Indicators of suboptimal response to anti-tumor necrosis factor therapy in patients from China with inflammatory bowel disease: results from the EXPLORE study.

BACKGROUND: Prevalence of inflammatory bowel disease (IBD) is increasing in China. The EXPLORE study evaluated the incidence and indicators of suboptimal responses to first-line anti-tumor necrosis factor (TNF) in patients with ulcerative colitis (UC) or Crohn's disease (CD). We present results for the mainland China subgroup. METHODS: A retrospective chart review was performed in adults with IBD at 10 centers in mainland China who initiated anti-TNF therapy between 01 March 2010 and 01 March 2015. The cumulative incidence of suboptimal response to first-line anti-TNF therapy was assessed over 24 months using the Kaplan-Meier method. Indicators of suboptimal response were: dose escalation, discontinuation, augmentation with non-biologic therapy, or IBD-related surgery/hospitalization. At site initiation, a survey was conducted with participating physicians to identify barriers to anti-TNF use. RESULTS: Of 287 patients (72% male) examined, 16/35 (45.7%) with UC and 123/252 (48.8%) with CD experienced a suboptimal response to first-line anti-TNF therapy at any point during the observation period (median 27.6 and 40.0 months, respectively). At 1 and 2 years post anti-TNF initiation, the cumulative incidence of suboptimal response was 51.4% and 75.7% for UC and 45.4% and 57.0% for CD, respectively. Median time to first suboptimal response was 7.2 months for UC and 14.3 months for CD. The most frequent indicator of suboptimal response was discontinuation of anti-TNF therapy (9/16, 56.3%) for UC and IBD-related hospitalization for CD (69/123, 56.1%) followed by augmentation with non-biologic therapy for both cohorts (5/16, 31.3% for UC and 28/123, 22.8% for CD). Dose escalation was the least frequent indicator of suboptimal response to anti-TNF therapy (CD: 4/123, 3.3%; UC: not cited as an indicator). The cumulative incidence of suboptimal response within 4 months of first-line anti-TNF therapy (primary non-response) was over 30% in both cohorts. Financial reasons and reimbursement were identified by surveyed physicians as the most common barriers to prescribing an anti-TNF therapy. CONCLUSIONS: Over one-half of patients with IBD are at risk of experiencing a suboptimal response to first-line anti-TNF therapy at 2 years post-initiation in China. This study highlights a substantial unmet need associated with anti-TNF therapies in China. (Clinicaltrials.gov identifier: NCT03090139).

Platelets provide robustness of spatial blood coagulation to the variation of initial conditions.

Activated platelets provide phospholipid surface and secrete coagulation factors, enhancing blood clotting. We investigated the role of platelets in the regulation of blood coagulation spatial dynamics. We activated blood clotting with tissue factor-bearing (TF) surface in platelet-rich plasma (PRP) or platelet-free plasma (PFP). When blood coagulation was initiated by high TF density, clot growth rate (V) in PRP (2 × 105/µL platelets) was only 15 % greater than in PFP. Spatial distribution of thrombin in PRP had a peak-like shape in the area of the fibrin clot edge, while in PFP thrombin was distributed in the shape of descending plateau. Platelet inhibition with prostaglandin E1 or cytochalasin D made spatial thrombin distribution look like in the case of PFP. Inhibition of blood coagulation by natural endogenous inhibitor heparin was diminished in PRP, while the effect of the exogenous or artificial inhibitors (rivaroxaban, nitrophorin, hirudin) remained undisturbed in the presence of platelets. Ten times decrease of the TF surface density greatly depressed blood coagulation in PFP. In PRP only clotting initiation phase was, while the propagation phase remained intact. Coagulation factor deficiency greatly reduced amount of thrombin and decreased V in PFP rather than in PPR. Thus, platelets were redundant for clotting in normal plasma under physiological conditions but provided robustness of the coagulation system to the changes in initial conditions.

Chronic bladder catheterization for precise urine collection in awake mice.

Metabolic chambers are routinely used for urine collection in rodents. In mice, due to small urination volume, evaporation in the metabolic chambers (≈50%) distorts diuresis and urinalysis parameters. We have developed a new technique of bladder catheterization enabling long-term accurate and contamination-free urine collection in awake male and female mice for 30 days or longer. Daily diuresis in catheterized mice was twice higher as compared to metabolic cages. The twofold difference in urine recovery was preserved when the circadian variation of diuresis, the effects of furosemide, desmopressin and water load were estimated using the two techniques. Urine osmolarity, urinalysis, and microbiological parameters evidence higher quality of the catheter-collected urine. Using phenol red, we demonstrate utility of our technique for pharmacokinetic studies. 30 days after the surgery the catheters were patent and had minimal impact on the animals' heath. Bladder catheterization is a useful tool for physiological, pharmacological, and toxicological studies.

