Cardiovascular Disease and Stroke in Immune TTP-Challenges and Opportunities.

Advances in the management of immune thrombotic thrombocytopenic purpura (iTTP) have dramatically improved outcomes of acute TTP episodes, and TTP is now treated as a chronic, relapsing disorder. It is now recognized that iTTP survivors are at high risk for vascular disease, with stroke and myocardial infarction occurring at younger ages than in the general population, and cardiovascular disease is the leading cause of premature death in this population. iTTP appears to have a phenotype of accelerated vascular aging with a particular predilection for cerebral circulation, and stroke is much more common than myocardial infarction. In addition to traditional cardiovascular risk factors, low ADAMTS13 activity during clinical remission may be a risk factor for some of these outcomes, such as stroke. Recent studies also suggest that Black patients, who are disproportionately affected by iTTP in the United States, are at higher risk of adverse cardiovascular outcomes, likely due to multifactorial reasons. Additional research is required to establish the risk factors and mechanisms underlying these complications in order to institute optimal screening strategies and identify interventions to improve outcomes.

Maternal and fetal outcomes of pregnancy occurring after a diagnosis of immune-mediated thrombotic thrombocytopenic purpura.

Pregnancy is a well-established trigger for a first episode or relapse of immune thrombotic thrombocytopenic purpura (iTTP). Other outcomes of subsequent pregnancy after a diagnosis of iTTP are less well described. We conducted this retrospective cohort study to evaluate maternal and fetal outcomes of pregnancy in women with prior iTTP from the Johns Hopkins Thrombotic Microangiopathy Cohort. Of 168 women in the cohort, 102 were of reproductive age at diagnosis. Fourteen pregnancies (in 9 women) that occurred after the initial iTTP episode were included in the analysis. iTTP relapse occurred in 9 (64%) pregnancies. Out of the 9 instances of relapse, 5 relapses occurred in 2 women. Seven pregnancies (50%) ended in fetal death or miscarriage in the setting of iTTP relapse and three were electively terminated due to fear of relapse. Four pregnancies (50% of the 8 that progressed beyond 20 weeks) were complicated by preeclampsia or HELLP syndrome, which is over ten-fold higher than that of the general population. No maternal deaths occurred. Only 4 pregnancies resulted in live births, of which, 2 were pre-term. Pregnancy in women with prior iTTP is associated with a substantial risk of iTTP relapse and fetal loss. Preeclampsia and HELLP syndrome is also more common than that in the general population. ADAMTS13 monitoring and preemptive therapy may improve pregnancy outcomes, which needs to be evaluated prospectively.

Race, rituximab, and relapse in TTP.

Immune-mediated thrombotic thrombocytopenic purpura (iTTP) is characterized by recurring episodes of thrombotic microangiopathy, causing ischemic organ impairment. Black patients are overrepresented in iTTP cohorts in the United States, but racial disparities in iTTP outcome and response to therapy have not been studied. Using the United States Thrombotic Microangiopathies Consortium iTTP Registry, we evaluated the impact of race on mortality and relapse-free survival (RFS) in confirmed iTTP in the United States from 1995 to 2020. We separately examined the impact of rituximab therapy and presentation with newly diagnosed (de novo) or relapsed iTTP on RFS by race. A total of 645 participants with 1308 iTTP episodes were available for analysis. Acute iTTP mortality did not differ by race. When all episodes of iTTP were included, Black race was associated with shorter RFS (hazard ratio [HR], 1.60; 95% CI, 1.16-2.21); the addition of rituximab to corticosteroids improved RFS in White (HR, 0.37; 95% CI, 0.18-0.73) but not Black patients (HR, 0.96; 95% CI, 0.71-1.31). In de novo iTTP, rituximab delayed relapse, but Black patients had shorter RFS than White patients, regardless of treatment. In relapsed iTTP, rituximab significantly improved RFS in White but not Black patients. Race affects overall relapse risk and response to rituximab in iTTP. Black patients may require closer monitoring, earlier retreatment, and alternative immunosuppression after rituximab treatment. How race, racism, and social determinants of health contribute to the disparity in relapse risk in iTTP deserves further study.

Major adverse cardiovascular events in survivors of immune-mediated thrombotic thrombocytopenic purpura.

