Association of Fusobacterium nucleatum infection with the clinicopathological characteristics in colorectal cancer patients.

BACKGROUND: Colorectal cancer (CRC) is a global health problem. The gut microbiome is now recognized as an important underlying factor to the initiation and progression of CRC. Fusobacterium nucleatum (FN) is one of the most studied bacteria in the aetiology of CRC. This study provided cohort evidence on the association of FN infection with clinicopathologic features in CRC patients. METHODS: We analysed the cancerous and adjacent non-cancerous formalin-fixed paraffin embedded (FFPE) tissue of 83 CRC patients from a single medical centre in Malaysia. TaqMan probe-based qPCR targeting the 16S rRNA gene was used to detect the presence of FN in the extracted FFPE DNA. The differences in FN expression between cancer and non-cancer tissues were evaluated. Association studies between FN infection in the tumour and relative FN abundance with available clinical data were conducted. RESULTS: FN was more abundant in the cancerous tissue compared to non-cancerous tissue (p = 0.0025). FN infection in the tumour was significantly associated with lymph node metastasis (p = 0.047) and cancer staging (p = 0.032), but not with other clinicopathologic variables. In double-positive patients where FN was detected in both cancerous and non-cancerous tissue, the expression fold-change of FN, calculated using 2-ΔΔCT formula, was significantly higher in patients with tumour size equal to or greater than 5 cm (p = 0.033) and in KRAS-mutated patients (p = 0.046). CONCLUSIONS: FN is enriched in CRC tumour tissue and is associated with tumour size, lymph node metastasis, cancer staging, and KRAS mutation in this single-centre small cohort study.

Adults with first-time nephrotic syndrome had increased risk for thromboembolic events, higher near time of diagnosis.

SOURCE CITATION: Vestergaard SV, Birn H, Darvalics B, et al. Risk of arterial thromboembolism, venous thromboembolism, and bleeding in patients with nephrotic syndrome: a population-based cohort study. Am J Med. 2022;135:615-25.e9. 34979093.

Canadian expert consensus: management of hypersensitivity reactions to intravenous iron in adults.

BACKGROUND AND OBJECTIVES: Rare but potentially life-threatening hypersensitivity reactions can occur during the administration of intravenous iron. To provide guidance to healthcare professionals caring for adults receiving intravenous iron, a panel of 10 Canadian clinical experts developed a practical algorithm for the identification and management of hypersensitivity reactions to intravenous iron. MATERIALS AND METHODS: A systematic search of PubMed to February 2018 was performed. Articles related to hypersensitivity reactions were selected for review. The algorithm was developed during a 1-day live meeting based on the literature review and clinical expertise where evidence was lacking. The algorithm was then refined through an iterative process involving a web-based platform and virtual meetings. RESULTS: The algorithm provides guidance to healthcare professionals in preparing for and administering IV iron, as well as recognizing and managing hypersensitivity reactions to intravenous iron. Considerations for re-challenging patients who have experienced prior reactions are provided. CONCLUSION: Healthcare professionals who are involved in the care of patients receiving intravenous iron should be trained to anticipate, recognize and manage hypersensitivity reactions to intravenous iron to optimize patient care.

Paediatric rheumatology clinic population in Southeast Asia: are we different?

Objectives: To examine the descriptive epidemiology of the patient population referred to paediatric rheumatology centres (PRCs) in Southeast Asia (SEA) and to compare the frequency of conditions encountered with other PRC populations. Methods: A web-based Registry for Childhood Onset Paediatric Rheumatic Diseases was established in 2009 and seven PRCs in four SEA countries, where paediatric rheumatologists are available, participated in a prospective 24 month data collection (43 months for Singapore). Results: The number of patients analysed was 4038 (788 from Malaysia, 711 from the Philippines, 1943 from Singapore and 596 from Thailand). Over 70% of patients evaluated in PRCs in Malaysia, the Philippines and Thailand had rheumatic diseases (RDs), as compared with one-half of the proportion seen in Singaporean PRCs, which was similar to the Western PRC experience. Among RDs diagnosed (n = 2602), JIA was the most common disease encountered in Malaysia (41%) and Thailand (61%) as compared with systemic vasculitides in the Philippines (37%) and Singapore (35%) among which Henoch-Schönlein purpura was the most prevalent. SLE and related diseases were more common, but idiopathic pain syndrome and abnormal immunological laboratory tests were rarer than those seen in the West. JIA subtype distributions were different among countries. Among non-RDs (n = 1436), orthopaedic and related conditions predominated (21.7-59.4%). Conclusion: The frequencies of RDs seen by SEA PRCs were different from those in the West. Systemic vasculitides and SLE were common in addition to JIA. Paediatric rheumatologist availability and healthcare accessibility partially explain these observed discrepancies.

