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Examination of red blood cell (RBC) morphology in peripheral blood smears can help diagnose hematologic disease, even in resource-limited settings, but this analysis remains subjective and semi-quantitative with low throughput. Prior attempts to develop automated tools have been hampered by poor reproducibility and limited clinical validation. Here, we present a novel, open-source machine-learning approach (denoted the 'RBC-diff') to quantify abnormal RBCs in peripheral smear images and generate an RBC morphology differential. RBC-diff cell counts showed high accuracy for single-cell classification (mean AUC: 0.93) and quantitation across smears (mean R2: 0.76 compared to experts, inter-experts R2: 0.75). RBC-diff counts were concordant with clinical morphology grading for 300,000+ images and recovered expected pathophysiologic signals in diverse clinical cohorts. Criteria using RBC-diff counts distinguished thrombotic thrombocytopenic purpura and hemolytic uremic syndrome from other thrombotic microangiopathies, providing greater specificity than clinical morphology grading (72% vs. 41%, p < 0.001), while maintaining high sensitivity (94-100%). Elevated RBC-diff schistocyte counts were associated with increased 6-month all-cause mortality in a cohort of 58,950 inpatients (9.5% mortality for schist. > 1%, vs. 4.7% for schist. < 0.5%, p < 0.001) after controlling for comorbidities, demographics, clinical morphology grading, and blood count indices. The RBC-diff also enabled estimation of single-cell volume-morphology distributions, providing insight into morphology influences on routine blood count measures. Our codebase and expert-annotated images are included here to spur further advancements. These results illustrate that computer vision can enable rapid and accurate RBC morphology quantitation, which may provide value in both clinical and research contexts.

Background Therapeutic plasma exchange (TPE) is often used to decrease serum triglyceride levels in hypertriglyceridemic pancreatitis (HTGP), although there is a lack of high-quality data directly attributing improved clinical outcomes to TPE. There are currently no large studies evaluating the treatment of HTGP without TPE. Study design and methods This study retrospectively analyzes clinical and laboratory outcomes of 115 encounters at Massachusetts General Hospital (MGH) wherein a HTGP patient was treated without TPE and compares these outcomes to those of HTGP patients in the literature treated with TPE. Results After management without TPE, the median reduction in serum triglycerides was 48% (IQR 29%-63%) on day one and 74% (IQR 60%-84%) on day two in 115 episodes of acute HTGP. The reductions were comparable to those reported in several large published case series after a course of TPE (65.8% to 81% reduction). In 25 episodes among 24 patients, treatment included admission to an intensive care unit. There was no significant difference in mortality or rates of local complication, mechanical ventilation, or use of vasoactive medication or renal replacement therapy between this ICU subset and published cohorts (all P > .05). Conclusions HTGP patients who do not receive TPE do not experience inferior outcomes compared to patients in the literature treated with TPE. The added value of TPE in HTGP, if any exists, needs to be demonstrated in controlled trials.

Refractoriness to platelet transfusion is a common clinical problem encountered by the transfusion medicine specialist. It is well recognized that most causes of refractoriness to platelet transfusion are not a consequence of alloimmunization to human leukocyte, platelet-specific, or ABO antigens, but are a consequence of platelet sequestration and consumption. This review summarizes the clinical factors that result in platelet refractoriness and highlights recent data describing novel biological mechanisms that contribute to this clinical problem., Highlights • Non-alloimmune pathophysiologic mechanisms lead to increased platelet consumption or sequestration in the majority of patients with thrombocytopenia and/or refractoriness to platelet transfusion. • Splenomegaly is associated with increased splenic platelet sequestration. • Sepsis can promote platelet consumption through effects on platelet activation, adhesion, apoptosis, and desialylation. • Neutrophil extracellular traps, endothelial activation, and decreased ADAMTS13 activity can also contribute to platelet consumption in sepsis. • There is an unmet need for effective strategies to improve hemostasis and the efficacy of platelet transfusion in patients with non-alloimmune causes of thrombocytopenia and/or refractoriness to platelet transfusion.

BACKGROUND The introduction of therapeutic plasma exchange (TPE) dramatically decreased mortality in patients with immune thrombotic thrombocytopenic purpura (iTTP). However, there are few modern descriptions of residual causes of death from iTTP and complications associated with TPE. STUDY DESIGN AND METHODS This was a retrospective study in a multi-institutional cohort of 109 patients with iTTP between 2004 and 2017. Complications of TPE were analyzed in a subset of this cohort (74 patients representing 101 treatment courses). RESULTS Death occurred in 8 of 109 patients (7.3%) and in 8 of 219 captured episodes of acute iTTP (mortality rate per episode: 3.7%). Neither the number of TPE treatments nor length of hospitalization predicted mortality. The majority of deaths (5/8) were associated with delay in the diagnosis of iTTP or initiation of TPE or presentation to the hospital in a moribund state. A subset of patients (N = 74) was analyzed for TPE-related complications. Most patients (56/74; 76%) had at least one minor or major complication of TPE. Seven of 101 (6.9%) discrete treatment courses were associated with one or more severe complications, including anaphylaxis and line-associated infections and thrombosis. Overall, the most frequent adverse events were mild allergic (urticarial) transfusion reactions, which affected 34 of 101 (34%) treatment courses. One patient died from a TPE-related complication, line-associated bacteremia. CONCLUSION Early identification of patients with iTTP and the rapid initiation of TPE are paramount in preventing mortality. While TPE was associated with a high rate of adverse events, the vast majority were treatable and TPE-related mortality is low.

Background In a recent study, we determined that 30% of frequent plateletpheresis donors collected using the Trima Accel Automated Blood Collection System (Terumo BCT) had a CD4+ T-cell count below 200 cells/μL. Whether CD4+ T-cell lymphopenia is associated with donation using other plateletpheresis instruments is unknown. Study design and methods We obtained blood samples from 30 current frequent Fenwal Amicus plateletpheresis donors. All participants had made 20 to 24 plateletpheresis donations in the most recent 365-day period, and all had previously donated over 50 times on the Fenwal Amicus instrument. Blood samples were analyzed to determine blood counts, including CD4+ and CD8+ counts. Results Of 30 study participants, none had a CD4+ count below 200 cells/μL. There was one participant with a CD4+ count between 200 and 300 cells/μL. This individual was over the age of 55 and had a history of more than 300 lifetime plateletpheresis sessions. One participant had a CD8+ count below the lower limit of normal (125 cells/μL) and a normal CD4+ count. Conclusion We did not detect severe CD4+ lymphopenia in frequent platelet donors undergoing plateletpheresis with the Fenwal Amicus. Since the Fenwal Amicus does not incorporate a leukoreduction system chamber, this finding supports the hypothesis that such chambers-found in the Trima Accel instrument-contribute to CD4+ lymphopenia in frequent platelet donors.

