Von-Willebrand factor antigen: a biomarker for severe pregnancy complications in women with hereditary TTP?

OBJECTIVES

To determine a possible association between severe obstetric morbidity (SOM) and elevated non-pregnant vWF antigen levels (NPvWF) in women with hereditary thrombotic thrombocytopenic purpura (hTTP) and whether the latter can predict the response to fresh frozen plasma (FFP) transfusion.

STUDY DESIGN

A cohort-based study of women with hTTP due to homozygous c.3772delA mutation of ADAMTS13 who had pregnancies both with and without FFP treatment. Occurrences of SOM were determined from medical records. GEE logistic regressions and ROC curve analysis determined the NPvWF antigen levels associated with development of SOM.

RESULTS

14 women with hTTP had 71 pregnancies; 17 (24%) culminated in pregnancy loss, 32 (45%) were complicated by SOM. FFP transfusions were administered in 32 (45%) of pregnancies. Treated women had decreased SOM (28% vs. 72%, p<0.001) and preterm TTP exacerbations (18% vs. 82%, p<0.001), and higher median NPvWF antigen levels than those with uncomplicated pregnancies (p=0.018). Amongst treated women, median NPvWF antigen levels were higher in those with SOM compared to those without (225% vs. 165%, p=0.047). Logistic regression models demonstrated a significant two-way association between elevated NPvWF antigen levels (OR 1.08 for SOM, 95% CI 1.001-1.165, p=0.046) and SOM (OR 1.6 for elevated NPvWF antigen, 95% CI 1.329-1.925, p<0.001). ROC curve analysis demonstrated that NPvWF antigen level of 195% had 75% sensitivity and 72% specificity for SOM.

CONCLUSION

Elevated NPvWF antigen levels are associated with SOM in women with hTTP. Women with levels >195% may benefit from increased surveillance and more intensive FFP treatment during pregnancy.

Hereditary thrombotic thrombocytopenic purpura and COVID-19: Impacts of vaccination and infection in this rare disease

Introduction

Severe COVID-19 is associated with an important increase of von Willebrand factor and mild lowering of ADAMTS13 activity that may, in the presence of a strong inflammatory reaction, increase the risk of acute thrombotic thrombocytopenic purpura (TTP). Although acute episodes of immune-mediated TTP associated with COVID-19 or SARS-CoV-2 vaccination have been reported, data about clinical evolution of hereditary TTP (hTTP) during the pandemic are scarce.

Method

We conducted a survey among adult patients of the International Hereditary TTP Registry about SARS-CoV-2 vaccination, COVID-19, and occurrence of acute hTTP episodes.

Results

Of 122 adult hTTP patients invited to participate, 86 (70.5%) responded. Sixty-five had been vaccinated (75.6%), of which 14 had received in addition a booster, resulting in 139 individual vaccine shots. Although vaccinations in patients on plasma prophylaxis were done within 1 week of the last plasma infusion, all 23 patients treated with plasma on demand were vaccinated without prior plasma infusions. One patient on uninterrupted weekly plasma infusions presented within 3 days from his second vaccination with neurological symptoms and computed tomography scan 9 days later showed subacute ischemic/hemorrhagic frontal lobe infarction. A second male patient developed acute myocarditis after his second dose of mRNA-1273 vaccine. Twelve (14%) patients had COVID-19, associated with an acute hTTP episode in three of them: one patient had a transient ischemic attack, one a stroke, and a pregnant woman was hospitalized to intensify plasma treatment.

Discussion

The risk of an acute episode triggered by COVID-19 seems higher than following vaccination in hTTP patients, who can be safely vaccinated against SARS-CoV-2.

