Therapies in Inflammatory Bowel Disease Patients with Extraintestinal Manifestations.

Extraintestinal manifestations (EIM) have become an important source of morbidity and disability as well as an identified risk factor for an unfavorably course of disease in inflammatory bowel diseases (IBD). Therefore, efforts have been put into a more global and interdisciplinary management of IBD patients in collaboration with rheumatologists, dermatologists, and ophthalmologists. A real therapeutic success has also been obtained with a more "systemic" IBD treatment associated with the development of monoclonal antibodies against TNF alpha and biological agents derived from the treatment of rheumatological disease (also called biological Disease-Modifying Antirheumatic Drugs). The prevalence of these EIM remains too low to undergo randomized controlled trials with this specific focus and therefore the evidence relies on case series and experts' opinions, which lowers the level of evidence. After a careful review of the most recent literature, this paper aims to update the reader on the latest therapeutic management of IBD patients with EIM.

Therapeutic Drug Monitoring to Guide Clinical Decision Making in Inflammatory Bowel Disease Patients with Loss of Response to Anti-TNF: A Delphi Technique-Based Consensus.

BACKGROUND: Loss of response is frequently encountered in patients with inflammatory bowel disease (IBD) treated with antitumor necrosis factor (TNF) agents. Therapeutic drug monitoring (TDM) and antidrug antibody measurement are increasingly used in this setting. METHODS: To establish a consensus on the use of TDM in the context of loss of response to anti-TNFs, we performed a vote using a Delphi-style process followed by an expert panel discussion among 8 IBD specialists practicing in Switzerland, Europe. Statements were rated on an even Likert-scale ranging from 1 (strong disagreement) to 4 (strong agreement), based on expert opinion and the available literature. RESULTS: The experts agreed on the following statements: (i) loss of response is associated with inadequate drug levels in both Crohn's disease and ulcerative colitis; (ii) best timepoint for measuring drug levels is prior to the next application (= trough levels) with different thresholds for anti-TNF agents (infliximab 5 µg/mL, adalimumab 8 µg/mL, certolizumab pegol 10 µg/mL); (iii) antidrug antibodies are predictive for loss of response; and (iv) antidrug-antibody titers and drug trough levels are key determinants in the treatment algorithm. Data about non-anti-TNF biologics were considered too limited to propose recommendations. CONCLUSION: A Delphi-style consensus among 8 IBD experts shows that TDM and measurement of antidrug-antibody titers are useful in the context of loss of response to anti-TNF. Optimal cutoff levels depend on the type of anti-TNF. These values are critical in the decision making process. More studies are needed to address the value of such measurements for non-anti-TNF biologics.

Frequency and type of drug-related side effects necessitating treatment discontinuation in the Swiss Inflammatory Bowel Disease Cohort.

BACKGROUND AND AIM: Systematic analyses of inflammatory bowel disease (IBD) drug-related side effects necessitating treatment cessation in large cohorts of patients with IBD are scarce. We aimed to assess the frequency and type of drug-related side effects requiring drug cessation in patients included in the Swiss IBD Cohort. PATIENTS AND METHODS: A retrospective review was performed of data from the Swiss IBD Cohort physician questionnaires documenting a treatment cessation for the following drug categories: aminosalicylates, topical and systemic steroids, thiopurines, methotrexate, tumor necrosis factor-antagonists, and calcineurin inhibitors (tacrolimus, cyclosporine). RESULTS: A total of 3192 patients were analyzed, of whom 1792 (56.1%) had Crohn's disease, 1322 (41.4%) had ulcerative colitis, and 78 (2.5%) had IBD unclassified. Of 3138 patients treated with IBD drugs, 2129 (67.8%) presented with one or several drug-related side effects necessitating drug cessation. We found a significant positive correlation between the number of concomitantly administered IBD drugs and the occurrence of side effects requiring drug cessation (P<0.001). Logistic regression modeling identified Crohn's disease diagnosis [odds ratio (OR)=1.361, P=0.017], presence of extraintestinal manifestations (OR=2.262, P<0.001), IBD-related surgery (OR=1.419, P=0.006), and the increasing number of concomitantly used IBD drugs [OR=2.007 (P<0.001) for two concomitantly used IBD drugs; OR=3.225 (P<0.001) for at least three concomitantly used IBD drugs] to be associated significantly with the occurrence of IBD drug-related adverse events that necessitated treatment cessation. CONCLUSION: Physicians should keep in mind that the number of concomitantly administered IBD drugs is the main risk factor for drug-related adverse events necessitating treatment cessation.

Alicaforsen, an Antisense Inhibitor of Intercellular Adhesion Molecule-1, in the Treatment for Left-Sided Ulcerative Colitis and Ulcerative Proctitis.