The impact of bleeding complications in patients receiving target-specific oral anticoagulants: a systematic review and meta-analysis.

Vitamin K antagonists (VKAs) have been the standard of care for treatment of thromboembolic diseases. Target-specific oral anticoagulants (TSOACs) have been developed and found to be at least noninferior to VKAs with regard to efficacy, but the risk of bleeding with TSOACs remains controversial. We performed a systematic review and meta-analysis of phase-3 randomized controlled trials (RCTs) to assess the bleeding side effects of TSOACs compared with VKAs in patients with venous thromboembolism or atrial fibrillation. We searched MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials; conference abstracts; and www.clinicaltrials.gov with no language restriction. Two reviewers independently performed study selection, data extraction, and study quality assessment. Twelve RCTs involving 102 607 patients were retrieved. TSOACs significantly reduced the risk of overall major bleeding (relative risk [RR] 0.72, P < .01), fatal bleeding (RR 0.53, P < .01), intracranial bleeding (RR 0.43, P < .01), clinically relevant nonmajor bleeding (RR 0.78, P < .01), and total bleeding (RR 0.76, P < .01). There was no significant difference in major gastrointestinal bleeding between TSOACs and VKAs (RR 0.94, P = .62). When compared with VKAs, TSOACs are associated with less major bleeding, fatal bleeding, intracranial bleeding, clinically relevant nonmajor bleeding, and total bleeding. Additionally, TSOACs do not increase the risk of gastrointestinal bleeding.

Guidance for the evaluation and treatment of hereditary and acquired thrombophilia.

Thrombophilias are hereditary and/or acquired conditions that predispose patients to thrombosis. Testing for thrombophilia is commonly performed in patients with venous thrombosis and their relatives; however such testing usually does not provide information that impacts management and may result in harm. This manuscript, initiated by the Anticoagulation Forum, provides clinical guidance for thrombophilia testing in five clinical situations: following 1) provoked venous thromboembolism, 2) unprovoked venous thromboembolism; 3) in relatives of patients with thrombosis, 4) in female relatives of patients with thrombosis considering estrogen use; and 5) in female relatives of patients with thrombosis who are considering pregnancy. Additionally, guidance is provided regarding the timing of thrombophilia testing. The role of thrombophilia testing in arterial thrombosis and for evaluation of recurrent pregnancy loss is not addressed. Statements are based on existing guidelines and consensus expert opinion where guidelines are lacking. We recommend that thrombophilia testing not be performed in most situations. When performed, it should be used in a highly selective manner, and only in circumstances where the information obtained will influence a decision important to the patient, and outweigh the potential risks of testing. Testing should not be performed during acute thrombosis or during the initial (3-month) period of anticoagulation.

Failure of anticoagulant thromboprophylaxis: risk factors in medical-surgical critically ill patients*.

OBJECTIVES: To identify risk factors for failure of anticoagulant thromboprophylaxis in critically ill patients in the ICU. DESIGN: Multivariable regression analysis of thrombosis predictors from a randomized thromboprophylaxis trial. SETTING: Sixty-seven medical-surgical ICUs in six countries. PATIENTS: Three thousand seven hundred forty-six medical-surgical critically ill patients. INTERVENTIONS: All patients received anticoagulant thromboprophylaxis with low-molecular-weight heparin or unfractionated heparin at standard doses. MEASUREMENTS AND MAIN RESULTS: Independent predictors for venous thromboembolism, proximal leg deep vein thrombosis, and pulmonary embolism developing during critical illness were assessed. A total of 289 patients (7.7%) developed venous thromboembolism. Predictors of thromboprophylaxis failure as measured by development of venous thromboembolism included a personal or family history of venous thromboembolism (hazard ratio, 1.64; 95% CI, 1.03-2.59; p = 0.04) and body mass index (hazard ratio, 1.18 per 10-point increase; 95% CI, 1.04-1.35; p = 0.01). Increasing body mass index was also a predictor for developing proximal leg deep vein thrombosis (hazard ratio, 1.25; 95% CI, 1.06-1.46; p = 0.007), which occurred in 182 patients (4.9%). Pulmonary embolism occurred in 47 patients (1.3%) and was associated with body mass index (hazard ratio, 1.37; 95% CI, 1.02-1.83; p = 0.035) and vasopressor use (hazard ratio, 1.84; 95% CI, 1.01-3.35; p = 0.046). Low-molecular-weight heparin (in comparison to unfractionated heparin) thromboprophylaxis lowered pulmonary embolism risk (hazard ratio, 0.51; 95% CI, 0.27-0.95; p = 0.034) while statin use in the preceding week lowered the risk of proximal leg deep vein thrombosis (hazard ratio, 0.46; 95% CI, 0.27-0.77; p = 0.004). CONCLUSIONS: Failure of standard thromboprophylaxis using low-molecular-weight heparin or unfractionated heparin is more likely in ICU patients with elevated body mass index, those with a personal or family history of venous thromboembolism, and those receiving vasopressors. Alternate management or incremental risk reduction strategies may be needed in such patients.