Thrombopoietin receptor agonist for treating bone marrow aplasia following anti-CD19 CAR-T cells-single-center experience

Anti CD-19 chimeric antigen receptor T (CAR-T) cells demonstrate effective early anti-tumor response; however, impaired hematopoietic recovery is observed in about 30% of patients with prolonged cytopenia appearing as an unmet need for optimal treatment. All adult patients given commercially available anti CD-19 CAR-T for diffuse large B cell lymphoma (DLBCL) were screened at 21-28 days after CAR-T infusion for cytopenia. In case of severe persistent cytopenia, patients were given TPO receptor agonists. Initial dose of eltrombopag was 50 mg/day and gradually increased to a maximal dose of 150 mg/day. Romiplostim was given as subcutaneous injection once a week for 2 doses (125 mcg). Response was defined as transfusion independency along with resolution of severe neutropenia (ANC > 500 /microL) and/or platelets > 20,000/microL for three consecutive values on different days. TPO receptor agonists were tapered down when response was met. From May 2019 to December 2021, 93 patients were eligible (74%, tisagenlecleucel and 26%, axicabtagene ciloleucel). The median age was 69 (range, 19-85) years. Six patients (6.5%) (tisagenlecleucel, n = 4 or axicabtagene ciloleucel, n = 2) demonstrated prolonged severe cytopenia and were treated with TPO receptor agonists (eltrombopag, n = 4; romiplastim, n = 1, both drugs, n = 1). Median time from CAR-T infusion to initiation of TPO receptor agonist was 43 (range, 21-55) days. All patients were transfusion-dependent and were given daily GCSF prior to TPO receptor agonist administration. Response to TPO receptor agonists was seen in all 6 patients. Median time from TPO receptor agonist initiation to resolution of cytopenia was 22 (range, 8-124) days for Hb, 27 (range, 6-38) days for platelets, and 29 (range, 7-61) days for neutrophils. A complete resolution of all blood counts (ANC > 500 /microL and platelets > 20,000/microL and hemoglobin > 8 gr/dL) was seen in 5/6 patients. No toxicity was observed during the therapy course. This paper supports further investigation of TPO receptor agonists in the treatment of persistent cytopenia following CAR-T cell therapy.

Does training make a difference? Proficiency training in transfusion guidelines and its effect on red blood cell administration

Background

Packed red blood cell (RBC) transfusion is a very common and frequently lifesaving therapeutic intervention, but a liberal transfusion policy may be associated with inferior patient outcomes. Various guidelines have been proposed to reduce the rate of unnecessary RBC transfusions. However, physicians' proficiency in such guidelines and the effect of training on RBC administration remain unknown.

Methods

We performed a questionnaire‐based assessment of physicians' knowledge of the guidelines in a tertiary hospital in Israel, followed by an analysis of RBC administration six months before and six months after training was delivered.

Results

The level of proficiency was higher among Israeli university graduates (Odds Ratio [OR] 2.59, p‐value = 0.02), internists (OR 2.8, p‐value = 0.02), and physicians beyond the step‐one residency exam (OR 3.08, p‐value = 0.02). There was no significant effect of training on the rates of RBC administration (incidence rate ratio [IRR] = 0.96 [CI 95% 0.81–1.14], p‐value = 0.655).

Conclusion

Educational intervention alone is an ineffective means of reducing the rates of RBC administration. A more complex approach is required to prevent unnecessary RBC transfusions.

Unfolding the pathophysiology of congenital thrombotic thrombocytopenic purpura in pregnancy: lessons from a cluster of familial cases

BACKGROUND

Thrombotic thrombocytopenic purpura (TTP), a rare, potentially life-threatening thrombotic microangiopathy, manifests either as congenital TTP or acquired forms. It is caused by the absence or severe depletion of a disintegrin and metalloproteinase with thrombospondin motifs 13 (ADAMTS13) protease, leading to the accumulation of ultra large von Willebrand factor multimers as well as extensive platelet adhesion and clumping, which can ultimately cause severe secondary end-organ damage. Pregnancy can provoke or exacerbate TTP, leading to maternal and fetal complications.

OBJECTIVE

In this report, we focused on pregnancy outcomes in a recently recognized cohort of congenital TTP patients of Bedouin Arab descent in southern Israel who were all homozygous for a novel c.3772delA variant of the ADAMTS13 gene, leading to the clinical manifestations of TTP largely during pregnancy.

