Performance Characteristics of DOAC-Remove for Neutralization of the Effects of Apixaban and Rivaroxaban in Lupus Anticoagulant Assays.

OBJECTIVES: This study established the performance characteristics of DOAC-Remove for neutralization of the effects of rivaroxaban and apixaban in lupus anticoagulant (LAC) testing. METHODS: Normal donor, LAC control, and patient samples were spiked with rivaroxaban or apixaban to simulate their effects on the dilute Russell's viper venom time (dRVVT), activated partial thromboplastin time (APTT), and dilute prothrombin time (dPT). Anti-Xa activity was measured after spiking and after DOAC-Remove neutralization. Accuracy, complex precision, and reference interval verification were evaluated. RESULTS: DOAC-Remove neutralized rivaroxaban and apixaban concentrations as high as 415 ng/mL and 333 ng/mL, respectively. Percentage positive and negative agreement between the baseline and postneutralization interpretations were 75% or higher for the dRVVT and APTT methods but not for the dPT method. Coefficients of variation (CVs) were 10% or less for all assays except the Staclot-LA delta, which had a standard deviation of 2.5 seconds or CV of 25% or less depending on the level. The laboratory's reference intervals were verified for the dRVVT and APTT assays after DOAC-Remove treatment but not for the dPT assays. CONCLUSIONS: DOAC-Remove appears to have acceptable performance characteristics for neutralizing the effects of rivaroxaban and apixaban in the dRVVT and APTT methods but not in the dPT method.

The Effects of Indirect- and Direct-Acting Anticoagulants on Lupus Anticoagulant Assays: A Large, Retrospective Study at a Coagulation Reference Laboratory.

OBJECTIVES: To investigate the effects of indirect- and direct-acting anticoagulants on the interpretation of lupus anticoagulant (LAC) assays. METHODS: A retrospective database review was performed to identify all LAC panels from November 2012 to November 2015. The positivity rates for three LAC tests were compared among various anticoagulant medications. RESULTS: This analysis included 7,721 LAC panels. Direct oral anticoagulants, warfarin, and unfractionated heparin (UFH) were associated with higher LAC positivity rates compared with patients not receiving documented anticoagulation (83% for argatroban, 58% for dabigatran, 72% for rivaroxaban, 53% for apixaban, 56% for warfarin, and 36% for UFH vs 29% for no anticoagulation, P < .025). Direct thrombin inhibitors mainly affected the activated partial thromboplastin time-based assays and the tissue thromboplastin inhibition index (TTI), while direct factor Xa inhibitors mainly affected the TTI and the dilute Russell viper venom ratio. CONCLUSIONS: Results of LAC testing performed while patients are receiving anticoagulant therapies should be interpreted with caution to avoid misdiagnosing patients with the antiphospholipid syndrome and potentially committing them to long-term anticoagulation therapy.

Enhanced strategies for prevention and management of blood loss in special, unusual, and unexpected surgical situations.

Typically, surgical and anesthesia teams work together in the operating room to control blood loss by thoroughly evaluating bleeding risk preoperatively and by using their training in the treatment of intraoperative blood loss. As a result, most bleeding is usually well controlled. In many cases a hematologist is consulted for recommendations preoperatively or, in urgent situations, even while the patient is in the operating room. In the end, however, it is usually the surgeons and anesthesiologists making decisions about how best to control bleeding. What follows is an update on currently available options in the management of surgical bleeding (Table 1).

Hereditary coagulopathies: practical diagnosis and management for the plastic surgeon.