Cardiovascular disease is a leading cause of death in survivors of immune-mediated thrombotic thrombocytopenic purpura (iTTP), but the epidemiology of major adverse cardiovascular events (MACE) in iTTP survivors is unknown. We evaluated the prevalence and risk factors for MACE, defined as the composite of non-fatal or fatal myocardial infarction (MI), stroke, and cardiac revascularization, during clinical remission in two large iTTP cohorts (Johns Hopkins University and Ohio State University). Of 181 patients followed for ≥ 3 months after recovery from acute iTTP, 28.6% had a MACE event over a median follow up of 7.6 years. Stroke was the most common type of MACE (18.2%), followed by non-fatal MI (6.6%), cardiac revascularization (4.9%) and fatal MI (0.6%). Compared to the general United States population, iTTP survivors were younger at first stroke in remission (males [56.5 years vs. 68.6 years, p = 0.031], females [49.7 years vs. 72.9 years, p < 0.001]) or MI in remission (males [56.5 years vs. 65.6 years, p < 0.001] and females [53.1 years vs. 72.0 years, p < 0.001]). Age (HR 1.03 [95% CI 1.002-1.054]), race (Black/Other vs. White) (HR 2.32 [95% CI 1.12-4.82]), and diabetes mellitus (HR 2.37 [95% CI 1.09-0.03]) were associated with MACE in a Cox regression model also adjusted for sex, hypertension, obesity, hyperlipidemia, chronic kidney disease, atrial fibrillation, autoimmune disease, and relapsing iTTP. Remission ADAMTS13 activity was not significantly associated with MACE. In conclusion, iTTP survivors experience high rates of MACE and may benefit from aggressively screening for and managing cardiovascular risk factors.

Therapeutic plasma exchange taper does not decrease exacerbations in immune thrombotic thrombocytopenic purpura patients.

BACKGROUND: Despite rapid and intensive treatments with therapeutic plasma exchange (TPE) and immunosuppression, immune thrombotic thrombocytopenic purpura (TTP) patients are at risk of disease exacerbation, i.e., early recurrence of TTP within 30 days of achieving treatment response. TPE taper, a practice of performing additional TPE procedures after achieving treatment response, is commonly performed for decreasing exacerbations, although no evidence supports this practice. STUDY DESIGN AND METHODS: In this prospective observational investigation over four years, our center switched its standard of care for treating all TTP patients from not performing TPE taper after achieving treatment response (i.e., no-taper cohort) to performance of TPE taper (i.e., yes-taper cohort) to characterize impacts on exacerbations. Continuous and categorical data were analyzed by Mann-Whitney, Fisher's exact, and log-rank tests; significance was defined as p < 0.05. RESULTS: The two cohorts were well matched and had no significant differences in demographics, presentation laboratory values, or TTP history (p > 0.05 for all). The yes-taper cohort of 26 patients with 29 consecutive episodes did not have a significantly different exacerbation rate from the no-taper cohort of 24 patients with 27 consecutive episodes (exacerbation rates of 37.9% vs. 33.3%, respectively; p = 0.78); however, treatment-related complications directly attributed to the TPE procedures, blood products, or central venous catheters were significantly greater in the yes-taper cohort (nine vs. one events, respectively; p = 0.01). CONCLUSION: Since TPE taper did not reduce exacerbations in our TTP patients, we no longer advocate for TPE taper and have reverted to our original standard of care.

Opioid exposure in haemophilia patients is common and underreported.

INTRODUCTION: In an era of increased opioid awareness, data on opioid exposure in haemophilia patients are lacking. AIM: The objectives of this study were to (a) provide a detailed description of opioid exposure in haemophilia patients based on written prescription data, (b) compare our findings to national haemophilia-specific and general population datasets and (c) identify predictors of opioid exposure in haemophilia patients. METHODS: Medical records of 183 adult and 135 paediatric patients from two haemophilia treatment centres (HTC) were reviewed over a 42-month period. Chronic exposure and acute opioid exposure were recorded, and results were compared to national haemophilia (ATHNdataset) and general population (CDC) data. RESULTS: We found that 56% of adult and 21% of paediatric patients were exposed to opioids, rates substantially higher than reported in the ATHNdataset (6%) and national population data from the CDC. In adults, but not children, severity of haemophilia was a significant predictor of opioid exposure. Most acute opioid prescriptions were not written by the HTC. CONCLUSIONS: This is the first study in the haemophilia population to examine opioid exposure based on prescription data. Opioid exposure was more common than predicted in both adult and paediatric study populations and was most often prescribed for acute pain or procedures by non-HTC providers. Haemophilia treatment centres need to take the lead in assessing pain in haemophilia patients, guiding treatment promoting non-opioid options, strengthen efforts to monitor opioid exposure and collect data on pain treatment in the haemophilia population.

The Impact of an Undergraduate Biology Class on Donor Recruitment at a Hospital-Based Blood Donor Center.