STUDY DESIGN

All patients presented in this study belong to 2 closely related families of Arab Bedouin descent and were found to be homozygous for a novel ADAMTS13-c.3772delA variant. The cohort consisted of 19 females; 16 of them had congenital TTP and had been pregnant and were thus included. Patient data were collected from electronic medical records.

RESULTS

Of note, 13 women from our cohort, who delivered 14 fetuses (owing to 1 twin pregnancy), were diagnosed with congenital TTP following complicated pregnancies, which included recurrent pregnancy loss, stillbirth, early onset preeclampsia (both mild and severe), hemolysis, elevated liver enzymes and low platelet count syndrome, intrauterine growth restriction with abnormal Doppler flow, preterm premature rupture of membranes, and a total perinatal mortality rate of 30.7% (4/13). An additional 3 women, who were diagnosed owing to complications outside of pregnancy and at older ages, experienced TTP during their pregnancies, which occurred before diagnosis. Subsequent pregnancies were treated with fresh frozen plasma leading to a 100% fetal survival rate in the pregnancies that reached fetal viability. All placentas had lesions consistent with maternal vascular underperfusion. However, the severity and frequency of these lesions were lower in the 8 placentas from pregnancies treated with fresh frozen plasma.

CONCLUSION

This case series details a distinctive cohort of congenital TTP patients, all homozygous for the same, novel ADAMTS13 variant, who presented with clinical complications during pregnancy and maternal vascular lesions of underperfusion in the placenta. Our findings imply that the variant identified in the ADAMTS13 gene in our cohort may have a specific functional impact on the placenta, and that treatment with fresh frozen plasma during pregnancy ameliorates the course of the disease, leading to a milder phenotype or a normal pregnancy in the majority of cases.

LMWH in the prevention of preeclampsia and fetal growth restriction in women without thrombophilia. A systematic review and meta-analysis

Placental mediated pregnancy complications such as preeclampsia and fetal growth restriction (FGR) are common, serious, and associated with increased morbidity and mortality. We conducted a systematic review and meta-analysis to determine the effect of treatment with low-molecular-weight heparins (LMWHs) for secondary prevention of these complications in non thrombophilic women. We searched the electronic databases PubMed, Scopus, and Cochrane Library for randomised controlled trials addressing this question. Five studies including 403 patients met the inclusion criteria, 68 developed preeclampsia and 118 FGR. The studies were very heterogeneous in terms of inclusion criteria, LMWH preparation, and dosage. Meta-analyses were performed using random-effect models. The overall use of LMWHs was associated with a risk reduction for preeclampsia (Relative risk (RR) 0.366; 95 % confidence interval (CI), 0.219-0.614) and FGR (RR 0.409; 95 % CI, 0.195-0.932) vs. no treatment. From the data available for analysis it appears that the use of Dalteparin is associated with a risk reduction for preeclampsia (p=0.002) and FGR (p<0.001); while Enoxaparin is associated with risk reduction for preeclampsia (p=0.013) but not for FGR (p=0.3). In spite of the small number of studies addressing the research question, and the high variability among them, our meta-analysis found a modest beneficial effect of LMWH for secondary prevention of preeclampsia and FGR. Further studies are needed to address these questions before a definite conclusion can be reached.

Celecoxib interferes to a limited extent with aspirin-mediated inhibition of platelets aggregation

AIMS

The aim of the study was to analyze the interaction between celecoxib and low dose aspirin for COX-1 binding and its consequences on the aspirin-mediated antiplatelet effects.

METHODS

We investigated ex vivo the interaction between celecoxib and aspirin for COX-1 binding and measured the resulting antiplatelet effects. We applied mechanism-based pharmacokinetic-pharmacodynamic (PKPD) modelling to analyze these data and to predict in vivo platelet aggregation for different doses and administration schedules of aspirin and celecoxib.

RESULTS

The predictions of the PK-PD model were consistent with results from previous studies that investigated interaction between aspirin and celecoxib. The modelling results indicate that celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. The extent of this interaction can be substantial (up to 15% increase in platelet aggregation by 200 mg day(-1) celecoxib when combined with low dose aspirin) during the first days of aspirin administration in patients who are already treated with celecoxib, and it cannot be prevented by separate administration of the interacting drugs.