Thrombotic risk in the antiphospholipid syndrome.

The antiphospholipid syndrome (APS) is characterized by venous or arterial thrombosis and/or pregnancy morbidity in patients with persistent presence of antiphospholipid antibodies (aPL). Patients who are diagnosed with APS are identified to have a high risk of recurrent thrombosis, which can occur despite anticoagulant therapy. The optimal type, intensity, and duration of anticoagulant therapy for the treatment of APS remain controversial issues, particularly for arterial thrombosis and recurrent thrombosis. Patients with persistently positive testing for lupus anticoagulant and elevated levels of anticardiolipin antibodies and anti-ß2 glycoprotein I antibodies-known as triple positivity-appear to be at increased risk for thrombosis compared with patients who test positive for a single aPL. Recognizing that patients with APS may potentially have different thrombotic risk profiles may assist clinicians in assessing the risks, benefits, and optimal duration of anticoagulation. Future studies that delineate thrombotic risk in APS and evaluate current and novel anticoagulants as well as nonanticoagulant therapies are required.

Selective D-dimer testing for diagnosis of a first suspected episode of deep venous thrombosis: a randomized trial.

BACKGROUND: D-Dimer testing is sensitive but not specific for diagnosing deep venous thrombosis (DVT). Changing the use of testing and the threshold level for a positive test result on the basis of risk for DVT might improve the tradeoff between sensitivity and specificity and reduce the need for testing. OBJECTIVE: To determine whether using a selective D-dimer testing strategy based on clinical pretest probability (C-PTP) for DVT is safe and reduces diagnostic testing compared with using a single D-dimer threshold for all patients. DESIGN: Randomized, multicenter, controlled trial. Patients were allocated using a central automated system. Ultrasonographers and study adjudicators but not other study personnel were blinded to trial allocation. (ClinicalTrials.gov: NCT00157677) SETTING: 5 Canadian hospitals. PATIENTS: Consecutive symptomatic patients with a first episode of suspected DVT. INTERVENTION: Selective testing (n = 860), defined as D-dimer testing for outpatients with low or moderate C-PTP (DVT excluded at D-dimer levels <1.0 µg/mL [low C-PTP] or <0.5 µg/mL [moderate C-PTP]) and venous ultrasonography without D-dimer testing for outpatients with high C-PTP and inpatients, or uniform testing (n = 863), defined as D-dimer testing for all participants (DVT excluded at D-dimer levels <0.5 µg/mL). MEASUREMENTS: The proportion of patients not diagnosed with DVT during initial testing who had symptomatic venous thromboembolism during 3-month follow-up and the proportion of patients undergoing D-dimer testing and ultrasonography. RESULTS: The incidence of symptomatic venous thromboembolism at 3 months was 0.5% in both study groups (difference, 0.0 percentage point [95% CI, -0.8 to 0.8 percentage points]). Selective testing reduced the proportion of patients who required D-dimer testing by 21.8 percentage points (CI, 19.1 to 24.8 percentage points). It reduced the proportion who required ultrasonography by 7.6 percentage points (CI, 2.9 to 12.2 percentage points) overall and by 21.0 percentage points (CI, 14.2 to 27.6 percentage points) in outpatients with low C-PTP. LIMITATION: Results may not be generalizable to all D-dimer assays or patients with previous DVT, study personnel were not blinded, and the trial was stopped prematurely. CONCLUSION: A selective D-dimer testing strategy seems as safe as and more efficient than having everyone undergo D-dimer testing when diagnosing a first episode of suspected DVT. PRIMARY FUNDING SOURCE: Heart and Stroke Foundation of Ontario.

