Bortezomib in relapsed/refractory immune thrombotic thrombocytopenic purpura: A single-centre retrospective cohort and systematic literature review.

Immune thrombotic thrombocytopenic purpura (iTTP) is a rare and life-threatening haematological condition. Initial treatment involves plasma exchange (PLEX), corticosteroids, caplacizumab and rituximab. In relapsed and refractory cases despite initial treatments, further immune-modulating therapy includes the proteasome inhibitor, bortezomib. Evidence for bortezomib in this setting is limited to case reports and case series. We report our experience and perform a systematic review of the literature. We identified 21 publications with 28 unique patients in addition to our cohort of eight patients treated with bortezomib. The median age of patients was 44 years (IQR: 27-53) and 69% female. They were usually in an initial, refractory presentation of iTTP where they had received PLEX, corticosteroids, rituximab and another line of therapy. After bortezomib administration, 72% of patients had a complete response, with 85% maintaining a durable response without relapse at the last follow-up.

A Scan of Pleiotropic Immune Mediated Disease Genes Identifies Novel Determinants of Baseline FVIII Inhibitor Status in Hemophilia-A.

Hemophilia-A (HA) is caused by heterogeneous loss-of-function factor (F)VIII gene (F8)-mutations and deficiencies in plasma-FVIII-activity that impair intrinsic-pathway-mediated coagulation-amplification. The standard-of-care for severe-HA-patients is regular infusions of therapeutic-FVIII-proteins (tFVIIIs) but ~30% develop neutralizing-tFVIII-antibodies called "FVIII-inhibitors (FEIs)" and become refractory. We used the PATH study and ImmunoChip to scan immune-mediated-disease (IMD)-genes for novel and/or replicated genomic-sequence-variations associated with baseline-FEI-status while accounting for non-independence of data due to genetic-relatedness and F8-mutational-heterogeneity. The baseline-FEI-status of 450 North American PATH subjects-206 with black-African-ancestry and 244 with white-European-ancestry-was the dependent variable. The F8-mutation-data and a genetic-relatedness matrix were incorporated into a binary linear-mixed model of genetic association with baseline-FEI-status. We adopted a gene-centric-association-strategy to scan, as candidates, pleiotropic-IMD-genes implicated in the development of either ³2 autoimmune-/autoinflammatory-disorders (AADs) or ³1 AAD and FEIs. Baseline-FEI-status was significantly associated with SNPs assigned to NOS2A (rs117382854; p=3.2E-6) and B3GNT2 (rs10176009; p=5.1E-6), which have functions in anti-microbial-/-tumoral-immunity. Among IMD-genes implicated in FEI-risk previously, we identified strong associations with CTLA4 assigned SNPs (p=2.2E-5). The F8-mutation-effect underlies ~15% of the total heritability for baseline-FEI-status. Additive genetic heritability and SNPs in IMD-genes account for >50% of the patient-specific variability in baseline-FEI-status. Race is a significant determinant independent of F8-mutation-effects and non-F8-genetics.

Short Video Addiction on the Interaction of Creative Self-Efficacy and Career Interest to Innovative Design Profession Students.

In recent years, a variety of emerging online media, such as TikTok, Kuaishou, YouTube and other short video application platforms, have appeared. The problem of short video addiction has become an issue to education experts and the general public, as students' excessive use of short video has become increasingly serious with many hidden concerns to the students' learning effectiveness. In addition, to meet the growing demand for innovative design talents worldwide, the Taiwan government has been committed to promoting policies related to the cultivation of innovative and creative talents nowadays, particularly for innovative design profession students who often use the Internet and short videos for learning. Therefore, the study aims to use questionnaires to understand the habits and addiction of the innovative design profession students in using short videos, and to further investigate the relation of short video addiction to the students' creative self-efficacy (CSE) and career interests. A total of 561 valid questionnaires were collected after eliminating invalid questionnaires and reliability analysis. Structural equation modeling and model validation were conducted afterwards. The results showed that short video addiction had a negative effect on CSE; CSE had a positive effect on career interests; and CSE had an indirect effect between short video addiction and career interests.