BACKGROUND: Data on the efficacy of intercellular adhesion molecule-1 antisense oligonucleotide alicaforsen in ulcerative colitis (UC) is inconsistent. METHODS: All patients, who had received at least one dose of alicaforsen, were analyzed retrospectively. Alicaforsen's efficacy was assessed in patients treated for left-sided UC and proctitis by comparing clinical and (if applicable) endoscopic disease activity before/after treatment. RESULTS: Twelve patients were treated for left-sided UC or proctitis. Eleven patients received a 6-week course of a once-daily 240 mg alicaforsen enema formulation. In 1 patient, treatment was discontinued, because it was found to be inefficient. Disease activity measured by the partial Mayo score and 6-point symptom score was significantly reduced after treatment (6.0 vs. 2.4, p = 0.011 and 3.7 vs. 1.4, p = 0.008). Faecal calprotectin showed a trend towards reduction (484.4 vs. 179.5 µg/g, p = 0.063). Clinical improvement was achieved in 10 patients (83.3%). In 7 patients, a relapse occurred (70%). Median duration of clinical improvement was 18.0 weeks (range 1-112). Three patients showed an ongoing improvement of >9 months. No adverse events were reported. CONCLUSIONS: A 6-week course of alicaforsen seemed to be safe and efficacious in inducing clinical improvement in patients with left-sided UC and proctitis. Prolonged clinical improvement was observed in many but not all patients.

Alicaforsen, an antisense inhibitor of ICAM-1, as treatment for chronic refractory pouchitis after proctocolectomy: A case series.

BACKGROUND AND AIMS: The published data about the efficacy of the intercellular adhesion molecule-1 (ICAM-1) antisense oligonucleotide termed alicaforsen in inflammatory bowel disease (IBD) is rather inconsistent. This case series analyzes its efficacy in chronic refractory pouchitis, after proctocolectomy. METHODS: We performed a retrospective analysis on all patients who had received at least one dose of alicaforsen for IBD at three referral centers in Switzerland. We assessed the drug's efficacy in patients treated for chronic refractory pouchitis, by comparing the clinical and/or endoscopic disease activity at baseline with a 2-3-month follow-up visit. RESULTS: We identified 22 patients who had received at least one dose. Among them, 13 patients were being treated for chronic refractory pouchitis. These patients had a median age of 38.0 years (95% CI 21.0-69.0) and five were female (38.5%). The median time since pouch surgery was 102.5 months (95% CI 16.0-288.0), with a median pouchitis duration of 16.0 months (95% CI 4.0-216.0). At 2-3 months after therapy, clinical and endoscopic disease activity was significantly reduced (stool frequency 9.0 versus 6.0, the Pouchitis Disease Activity Index (PDAI) clinical subscore was 4.0 versus 1.0, and the endoscopic disease activity was 4.0 versus 2.0). Clinical improvement was achieved in 11 out of 13 pouchitis patients (84.6%); however, a relapse was observed in nine of these patients (81.8%). The median time from clinical improvement to relapse was 16 weeks (95% CI 9.0-23.0). CONCLUSIONS: Alicaforsen seemed to be efficacious in inducing clinical and/or endoscopic improvement in chronic refractory pouchitis and may be a promising treatment alternative in those patients; however, given the high proportion of relapse, one 6-week course of alicaforsen may not be sufficient.

Monitoring disease activity and progression in Crohn's disease. A Swiss perspective on the IBD ahead 'optimised monitoring' recommendations.

BACKGROUND AND AIMS: The structured IBD Ahead 'Optimised Monitoring' programme was designed to obtain the opinion, insight and advice of gastroenterologists on optimising the monitoring of Crohn's disease activity in four settings: (1) assessment at diagnosis, (2) monitoring in symptomatic patients, (3) monitoring in asymptomatic patients, and (4) the postoperative follow-up. For each of these settings, four monitoring methods were discussed: (a) symptom assessment, (b) endoscopy, (c) laboratory markers, and (d) imaging. Based on literature search and expert opinion compiled during an international consensus meeting, recommendations were given to answer the question 'which diagnostic method, when, and how often'. The International IBD Ahead Expert Panel advised to tailor this guidance to the healthcare system and the special prerequisites of each country. The IBD Ahead Swiss National Steering Committee proposes best-practice recommendations adapted for Switzerland. METHODS: The IBD Ahead Steering Committee identified key questions and provided the Swiss Expert Panel with a structured literature research. The expert panel agreed on a set of statements. During an international expert meeting the consolidated outcome of the national meetings was merged into final statements agreed by the participating International and National Steering Committee members - the IBD Ahead 'Optimized Monitoring' Consensus. RESULTS: A systematic assessment of symptoms, endoscopy findings, and laboratory markers with special emphasis on faecal calprotectin is deemed necessary even in symptom-free patients. The choice of recommended imaging methods is adapted to the specific situation in Switzerland and highlights the importance of ultrasonography and magnetic resonance imaging besides endoscopy. CONCLUSION: The recommendations stress the importance of monitoring disease activity on a regular basis and by objective parameters, such as faecal calprotectin and endoscopy with detailed documentation of findings. Physicians should not rely on symptoms only and adapt the monitoring schedule and choice of options to individual situations.

