Elizabeth T. Clark

Autologous Hematopoetic Stem Cell Transplantation for Refractory Crohn Disease: A Randomized Clinical Trial.

IMPORTANCE Case reports and series suggest hematopoietic stem cell transplantation (HSCT) may benefit some patients with Crohn disease. OBJECTIVE To evaluate the effect of autologous HSCT on refractory Crohn disease. DESIGN, SETTING, AND PARTICIPANTS Parallel-group randomized clinical trial conducted in 11 European transplant units from July 2007 to September 2011, with follow-up through March 2013. Patients were aged 18 to 50 years with impaired quality of life from refractory Crohn disease not amenable to surgery despite treatment with 3 or more immunosuppressive or biologic agents and corticosteroids. INTERVENTIONS All patients underwent stem cell mobilization before 1:1 randomization to immunoablation and HSCT (n = 23) or control treatment (HSCT deferred for 1 year [n = 22]). All were given standard Crohn disease treatment as needed. MAIN OUTCOMES AND MEASURES Sustained disease remission at 1 year, a composite primary end point comprising clinical remission (Crohn Disease Activity Index (CDAI) <150 [range, 0-600]), no use of corticosteroids or immunosuppressive or biologic drugs for at least the last 3 months, and no endoscopic or radiological evidence of active (erosive) disease anywhere in the gastrointestinal (GI) tract. Secondary outcomes were individual components of the primary composite outcome and other measures of disease activity, laboratory results, quality of life and functional status, and GI tract imaging. RESULTS Twenty-three patients underwent HSCT and 22 received standard Crohn disease treatment (controls). Sustained disease remission was achieved in 2 patients undergoing HSCT (8.7%) vs 1 control patient (4.5%) (absolute difference, 4.2% [95% CI, -14.2% to 22.6%]; P = .60). Fourteen patients undergoing HSCT (61%) vs 5 control patients (23%) had discontinued immunosuppressive or biologic agents or corticosteroids for at least 3 months (difference, 38.1% [95% CI, 9.3% to 59.3%]; P = .01). Ten vs 2 patients had a CDAI less than 150 (remission) at the final evaluation, 8 (34.8%) vs 2 (9.1%) for 3 or more months (difference, 25.7% [95% CI, 1.1% to 47.1%]; P = .052). Eight (34.8%) vs 2 (9.1%) patients were adjudicated free of active disease on endoscopy and radiology at final assessment (difference, 25.7% [95% CI, 1.1% to 47.1%]; P = .054). There were 76 serious adverse events in patients undergoing HSCT vs 38 in controls. One patient undergoing HSCT died. CONCLUSIONS AND RELEVANCE Among adult patients with refractory Crohn disease not amenable to surgery who had impaired quality of life, HSCT, compared with conventional therapy, did not result in a statistically significant improvement in sustained disease remission at 1 year and was associated with significant toxicity. These findings do not support the widespread use of HSCT for patients with refractory Crohn disease. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00297193.

The ankle-brachial index is associated with the magnitude of impaired walking endurance among men and women with peripheral arterial disease

Previous reports suggest that the severity of peripheral arterial disease (PAD), measured by the ankle—brachial index (ABI), is not associated with the magnitude of walking impairment, measured by treadmill testing. These prior studies have had small sample sizes and included only PAD participants with symptoms of intermittent claudication. We studied the association of the ABI with diverse measures of walking performance in a cross-sectional study of 156 participants with PAD with and without intermittent claudication symptoms. Outcomes included the Gardner—Skinner treadmill test, 6-minute walk, 4-meter walking velocity at usual and fastest pace, and the walking impairment questionnaire (WIQ). Adjusting for age, sex, race, comorbidities, leg symptoms, and other confounders, lower ABI values were associated with shorter distance achieved in the 6-minute walk (ABI < 0.50: 286 meters; ABI 0.50—0.70: 316 meters; ABI 0.71—0.95: 355 meters, p trend < 0.001), shorter maximal treadmill walking time (ABI < 0.50: 6.0 minutes; ABI 0.50—0.70: 6.9 minutes; ABI 0.71—0.95: 8.3 minutes, p trend = 0.009), and lower WIQ distance scores (p trend = 0.007) among PAD participants. The ABI was not associated significantly with walking velocity over 4 meters, treadmill time to onset of leg symptoms, or the WIQ speed or stair-climbing scores. In conclusion, among 156 participants with PAD with and without intermittent claudication, lower ABI values are associated significantly with poorer walking endurance, assessed by three distinct measures. Clinical Trial Registration — URL: http://www.clinicaltrials.gov. Unique identifier: NCT00106327

Intermittent ischemia potentiates intestinal reperfusion injury.