Construction of SARS-CoV-2 receptor binding domain molecular probe and its application in the isolation of neutralizing antibodies / 中国热带医学

@#Abstract: Objective　To construct SARS-CoV-2 receptor binding domain molecular probe for monoclonal memory B cell sorting and obtain RBD specific neutralizing antibodies from peripheral blood mononuclear cells (PBMCs) of COVID-19 convalescents by single-cell sorting. Methods　The SARS-CoV-2 RBD sequence was downloaded from GenBank, and the Avi tag and 6-histidine tags were added at the C-terminal. After codon optimization, it was chemically synthesized, cloned into the pDRVI1.0 vector, expressed after transfection of 293F cells, and biotinylated consequently. RBD-specific B cells were sorted out with this probe1 from the PBMCs of convalescents recovered from COVID-19. After B cells were lysed, the variable regions of heavy chain and light chain were amplified, cloned into the antibody expression vector, and transfected into 293F cells to express the antibody. Then the antibody was purified from the supernatant using protein A column and SARS-CoV-2 pseudovirus was used to test their neutralizing activity. Results　RBD-Avi probe was produced and successfully biotinylated sequentially with an efficiency of 30%-50%. Western blot analysis revealed that the biotinylated probe was recognized by the antibodies purified from COVID-19 convalescent plasma. Using this probe, 7 and 16 RBD-specific memory B cells were successfully isolated from the PBMCs of two convalescent individuals, accounting for 0.24% and 0.17% of the total cell population, respectively. After amplifying the variable regions of antibody heavy and light chains from the lysed B cells, 7 and 12 pairs of antibody heavy-light chains were obtained. A total of 16 antibodies were expressed in the convalescent individuals, and most of the purified antibodies showed neutralizing activity against the pseudovirus, with IC50 values of 6 antibodies below 1 μg/mL. The IC50 values of XJ-A9 and SCF-F1 against the wild-type pseudovirus were 0.07 μg/mL and 0.35 μg/mL, respectively. Conclusion　The SARS-CoV-2 RBD molecular probe constructed in this study has good antigenicity, and the isolated antibodies present neutralizing activity against wild-type SARS-CoV-2 pseudovirus.

Successful use of lenalidomide to treat refractory acquired von Willebrand disease associated with monoclonal gammopathy.

Acquired von Willebrand syndrome (AVWS) is a rare hematologic disorder characterized by quantitative or qualitative defects of von Willebrand factor (vWF), a protein crucial for normal hemostasis. AVWS has been described in association with several pathologic entities with varied mechanisms. Among these, lymphoproliferative disorders are the most common, with monoclonal gammopathy of undetermined significance (MGUS) being the most frequently reported. AVWS in this setting is commonly associated with the development of bleeding that is clinically challenging to manage due to accelerated clearance of vWF, limiting the utility of many conventional treatment modalities such as DDAVP or vWF/FVIII. We report a case of a 43-year-old male who was sent to our institution for new-onset easy bruising and laboratories concerning for von Willebrand disease (vWD). Further diagnostic workup revealed evidence of an IgG monoclonal gammopathy and findings suggestive of vWF inhibition. Ultimately, he was found to have monoclonal gammopathy of clinical significance (MGCS)-associated AVWS refractory to conventional treatment but responsive to lenalidomide and dexamethasone. This case suggests that lenalidomide may be suitable for patients with AVWS secondary to MGCS.

Utilization of emicizumab in acquired hemophilia A: A case report.

BACKGROUND: Acquired Hemophilia A (AHA) is a rare autoimmune disorder associated with the development of autoantibodies against factor VIII (FVIII). Although obtaining hemostatic control through the use of recombinant factor VIIa, activated prothrombin complex concentrate and recombinant porcine FVIII are cornerstones in the clinical management of AHA, these therapies have several disadvantages, including a higher risk for the development of thromboembolic events, unpredictable efficacy and short half-lives. While emicizumab has been FDA licensed for use in bleeding prophylaxis for patients with Congenital Hemophilia A (CHA) with and without inhibitors, it has not been approved for use in AHA, with only a few reports describing its use in this context. CASE REPORT: We report our experience with the use of emicizumab in an 83-year old male with AHA, complicated by the onset of atrial fibrillation following admission, drug-induced thrombocytopenia, infectious complications, and the identification of a low-grade lymphoproliferative disorder, in which emicizumab prophylaxis was used for bleeding prophylaxis in the context of persistently elevated inhibitor titers without evidence of thrombotic events or thrombotic microangiopathy.

Scurvy: a rare cause of haemarthrosis.