BACKGROUND: Venous thromboembolism is a devastating complication representing one of the major causes of postoperative death in plastic surgery. Within the scope of plastic surgery, body-contouring procedures are often considered to carry a higher risk of venous thromboembolism. Hereditary thrombophilias comprise a group of conditions defined by a genetic predisposition to thrombosis development. Collectively, hereditary thrombophilias are present in at least 15 percent of Western populations and underlie approximately half of thromboembolic events. Although the topic of venous thromboembolism is discussed widely throughout the literature, there is little published on the diagnosis and management of hereditary thrombophilias in the plastic surgery literature. The goals of this study were to present a review of the major inherited thrombophilias, to delineate the risk of these disorders, and to recommend a practical algorithm for patient screening and management before major plastic surgery. METHODS: A MEDLINE search was performed from 1965 to the present to review the literature on inherited thrombophilia disorders. RESULTS: Based on the English language literature and clinical experience, the authors suggest practical guidelines for screening and management of hereditary thrombophilias. A thorough medical history and preoperative evaluation are key to reducing venous thromboembolism complications. CONCLUSIONS: Hereditary thrombophilias are present in a significant number of thromboembolic events. Preoperative vigilance on the part of the plastic surgeon may help to identify patients with undiagnosed hereditary thrombophilias and thereby decrease the incidence of venous thromboembolism.

The relationship of phthalocyanine 4 (pc 4) concentrations measured noninvasively to outcome of pc 4 photodynamic therapy in mice.

The ability to noninvasively measure photosensitizer concentration at target tissues will allow optimization of photodynamic therapy (PDT) and could improve outcome. In this study, we evaluated whether preirradiation tumor phthalocyanine 4 (Pc 4) concentrations, measured noninvasively by the optical pharmacokinetic system (OPS), correlated with tumor response to PDT. Mice bearing human breast cancer xenografts were treated with 2 mg kg(-1) Pc 4 iv only, laser irradiation (150 J cm(-2)) only, Pc 4 followed by fractionated irradiation or Pc 4 followed by continuous irradiation. Laser irradiation treatment was initiated when the tumor to skin ratio of Pc 4 concentration reached a maximum of 2.1 at 48 h after administration. Pc 4 concentrations in tumor, as well as in Intralipid in vitro, decreased monoexponentially with laser fluence. Pc 4-PDT resulted in significant tumor regression, and tumor response was similar in the groups receiving either fractionated or continuous irradiation treatment after Pc 4. Tumor growth delay following Pc 4-PDT correlated with OPS-measured tumor Pc 4 concentrations at 24 h prior to PDT (R2=0.86). In excised tumors, OPS-measured Pc 4 concentrations were similar to the HPLC-measured concentrations. Thus, OPS measurements of photosensitizer concentrations can be used to assist in the scheduling of Pc 4-PDT.

Apolipoprotein H promoter polymorphisms in relation to lupus and lupus-related phenotypes.

OBJECTIVE: Sequence variation in gene promoters is often associated with disease risk. We tested the hypothesis that common promoter variation in the APOH gene (encoding for ss(2)-glycoprotein I) is associated with systemic lupus erythematosus (SLE) risk and SLE-related clinical phenotypes in a Caucasian cohort. METHODS: We used a case-control design and genotyped 345 women with SLE and 454 healthy control women for 8 APOH promoter single-nucleotide polymorphisms (SNP; -1284C>G, -1219G>A, -1190G>C, -759A>G, -700C>A, -643T>C, -38G>A, and -32C>A).Association analyses were performed on single SNP and haplotypes. Haplotype analyses were performed using EH (Estimate Haplotype-frequencies) and Haploview programs. In vitro reporter gene assay was performed in COS-1 cells. Electrophoretic mobility shift assay (EMSA) was performed using HepG2 nuclear cells. RESULTS: Overall haplotype distribution of the APOH promoter SNP was significantly different between cases and controls (p = 0.009). The -643C allele was found to be protective against carotid plaque formation (adjusted OR 0.37, p = 0.013) among patients with SLE. The -643C allele was associated with a ~2-fold decrease in promoter activity as compared to wild-type -643T allele (mean +/- standard deviation: 3.94 +/- 0.05 vs 6.99 +/- 0.68, p = 0.016). EMSA showed that the -643T>C SNP harbors a binding site for a nuclear factor. The -1219G>A SNP showed a significant association with the risk of lupus nephritis (age-adjusted OR 0.36, p = 0.016). CONCLUSION: Our data indicate that APOH promoter variants may be involved in the etiology of SLE, especially the risk for autoimmune-mediated cardiovascular disease.

Genetic variation in C-reactive protein (CRP) gene may be associated with risk of systemic lupus erythematosus and CRP concentrations.