We hypothesized that even brief periods of reperfusion interjected between ischemic episodes would increase tissue injury. Studies were performed in a rat small intestine preparation in which metabolic, hemodynamic, and histologic responses to ischemia have been well characterized. Animals were subjected to a total of 30 or 45 minutes of complete intestinal ischemia. Flow interruption was continuous (C, single episode) or intermittent (I, two or three episodes of 15-minute ischemia separated by 5 minutes of reperfusion). In some experiments 5-minute reperfusions were performed with arterial blood depleted of leukocytes (IL). This additional perturbation was included to determine the role of neutrophils that have been strongly implicated in reperfusion injury. In all three protocols histologic sections were obtained after each ischemic insult and after 1 hour of reperfusion with arterial blood. Villous histology was graded in a blinded fashion with 1 = normal and 5 = severe injury. No significant differences were found between groups in immediate postischemic histologies before reperfusion. After 1 hour of reperfusion, intermittent episodes of ischemia were associated with significantly worse histologic injury than that seen with comparable durations of continuous ischemia (30 min: I, 4.4 +/- 0.5 vs C, 2.7 +/- 0.4; 45 min: I, 4.9 +/- 0.2 vs C, 2.8 +/- 0.3). However, if 5-minute reperfusions were with leukopenic blood, this effect was markedly reduced (30 min IL, 3.4 +/- 0.3; 45 min IL, 3.6 +/- 0.2). Even short periods of reperfusion during an ischemic insult greatly increased mucosal injury.(ABSTRACT TRUNCATED AT 250 WORDS)

Inflammatory markers, D-dimer, pro-thrombotic factors, and physical activity levels in patients with peripheral arterial disease

Men and women with lower extremity peripheral arterial disease (PAD) have reduced physical activity levels compared with persons without PAD. We describe associations between physical activity levels with D-dimer, pro-coagulant factors, and inflammatory markers in patients with PAD. Participants were188 patients with PAD identified from non-invasive vascular laboratories. Physical activity was measured over 7 days with a vertical accelerometer. We measured the ankle brachial index (ABI) and levels of D-dimer, C-reactive protein (CRP), fibrinogen, serum amyloid A (SAA), prothrombin 1.2, t-PA antigen, PAI-1, and the t-PA antigen=PAI-1 ratio. Adjusting for age, sex, race, body mass index, ABI, comorbidities, smoking, total cholesterol=HDL ratio and statin use (for CRP only), we found significant inverse linear associations between physical activity levels and log D-dimer (p 1/4 0.002), log CRP (p < 0.001), fibrinogen (p 1/4 0.014), and log SAA (p 1/4 0.012). There were no significant associations between physical activity levels and other blood factors. In an analysis adjusting for all blood factors simultaneously along with known and potential confounders, log D-dimer was the only blood factor associated significantly with physical activity levels (p 1/4 0.036). Based on these findings, future studies should assess whether interventions to increase physical activity in patients with PAD reduce levels of D-dimer and inflammatory markers.

Superficial femoral artery plaque and functional performance in peripheral arterial disease: walking and leg circulation study (WALCS III).

OBJECTIVES We studied associations of magnetic resonance imaging measurements of plaque area and relative percent lumen reduction in the proximal superficial femoral artery with functional performance among participants with peripheral arterial disease. BACKGROUND The clinical significance of directly imaged plaque characteristics in lower extremity arteries is not well established. METHODS A total of 454 participants with an ankle brachial index <1.00 underwent magnetic resonance cross-sectional imaging of the proximal superficial femoral artery and completed a 6-min walk test, measurement of 4-m walking velocity at usual and fastest pace, and measurement of physical activity with a vertical accelerometer. RESULTS Adjusting for age, sex, race, body mass index, smoking, statin use, comorbidities, and other covariates, higher mean plaque area (1st quintile [least plaque]: 394 m, 2nd quintile: 360 m, 3rd quintile: 359 m, 4th quintile: 329 m, 5th quintile [greatest plaque]: 311 m; p trend <0.001) and smaller mean percent lumen area (1st quintile [greatest plaque]: 319 m, 2nd quintile: 330 m, 3rd quintile: 364 m, 4th quintile: 350 m, 5th quintile: 390 m; p trend <0.001) were associated with shorter distance achieved in the 6-min walk test. Greater mean plaque area was also associated with slower usual-paced walking velocity (p trend = 0.006) and slower fastest-paced 4-m walking velocity (p trend = 0.003). Associations of mean plaque area and mean lumen area with 6-min walk distance remained statistically significant even after additional adjustment for the ankle brachial index and leg symptoms. CONCLUSIONS Among participants with peripheral arterial disease, greater plaque burden and smaller lumen area in the proximal superficial femoral artery are associated independently with poorer functional performance, even after adjusting for the ankle brachial index and leg symptoms.