Patients with immune-mediated thrombotic thrombocytopenic purpura (iTTP) often experience life-threatening relapses of the disease, and rituximab (RTX) can be used to mitigate relapse risk. However, the predictors of relapse in iTTP and the magnitude and duration of effect of RTX remain key unanswered questions. Using a multi-institutional cohort of consecutive adult patients with iTTP, we used survival analysis to compare relapse rates between patients who received RTX during the index presentation with acute iTTP and those who did not. Of 124 patients, 60 (48%) received RTX and 34 (27%) experienced relapse. Median time to relapse was 3.71 (interquartile range, 1.75-4.9) and 1.33 (interquartile range, 0.43-2.35) years for RTX-treated and untreated patients, respectively. RTX conferred protection from relapse at 1 year of follow-up (P = .01) but not at 5 years of follow-up. Extended Cox regression was then used to identify predictors of relapse and to estimate the protective effect of RTX. The following parameters were independently associated with increased risk for subsequent relapse: presenting in iTTP relapse (hazard ratio [HR], 2.97; 95% confidence interval [CI], 1.4-6.4), age younger than 25 years (HR, 2.94; 95% CI, 1.2-7.2), and non-O blood group (HR, 2.15; 95% CI, 1.06-4.39). RTX initially provided protection from relapse (HR, 0.16; 95% CI, 0.04-0.70), but this effect gradually diminished, returning to the baseline risk for untreated patients at approximately 2.6 years. Patients who are young, have non-O blood group, or present with relapsed iTTP are at increased risk for subsequent relapse. RTX appears to confer short-term protection from relapse.

ObjectivesNo validated screening methods identify patients at risk for human leukocyte antigen (HLA) alloimmune-mediated platelet refractoriness (alloPR). We determined if bead-based HLA antibody tests could predict risk of developing HLA alloPR.MethodsHematopoietic progenitor cell transplant patients screened for HLA antibodies without prior refractoriness were identified. Phenotype bead screening results were compared between patients who later did and did not develop alloPR.ResultsSeven of 27 patients identified subsequently developed alloPR. The panel reactive antibody (PRA) and mean fluorescence intensity (MFI) of the 10 most reactive beads in the initial screen were significantly higher among patients who later developed alloPR (P < .001). Specifically, PRA of more than 30% and mean MFI of 1,500 or more in the most reactive beads identified at-risk patients. Administration of HLA-compatible platelets yielded significant posttransfusion count increments compared with routine platelets.ConclusionsHLA antibody screening by phenotype bead assay may prospectively identify at-risk patients for the development of alloPR. However, clinical trials are needed to validate these findings.

Introduction: Transplant-associated thrombotic microangiopathy (TA-TMA) is an increasingly recognized hematologic complication after allogeneic hematopoietic cell transplantation (HCT). While few studies have reported germline association with rare variants in complement genes using targeted next generation sequencing (NGS) method, they were limited by small sample size (≤40 TMA cases) and lack of analysis of non-complement genes (PMIDs 26603840, 32131130). In the present study, we employed whole exome sequencing (WES) to assess rare variant contribution to the development of TMA in a hypothesis-driven pathway-specific approach. Methods: In the current case-control genetic association study conducted at Fred Hutchinson Cancer Research Center, we selected 100 patients with a diagnosis of TMA and pre-transplant DNA samples (case definition described previously in PMID 30940363, 33836868). We then performed incidence density sampling to randomly select 100 non-TMA controls after allogeneic HCT matching by age, sex, race, and year of HCT. WES (germline variant detection 40x) was conducted using Illumina NovaSeq. Sequence reads were mapped to hg38 reference genome followed by deduplication and base quality score recalibration. Joint-genotyping was performed to call single nucleotide polymorphism (SNPs) and insertion/deletion (indels) using the GATK v3.3 and Atlas2. Variants were filtered during quality control (QC) and variant quality score recalibration (VQSR) and annotated using ANNOVAR and Ensembl VEP. To optimize signal detection by reducing neutral background variation, we defined qualifying variants as those meeting all 3 criteria: 1) novel or rare variants with a minor allele frequency (MAF) We then focused on the exome profiles of 5 a priori selected genetic pathways: complement regulation (17 genes), VWF and coagulation (7 genes), VWF clearance (10 genes), ADAMTS13 mimics or interacting proteins (10 genes), and angiopoietin family and endothelial activation (7 genes). Pathway-based and gene-based collapsing association tests were performed using the Optimized Sequence Kernel Association (SKAT-O) test as an optimal test combining burden test and SKAT. Results: After joint variant calling, 91 TMA cases and 93 non-TMA controls passed all QC filters (Table 1). Among 1,485 variants detected in the 5 pathways after QC, 60 variants (73 total mutations) were considered as qualifying variants with MAF Conclusion: Contrary to the initial hypothesis, we did not observe pathogenic germline rare variants in the complement regulation pathway in patients with TA-TMA. Instead, we found a significant association in the VWF clearance pathway, particularly that of the LRP1 gene. In recent years, researchers have shown that VWF can bind to and activate complement proteins. Impaired VWF clearance could lead to the higher predisposition for complement activation observed in patients with TA-TMA. Future functional studies are needed to determine the impact of VWF clearance on the pathogenesis of the disease. Figure 1 Figure 1. Disclosures Sartain: Alexon Pharamaceuticals: Membership on an entity's Board of Directors or advisory committees. Lee: Incyte: Research Funding; Janssen: Other; Takeda: Research Funding; Novartis: Membership on an entity's Board of Directors or advisory committees, Research Funding; Pfizer: Research Funding; Kadmon: Research Funding; National Marrow Donor Program: Membership on an entity's Board of Directors or advisory committees; Syndax: Research Funding; AstraZeneca: Research Funding; Amgen: Research Funding.

BACKGROUND The a disintegrin and metalloprotease with thrombospondin type 1 motifs, member 13 (ADAMTS13) activity assay has become important in distinguishing autoimmune thrombotic thrombocytopenic purpura from other forms of thrombotic microangiopathy (TMA). Although the significance of severe deficiency in ADAMTS13 (activity levels 10% or less) has been well defined, little data are available on the clinical importance of mild to moderate deficiency (activity levels 11%-70%) among patients with TMA. STUDY DESIGN AND METHODS We conducted a retrospective study using the Harvard TMA Research Collaborative Registry. Among 254 patients who met the inclusion criteria for TMA, 186 patients with ADAMTS13 activity levels greater than 10% were divided into moderate-deficiency (11%-40%), mild-deficiency (41%-70%), and no-deficiency (greater than 70%). RESULTS Compared with mild or no deficiency, moderate ADAMTS13 deficiency correlated with older age; higher bilirubin and international normalized ratio; and increased frequency of sepsis, shock, or multiorgan failure. Platelet counts, lactate dehydrogenase levels, and the presence of renal or neurologic dysfunction did not vary across the three patient cohorts. While moderate ADAMTS13 deficiency was associated with increased 90-day mortality in univariate analysis, this association was no longer significant in multivariate analysis. Variables that independetly predicted 90-day mortality in this cohort of patients included Charlson comorbidity index, alanine aminotransferase level, platelet count, creatinine, and the presence of sepsis, shock, or multiorgan failure. CONCLUSION Moderately deficient ADAMTS13 activity identifies a cohort of patients with TMA who are at increased risk for 90-day mortality. The ADAMTS13 activity level in this group is not an independent predictor of poor outcomes but instead appears to be a marker of disease acuity.