Evaluation of a diagnostic platelet aggregation test strategy for platelet rich plasma samples with low platelet counts.

INTRODUCTION: Light transmission aggregometry (LTA) is important for diagnosing platelet function disorders (PFD) and von Willebrand disease (VWD) affecting ristocetin-induced platelet aggregation (RIPA). Nonetheless, data is lacking on the utility of LTA for investigating thrombocytopenic patients and platelet rich plasma samples with low platelet counts (L-PRP). Previously, we developed a strategy for diagnostic LTA assessment of L-PRP that included: (1) acceptance of referrals/samples, regardless of thrombocytopenia severity, (2) tailored agonist selection, based on which are informative for L-PRP with mildly or severely low platelet counts, and (3) interpretation of maximal aggregation (MA) using regression-derived 95% confidence intervals, determined for diluted control L-PRP (C-L-PRP). METHODS: To further evaluate the L-PRP LTA strategy, we evaluated findings for a subsequent patient cohort. RESULTS: Between 2008 and 2021, the L-PRP strategy was applied to 211 samples (11.7% of all LTA samples) from 192 unique patients, whose platelet counts (median [range] × 109 /L) for blood and L-PRP were: 105 [13-282; 89% with thrombocytopenia] and 164 [17-249], respectively. Patient-L-PRP had more abnormal MA findings than simultaneously tested C-L-PRP (p-values <0.001). Among patients with accessible electronic medical records (n = 181), L-PRP LTA uncovered significant aggregation abnormalities in 45 (24.9%), including 18/30 (60%) with <80 × 109 platelets/L L-PRP, and ruled out PFD, and VWD affecting RIPA, in others. The L-PRP LTA strategy helped diagnose VWD affecting RIPA, Bernard Soulier syndrome, familial platelet disorder with myeloid malignancy, suspected ITGA2B/ITGB3-related thrombocytopenia, and acquired PFD. CONCLUSION: Diagnostic LTA with L-PRP, using a strategy that considers thrombocytopenia severity, is feasible and informative.

Periprocedural heparin bridging in patients receiving vitamin K antagonists: systematic review and meta-analysis of bleeding and thromboembolic rates.

BACKGROUND: Periprocedural bridging with unfractionated heparin or low-molecular-weight heparin aims to reduce the risk of thromboembolic events in patients receiving long-term vitamin K antagonists. Optimal periprocedural anticoagulation has not been established. METHODS AND RESULTS: MEDLINE, EMBASE, and Cochrane databases (2001-2010) were searched for English-language studies including patients receiving heparin bridging during interruption of vitamin K antagonists for elective procedures. Data were independently collected by 2 investigators (κ=0.90). The final review included 34 studies with 1 randomized trial. Thromboembolic events occurred in 73 of 7118 bridged patients (pooled incidence, 0.9%; 95% confidence interval [CI], 0.0.0-3.4) and 32 of 5160 nonbridged patients (pooled incidence, 0.6%; 95% CI, 0.0-1.2). There was no difference in the risk of thromboembolic events in 8 studies comparing bridged and nonbridged groups (odds ratio, 0.80; 95% CI, 0.42-1.54). Bridging was associated with an increased risk of overall bleeding in 13 studies (odds ratio, 5.40; 95% CI, 3.00-9.74) and major bleeding in 5 studies (odds ratio, 3.60; 95% CI, 1.52-8.50) comparing bridged and nonbridged patients. There was no difference in thromboembolic events (odds ratio, 0.30; 95% CI, 0.04-2.09) but an increased risk of overall bleeding (odds ratio, 2.28; 95% CI, 1.27-4.08) with full versus prophylactic/intermediate-dose low-molecular-weight heparin bridging. Low-thromboembolic-risk and/or non-vitamin K antagonist patient groups were used for comparison. Study quality was poor with heterogeneity for some analyses. CONCLUSIONS: Vitamin K antagonist-treated patients receiving periprocedural heparin bridging appear to be at increased risk of overall and major bleeding and at similar risk of thromboembolic events compared to nonbridged patients. Randomized trials are needed to define the role of periprocedural heparin bridging.