True Aneurysmal Disease in the Hand and Upper Extremity

Ten patients with true aneurysmal disease of the hand and forearm vessels were treated at our institution between 1981 and 1990. Pseudoaneurysms resulting from penetrating trauma or mycotic aneurysms were specifically excluded. Eight patients were male, two were female; mean patient age was 38 years (range 26 to 72 years). A history of repetitive occupational or recreational trauma was elicited in five patients. All patients presented with painful masses or neurologic symptoms due to nerve compression. Ischemic changes were evident in five patients due to thrombosis or distal embolization. Arteriography and transcutaneous Doppler ultrasound aided in documentation of flow characteristics and planning for operative intervention. Three patients underwent excision and ligation once collateral flow was demonstrated to be adequate and reconstruction was not felt to be feasible. Seven patients underwent resection with vein graft reconstruction. Immediate postoperative and interval patency rates were 100%. No digital amputations were required even in those patients presenting with severe distal ischemia.

Glucagon potentiates intestinal reperfusion injury

Vasoactive agents, including glucagon, have been used in treatment of mesenteric ischemia. Such drugs change both intestinal blood flow and metabolism. Since reperfusion injury reflects the metabolic state of an organ as well as the duration and severity of ischemia, we investigated the effect of glucagon in a standard model of intestinal ischemia. Data were generated from denervated isoperfused rat small intestinal preparations (n = 39). Arterial and venous pressures, intestinal blood flow, and oxygen consumption were monitored. Animals were subjected to 15, 30, or 45 minutes of ischemia followed by 1 hour reperfusion. Experiments were performed without drug infusion or during intravenous glucagon administration (0.1, 0.2, or 0.4 micrograms/kg/min). After the rats were killed, histologic sections of intestine were graded 1 through 5 in a blinded fashion with 1 = normal villi and 5 = severe injury. Results (mean +/- SD) were analyzed by analysis of variance (*p less than 0.05). Glucagon at all concentrations increased intestinal blood flow and oxygen consumption before ischemia. For example, with 0.2 micrograms/kg/min glucagon, intestinal blood flow increased from 80.78 +/- 13.5 to 114.79 +/- 21.02 ml/min.100 gm* and oxygen consumption increased from 3.65 +/- 0.73 to 5.73 +/- 1.37 ml/min.100 gm.* Mucosal injury after ischemia reflected duration of ischemia and glucagon infusion rate. At all ischemic intervals, increased glucagon concentrations were associated with greater mucosal injury. In fact the histologic injury with 15 minutes of ischemia + 0.2 microgram/kg/min glucagon (3.04 +/- 0.49) exceeded that of 30 minutes of ischemia (2.87 +/- 0.06).(ABSTRACT TRUNCATED AT 250 WORDS)

Limiting oxygen delivery attenuates intestinal reperfusion injury

Since free radical-mediated injury is dependent on the reintroduction of oxygen into ischemic tissues, restriction of oxygen content in the initial reperfusate has therapeutic potential. The degree to which oxygen must be restricted is crucial since hypoxic injury would continue if reperfusion O2 delivery remained below the ischemic threshold of the tissue. We examined this treatment strategy in 20 pump-perfused intestinal preparations subjected to 30 min of flow interruption. The oxygen content of the reperfusate was varied by utilizing arterial (A) or venous (V) blood; as a further modification, we also performed experiments in which hemodiluted arterial blood (HD) was the reperfusate at normal (NHD) and high (HHD) flow rates. The flow rates and O2 contents of the reperfusates were adjusted to produce either high (approximately 12 ml O2/min/100 g) or low (approximately 8 ml O2/min/100 g) levels of O2 delivery. Histologic sections, obtained after ischemia and after 1 hr of reperfusion, were blindly evaluated for mucosal injury (1 = normal to 5 = severe injury). Immediately after 30 min of ischemia, all groups had comparable histologic grades (A 2.0 +/- 0.3, V 1.8 +/- 0.3, NHD 1.6 +/- 0.3, HHD 2.3 +/- 0.3). One hour after reperfusion, intestines reperfused with blood with high O2 content and hence high O2 delivery showed significantly more damage (P < 0.001) than those with exposed to low O2 delivery during reperfusion: A 3.9 +/- 0.5 and HHD 4.4 +/- 0.4 versus V 2.7 +/- 0.5 and NHD 2.9 +/- 0.3.(ABSTRACT TRUNCATED AT 250 WORDS)

Autologous stem-cell transplantation in treatment-refractory Crohn's disease: an analysis of pooled data from the ASTIC trial

