For all patients, the sensitivities for the rapid D-dimer methods were: SimpliRED, 82.3% [95% confidence interval (CI), 80.3-84.3%]; VIDAS D-Dimer, 91.4% (95% CI, 89.9-92.9%); MiniQuant D-Dimer, 96.3% (95% CI, 95.1-97.5%); and Advanced D-Dimer, 97.1% (95% CI, 96.3-97.9%). The sensitivity improved for SimpliRED (86.4%; 95% CI, 83.3-89.4%), VIDAS D-Dimer (95.5%; 95% CI, 85.0-100%), MiniQuant D-Dimer (100%; 95% CI, 96.9-100%) and Advanced D-Dimer (100%; 95% CI, 98.9-100%) in the inpatient population. The automated immunoturbidometric methods, the MiniQuant D-Dimer and Advanced D-Dimer, demonstrated comparable sensitivities and NPV with the VIDAS D-Dimer method in symptomatic patients suspected of DVT, which would suggest that these newer D-dimer methods could be used as part of the diagnostic algorithm for patients suspected of DVT.

Klippel-Trenaunay-Weber syndrome (KTWS) is a rare, congenital disorder characterized by the triad of varicose veins, cutaneous hemangiomas, and hypertrophy of soft tissue and bone. We present the case of a woman with KTWS, cor pulmonale, and death due to recurrent pulmonary embolism (PE). The risk of deep venous thrombosis and PE in patients with KTWS is evaluated, and treatment recommendations are made with emphasis on the role of early, aggressive management in the subset of patients with KTWS known to have thromboembolic disease.