Thrombotic microangiopathies (TMAs) are a group of rare but potentially lethal hematologic disorders characterized by platelet-rich thrombi in the microvasculature. In evaluating patients with TMA, it is crucial to identify those who have thrombotic thrombocytopenic purpura (TTP), a subtype of TMA that occurs due to a severe deficiency in ADAMTS13 (a disintegrin and metalloprotease with thrombospondin type 1 motif, member 13). Individuals with TTP require urgent therapeutic plasma exchange, which is associated with a significant reduction in mortality; however, at most centers, the results of ADAMTS13 activity testing are usually not available for 3 to 5 days. Given the possible need for urgent intervention and the lack of timely test results to guide therapy, the assessment of patients with TMA represents an ideal situation for the deployment of diagnostic scoring systems to predict the presence of severe ADAMTS13 deficiency. Here, we review the literature surrounding clinical prediction tools in the diagnosis and prognostication of patients with TMA, describe the experience at our center with evaluating TMA patients, and discuss the utility of clinical scoring systems for TMA in the context of patient care.

BACKGROUND Alloantibodies recognizing human leukocyte antigens (HLA) can cause immune-mediated refractoriness to platelet transfusion. An association between HLA alloimmunization and red blood cell (RBC) alloimmunization has been suggested but remains uncertain. STUDY DESIGN AND METHODS We tested for HLA alloantibodies in 660 patients with and without RBC alloantibodies. Calculated panel reactive antibody (cPRA) values were determined for HLA alloimmunized patients. Current and historical diagnoses and blood product exposure were catalogued. Variables associated with high-level HLA alloimmunization (cPRA ≥ 90%) were evaluated. RESULTS The cohort included 366 women and 294 men with median age of 66 years (interquartile range [IQR], 53-76). The number of patients with and without RBC alloantibodies was 447 and 213, respectively. Among patients with and without RBC alloantibodies, 20.6% and 8.5% had a cPRA ≥ 90%, respectively (p

The PLASMIC score is a recently described clinical scoring algorithm that rapidly assesses the probability of severe ADAMTS13 (a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13) deficiency among patients presenting with microangiopathic haemolytic anaemia. Using a large multi-institutional cohort, we explored whether an approach utilizing the PLASMIC score to risk-stratify patients with suspected immune thrombotic thrombocytopenic purpura (iTTP) could lead to significant cost savings. Our consortium consists of institutions with an unrestricted approach to ADAMTS13 testing (Group A) and those that require pre-approval by the transfusion medicine service (Group B). Institutions in Group A tested more patients than those in Group B (P < 0·001) but did not identify more cases of iTTP (P = 0·29) or have lower iTTP-related mortality (P = 0·84). Decision tree cost analysis showed that applying a PLASMIC score-based strategy to screen patients for ADAMTS13 testing in Group A would have reduced costs by approximately 27% over the 12-year period of our study compared to the current approach. Savings were primarily driven by a reduction in unnecessary therapeutic plasma exchanges, but lower utilization of ADAMTS13 testing and subspecialty consultations also contributed. Our data indicate that using the PLASMIC score to guide ADAMTS13 testing and the management of patients with suspected iTTP could be associated with significant cost savings.

BACKGROUND Therapeutic plasma exchange (TPE) is a proven treatment for thrombotic thrombocytopenic purpura (TTP) characterized by severe ADAMTS13 deficiency, but the efficacy of TPE in suspected TTP with an ADAMTS13 activity level of more than 10% remains controversial. STUDY DESIGN AND METHODS We conducted a propensity score (PS)-matched study of 186 adult patients included in the Harvard Thrombotic Microangiopathy (TMA) Research Collaborative registry who presented with TMA suggestive of TTP but an ADAMTS13 activity level of more than 10%. RESULTS Before matching, patients treated with TPE (n = 71) differed from untreated patients (n = 115) by several clinical measures. PS matching was performed to address clinical disparities between the two groups and resulted in a well-balanced cohort of 59 TPE-treated patients paired with 59 untreated controls, all of whom had TMA. After matching, we observed no significant difference in the primary outcome of 90-day survival between the treated and untreated groups (hazard ratio, 0.88; 95% confidence interval [CI], 0.44-1.77; p = 0.72). In-hospital mortality (odds ratio [OR], 0.77; 95% CI, 0.34-1.75; p = 0.53) and the percentage of patients with platelet count recovery (OR, 1.58; 95% CI, 0.77-3.26; p = 0.21) also did not differ significantly between the two matched groups. CONCLUSION Our data suggest that routine use of TPE in the diverse group of TMA patients without severe ADAMTS13 deficiency may not significantly improve outcomes.

A 22-year-old man with sickle cell disease presented with headache and difficulty speaking after smoking marijuana. He had anomia, apraxia, and alexia and was unable to perform arithmetic. Diagnostic tests were performed, and management decisions were made.

The Harvard TMA Research Collaborative is a multi-institutional registry-based effort to study thrombotic microangiopathies (TMA). Laboratory and clinical parameters were recorded for 254 cases of suspected autoimmune thrombotic thrombocytopenic purpura (TTP). Patients with severe ADAMTS13 deficiency (activity ≤10%, N = 68) were more likely to be young, female and without a history of cancer treatment or transplantation. While all patients with severe deficiency were diagnosed with autoimmune TTP, those without severe deficiency frequently had disseminated intravascular coagulation, drug-associated TMA and transplant-related TMA. Patients with severe ADAMTS13 deficiency had superior overall survival at 360 d compared to those without severe deficiency (93·0% vs. 47·5%, P 0·0001). Almost all patients with severe deficiency received therapeutic plasma exchange (TPE), but the use of TPE in patients with ADAMTS13 activity10% varied significantly across the institutions in our consortium (13·2-63·8%, P 0·0001). Nevertheless, 90-d mortality was not different in patients with ADAMTS13 activity10% between the three hospitals (P = 0·98). Our data show that patients with severe ADAMTS13 deficiency represent a clinically distinct cohort that responds well to TPE. In contrast, TMA without severe ADAMTS13 deficiency is associated with increased mortality that may not be influenced by TPE.

BACKGROUND Collection of hematopoietic progenitor cells by apheresis (HPC-A) requires separation of cells by density. Previous studies highlighted the challenges of HPC-A collection from patients with abnormal red blood cells (RBCs). TEMPI syndrome is a recently described condition defined by teleangiectasias, elevated erythropoietin and erythrocytosis, monoclonal gammopathy, perinephric fluid collections, and intrapulmonary shunting. Patients with TEMPI syndrome have responded to therapies used to treat plasma cell dyscrasias and may benefit from autologous HPC transplantation. We report HPC-A collection from a patient with TEMPI syndrome that was complicated by severe iron deficiency. STUDY DESIGN AND METHODS The patient received granulocyte–colony-stimulating factor (G-CSF) and plerixafor for HPC mobilization and underwent 3 days of HPC-A collection. RESULTS The patient presented for collection with a microcytic erythrocytosis. Over 3 days, approximately 50 L of whole blood was processed, and 2 × 108 CD34+ cells were collected (2.8 × 106 CD34+ cells/kg). The mean collection efficiency (CE), percentage of mononuclear cells, hematocrit (Hct), and RBC count were 18%, 90%, 14%, and 9 × 1011, respectively. Altering collection variables to avoid RBC contamination reduced CE. Ficoll preparations of the products after freeze-thaw showed RBC contamination and hemolysis. Postthaw viability exceeded 95%. The products were not RBC reduced or washed. There were no adverse reactions during or after infusion. CONCLUSIONS HPC-A collection from a patient with TEMPI syndrome was complicated by microcytic erythrocytosis, leading to RBC contamination and hemolysis in the product. Adequate HPCs were collected and the patient tolerated infusion without RBC depletion or washing. Our report highlights difficulties of HPC-A collection from iron-deficient patients.