A male in his 60s with a history of previously treated locally advanced head and neck cancer presented to the emergency department with atraumatic left knee pain and upper and lower extremity ecchymoses that had been present for 3 weeks. His initial laboratory results showed a normocytic anaemia, normal platelet count, slightly abnormal coagulation studies and normal inflammatory markers. Arthrocentesis of the left knee revealed haemarthrosis, and additional laboratory workup found an undetectable serum vitamin C (ascorbic acid) level consistent with scurvy. It was determined that scurvy had predisposed the patient to injury, leading to haemarthrosis. Following vitamin C supplementation, dietary and activity modifications, and acetaminophen as needed, the patient's serum vitamin C level normalised and his left knee pain and swelling improved. Scurvy is a rare cause of haemarthrosis, but it should be recognised in at-risk patients since treatment is effective.

Lymphomatoid granulomatosis of the central nervous system (CNS-LYG) posing a management challenge.

Isolated central nervous system lymphomatoid granulomatosis (CNS-LYG) can mimic aggressive glioblastomas. We describe a complex presentation of CNS-LYG coexisting with immune thrombocytopenia successfully managed with rituximab and ultra-low-dose radiation therapy.

Protein Phosphatase 2A Activation Via ApoER2 in Trophoblasts Drives Preeclampsia in a Mouse Model of the Antiphospholipid Syndrome.

[Figure: see text].

Comparison of low fixed dose versus standard-dose rituximab to treat thrombotic thrombocytopenic purpura in the acute phase and preemptively during remission.

The standard dose of rituximab used in B-cell hematological malignancies, 375 mg/m2 weekly, may be excessive for autoimmune conditions. Successful use of a low, fixed dose of 100-200 mg of rituximab, weekly for 4 weeks, has been reported in the literature in the treatment of autoimmune thrombotic thrombocytopenic purpura (aTTP). We retrospectively analyzed our rituximab data in aTTP over a 13-year-period for 39 patients, with the aim of comparing response and outcomes with a standard lymphoma-dose course versus a low fixed 100 mg-dose course. Compared to the standard dose (17 patients, 17 courses of 4 infusions), our patients who received a low dose (8 patients, 9 courses of 4 infusions) had a possibly lower baseline risk but did achieve a similar time to remission and number of plasma exchange procedures to remission. Preemptive low-dose courses for ADAMTS13 activity <50 % during remission (6 patients, 10 courses of 4 infusions) achieved a median peak ADAMTS13 activity of 99 %, in a median of 1 month, with no clinical relapses. Our results provide additional evidence for the efficacy of low-dose rituximab, with the benefit of much lower cost, less infusion time, and theoretically lower risk of toxicity.

Antiphospholipid antibodies induce thrombosis by PP2A activation via apoER2-Dab2-SHC1 complex formation in endothelium.

In the antiphospholipid syndrome (APS), antiphospholipid antibody (aPL) recognition of ß2 glycoprotein I promotes thrombosis, and preclinical studies indicate that this is due to endothelial nitric oxide synthase (eNOS) antagonism via apolipoprotein E receptor 2 (apoER2)-dependent processes. How apoER2 molecularly links these events is unknown. Here, we show that, in endothelial cells, the apoER2 cytoplasmic tail serves as a scaffold for aPL-induced assembly and activation of the heterotrimeric protein phosphatase 2A (PP2A). Disabled-2 (Dab2) recruitment to the apoER2 NPXY motif promotes the activating L309 methylation of the PP2A catalytic subunit by leucine methyl transferase-1. Concurrently, Src homology domain-containing transforming protein 1 (SHC1) recruits the PP2A scaffolding subunit to the proline-rich apoER2 C terminus along with 2 distinct regulatory PP2A subunits that mediate inhibitory dephosphorylation of Akt and eNOS. In mice, the coupling of these processes in endothelium is demonstrated to underlie aPL-invoked thrombosis. By elucidating these intricacies in the pathogenesis of APS-related thrombosis, numerous potential new therapeutic targets have been identified.

Identifying Additional Risk Factors for Thrombosis and Pregnancy Morbidities Among Antiphospholipid Antibodies Carriers.