BACKGROUND The randomised controlled ASTIC trial showed no benefit of mobilisation and autologous haematopoietic stem-cell transplantation (HSCT) compared with mobilisation followed by conventional therapy using a stringent primary endpoint (steroid-free clinical remission for 3 months with no endoscopic or radiological evidence of intestinal inflammation) in patients with treatment-refractory Crohns disease. We now assess HSCT in patients enrolled in the ASTIC trial using endpoints that are traditional for clinical trials in Crohns disease, and identify factors that predict benefit or harm. METHODS Patients who underwent mobilisation and were randomly assigned to conventional therapy in the ASTIC trial were offered HSCT at 1 year and underwent complete assessment for a further year. We report analyses of the combined cohort of patients who underwent HSCT at any time during the ASTIC trial programme. The primary outcome for this analysis was 3-month steroid-free clinical remission at 1 year after HSCT (Crohns Disease Activity Index [CDAI] <150). We also examined the degree of endoscopic healing at 1 year. Multivariate analysis was performed to identify factors associated with achieving the primary endpoint by using logistic regression, and factors associated with experiencing a serious adverse event using Poisson regression. Participants were not masked to treatment, but the adjudication panel that reviewed radiology and endoscopy was masked to allocation and visits. All patients who underwent HSCT and had data available at baseline and 1-year follow-up were included in the primary and safety analysis. This trial is registered with ClinicalTrials.gov, number NCT00297193. FINDINGS Between June 28, 2007, and Sept 1, 2011, 45 patients were enrolled in the ASTIC trial from 11 European transplant units. 23 patients were randomly assigned to immediate HSCT, and 22 patients were assigned to mobilisation followed by conventional care. After completion of the ASTIC trial, 17 patients from the conventional care group received HSCT. In the combined cohort, data were available for 40 patients at baseline and 38 patients at 1 year after HSCT (one patient died, one withdrew). At 1 year after HSCT, 3-month steroid-free clinical remission was seen in 13 (38%, 95% CI 22-55) of 34 patients with available data for the whole year. Complete endoscopic healting was noted in 19 (50%, 34-66) of 38 patients. On multivariate analyses, factors associated with the primary outcome were short disease duration (odds ratio [OR] 0·64, 95% CI 0·41-0·997 per year; p=0·048) and low baseline CDAI (0·82, 0·74-0·98 per 10 units; p=0·031). 76 serious adverse events occurred in 23 of 40 patients with available data. The most common serious adverse event was infection, most of which were treatment related. Smoking and perianal disease at baseline were independent factors associated with the number of serious adverse events (OR 3·07 [95% CI 1·75-5·38; p=0·0001] for smoking and 3·97 [2·17-7·25; p<0·0001] for perianal disease) on multivariate analysis. INTERPRETATION When assessed using endpoints traditional for clinical trials of conventional therapy in Crohns disease, HSCT resulted in clinical and endoscopic benefit, although it was associated with a high burden of adverse events. The prognostic factors identified could allow the therapy to be targeted to patients most likely to benefit and not experience serious adverse events. FUNDING Broad Medical Research Program, National Institute for Health Research Senior Investigator Award, The University of Nottingham Medical School Deans Fund, and The Nottingham University Hospitals NHS Trust Research and Development Fund.

Serum proteins facilitate neutrophil induction of endothelial leukocyte adhesion molecule 1.

BACKGROUND Although the individual actions of neutrophils and serum proteins such as complement in acute inflammation are well characterized, less is known about their effects in combination. We investigated the combined effects of neutrophil contact and active serum proteins on the expression of endothelial leukocyte adhesion molecule 1 (ELAM-1). METHODS Confluent monolayers of human umbilical vein endothelial cells were incubated with neutrophils in the presence and absence of fresh human serum. Flow cytometry was used to assess expression of endothelial intercellular adhesion molecule 1 (ICAM-1) and ELAM-1. In addition, neutrophils were retained in a semipermeable insert, which allowed their secretions to contact the endothelium but restricted neutrophil-endothelial contact. RESULTS ELAM-1 expression was significantly increased on the cells coincubated with neutrophils and fresh human serum (25.8%; p < 0.001). There was no significant change in ELAM-1 expression on endothelial cells incubated with fresh human serum alone (3.9%; p > 0.01) or in those incubated with neutrophils and heat-inactivated serum (9.3%; p > 0.01). In the absence of neutrophil contact, ELAM-1 expression was increased only in the presence of fresh human serum (9.6%; p < 0.05). CONCLUSIONS These findings suggest that serum proteins may potentiate the volume or potency of neutrophil-derived diffusable mediators of ELAM-1 expression. These effects are eliminated with the heat inactivation of serum proteins, implicating a heat sensitive mediator such as the complement cascade.