No clinical consult raises the heart rate of a transfusion medicine specialist quite like that involving thrombotic microangiopathy (TMA) concerning for thrombotic thrombocytopenic purpura (TTP). The differential diagnosis is complex and challenging, the patients tend to be very ill, and effective treatment requires providing therapy directed at the underlying pathology as quickly as possible. Clinical pathologists are well positioned to provide guidance in these cases since they are usually alerted to all patients in the hospital with suspected TTP and therefore have considerable experience to offer. In contrast, the consulting physician may be somewhat less experienced in formulating a diagnostic and therapeutic plan of care for these patients and might opt for therapeutic plasma exchange (TPE) when in fact a more careful evaluation is merited and other therapies might be more effective. The article by Williams and Marques1 in this issue of the Journal highlights the key role played by the clinical pathologist in the care of patients with TMA, focusing on the important distinction between TTP, hemolytic uremic syndrome (HUS), and atypical uremic syndrome (aHUS) and providing a clear and logical approach to these disorders. TMA should be viewed as a manifestation of diverse pathologies involving either hemostasis (inappropriate platelet activation or thrombin generation) or the endothelium (exposure to Shiga toxin, uncontrolled complement deposition).2 Treatments differ depending on the underlying mechanism of disease. Whereas TPE is an effective treatment for TTP,3,4 eculizumab has emerged as an important new therapy for aHUS,5 providing superior renal survival in comparison to outcomes observed following treatment with TPE alone.6 The understanding that aHUS results from dysregulation of the alternative complement pathway and is associated with inherited mutations in complement regulatory proteins while TTP results from severe deficiency of the ADAMT13 enzyme caused by autoantibodies to this … Corresponding author: Robert S. Makar, MD, PhD, Massachusetts General Hospital Blood Transfusion Service, GRJ-148, 55 Fruit St, Boston, MA 02114; rmakar{at}mgh.harvard.edu.

The a disintegrin and metalloprotease with thrombospondin type 1 motifs, member 13 (ADAMTS13) activity assay has become important in distinguishing autoimmune thrombotic thrombocytopenic purpura from other forms of thrombotic microangiopathy (TMA). Although the significance of severe deficiency in ADAMTS13 (activity levels 10% or less) has been well defined, little data are available on the clinical importance of mild to moderate deficiency (activity levels 11%-70%) among patients with TMA.We conducted a retrospective study using the Harvard TMA Research Collaborative Registry. Among 254 patients who met the inclusion criteria for TMA, 186 patients with ADAMTS13 activity levels greater than 10% were divided into moderate-deficiency (11%-40%), mild-deficiency (41%-70%), and no-deficiency (greater than 70%).Compared with mild or no deficiency, moderate ADAMTS13 deficiency correlated with older age; higher bilirubin and international normalized ratio; and increased frequency of sepsis, shock, or multiorgan failure. Platelet counts, lactate dehydrogenase levels, and the presence of renal or neurologic dysfunction did not vary across the three patient cohorts. While moderate ADAMTS13 deficiency was associated with increased 90-day mortality in univariate analysis, this association was no longer significant in multivariate analysis. Variables that independetly predicted 90-day mortality in this cohort of patients included Charlson comorbidity index, alanine aminotransferase level, platelet count, creatinine, and the presence of sepsis, shock, or multiorgan failure.Moderately deficient ADAMTS13 activity identifies a cohort of patients with TMA who are at increased risk for 90-day mortality. The ADAMTS13 activity level in this group is not an independent predictor of poor outcomes but instead appears to be a marker of disease acuity.

Objectives The scope of activities performed by clinical laboratory directors is sometimes unfamiliar to other physicians or hospital administrators. Consequently, hospital leadership may undervalue the role and assume that many director level activities could be delegated to a professional manager. In this study, we sought to define the activities of academic laboratory directors, and to determine which activities require doctorate level medical or scientific expertise. Methods We performed an audit of laboratory director activities at a large academic medical center by reviewing electronic calendars and other available records from the preceding 12 consecutive months. For episodic activities, the directors estimated the average number of hours devoted over the 1-year period. Results On average, directors worked 54.9 hours per week and performed at least some service work 47.7 weeks per year. Administrative duties accounted for the greatest proportion of effort (47.1%), followed by clinical activities (33.1%) and academic activities (19.8%). Among administrative duties, those that required doctorate level medical or scientific expertise comprised 60.3% of the total administrative effort, whereas the remaining 39.7% (18.7% of total activity) could be performed by a professional manager.. Conclusions Although the activities of clinical laboratory directors have been described elsewhere, this is the first study detailing the effort allocated to these various activities in quantitative terms. The study demonstrated that less than 20% of an academic laboratory director's effort involves administrative activities that could potentially be performed by a professional manager lacking doctorate level medical or scientific expertise.

Alloimmune platelet refractoriness (alloPR) among actively bleeding surgical patients with thrombocytopenia represents a life-threatening problem. Here we present three cases in which surgical bleeding was complicated by life-threatening thrombocytopenia and alloPR. We demonstrate that the human leukocyte antigens (HLA) antibodies associated with alloPR are broadly reactive and in high concentration, are not removed by hemodilution, and are not absorbed by transfusion of multiple doses of platelet concentrates. HLA alloPR may be under-recognized among surgical patients. Research is needed to develop pre-operative screening methods that will identify patients in need of specialized platelet support using HLA compatible donor products.

Purpose: To report a well-characterized Waldenstrom's macroglobulinemia (WM) case that provides insight into the mechanisms of two paraneoplastic complications -- cancer-associated retinopathy (CAR) and small fiber polyneuropathy (SFPN).Methods: Retrospective medical chart review.Results: A 58-year old man with WM developed vision loss and bilateral lower extremity pain. CAR was diagnosed by history, a depressed electroretinogram (ERG) and positive anti-retinal antibodies. SFPN diagnosis was based on abnormal autonomic nerve function testing and a distal-leg skin biopsy that demonstrated absent epidermal small-fiber innervation, IgM and complement deposition and microvasculopathy. Plasma exchange (PLEX) led to dramatic pain relief and subjective improvement in eye symptoms along with improvement of some ERG parameters. Repeat skin biopsy after treatment showed less microvascular abnormalities and decreased complement deposition.Conclusions: The concurrence of CAR and SFPN in this patient suggest t...

