Genetic and epigenetic dysregulation of CR1 is associated with catastrophic antiphospholipid syndrome.

Objectives: Catastrophic antiphospholipid syndrome (CAPS) is a complement-driven thrombotic disorder, characterised by widespread thrombosis and multiorgan failure. We identified rare germline variants including complement receptor 1 (CR1) in 50% of patients with CAPS. Here, we define CR1 dysregulation mechanisms (genetic/epigenetic) underlying complement-mediated thrombosis in CAPS and support C5 inhibition as a potential therapy.

Progressive Silent Cerebral Infarction is Associated with Stroke and Persistent Cognitive Impairment in iTTP Survivors.

Immune thrombotic thrombocytopenic purpura (iTTP) survivors face an increased risk of cerebrovascular disease, including silent cerebral infarction (SCI), cognitive impairment, and stroke. The prospective Neurologic Sequelae of iTTP (NeST) study evaluated the natural history of SCI (by brain MRI) during clinical remission and its association with stroke risk and cognitive impairment, measured by the NIH Toolbox Cognition Battery. SCI burden was quantified using the modified Age-Related White Matter Changes (ARWMC) score.

Navigating the paroxysmal nocturnal hemoglobinuria (PNH) landscape.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal hematopoietic stem cell disorder in which a somatic mutation in PIGA leads to reduced or absent expression of glycosylphosphatidylinositol-anchored complement regulatory proteins. PNH presents with the central manifestations of complement-mediated hemolytic anemia, bone marrow failure, and thrombosis. The introduction of terminal complement inhibitors that block complement protein 5 (C5) has revolutionized the management of PNH by reducing the risk for thrombosis, extending survival to be similar to that of healthy controls, and improving quality of life.

Genetic and Epigenetic Dysregulation of CR1 is Associated with Catastrophic Antiphospholipid Syndrome (CAPS).

Objective: Catastrophic antiphospholipid syndrome (CAPS), characterized by widespread thrombosis and multi-organ failure, is associated with high morbidity and mortality. We previously established complement activation as a pathogenic driver of CAPS and identified rare germline variants in complement-regulatory genes including Complement Receptor 1 () in 50% of CAPS.

Methods: We quantified CR1 expression by flow cytometry across hematopoietic cell types.

Management of patients with concurrent clonal plasma cell and myeloid disorders: A single center descriptive case series.

Both clonal plasma cell and myeloid disorders occur more frequently with age. Patients with concurrent clonal plasma cell and myeloid disorders (CPCMD) can present clinical and therapeutic challenges. In this single-institution cohort of patients with CPCMD ( = 18), we abstracted clinically relevant themes.

Thrombosis and meningococcal infection rates in pegcetacoplan-treated patients with paroxysmal nocturnal hemoglobinuria in the clinical trial and postmarketing settings.

Background: Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired hematologic disease characterized by complement-mediated hemolysis and thrombosis. Complement component 5 (C5) inhibitors have decreased PNH-related thrombosis rates and reduced mortality compared with those of age-matched controls. A small but significantly increased risk of life-threatening infections, especially , represents a long-term safety risk of complement inhibition.

Medical consult: aHUS, TTP? How to distinguish and what to do.

Immune thrombotic thrombocytopenic purpura (iTTP) caused by an autoantibody-mediated deficiency of ADAMTS13 and atypical hemolytic syndrome (aHUS) caused by alternative complement dysregulation are the most common primary thrombotic microangiopathies (TMAs). The evaluation of a patient with TMA is a medical emergency since it is critical to quickly distinguish iTTP and aHUS from other causes of TMA. Untreated iTTP is rapidly fatal, and delays in initiating complement inhibition in aHUS increase the risk of irreversible renal failure.

Complement biomarkers in the antiphospholipid syndrome - Approaches to quantification and implications for clinical management.

Complement is a major driver of antiphospholipid syndrome (APS) and a promising therapeutic target in refractory and catastrophic APS. Complement testing in APS is largely limited to research settings, and reliable, rapid-turnaround biomarkers are needed to predict those at risk for adverse clinical outcomes and most likely to benefit from complement inhibition. We review complement biomarkers and their association with thrombosis and obstetric outcomes, including: (i) complement proteins and activation fragments in the fluid phase; (ii) assays that evaluate complement on cell membranes (e.

Silent cerebral infarction during immune TTP remission: prevalence, predictors, and impact on cognition.

Immune thrombotic thrombocytopenic purpura (iTTP) survivors have increased risk of cardiovascular disease, including strokes, and report persistent cognitive difficulties during remission. We conducted this prospective study involving iTTP survivors during clinical remission to determine the prevalence of silent cerebral infarction (SCI), defined as magnetic resonance imaging (MRI) evidence of brain infarction without corresponding overt neurodeficits. We also tested the hypothesis that SCI is associated with cognitive impairment, assessed using the National Institutes of Health ToolBox Cognition Battery.

SARS-CoV-2 infection results in upregulation of Plasminogen Activator Inhibitor-1 and Neuroserpin in the lungs, and an increase in fibrinolysis inhibitors associated with disease severity.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection results in coagulation activation although it is usually not associated with consumption coagulopathy. D-dimers are also commonly elevated despite systemic hypofibrinolysis. To understand these unusual features of coronavirus disease 2019 (COVID-19) coagulopathy, 64 adult patients with SARS-CoV-2 infection (36 moderate and 28 severe) and 16 controls were studied.

A bispecific inhibitor of complement and coagulation blocks activation in complementopathy models via a novel mechanism.

Inhibitors of complement and coagulation are present in the saliva of a variety of blood-feeding arthropods that transmit parasitic and viral pathogens. Here, we describe the structure and mechanism of action of the sand fly salivary protein lufaxin, which inhibits the formation of the central alternative C3 convertase (C3bBb) and inhibits coagulation factor Xa (fXa). Surface plasmon resonance experiments show that lufaxin stabilizes the binding of serine protease factor B (FB) to C3b but does not detectably bind either C3b or FB alone.

Pegcetacoplan for paroxysmal nocturnal hemoglobinuria.

Approximately a third of patients with paroxysmal nocturnal hemoglobinuria (PNH) remain transfusion dependent or have symptomatic anemia despite treatment with a C5 inhibitor. Pegcetacoplan inhibits complement proximally at the level of C3 and is highly effective in treating persistent anemia resulting from C3-mediated extravascular hemolysis. We describe the rationale for C3 inhibition in the treatment of PNH and discuss preclinical and clinical studies using pegcetacoplan and other compstatin derivatives.