OBJECTIVES: A biology class, BIOL 294H, taught undergraduates about platelet donation while partnering with the University of North Carolina's (UNC's) hospital-based Blood Donation Center to recruit apheresis platelet donors. We identified our platelet donors' demographics and learned how BIOL 294H affected recruitment. METHODS: Every platelet donor presenting to the UNC Blood Donation Center from February 7, 2017, to March 10, 2017, was asked to complete an electronic 10-question survey. RESULTS: A total of 159 unique donors completed the survey; 64% were female and 75% were between ages 18 and 25 years. Overall, 70% were UNC undergraduate students. Over half (56%) reported first learning about platelet donation through word of mouth, and 22% cited specific efforts associated with BIOL 294H. CONCLUSIONS: Recruitment of undergraduate platelet donors primarily included BIOL 294H peer interactions and deliverables from the class, such as social media updates and events on campus. The sustained recruiting efforts of our students over many years contributed to recruitment of a majority of our platelet donors.

Heparin-induced thrombocytopenia associated with collection of hematopoietic progenitor cells by apheresis.

Heparin-induced thrombocytopenia (HIT) can occur following exposure to heparin and is characterized by thrombocytopenia with increased risk for thrombosis. This condition is mediated by formation of immunoglobulin G antibodies against platelet factor 4/heparin complexes that can subsequently lead to platelet activation. Herein, we detail the clinical and laboratory findings, treatments, and outcomes of two patients who developed HIT and thrombosis after undergoing collection of hematopoietic progenitor cells by apheresis (HPC-A) for autologous HPC transplant. Given that heparin may be used during HPC-A collections, these cases emphasize the importance of prompt consideration of HIT in patients that develop thrombocytopenia and thrombosis following HPC-A collection with heparin anticoagulation.

Taking Empiricism out of Immune Thrombotic Thrombocytopenic Purpura: Current and Future Treatment Strategies.

Immune thrombotic thrombocytopenic purpura (iTTP) is a chronically relapsing, humorally-mediated autoimmune disorder characterized by unpredictable episodes of microangiopathic hemolytic anemia and thrombocytopenia, commonly associated with neurologic dysfunction, kidney injury, and fever. Episodes are caused by immune destruction or inhibition of the von Willebrand Factor (vWF) cleaving protease ADAMTS13. Currently, the standard of care is therapeutic plasma exchange (TPE), and most add immunosuppression with corticosteroids - a standard that is unchanged for nearly 30 years. There are multiple strategies for adding corticosteroids to TPE and the limited data available suggests that corticosteroids reduce the duration of ADAMTS13 deficiency in iTTP. Rituximab is also frequently used in the treatment of iTTP and evidence suggests that while it may not reduce the number TPE procedures required to induce remission, it likely increases relapse-free survival. Novel approaches to immunosuppression that have been reported include low-dose rituximab (also currently in clinical trials) and proteasome inhibition. A more targeted approach includes the anti-vWF nanobody, caplacizumab, recently approved for iTTP in Europe and United States, which in two large randomized controlled trials significantly shortened the time to normalization of platelet count, appreciably lowered the 30-day recurrence rate, and decreased the rate of the composite endpoint of death, recurrence, and major thromboembolic events. Recombinant ADAMTS13 has been tested in congenital TTP and could be tested in iTTP as well, along with novel approaches of modifying the enzyme to avoid the immune response or leveraging other vWF cleaving proteases such as plasmin to bypass ADAMTS13. Also, therapies that target preformed antibodies that are currently being tested in other humorally-mediated disorders could cross over to iTTP. Finally, progress has long been hampered in iTTP due to difficulty with accrual and disagreement about trial design. A good surrogate endpoint for relapse-free survival is also needed. Despite these challenges, a new era of precision medicine is likely soon emerging for treatment of iTTP, and with it comes the opportunity to further improve outcomes in this rare and deadly disease.

The top 10 things to know about transfusion medicine before intern year: an evidence-based course for graduating medical students.

BACKGROUND: Transfusion medicine (TM) knowledge varies widely among physician trainees. In addition, there have been few instances in which curricular changes have been meaningfully assessed for TM education in medical school. METHODS: We created and presented a novel lecture to improve TM knowledge for graduating medical students using eight objectives designed to reinforce critical information about blood management. Each objective was coded according to unique color schemes, fonts, and graphics to create visual associations while quickly and clearly presenting complex concepts. The validated BEST Collaborative exam was used to measure changes in student TM knowledge, while a survey was conducted to gauge changes in confidence for each objective. Students were asked to submit anonymous feedback about their experiences. RESULTS: The mean student post-course exam score was 50.0%, while the pre-course baseline score was 27.5% (P<0.0001). Mean confidence levels increased significantly for all objectives. Student feedback was universally positive. CONCLUSION: This study improved knowledge and confidence for graduating medical students by utilizing engaging and visually stimulating presentations to display high-impact TM material. However, further efforts are needed to optimize learning.