Among the syndromes characterised by thrombotic microangiopathy, thrombotic thrombocytopenic purpura is distinguished by a severe deficiency in the ADAMTS13 enzyme. Patients with this disorder need urgent treatment with plasma exchange. Because ADAMTS13 activity testing typically requires prolonged turnaround times and might be unavailable in resource-poor settings, a method to rapidly assess the likelihood of severe ADAMTS13 deficiency is needed.All consecutive adult patients presenting to three large academic medical centres in Boston, MA, USA, with thrombotic microangiopathy and a possible diagnosis of thrombotic thrombocytopenic purpura between Jan 8, 2004, and Dec 6, 2015, were included in an ongoing multi-institutional registry (the Harvard TMA Research Collaborative). Univariate analysis was used to identify covariates for a logistic regression model predictive of severe ADAMTS13 deficiency (≤10% activity). A clinical point score was generated, and its diagnostic performance was assessed using internal and external validation cohorts and compared to clinical assessment alone.214 patients with thrombotic microangiopathy were included in the derivation cohort. A seven-component clinical prediction tool, termed the PLASMIC score, was developed and found to reliably assess the pretest probability of severe ADAMTS13 deficiency (C statistic 0·96, 95% CI 0·92-0·98). Our diagnostic model was reproducibly accurate in both the internal (0·95, 0·91-0·98) and external (0·91, 0·85-0·95) validation cohorts. The scoring system also more consistently diagnosed thrombotic microangiopathy due to severe ADAMTS13 deficiency than did standard clinical assessment, as measured by C statistic (0·96, 95% CI 0·92-0·98 for PLASMIC vs 0·83, 0·77-0·88 for clinical assessment; p0·0001) and mean Brier score (0·065 for PLASMIC vs 0·111 for clinical assessment; mean paired difference 0·05, 95% CI 0·01-0·08; p0·0001). When utilised in addition to clinical assessment, the PLASMIC score contributed significant discriminatory power (integrated discrimination improvement 0·24, 95% CI 0·11-0·37).We have developed and validated a clinical prediction tool-the PLASMIC score-to stratify patients with thrombotic microangiopathy according to their risk of having severe ADAMTS13 deficiency. We have shown that this scoring system is superior to standard clinical assessment in addressing the diagnostic challenge presented by thrombotic microangiopathy. Its use, together with clinical judgment, may facilitate treatment decisions in patients for whom timely results of ADAMTS13 activity testing are unavailable.The Luick Family Fund of Massachusetts General Hospital.

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a rare form of microangiopathic hemolytic anemia characterized by congenital or acquired deficiency of the enzyme ADAMTS13. Both inherited TTP (Upshaw-Schulman Syndrome) and acquired TTP can present in childhood. As TTP is particularly uncommon in pediatric patients, there are frequent delays in diagnosis that can prolong time to life-saving treatment with therapeutic plasma exchange (TPE). The PLASMIC score is a validated clinical prediction tool used to stratify adult patients with thrombotic microangiopathies (TMAs) based upon their risk of having severe ADAMTS13 deficiency. The purpose of this study is to characterize a cohort of pediatric patients presenting with TMAs and to determine whether the PLASMIC score can accurately identify those children at risk for severe ADAMTS13 deficiency. Methods: We created a registry of all consecutive pediatric cases of suspected TTP at 3 academic medical centers in Boston, MA from January 2004 through November 2018. Suspected cases were defined as any patient with TMA who received ADAMTS13 activity testing during this period. Patients were included in the cohort if they were ≤18 years-old, thrombocytopenic (platelet count less than lower limit of normal for age), and had schistocytes on peripheral blood smear. Exclusion criteria included individuals tested as outpatients and potential interferents with ADAMTS13 testing (hemolyzed specimen, total bilirubin >15 mg/dL, sample sent less than 24 hours after exposure to plasma). For each patient, the ADAMTS13 test result as well as additional laboratory, demographic, and clinical parameters were recorded. The PLASMIC score was calculated for each patient. Results: Of the 125 unique pediatric patients who underwent ADAMTS13 testing during the study period, 59 presented with a thrombotic microangiopathy and met the inclusion criteria. Nine of the 59 patients (15.3%) had severe ADAMTS13 deficiency with ADAMTS13 activity of ≤10%. Eight of these 9 patients had detectable autoantibody inhibitor titers, consistent with acquired/immune TTP. One patient with severe ADAMTS13 deficiency had a history of renal transplant and was the only patient with ADAMTS13 levels ≤10% who had no detectable inhibitor. Compared to patients with ADAMTS13 levels >10%, patients with severe ADAMTS13 deficiency were older, predominantly female, and more frequently presented with neurological symptoms (see table). At the time of ADAMTS13 testing, patients with severe ADAMTS13 deficiency also had a lower platelet count, a higher LDH, a higher reticulocyte count, and higher levels of total and indirect bilirubin. There were non-significant trends toward improved one-year and overall survival in patients with ADAMTS13 levels ≤10%. Forty-eight patients in the cohort had all necessary data for calculation of the PLASMIC score. As the youngest patient with severe ADAMTS13 deficiency in this cohort was 3 years-old, we restricted our analysis to patients 2 years and older (N=41). All pediatric patients with ADAMTS13% ≤10% in our cohort had a PLASMIC score of 6 or 7. Nine out of 16 patients with a PLASMIC score of >5 had severe ADAMTS13 deficiency. The C statistic for the resultant ROC curve was 0.92 (95% CI 0.796 to 0.983). Conclusion: The small number of pediatric patients with TTP identified over the 14-year period of our study cohort emphasizes the rarity of this disease in children and the potential utility for a clinical prediction tool to aid in diagnosis and to help determine on whom ADAMTS13 testing should be performed. The PLASMIC score can accurately identify pediatric patients at high risk for severe ADAMTS13 deficiency, facilitating rapid diagnosis and initiation of appropriate therapy. Figure Disclosures No relevant conflicts of interest to declare.

Therapeutic plasma exchange (TPE) is a proven treatment for thrombotic thrombocytopenic purpura (TTP) characterized by severe ADAMTS13 deficiency, but the efficacy of TPE in suspected TTP with an ADAMTS13 activity level of more than 10% remains controversial.We conducted a propensity score (PS)-matched study of 186 adult patients included in the Harvard Thrombotic Microangiopathy (TMA) Research Collaborative registry who presented with TMA suggestive of TTP but an ADAMTS13 activity level of more than 10%.Before matching, patients treated with TPE (n = 71) differed from untreated patients (n = 115) by several clinical measures. PS matching was performed to address clinical disparities between the two groups and resulted in a well-balanced cohort of 59 TPE-treated patients paired with 59 untreated controls, all of whom had TMA. After matching, we observed no significant difference in the primary outcome of 90-day survival between the treated and untreated groups (hazard ratio, 0.88; 95% confidence interval [CI], 0.44-1.77; p = 0.72). In-hospital mortality (odds ratio [OR], 0.77; 95% CI, 0.34-1.75; p = 0.53) and the percentage of patients with platelet count recovery (OR, 1.58; 95% CI, 0.77-3.26; p = 0.21) also did not differ significantly between the two matched groups.Our data suggest that routine use of TPE in the diverse group of TMA patients without severe ADAMTS13 deficiency may not significantly improve outcomes.