OBJECTIVE: The gene coding for C-reactive protein (CRP) is located on chromosome 1q23.2, which falls within a linkage region thought to harbor a systemic lupus erythematosus (SLE) susceptibility gene. Recently, 2 single-nucleotide polymorphisms (SNP) in the CRP gene (+838, +2043) have been shown to be associated with CRP concentrations and/or SLE risk in a British family-based cohort. Our study was done to confirm the reported association in an independent population-based case-control cohort, and also to investigate the influence of 3 additional CRP tagSNP (-861, -390, +90) on SLE risk and serum CRP concentrations. METHODS: DNA from 337 Caucasian women who met the American College of Rheumatology criteria for definite (n = 324) or probable (n = 13) SLE and 448 Caucasian healthy female controls was genotyped for 5 CRP tagSNP (-861, -390, +90, +838, +2043). Genotyping was performed using restriction fragment length polymorphism-polymerase chain reaction, pyrosequencing, or TaqMan assays. Serum CRP levels were measured using ELISA. Association studies were performed using the chi-squared distribution, Z-test, Fisher's exact test, and analysis of variance. Haplotype analysis was performed using EH software and the haplo.stats package in R 2.1.2. RESULTS: While none of the SNP were found to be associated with SLE risk individually, there was an association with the 5 SNP haplotypes (p < 0.001). Three SNP (-861, -390, +90) were found to significantly influence serum CRP level in SLE cases, both independently and as haplotypes. CONCLUSION: Our data suggest that unique haplotype combinations in the CRP gene may modify the risk of developing SLE and influence circulating CRP levels.

Genetic variation in the paraoxonase-3 (PON3) gene is associated with serum PON1 activity.

Low serum paraoxonase1 (PON1) activity determined by paraoxon substrate is associated with coronary heart disease (CHD), diabetes and systemic lupus erythematosus (SLE) risk. In this investigation, we have examined the role of genetic variation in the PON3 gene in relation to PON1 activity and SLE risk in a biracial sample comprising 377 SLE patients and 482 controls from US whites and blacks. We genotyped six PON3 tagging single nucleotide polymorphisms (tagSNPs) and examined their associations with PON1 activity, SLE risk, antiphopholipid autoantibodies (APA), lupus nephritis, carotid vascular disease, and inflammation. With the exception of PON1 activity, no other significant associations were found with PON3 SNPs. Multiple regression analysis including all six PON3 tagSNPs and PON1/Q192R and L55M SNPs revealed significant association of PON1 activity with 4 SNPs: PON3/A10340C (p < 0.0001), PON3/A2115T (p = 0.002), PON1/L55M (p < 0.0001) and PON1/Q192R (p < 0.0001). These four SNPs explained 2%, 1%, 8% and 19% of the variation in PON1 activity, respectively. In summary, our new data indicate that genetic variation in the PON3 gene influences serum PON1 activity independently of the known effect of PON1 genetic variation. To our knowledge, this is the first study reporting the association of the PON3 gene variants with PON1 activity.

Association study of Toll-like receptor 5 (TLR5) and Toll-like receptor 9 (TLR9) polymorphisms in systemic lupus erythematosus.

OBJECTIVE: Toll-like receptors (TLR) play an important role in both adaptive and innate immunity. Variations in TLR genes have been shown to be associated with various infectious and inflammatory diseases. We investigated the association of TLR5 (Arg392Stop, rs5744168) and TLR9 (-1237T-->C, rs5743836) single nucleotide polymorphisms (SNP) with systemic lupus erythematosus (SLE) in Caucasian American subjects. METHODS: We performed a case-control association study and genotyped 409 Caucasian women with SLE and 509 Caucasian healthy female controls using TaqMan allelic discrimination (rs5744168) or polymerase chain reaction-restriction fragment length polymorphism analysis (rs5743836). RESULTS: None of the 2 TLR SNP showed a statistically significant association with SLE risk in our cohort. CONCLUSION: Our results do not indicate a major influence of these putative functional TLR SNP on the susceptibility to (or protection from) SLE.