How targeted therapy disrupts the treatment paradigm for acquired TTP: the risks, benefits, and unknowns.

Insights into immune-mediated thrombotic thrombocytopenic purpura (iTTP) pathophysiology have led to novel targeted therapies. Immunomodulatory strategies target anti-ADAMTS13 antibodies: rituximab is effective in inducing responses in refractory/relapsed TTP and increasing relapse-free survival; caplacizumab targets the von Willebrand factor-platelet interaction to hasten platelet count recovery and reduce mortality and TTP-related ischemic events. Bortezomib and recombinant ADAMTS13 are under investigation. This review examines how targeted therapies are disrupting current treatment paradigms to improve outcomes of iTTP.

Predictive Value of Schistocytes in Recurrence of Acquired Thrombotic Thrombocytopenic Purpura With Severe ADAMTS13 Deficiency at Discontinuation of Daily Therapeutic Plasma Exchange.

Acquired thrombotic thrombocytopenic purpura (TTP) is characterized by microangiopathic hemolytic anemia, thrombocytopenia, and commonly ADAMTS13 deficiency. Patients with TTP and severe ADAMTS13 deficiency have high risk of disease recurrence, yet the ability to predict which patients will have recurrence remains limited. We assessed whether the presence of persistent schistocytes in TTP patients with severe ADAMTS13 deficiency at the time of daily therapeutic plasma exchange (TPE) discontinuation was predictive of disease recurrence. We retrospectively reviewed the electronic medical records of all patients with a diagnosis of TTP treated with TPE at our university medical center between August 1991 and April 2013. Exacerbation was defined as disease recurrence within 30 days of cessation of daily TPE, and relapse was defined as disease recurrence >30 days after cessation of daily TPE. Comparisons were performed with a two-sided Fisher's exact test or χ2 test. Of the 46 total TTP patients eligible for analysis, nine had residual schistocytosis (20%), four of the nine (44%) had exacerbations, and two of the nine (22%) relapsed. Of the 37 patients without residual schistocytosis, 16 (43%) had exacerbations and 11 (30%) relapsed. There were no statistically significant differences in the exacerbation or relapse rates with or without residual schistocytosis (P = 1.00 and 1.00, respectively). Residual schistocytes after discontinuation of daily TPE were not uncommon. The persistence of schistocytes had poor sensitivity, specificity, and both positive and negative predictive values. After the initial diagnosis of TTP is made, there is no reason to continue documenting the presence or absence of schistocytes.

The frequency of joint hemorrhages and procedures in nonsevere hemophilia A vs B.

Data are needed on minimal factor activity (FA) levels required to prevent bleeding in hemophilia. We aimed to evaluate associations between hemophilia type and FA level and joint bleeding and orthopedic procedures using longitudinal data. Data were collected over an 11-year period on males with nonsevere hemophilia A or B without inhibitors who were receiving on-demand factor replacement therapy. Data on the number of joint bleeds in the previous 6 months and data on procedures from clinical records were analyzed using regression models. Data were collected on 4771 patients (hemophilia A, 3315; hemophilia B, 1456) from 19 979 clinic visits. Ages ranged from 2 to 91 years and baseline FA level ranged from 1% to 49% with a mean of 9.4%. Joint bleeding rates were heterogeneous across the FA range and were highest among men age 25 to 44 years. Adjusted for FA level, the mean number of joint bleeds per 6 months was 1.4 and 0.7 for patients with hemophilia A and B, respectively (P < .001). Regression models predicted 1.4 and 0.6 bleeds per year for hemophilia A and B patients, respectively, at an FA level of 15%. Patients with hemophilia B were 30% less likely than those with hemophilia A to have undergone an orthopedic procedure. We conclude that joint bleed rates for any given FA level were higher among hemophilia A than hemophilia B patients, and target FA levels of 15% are unlikely to prevent all joint bleeding in US males with hemophilia.

Treatment of acquired Thrombotic Thrombocytopenic Purpura in the U.S. remains heterogeneous: Current and future points of clinical equipoise.