The prevention of Rhesus D alloimmunization through Rh immune globulin (RhIg) administration is the major indication for the accurate detection and quantification of fetomaternal hemorrhage (FMH). In the setting of D incompatibility, D-positive fetal cells can sensitize the D-negative mother, resulting in maternal anti-D alloantibody production. These anti-D alloantibodies may lead to undesirable sequelae such as hemolytic disease of the newborn (HDN). Since the widespread adoption of FMH screening and RhIg immunoprophylaxis, the overall risk of Rh alloimmunization and infant mortality from HDN has substantially decreased. The rosette screen, the initial test of choice, is highly sensitive in qualitatively detecting 10 mL of fetal whole blood in the maternal circulation. As the screen is reliant on the presence of the D antigen to distinguish fetal from maternal cells, it cannot be used to detect FMH in D-positive mothers or in D-negative mothers carrying a D-negative fetus. The Kleihauer-Betke acid-elution test, the most widely used confirmatory test for quantifying FMH, relies on the principle that fetal RBCs contain mostly fetal hemoglobin (HbF), which is resistant to acid-elution whereas adult hemoglobin is acid-sensitive. Although the Kleihauer-Betke test is inexpensive and requires no special equipment, it lacks standardization and precision, and may not be accurate in conditions with elevated F-cells. Anti-HbF flow cytometry is a promising alternative, although its use is limited by equipment and staffing costs. Hematology analyzers with flow cytometry capabilities may be adapted for fetal cell detection, thus giving clinical laboratories a potentially attractive automated alternative for quantifying FMH.

BACKGROUND: Cytometric-based microbead assays for HLA alloantibodies may be effective tools for transfusion-related acute lung injury (TRALI) risk reduction. However, the optimal cutoff for donor screening is unclear. STUDY DESIGN AND METHODS: To optimize the screening test cutoff in sensitized donors, sera were screened with a cytometric microbead assay. Confirmatory testing was performed on samples with a normalized background (NBG) ratio of 2.4 or more. RESULTS: Sera with a NBG of 2.4 to 9.9 had positive predictive values (PPVs) of 78.2% (95% confidence interval [CI], 67.8%-86.0%) and 71.1% (95% CI, 56.5%-82.4%) for Class I and II antibodies, respectively. Sera with a NBG of 10 or more had PPVs of 98.9% (95% CI, 93.3%-100%) and 99.1 (95% CIs, 94.7%-100%) for Class I and II, respectively. The percent panel-reactive antibody (PRA) of confirmed HLA alloantibodies from sera with a NBG of 2.4 to 9.9 was 29.3 ± 17% (mean ± standard deviation) for Class I and 22.3 ± 16.7% for Class II, but for antibodies from sera with a NBG of 10 or more the PRAs were 65.3 ± 24.0 and 64.1 ± 25.2% for Class I and II, respectively (p

A 16-year-old girl with a history of lupus nephritis was seen in the emergency department because of altered mental status. She was somnolent and agitated and had no focal neurologic signs. Brain CT revealed no abnormalities. Laboratory studies revealed anemia and thrombocytopenia.

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a distinct and lethal subtype of thrombotic microangiopathy (TMA) requiring treatment with therapeutic plasma exchange (TPE). However, a significant proportion of patients suffer relapses of TTP, and predictors of relapse remain unclear. Whether rituximab (RTX) affects relapse rates in TTP is uncertain. We employed a multi-institutional, registry-based approach to study the effect of RTX on relapse in autoimmune TTP and identify predictors of relapse. Methods: Consecutive adult patients presenting with acute autoimmune TTP (thrombocytopenia ( Results: Within our combined dataset, we identified 124 patients with autoimmune TTP. Patients were treated with a median (IQR) of 14 (8-22) TPE treatments until clinical remission was achieved. Seventy-five percent of patients experienced at least one complication from TPE; most common were mild urticarial reactions, but more serious allergic reactions including anaphylaxis occurred in 19% of TPE courses, and one patient died as the result of line-associated bacteremia during TPE. Of the 109 patients with 90-day or more follow up data, 8 (7.3%) died following presentation with TTP; five of these 8 deaths occurred in patients who presented in a moribund state or did not received TPE within the first 24 hours of hospitalization. Thirty-four patients (27%) subsequently relapsed, with a median time to relapse of 1.75 years. RTX was given to 48% of patients. The median time to the first dose of RTX was 12 (7-23) days following presentation. We observed a 3.6% increase per year in the proportion of patients presenting for the first time with acute TTP who were treated with RTX. Kaplan Meier analysis performed on the entire cohort did not show an overall difference in relapse free survival between patients who received RTX and those who did not (Figure 1) but did suggest the presence of a short-term benefit from RTX. A sensitivity analysis using only patients who presented with a first episode of TTP yielded similar results. Extended Cox multivariate analysis showed that the following parameters were independently associated with increased risk of relapse: younger age (HR=2.94, 95% CI: 1.2-7.2, P=0.018), non-O blood group (HR=2.11, 95% CI: 1.03-4.3, P=0.041), and history of a prior episode of TTP (HR=3.05, 95% CI: 1.4-6.6, P=0.005). By contrast, RTX reduced the risk of relapse (HR=0.15, 95% CI 0.03-0.68) but this protective effect appeared to diminish over time. ADAMTS13 inhibitor titer at initial presentation did not predict relapse. Conclusions: Although a significant number of patients experienced complications from treatment with TPE, death from TTP was infrequent and generally associated with delay in seeking medical care or initiating treatment. Use of RTX was associated with short-term protection from relapse but not long-term relapse free survival. Age, non-O blood group, and prior TTP were significantly associated with an increased risk of relapse. Further studies in independent datasets are required to validate the role of these risk factors in identifying patients who would benefit most from therapies directed at prevention of relapse in TTP. Disclosures No relevant conflicts of interest to declare.

Background Endovascular aneurysm repair (EVAR) reduces the morbidity and mortality associated with abdominal aortic aneurysm repair, but in some patients endoleak or aneurysm expansion may necessitate secondary open conversion (SOC). We reviewed the outcomes after delayed SOC following EVAR in consecutive patients at a single center. Methods We retrospectively reviewed all patients undergoing EVAR to identify a cohort undergoing delayed SOC in a single center between 1998 and 2008. We analyzed delayed SOC patients for operative indications, technique, and early outcomes. We made specific comment on the surgical techniques used, with respect to partial or total endograft explantation. Results Delayed SOC was carried out in 10/285 (3.5%) consecutive patients implanted with the Zenith endograft; during this period, two further patients had SOC after initial EVAR in another center. Graft types were Zenith ( n = 10), Talent ( n = 1), and AneuRx ( n = 1). Indications for open conversion were infected graft ( n = 3), sac expansion ( n = 3), type 1 endoleak ( n = 2), type 2 endoleak ( n = 2), juxtarenal aneurysm ( n = 1), and rupture ( n = 1). Explantation techniques were partial explantation with in situ replacement ( n = 7), full explantation with axillobifemoral bypass ( n = 3), in situ replacement ( n = 1), and suturing ( n = 1)Complete stent explantation was required in 4 patients with axillo-bifemoral bypass in three of them. 7 patients had partial stent explantation and one patient stent was left insitu. Postoperative morbidities included myocardial infarction ( n = 1), renal dialysis ( n = 1), and chest infection ( n = 3). No 30-day mortality was noted, and all patients were discharged from hospital and remain well with median follow-up of 5 months (interquartile range 1.7-26.7). Conclusion SOC after EVAR is feasible in selected patients with low morbidity and mortality. Partial explantation with in situ replacement, in the absence of sepsis, may be the preferred revascularization option but may require long-term follow-up.

