Methods: In this prospective study, twenty-seven adult patients with ASUC and 25 control patients with quiescent ulcerative colitis were recruited. Thrombin generation (endogenous thrombin potential), rotational thromboelastometry (EXTEM and FIBTEM maximum clot firmness), procoagulant factors, anticoagulant factors, and fibrinolytic markers were assessed for those with ASUC on admission (Day 1), Day 5, 4 weeks, and at 8–12 weeks. These assessments were performed on a single occasion for control patients.
Key findings:
Discussion:
“Patients with ASUC had a hypercoagulable profile on initial presentation to the hospital, before receipt of LMWH, which was consistently demonstrated by individual and global assays of coagulation. The most marked elevations of individual factors at presentation were seen in the levels of Clauss fibrinogen, platelets, VWF, and FVIII, alongside heightened levels of the inhibitors of fibrinolysis PAI-1 and TAFIa.”
“This hypercoagulable state persisted for many weeks after hospital discharge, with levels of FVIII, fibrinogen, VWF, and inhibitors of fibrinolysis (TAFIa) remained significantly elevated at all timepoints up to 12 weeks, compared with the control population. This is despite intensive treatment for ASUC in all patients.”
“VTE and pulmonary embolism are 1 of the leading causes of morbidity and mortality during IBD flare-ups. The findings from this study reinforce the importance of thromboprophylaxis administration to all patients with ASUC at first presentation to hospital.”
My take: This study is in adults; the risk of VTE is lower in children and guidance on VTE prophylaxis is not clear.
Methods: In this open-label, multicenter, randomized controlled trial, patients aged 18 years or older from 13 Australian tertiary hospitals with intravenous steroid-refractory ASUC were randomly assigned (1:2) to receive a first dose of 10 mg/kg infliximab or 5 mg/kg infliximab (randomization 1). Block randomization was used and stratified by history of thiopurine exposure and study site, with allocation concealment maintained via computer-generated randomization. Patients in the 10 mg/kg group (intensified induction strategy [IIS]) received a second dose at day 7 or earlier at the time of non-response; all patients in the 5 mg/kg group were re-randomized between day 3 and day 7 (1:1; randomization 2) to a standard induction strategy (SIS) or accelerated induction strategy (AIS), resulting in three induction groups. Patients in the SIS group received 5 mg/kg infliximab at weeks 0, 2, and 6, with an extra 5 mg/kg dose between day 3 and day 7 if no response. Patients in the AIS group received 5 mg/kg infliximab at weeks 0, 1, and 3, with the week 1 dose increased to 10 mg/kg and given between day 3 and day 7 if no response.
Thus, this was the first RCT comparing an intensified induction strategy (IIS; 10 mg/kg infliximab at weeks 0 and 1, with the second dose given earlier if no clinical response), an accelerated induction strategy (AIS; 5 mg/kg infliximab at weeks 0, 1, and 3, with the second dose increased to 10 mg/kg and given earlier if no response), and a standard induction strategy (SIS; 5 mg/kg at weeks 0, 2 and 6; with an extra 5 mg/kg dose before day 7 if no response) in steroid-refractory patients with ASUC.
Key findings:
There was no significant difference in the proportion of patients who had a clinical response by day 7 between the 10 mg/kg and 5 mg/kg groups: 65% vs 61%
In patients with a baseline albumin of less than 25 g/L, a day 7 response occurred in nine (64%) of 14 patients in the 10 mg/kg group versus 14 (45%) of 31 in the 5 mg/kg group (RR 1·43, p=0·17)
In patients with a baseline CRP of 50 mg/L or higher, a day 7 response occurred in six (60%) of ten patients in the 10 mg/kg group versus eight (42%) of 19 in the 5 mg/kg group (RR 1·39, p=0·34)
The proportions of patients with clinical response at day 14: 74% in the IIS group, 73% in the AIS group, and 68% of 44 in the SIS group.
The clinical remission at month 3: 50% in the IIS group, 52% in the AIS group, and 48% in the SIS group
The steroid-free remission at month 3: 41% in the IIS group, 42% in the AIS group, and 41% in the SIS group
The endoscopic remission at month 3: 46% in the IIS group, 46% in the AIS group, and 48% in the SIS group
The colectomy rate at month 3: 7% in the IIS group, 19% in the AIS group, and 12% in the SIS group colectomy at month 3 were not significantly different between group (P=0.20)
The colectomy rate at month 12: 7% in the IIS group, 22% in the AIS group, and 15% in the SIS group colectomy at month 3 were not significantly different between group (p=0.13)
In post-hoc analysis of second-dose salvage strategies (among the group who had not responded at day7), a clinical response was observed in 19 (59%) of 32 patients who received a 10 mg/kg salvage dose versus nine (64%) of 14 who received a 5 mg/kg salvage dose (RR 0·92). Endoscopic remission at month 3 was observed in 11 (34%) who received 10 mg/kg salvage versus six (43%) who received 5 mg/kg salvage (RR 0·80). Colectomy by 3 months occurred in ten (31%) who received 10 mg/kg salvage compared with three (21%) who received 5 mg/kg salvage (HR 1·46)
Higher proportions of patients with clinical and biochemical remission between weeks 2 and 6 were apparent in the IIS and AIS groups versus the SIS group, but by 3 months, these differences were lost
My take: Intensified, accelerated, and standard induction regimens in the PREDICT-UC study did not result in a statistically-significant difference in clinical response by day 14 or in remission or colectomy rates by month 3. However, there are some important caveats:
There appeared to be a trend towards a lower colectomy rate in the IIS group.
There appeared to be a favorable trend towards an improved response to IIS group in those with low albumin (<25 g/L) and high CRP (>5 mg/L). The smaller numbers in these subgroups could have precluded statistical significance
Also, even the SIS group were able to receive a 4th induction 5 mg/kg dose between days 3-7 if they had not responded to treatment
In patients who had not responded to either 10 mg/kg or 5 mg/kg, a salvage dose at day 7 resulted in a >60% response rate
It is possible that a sustained strategy of more aggressive dosing (not done in this study) aided with therapeutic drug monitoring could result in better outcomes following IIS
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