CONCLUSIONS

At the recommended therapeutic doses, celecoxib can attenuate to a limited extent the in vivo antiplatelet effects of low dose aspirin. Patients receiving a combination of low dose aspirin and the recommended doses of celecoxib were not identified to have increased risk of cardiovascular and cerebrovascular events due to competition between these drugs for COX-1 binding. Interaction between low dose aspirin and other COX-2 inhibitors and its clinical consequences requires further investigation.

The impact of sleep deprivation on sleepiness, risk factors and professional performance in medical residents

BACKGROUND

Prolonged working hours and sleep deprivation can exert negative effects on professional performance and health.

OBJECTIVES

To assess the relationship between sleep deprivation, key metabolic markers, and professional performance in medical residents.

METHODS

We compared 35 residents working the in-house night shift with 35 senior year medical students in a cross-sectional cohort study. The Epworth Sleepiness Scale (ESS) questionnaire was administered and blood tests for complete blood count (CBC), blood chemistry panel, lipid profile and C-reactive protein (CRP) were obtained from all participants.

RESULTS

Medical students and medical residents were comparable demographically except for age, weekly working hours, reported weight gain, and physical activity. The ESS questionnaires indicated a significantly higher and abnormal mean score and higher risk of falling asleep during five of eight daily activities among medical residents as compared with medical students. Medical residents had lower high density lipoprotein levels, a trend towards higher triglyceride levels and higher monocyte count than did medical students. CRP levels and other laboratory tests were normal and similar in both groups. Among the residents, 5 (15%) were involved in a car accident during residency, and 63% and 49% reported low professional performance and judgment levels after the night shift, respectively.

CONCLUSIONS

Medical residency service was associated with increased sleepiness, deleterious lifestyle changes, poorer lipid profile, mild CBC changes, and reduced professional performance and judgment after working the night shift. However, no significant changes were observed in CRP or in blood chemistry panel. Larger prospective cohort studies are warranted to evaluate the dynamics in sleepiness and metabolic factors overtime.

INO-8875, a highly selective A1 adenosine receptor agonist: evaluation of chronotropic, dromotropic, and hemodynamic effects in rats

Selective pharmacological activation of the adenosine 1 receptor (A(1)R) is a promising new approach to achieve a potent block of atrioventricular (A-V)-nodal conduction without significant cardiovascular side effects. The purpose of the present study was to evaluate the cardiovascular profile of INO-8875, a highly selective A(1)R agonist, and to compare its properties with N-[3(R)-tetrahydrofuranyl]-6-aminopurine riboside (CVT-510), which has already been shown to induce negative dromotropic effects with minimal cardiovascular side effects in animals and in clinical studies. Dose-response experiments in the isolated hearts of rats were used to evaluate the functional selectivity of INO-8875 for the slowing of A-V-nodal conduction. Ventilated adult rats were used to study the effects of INO-8875, in vivo, on arterial blood pressure as well as on supraventricular electrophysiology. Ex vivo, INO-8875 (100 nM to 3 μM) progressively prolonged A-V-nodal conduction without reducing left ventricular function or coronary resistance. In vivo, INO-8875 up to a dose of 50 μg/kg did not reduce the carotid arterial blood pressure (n = 4). INO-8875 (1-50 μg/kg) and CVT-510 (20 and 50 μg/kg) both induced a dose-dependent decrease in heart rate and atrial refractoriness, as well as slowing of A-V-nodal conduction. However, compared with CVT-510, the activity of INO-8875 was more pronounced in A-V-nodal function. INO-8875 exhibited a greater duration of action, lasting up to 2.5 hours post dosing, whereas the effects of CVT-510 dissipated over 1 hour. INO-8875 demonstrates functional properties of a highly selective A(1)R agonist. INO-8875 exhibits an increased dromotropic effect and greater duration of action compared with CVT-510.

INO-8875, a Highly-Selective A1 Adenosine Receptor Agonist: Evaluation of Chronotropic, Dromotropic and Hemodynamic Effects in Rats

Publication of this article is suspended until the authors can provide full identification and verification of the chemical structure of INO-8875.