Objectif Le traitement endovasculaire des anevrysmes (EVAR) reduit la morbidite et la mortalite associees a la reparation des anevrysmes de l’aorte abdominale et certains patients presentant des endofuites ou une expansion anevrysmale peuvent necessiter une conversion ouverte secondaire (COS). Nous avons revu les resultats de la COS differee apres EVAR chez des patients consecutifs dans un centre unique. Methodes Nous avons revu retrospectivement tous les patients ayant une EVAR afin d’identifier une cohorte de patients ayant une COS differee dans une seule institution entre 1998 et 2008. Nous avons analyse les patients ayant une COS differee en fonction des indications operatoires, des techniques et des resultats precoces. Nous avons analyse de maniere specifique les details de la technique chirurgicale utilisee en fonction de l’explantation partielle ou totale de l’endoprothese. Resultats Une COS differee a ete effectuee chez 10/285 (3,5%) patients consecutifs ayant eu l’implantation d’une endoprothese Zenith. Au cours de cette periode, deux autres patients ont eu une COS apres une EVAR effectuee initialement dans un autre centre. Le type de prothese etait une Zenith (n = 10), une Talent (n = 1) et une AneuRx (n = 1). Les indications de conversion ouverte etaient une infection de prothese (n = 3), une expansion du sac anevrysmal (n = 3), une endofuite de type I (n = 2), une endofuite de type II (n = 2), un anevrysme juxta-renal (n = 1) et une rupture (n = 1). Les techniques d’explantation ont ete l’explantation partielle avec un remplacement in situ (n = 7), l’explantation complete avec pontage axillo-bifemoral (n = 3), le remplacement in situ (n = 1) et la suture (n = 1). L’explantation complete du stent a ete necessaire chez quatre patients dont trois ont recu un pontage axillo-bifemoral. Sept patients ont eu l’explantation partielle du stent et le stent a ete laisse in situ chez un patient. La morbidite post-operatoire a inclus un infarctus du myocarde (n = 1), une dialyse renale (n = 1) et trois infections pulmonaires (n = 3). Le taux de mortalite a 30 jours a ete nul. Tous les patients ont pu quitter l’hopital pour rester en bonne forme avec un suivi median de 5 mois (extremes 1,7 a 26,7). Conclusion Une COS est possible avec de faibles taux de morbidite et de mortalite apres une EVAR, chez des patients selectionnes. L’explantation partielle avec remplacement in situ, en l’absence de sepsis, pourrait etre l’option preferable de revascularisation mais un suivi a long terme doit etre obtenu.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related fatality reported to the Food and Drug Administration. Donor screening may reduce TRALI risk. This study sought to compare the efficacy and safety of different TRALI risk-reduction strategies at a hospital-based donor center. STUDY DESIGN AND METHODS: Samples from 1053 donors who answered questions regarding pregnancy and transfusion history were tested for HLA Class I and II antibodies using a flow cytometry–based screening assay. Donor history was compared with the presence of HLA alloantibodies. These data were used to model several TRALI risk-reduction strategies. The medical records of patients transfused fresh-frozen plasma (FFP) from highly alloimmunized donors were retrospectively reviewed for TRALI. RESULTS: HLA alloimmunization was observed among 25.4 percent (256/1009) of all female donors and among 12.0 percent (3/25) of those male donors who gave a history of prior transfusion. Prior pregnancy, reported by 52.6 percent (531/1009) of females, correlated significantly with HLA alloimmunization (p

BACKGROUND: Warm autoimmune hemolytic anemia and antiphospholipid antibodies (which include lupus anticoagulants and anticardiolipin [ACL] antibodies) are associated, respectively, with approximately 10 and 40 percent of cases of systemic lupus erythematosus (SLE). This study reports a case of SLE presenting with an unusual constellation of findings that included an immunoglobulin M (IgM) cold autoantibody of high thermal amplitude, high-titer ACL antibodies, and transient acquir ed activated protein C resistance. CASE REPORT: A previously untransfused, nulligravid 17-year-old woman without a significant medical history presented with signs and symptoms of SLE and an extravascular hemolytic anemia. Spontaneous agglutination was noted in blood samples collected for testing. Serologic testing revealed a normal-titer, high-thermal-amplitude IgM red blood cell (RBC) autoantibody but no additional RBC antibodies in the patient's plasma. Additional testing was significant for a high-titer ACL IgM and a positive test for activated protein C resistance (a screening test for the Factor [F]V Leiden mutation), which prompted initiation of prophylactic anticoagulation. Confirmatory DNA testing for FV Leiden, however, was negative. The patient's symptoms, anemia, RBC autoagglutinins, ACL antibodies, and activated protein C resistance all resolved after 6 weeks of immunosuppression. CONCLUSION: This case illustrates the wide range of clinical and laboratory findings that autoantibodies against cellular membranes may produce. IgM autoagglutinins of high thermal amplitude associated with a significant extravascular hemolytic anemia may be a presenting feature of SLE. Concomitant antiphospholipid antibodies may interfere with partial thromboplastin time–based tests of hypercoagulability such as that for activated protein C resistance.

Cross-presentation is increasingly recognized as a key mechanism by which specific antigen-presenting cells (APCs) activate the cellular immune system against virally infected or neoplastic cells. These APCs have the capacity to acquire exogenous proteins by phagocytosis or endocytosis, derive antigenic peptides, and then cross-present them in the context of class I major histocompatibility complex molecules. Because APCs provide both an antigenic stimulus and costimulatory signals, they can effectively activate naive CD8 + T lymphocytes, resulting in a brisk cellular immune response. The precise cellular pathways that permit an exogenous antigen to be presented in the context of class I major histocompatibility complex is the focus of intense investigation that has illuminated our understanding of the cell biology of APCs. This article reviews our understanding of how APCs cross-present antigen, illustrating how this process differs from the canonical pathways of antigen presentation. We define the central players required for cross-presentation and then focus on recent studies that reveal the molecular mechanisms underlying this phenomenon. Understanding these mechanisms will likely inform the development of effective cell-based vaccines and other cellular immunotherapies and is therefore of interest to practitioners of transfusion medicine.

Transfusion-related acute lung injury (TRALI) is a leading cause of transfusion-associated morbidity and mortality. The National Heart, Lung, and Blood Institute (NHLBI) and Canadian Consensus Conference definitions of TRALI exclude cases of mild TRALI. As a result, many cases of mild TRALI are likely to be missed. Three cases are reported in which patients experienced the acute onset of breathlessness in association with transfusion of blood components containing human leukocyte antigen (HLA) antibodies reactive with recipient HLA antigens. Despite the sudden onset of a pulmonary syndrome in association with transfusion, clinicians caring for these patients did not consider TRALI, and no case would meet recent consensus definitions. Nevertheless, supporting clinical and serologic evidence for TRALI was found in each case. Benefits in recognizing mild cases of TRALI include quantifying the true incidence of TRALI, understanding the physiology of mild versus severe TRALI, and preventing subsequent cases of TRALI due to donors found to have HLA antibodies.