BACKGROUND: The purpose of this survey was to describe current practices in the U.S. for treatment of acquired Thrombotic Thrombocytopenic Purpura (TTP), compare these with prior U.S. and current Canadian practices, and identify areas of clinical equipoise. STUDY DESIGN AND METHODS: A research team member administered the survey by telephone. Questions included an estimate of the annual patient volume treated, apheresis and medical therapy practices for acquired TTP. RESULTS: 32 centers from 22 states were surveyed. ADAMTS13 activity is used for confirmation of the diagnosis of acquired TTP (97%). Most commonly, daily plasma exchange (therapeutic plasma exchange [TPE]) is initiated with plasma as replacement fluid (91%) at 1.0 Plasma Volume (72%) and stopped with a platelet count of 150 × 109 /L (66%), and then TPE is tapered off (69%). Compared with a U.S. survey from 1998, a greater proportion of centers use plasma exclusively as the replacement fluid exclusively (29/32 vs 2/14 in 1998; P < .0001) and taper TPE (22/32 vs 8/20 in 1998, P = .0499). Compared with Canadian survey in 2016, a greater proportion of U.S. centers use plasma over cryosupernatant (29/32 vs 2/13 CAG centers, P < .0001) and initiate TPE with 1.0 PV compared with 1.5 PV (23/32 vs 0/14 CAG centers, P < .0001). Corticosteroid use is common but not universal (U.S. and CAG) and use of rituximab heterogeneous. CONCLUSION: Treatment of acquired TTP in the U.S. remains heterogeneous. Points of clinical equipoise identified were PV exchanged (1.0 vs >1.0), tapering of TPE versus none, and rituximab use.

Men with severe hemophilia in the United States: birth cohort analysis of a large national database.

The availability of longitudinal data collected prospectively from 1998 to 2011 at federally funded US hemophilia treatment centers provided an opportunity to construct a descriptive analysis of how outcomes of men with severe hemophilia have been altered by the incremental advances and setbacks in hemophilia care in the last 50 years in the United States. This surveillance collaboration with the US Centers for Disease Control and Prevention assembled the largest uniformly examined population with severe hemophilia (n = 4899 men with severe factor VIII and IX deficiency). To address the heterogeneity of this population, 4 successive birth cohorts, differentially affected by eras of hemophilia care, were examined separately in regard to demographics, complications of hemophilia and its treatment, and mortality. Severely affected men in each birth cohort were compared also with the corresponding mild hemophilia birth cohorts (n = 2587 men total) to control for outcomes that might be attributable to aging and environment independent of severely defective hemostasis. The analysis demonstrates improving access to standard of care therapy, correlating the proportion of men on prophylactic factor replacement and reduced bleeding frequency for the youngest men. Frequent bleeding persisted in one third to one half of men across all ages, however, and the disability gap between severe and mild hemophilia did not narrow. The greatest cause of death was liver failure, but attempted anti-hepatitis C virus therapy and cure were low. The study suggests a continued need for national surveillance to monitor and inform hemophilia interventions and outcomes.

Two cases of asymptomatic massive fetomaternal hemorrhage.

Evaluation of fetomaternal hemorrhage (FMH) in the immediate postpartum period is critical for the timely administration of Rh immunoglobulin (RhIG) prophylaxis to minimize the risk of alloimmunization in D-negative mothers of D-positive newborns. We report a series of two clinically-unsuspected cases of massive FMHs identified at our university medical center. Retrospective records of two cases of massive FMH were investigated using the electronic medical record. After positive fetal bleed screens, flow cytometric analysis for hemoglobin F was performed to quantify the volume of the hemorrhages in both cases. Flow cytometric enumeration with anti-D was also performed in one case. The two patients had 209.5 and 75 mL of fetal blood in circulation, resulting in 8 and 4 doses of RhIG administered, respectively. For the former patient, flow cytometric analysis with anti-D ruled out hereditary persistence of fetal hemoglobin and supported the fetal origin of the red cells. Due to the clinically-silent nature of both hemorrhages, further evaluation of the newborns' blood was not performed. These cases highlight the importance of rapidly obtaining accurate measurements of fetal blood loss via flow cytometric analysis in cases of FMH, particularly in clinically-unsuspected cases, to ensure timely administration of adequate immunoprophylaxis to D-negative mothers.

How we approach an acquired thrombotic thrombocytopenic purpura patient.

Acquired thrombotic thrombocytopenic purpura (TTP) is a disease characterized by microangiopathic hemolytic anemia and thrombocytopenia, in addition to variable fever and neurologic and renal dysfunction, without an underlying cause. Recent advances in elucidating the pathophysiology of acquired TTP have led to new testing that we have incorporated into our current management of patients with suspected acquired TTP. Despite these developments, much of the treatment for acquired TTP beyond therapeutic plasma exchange (TPE) is based on low-quality evidence. Our group has a sustained interest in studying and optimizing the use of TPE, along with other concurrent therapies, in acquired TTP patients. Described herein is a summary of how our apheresis consult service approaches requests for TPE in patients with suspected acquired TTP.