The evaluation of thrombotic and pregnancy risks associated with antiphospholipid antibodies (aPL)in individual patients without antiphospholipid syndrome (APS) clinical manifestation is challenging. Our aim is to identify additional risk factors or potential candidate "second hits" for APS clinical events in a large cohort of ethnically diverse aPL-positive patients. We included 219 consecutive aPL-positive patients who attended clinic at our institution. All patients had at least 1 persistent high titer (≥99 percentiles) aPL. Independent risk factors for thrombosis and pregnancy morbidities among patients with positive aPL were evaluated. When assessing risk factors associated with pregnancy morbidities, only female controls of reproductive age (age ≤45) were used. Pearson χ2 analysis and multivariable logistic regression were used to evaluate correlation between different risk factors and clinical manifestations. Of the 219 aPL-positive patients, 120 (54.8%) patients had criteria APS clinical manifestations and 99 patients did not. A total of 46.1% were Caucasian, 26.4% of African descent, 16.9% Hispanic, 1.8% Asian, and 8.7% were unspecified. Among traditional risk factors and signs of endothelial injury, only hypertension demonstrated an independent association with arterial thrombosis (odds ratio [OR] = 3.826, 95% confidence interval [CI]: 1.597-9.167, P = .0026), and lupus anticoagulant (LA) demonstrated an independent association with venous thrombosis (OR = 3.308, 95% CI: 1.544-7.085, P = .0021). None of the evaluated risk factors demonstrated a significant association with pregnancy morbidity. Hypertension is a potential predictor of arterial thrombosis and the presence of LA is a potential predictor of venous thrombosis in aPL-positive patients.

A case of autoimmune severe acquired von Willebrand syndrome (type 3-like).

Von Willebrand disease (VWD) is the most common congenital bleeding disorder and is due to quantitative or qualitative defects of von Willebrand factor (VWF). Acquired defects of VWF, termed acquired von Willebrand syndrome (AVWS), are due to a host of different mechanisms. Autoantibody-mediated AVWS may be associated with lymphoproliferative or immunological disorders, such as systemic lupus erythematosus (SLE). A large majority of AVWS cases are type 1 or type 2A-like and patients tend to have a mild to moderate bleeding tendency. We report a case of severe autoimmune AVWS in a woman with SLE who presented with clinical and laboratory features of type 3 VWD (undetectable VWF antigen, ristocetin cofactor activity, and VWF multimers). A mixing study demonstrated an inhibitor to VWF (6BU/mL). Her bleeds were managed with antifibrinolytics, recombinant activated factor VII, and activated prothrombin complex concentrate. She was initially treated with steroids and intravenous immunoglobulin therapy. However, her bleeding symptoms continued until she was treated with rituximab, and her VWF parameters normalized. She relapsed two years later due to non-compliance with her immunosuppressive medications and expired another two years later secondary to complications of sepsis and uremic pericarditis. This case emphasizes the importance of aggressive initial therapy of SLE to reduce secondary complications, frequent patient monitoring, and continued treatment of the underlying autoimmune disorder in patients with AVWS.

Clinical evaluation of thrombotic microangiopathy: identification of patients with suspected atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a rare genetic disorder caused by defective complement regulation resulting in thrombotic microangiopathy (TMA). Patients can present as children or adults. The syndrome consists of hemolytic anemia with schistocytosis, thrombocytopenia, significant renal damage, and/or other organ system dysfunction(s). Patients with aHUS may succumb to the complications of the disease with the very first manifestation; surviving patients often suffer from progressive organ dysfunction with significant morbidity and mortality despite plasma infusion or plasma exchange. Eculizumab, a humanized monoclonal antibody to C5, was approved for treatment of aHUS in 2011. This is an expensive but highly effective therapy changing the lives and improving the outcome of patients with aHUS. Making timely and accurate diagnosis of aHUS can be life-saving if eculizumab treatment is begun promptly. Finding a genetic mutation in a complement regulatory protein is diagnostic with the appropriate clinical syndrome, but at least 30 % of patients do not have defined or reported mutations. Thus the diagnosis rests on the clinical acumen of the physician. However, the clinical manifestations of aHUS are shared by other etiologies of thrombotic microangiopathy. While laboratory finding of undetectable ADAMTS13 activity defines TTP, distinguishing aHUS from the other causes of TMA remains an art. In addition, aHUS can be unmasked by conditions with enhanced complement activation, such as systemic lupus erythematosus, pregnancy, malignant hypertension, and hematopoietic stem cell transplantation. Thus if TMA occurs in the setting of enhanced complement activation, one must consider aHUS as an underlying etiology, especially if treatment of the condition does not resolve the TMA.