Tuba is a multidomain scaffolding protein that links cytoskeletal dynamics and membrane trafficking pathways. The N-terminus of Tuba binds dynamin1, and the C-terminus contains domains that can interact with signaling pathways and cytoskeletal regulatory elements. We investigated Tuba localization, distribution and function in B16 melanoma cells. Tuba overexpression stimulated dorsal ruffles that occurred independently of dynamin function. Tuba expression induced actin-driven motility of small puncta that required the C-terminal SH3, GEF and BAR domains. Additionally, Tuba was recruited to lipid vesicles generated by overexpression of phosphatidylinositol-4-phosphate 5-kinase type Iα (PIP5Kα), localizing prominently to the head of the comets and at lower levels along the actin tail. We propose that Tuba facilitates dorsal ruffling of melanoma cells through direct interaction with actin-regulatory proteins and the recruitment of signaling molecules to lipid microdomains for the coordinated assembly of a cytoskeletal network. Knockdown of Tuba by RNA interference (RNAi) attenuated PIP5Kα-generated comet formation and the invasive behavior of B16 cells, implying that Tuba function is required for certain aspects of these processes. These results suggest first that Tuba-stimulated dorsal ruffling might represent a novel mechanism for the coordination of N-WASP-dependent cytoskeletal rearrangements and second that Tuba function is implicated in motility processes.

Immunoglobulin A (IgA) deficiency may result in the development of anti-IgA antibodies. Such antibodies may result in anaphylaxis when patients receive standard blood products. Hemophilia A is a deficiency of clotting factor VIII that results in a significant coagulopathy and bleeding in the perioperative period unless precautions are taken. We present a case of successful management of combined hemophilia A and IgA deficiency in a patient undergoing repeated sternotomy for aortic valve replacement.

West Nile virus (WNV) is an enzootic disease affecting birds which was introduced to the eastern United States in 1999 and has since spread rapidly across the country. Humans and other mammals are tangential hosts, acquiring the disease from the bite of an infected mosquito. In 2002, WNV was responsible for the largest outbreak of viral meningoencephalitis ever seen in the U.S., claiming thousands of victims. Despite these frightening numbers, WNV infection of humans is usually asymptomatic or results in a relatively mild febrile illness. WNV has not only challenged public health officials but has stimulated great interest among blood bankers. It has become clear that blood donated by people with asymptomatic WNV infection or clinically mild disease can transmit WNV to recipients, causing severe morbidity and mortality. To protect the blood supply from WNV, blood collection agencies are now testing donated blood for WNV using nucleic acid amplification tests. Although this effort will significantly decrease the incidence of transfusion-transmitted WNV, risk of infection remains, and new testing methods will likely need to be developed.

Presentation of Case A 50-year-old man was admitted to the hospital because of fever, a seizure, and confusion. The patient was a native of Colombia who had traveled to the United States six weeks before admission to visit relatives. Two weeks before admission, he had had a respiratory infection characterized by sore throat, coryza, and fever. Three days before admission, fever, headache, and dizziness developed, and his family observed progressive confusion. One day before admission, his wife noticed that he appeared pale and then “blue” and then lost consciousness for 10 to 15 minutes, during which time he made extension . . .

Presentation of Case A newborn boy was admitted to a special-care nursery because of petechiae and thrombocytopenia. The boy had been delivered at this hospital at 39 weeks' gestation to a 32-year-old woman who had had premature rupture of the membranes 16 hours before delivery. A single dose of penicillin was administered to the mother before vacuum-assisted delivery. The Apgar score was 9 at one minute and at five minutes. A diffuse petechial rash, most prominent on the face and trunk, was noted at delivery, and the baby was transferred to a newborn nursery. The mother had never smoked, and . . .

Collection of hematopoietic progenitor cells by apheresis (HPC-A) requires separation of cells by density. Previous studies highlighted the challenges of HPC-A collection from patients with abnormal red blood cells (RBCs). TEMPI syndrome is a recently described condition defined by teleangiectasias, elevated erythropoietin and erythrocytosis, monoclonal gammopathy, perinephric fluid collections, and intrapulmonary shunting. Patients with TEMPI syndrome have responded to therapies used to treat plasma cell dyscrasias and may benefit from autologous HPC transplantation. We report HPC-A collection from a patient with TEMPI syndrome that was complicated by severe iron deficiency.The patient received granulocyte-colony-stimulating factor (G-CSF) and plerixafor for HPC mobilization and underwent 3 days of HPC-A collection.The patient presented for collection with a microcytic erythrocytosis. Over 3 days, approximately 50 L of whole blood was processed, and 2 × 10(8) CD34+ cells were collected (2.8 × 10(6) CD34+ cells/kg). The mean collection efficiency (CE), percentage of mononuclear cells, hematocrit (Hct), and RBC count were 18%, 90%, 14%, and 9 × 10(11) , respectively. Altering collection variables to avoid RBC contamination reduced CE. Ficoll preparations of the products after freeze-thaw showed RBC contamination and hemolysis. Postthaw viability exceeded 95%. The products were not RBC reduced or washed. There were no adverse reactions during or after infusion.HPC-A collection from a patient with TEMPI syndrome was complicated by microcytic erythrocytosis, leading to RBC contamination and hemolysis in the product. Adequate HPCs were collected and the patient tolerated infusion without RBC depletion or washing. Our report highlights difficulties of HPC-A collection from iron-deficient patients.

Acquired cold urticaria is a condition characterized by the onset of pruritic hives, swelling, and occasional severe systemic reactions, during the rewarming phase, after cold exposure. Pulmonary thromboendarterectomy (PTE) is a cardiac surgical procedure where organized thrombus is excised from the pulmonary vasculature in order to improve pulmonary blood flow and relieve pressure on the right ventricle. A PTE requires institution of deep hypothermic circulatory arrest (DHCA) in order to reduce blood flow from collateral vessels during thrombus excision. We describe a case of PTE performed under DHCA in a patient with ACU.

LVP is used to manage diuretic-resistant ascites in cirrhotic patients. Albumin administration prevents complications including acute kidney injury and paracentesis-induced circulatory dysfunction, but the optimal dose is unclear. We sought to assess adherence to guidelines enacted in July 2011 at our center for reducing the albumin dose administered at large-volume paracentesis (LVP) and evaluate the cost and rate of complications of LVPs before and after guideline enactment. All LVPs performed on cirrhotic patients in our center’s Department of Radiology between July 2009 and January 2014 were studied. Outcomes included adherence to guidelines, LVP complications, and administered albumin cost. Groups were compared using Student’s t tests for continuous data and Chi-square or Fisher’s exact tests for categorical data. A repeated measurements model accounted for patients with multiple LVPs. Of the 935 LVPs, 288 occurred before guideline implementation (group 1) and 647 occurred after (group 2). The mean dose of albumin administered was 13.7 g/L of ascites removed in group 1 versus 10.3 g/L in group 2 (p