Heparin thromboprophylaxis in medical-surgical critically ill patients: a systematic review and meta-analysis of randomized trials.

OBJECTIVE: Venous thromboembolism prevention during critical illness is a widely used quality metric. The objective of this systematic review was to systematically review the efficacy and safety of heparin thromboprophylaxis in medical-surgical patients in the ICU. DATA SOURCES: We searched EMBASE, MEDLINE, the Cochrane Controlled Trials Register, Clinicaltrials.gov, and personal files through May 2012. STUDY SELECTION: Randomized trials in adult medical-surgical ICU patients comparing any heparin (unfractionated heparin or low-molecular-weight heparin) with each other or no anticoagulant prophylaxis, evaluating deep vein thrombosis, pulmonary embolism, major bleeding, or mortality. DATA EXTRACTION: Independently, in duplicate, we abstracted trial characteristics, outcomes, and risk of bias. DATA SYNTHESIS: Seven trials involved 7,226 patients. Any heparin thromboprophylaxis compared with placebo reduced rates of deep vein thrombosis (pooled risk ratio, 0.51 [95% CI, 0.41, 0.63]; p<0.0001; I=77%) and pulmonary embolism (risk ratio, 0.52 [95% CI, 0.28, 0.97]; p=0.04; I=0%) but not symptomatic deep vein thrombosis (risk ratio, 0.86 [95% CI, 0.59, 1.25]; p=0.43). Major bleeding (risk ratio, 0.82 [95% CI, 0.56, 1.21]; p=0.32; I=50%) and mortality (risk ratio, 0.89 [95% CI, 0.78, 1.02]; p=0.09; I=0%) rates were similar. Compared with unfractionated heparin, low-molecular-weight heparin reduced rates of pulmonary embolism (risk ratio, 0.62 [95% CI, 0.39, 1.00]; p=0.05; I=53%) and symptomatic pulmonary embolism (risk ratio, 0.58 [95% CI, 0.34, 0.97]; p=0.04) but not deep vein thrombosis (risk ratio, 0.90 [95% CI, 0.74, 1.08]; p=0.26; I=0%), symptomatic deep vein thrombosis (risk ratio, 0.87 [95% CI, 0.60, 1.25]; p=0.44; I=0%), major bleeding (risk ratio, 0.97 [95% CI, 0.75, 1.26]; p=0.83; I=0%), or mortality (risk ratio, 0.93 [95% CI, 0.82, 1.04]; p=0.20; I=31%). CONCLUSIONS: Trial evidence to date suggests that any type of heparin thromboprophylaxis decreases deep vein thrombosis and pulmonary embolism in medical-surgical critically ill patients, and low-molecular-weight heparin compared with bid unfractionated heparin decreases pulmonary embolism and symptomatic pulmonary embolism. Major bleeding and mortality rates do not appear to be significantly influenced by heparin thromboprophylaxis in the ICU setting. Trial methodology, indirectness, and the heterogeneity and imprecision of some results temper inferences from this literature.

The American Society of Hematology 2011 evidence-based practice guideline for immune thrombocytopenia.

Immune thrombocytopenia (ITP) is commonly encountered in clinical practice. In 1996 the American Society of Hematology published a landmark guidance paper designed to assist clinicians in the management of this disorder. Since 1996 there have been numerous advances in the management of both adult and pediatric ITP. These changes mandated an update in the guidelines. This guideline uses a rigorous, evidence-based approach to the location, interpretation, and presentation of the available evidence. We have endeavored to identify, abstract, and present all available methodologically rigorous data informing the treatment of ITP. We provide evidence-based treatment recommendations using the GRADE system in those areas in which such evidence exists. We do not provide evidence in those areas in which evidence is lacking, or is of lower quality--interested readers are referred to a number of recent, consensus-based recommendations for expert opinion in these clinical areas. Our review identified the need for additional studies in many key areas of the therapy of ITP such as comparative studies of "front-line" therapy for ITP, the management of serious bleeding in patients with ITP, and studies that will provide guidance about which therapy should be used as salvage therapy for patients after failure of a first-line intervention.

A blinded study of bone marrow examinations in patients with primary immune thrombocytopenia.