Incidence of suboptimal response to tumor necrosis factor antagonist therapy in inflammatory bowel disease in newly industrialised countries: The EXPLORE study.

BACKGROUND: Incidence of inflammatory bowel disease (IBD) is increasing in newly industrialised countries (NICs); however, data on suboptimal response to anti-tumor necrosis factor (anti-TNF) agents are limited. OBJECTIVES: To assess incidence and indicators of suboptimal response to first anti-TNF therapy in IBD patients in NICs. METHODS: A chart review was conducted in ten countries from Asia-Pacific (APAC), Latin America (LatAm), and Russia and the Middle East (RME) regions among patients diagnosed with ulcerative colitis (UC) or Crohn's disease (CD), initiating anti-TNF therapy in 2010-2015. The cumulative incidence of suboptimal response to anti-TNF therapy was assessed using the following indicators: dose escalation or discontinuation, augmentation with non-biologic therapy, IBD-related hospitalization, or surgery. RESULTS: The study included 1,674 patients (570 UC; 1,104 CD). At 24 months, 32.9% of UC (APAC: 45.1%; LatAm: 38.2%; RME: 23.8%) and 41.2% of CD patients (APAC: 54.1%; LatAm: 42.5%; RME: 29.5%) had experienced suboptimal response. The most frequent first indicator was non-biologic therapy augmentation in LatAm (41.7%), IBD-related hospitalization in RME (UC: 50.7%; CD:37.3%) and in APAC for CD (39.1%), and anti-TNF discontinuation in APAC for UC (38.3%). CONCLUSION: Suboptimal response to anti-TNF agents is common in IBD patients in NICs. Observed regional differences in the incidence and indicators may reflect local practice and anti-TNF restrictions in IBD management. NCT REGISTRATION NUMBER: NCT03090139.

Drug-drug interaction of the anti-TFPI aptamer BAX499 and factor VIII: studies of spatial dynamics of fibrin clot formation in hemophilia A.

BACKGROUND: In recent years, a number of tissue factor pathway inhibitor (TFPI) antagonists have been developed to serve as bypassing agents to improve hemostasis in hemophilia A. Since TFPI antagonists and FVIII concentrates are procoagulants, their combined effect on spatial clot formation could be potentially pro-thrombotic. OBJECTIVE: To investigate the cooperative effect of TFPI inhibition and supplementation of FVIII in hemophilia A in a spatial, reaction-diffusion experiment in vitro. METHODS: Plasma was collected at different time points from hemophilia A patients undergoing prophylaxis and was supplemented in vitro with TFPI inhibitor BAX499 (formerly ARC19499) at concentrations from 0 up to 600nM. Clotting propagation in recalcified plasma activated by a surface with immobilized tissue factor (TF) was monitored by videomicroscopy. RESULTS: Increasing concentration of BAX499 improved coagulation for all hemophilia A plasma samples activated with TF at 1.6pmole/m(2) by shortening lag time and increasing initial clot growth velocity and clot size. In contrast, plasma concentration of FVIII had little effect on lag time, but increased spatial clot growth velocity. There was a decrease in the BAX499 efficiency as FVIII concentration increased (lag time shortened by 50% if FVIII:C<5%, but the effect was only 25% if FVIII:C>30%). CONCLUSIONS: The results indicate that BAX499 has an effect on clotting in hemophilia A plasma at low FVIII concentrations, however has little effect at high FVIII concentrations.

Predicting prothrombotic tendencies in sepsis using spatial clot growth dynamics.

Inflammation in sepsis is associated with hypercoagulation that may lead to thrombosis and disseminated intravascular coagulation. Conventional diagnostic assays are poorly sensitive to procoagulant changes in sepsis. Objectives of the article is to study changes in hemostatic state of septic patients using spatial clot growth assay (currently being developed under the trademark of thrombodynamics) and to compare the sensitivity of this method with the sensitivity of conventional methods. Sixteen patients with hematological malignancies and sepsis were enrolled in the study. All patients had been surveyed for a month following the infection onset. Spatial clot growth assay monitors fibrin clot development in a nonstirred thin layer of platelet-free plasma activated by immobilized tissue factor. Clotting time tests, thromboelastography, D-dimer assays were also performed. Spatial clot growth revealed hypercoagulation in six patients. D-dimer levels increase (with vein thrombosis in one case) was subsequently observed in five of them. D-dimer levels did not increase when spatial clot growth was normal. At the next time point, after spatial clot growth assay showed hypercoagulation, the mean D-dimer concentration was significantly higher than after a normal analysis (457 versus 234 µg/l; P < 0.05); there was no such correlation for other assays. The remaining 10 patients had elevated D-dimer levels on the first day; this either decreased gradually or remained elevated. Spatial clot growth showed normalization in survivors and growing hypocoagulation in nonsurvivors. Measuring spatial clot growth dynamics has potential diagnostic utility for the evaluation of thrombotic risk.