OBJECTIVE: The role of bone marrow examinations in patients with primary immune thrombocytopenia (ITP) is uncertain. The objectives of this study were to determine the inter-rater reliability of bone marrow examinations and to identify distinguishing morphological features of ITP bone marrows under controlled conditions. METHODS: Histological slides of bone marrow biopsy specimens and aspirates from 32 adult patients with severe primary ITP who had failed a median of two treatments, and 51 non-thrombocytopenic controls were retrieved from hospital archives. Slides were arranged in random order in a slide box and coded. Blinded to the diagnosis and platelet counts, three independent hematopathologists were asked to identify the ITP bone marrows and to evaluate megakaryocyte number, morphology, and distribution. RESULTS: Overall chance-corrected agreement on ITP classification among the three raters was poor [kappa (κ) = 0.30; 95% confidence interval 0.22-0.38]. Raters were generally unable to correctly identify the ITP bone marrows from controls. Increased number of megakaryocytes, while an uncommon finding, was more frequent among ITP patients compared with controls (6/32, 18.8%; vs. 2/51, 3.9%; P = 0.05), and abnormal megakaryocyte morphology often led individual raters to reach a diagnosis of ITP. Overall sensitivity and specificity of bone marrow examinations were 24% and 90%, respectively. CONCLUSIONS: This study confirms methodologically that bone marrow examinations are unreliable and frequently non-diagnostic in ITP. Thus, they are not useful for patients with typical disease. Rare subsets of patients with severe ITP demonstrated unique features such as increased number of megakaryocytes.

Stability studies of ALD-52 and its homologue 1P-LSD.

With the emergence of new psychoactive substances (NPSs) over the years, the substances detected on stamps (also known as blotter papers) have also evolved from the traditional drug-lysergic acid diethylamide (LSD) to the multiple variants of lysergamides such as ALD-52 and 1P-LSD. The analysis of such blotter papers is usually done by solvent extraction followed by identification using gas chromatography-mass spectrometry (GC-MS). This study has shown that hydrolysis to form LSD was observed in GC-MS analysis when ALD-52 was extracted with methanol. The extraction of ALD-52 using other solvents such as acetonitrile, ethanol, isopropyl alcohol, ethyl acetate, and acetone, followed by GC-MS analysis, was investigated. It is shown that alcoholic solvents such as methanol and ethanol will result in the conversion of ALD-52 to LSD during GC-MS analysis, whereas the sterically hindered isopropyl alcohol will prevent this conversion. Investigation also shows that the hydrolysis of ALD-52 to LSD occurs at the GC injector port. It was also observed that the degree of hydrolysis was more pronounced at a lower concentration (0.1 mg/mL). The study was extended to a close analog-1P-LSD, and the results showed that 1P-LSD similarly hydrolyzes to LSD. However, 1P-LSD was observed to be more stable than ALD-52 due to steric hindrance because of the propanoyl group.

Systematic review and meta-analysis methodology.

Systematic reviews and meta-analyses are being increasingly used to summarize medical literature and identify areas in which research is needed. Systematic reviews limit bias with the use of a reproducible scientific process to search the literature and evaluate the quality of the individual studies. If possible the results are statistically combined into a meta-analysis in which the data are weighted and pooled to produce an estimate of effect. This article aims to provide the reader with a practical overview of systematic review and meta-analysis methodology, with a focus on the process of performing a review and the related issues at each step.

Complement and the antiphospholipid syndrome.

PURPOSE OF REVIEW: The antiphospholipid antibody syndrome (APS) is characterized by arterial or venous thrombosis or pregnancy morbidity in patients with persistent antiphospholipid antibodies (aPL). Experimental data supporting activation of the complement cascade has provided critical insight into the underlying pathophysiology of aPL-induced pregnancy loss and thrombosis. RECENT FINDINGS: Although the mechanism by which pregnancy loss and thrombosis is incompletely elucidated, studies using mice deficient in complement components and specific inhibitors to complement have demonstrated that activation of complement contributes to fetal loss, growth restriction and thrombosis. Inhibition of complement activation can prevent these complications. Use of a specific complement inhibitor to C5 has been used successfully in a patient with catastrophic APS undergoing renal transplantation. SUMMARY: Activation of complement plays an important role in the pathogenesis of aPL-induced pregnancy morbidity and thrombosis. This understanding has been advanced primarily using mouse models of APS and clinical studies in patients with APS are needed. Although there is currently no specific complement-targeted therapy approved for APS, developing and evaluating complement-targeted therapies in patients with APS are warranted. Complement inhibition may provide a novel upstream treatment option for patients with APS compared with the current standard treatment of anticoagulation.