Macrophages transmit potent proangiogenic effects of oxLDL in vitro and in vivo involving HIF-1α activation: a novel aspect of angiogenesis in atherosclerosis.

Neovascularization has been linked to the progression and vulnerability of atherosclerotic lesions. Angiogenesis is increased in lipid-rich plaque. Hypoxia-inducible factor alpha (HIF-1α) is a key transcriptional regulator responding to hypoxia and activating genes, which promote angiogenesis, among them vascular endothelial growth factor (VEGF). Oxidized low-density lipoprotein (oxLDL) is generated in lipid-rich plaque by oxidative stress. It triggers an inflammatory response and was traditionally thought to inhibit endothelial cells. New data, however, suggest that oxLDL can activate HIF-1α in monocytes in a hypoxia-independent fashion. We hypothesized that HIF-1α activation in monocyte-macrophages could transmit proangiogenic effects of oxLDL linking hyperlipidemia, inflammation, and angiogenesis in atherosclerosis. First, we examined the effect of oxLDL on HIF-1α and VEGF expression in monocyte-macrophages and on their proangiogenic effect on endothelial cells in vitro in a monocyte-macrophage/endothelial co-culture model. OxLDL strongly induced HIF-1α and VEGF in monocyte-macrophages and significantly increased tube formation in co-cultured endothelial cells. HIF-1α inhibition reversed this effect. Second, we demonstrated a direct proangiogenic effect of oxLDL in an in vivo angiogenesis assay. Again, HIF-1α inhibition abrogated the proangiogenic effect of oxLDL. Third, in a rabbit atherosclerosis model, we studied the effect of dietary lipid lowering on arterial HIF-1α and VEGF expression. The administration of low-lipid diet significantly reduced the expression of both HIF-1α and VEGF, resulting in decreased plaque neovascularization. Our data point to oxLDL as a proangiogenic agent linking hyperlipidemia, inflammation, and angiogenesis in atherosclerosis. This effect is dependent on macrophages and, at least in part, on the induction of the HIF-1α pathway.

Efficacy and safety of certolizumab pegol in an unselected crohn's disease population: 26-week data of the FACTS II survey.

BACKGROUND: Certolizumab pegol (Cimzia, CZP) was approved for the treatment of Crohn's disease (CD) patients in 2007 in Switzerland as the first country worldwide. This prospective phase IV study aimed to evaluate the efficacy and safety of CZP over 26 weeks in a multicenter cohort of practice-based patients. METHODS: Evaluation questionnaires at baseline, week 6, and week 26 were completed by gastroenterologists in hospitals and private practices. Adverse events were evaluated according to World Health Organization (WHO) guidelines. RESULTS: Sixty patients (38F/22M) were included; 53% had complicated disease (stricturing or penetrating), 45% had undergone prior CD-related surgery. All patients had prior exposure to systemic steroids, 96% to immunomodulators, 73% to infliximab, and 43% to adalimumab. A significant decrease of the Harvey-Bradshaw Index (HBI) was observed under CZP therapy (12.2 ± 4.9 at week 0 versus 6.3 ± 4.7 at week 6 and 6.7 ± 5.3 at week 26, both P < 0.001). Response and remission rates were 70% and 40% (week 6) and 67% and 36%, respectively (week 26). The complete perianal fistula closure rate was 36% at week 6 and 55% at week 26. The frequency of adverse drug reactions attributed to CZP was 5%. CZP was continued in 88% of patients beyond week 6 and in 67% beyond week 26. CONCLUSIONS: In a population of CD patients with predominantly complicated disease behavior, CZP proved to be effective in induction and maintenance of response and remission. This series provides the first evidence of CZP's effectiveness in perianal fistulizing CD in clinical practice.

Efficacy and safety of certolizumab pegol induction therapy in an unselected Crohn's disease population: results of the FACTS survey.

BACKGROUND: Switzerland was the first country to approve certolizumab pegol (Cimzia, CZP) for the treatment of patients with moderate to severe Crohn's disease (CD) in September 2007. This phase IV study aimed to evaluate the efficacy and safety of CZP in a Swiss multicenter cohort of practice-based patients. METHODS: Baseline and Week 6 evaluation questionnaires were sent to all Swiss gastroenterologists in hospitals and private practices. Disease activity was assessed with the Harvey-Bradshaw Index (HBI) and adverse events were evaluated according to WHO guidelines. RESULTS: Fifty patients (31 women, 19 men) were included; 56% had complicated disease (stricture or fistula) and 52% had undergone prior CD-related surgery. All patients had prior exposure to systemic steroids, 96% to immunomodulators, 78% to infliximab, and 50% to adalimumab. A significant decrease in HBI was observed at Week 6 (versus Week 0) following induction therapy with CZP 400 mg subcutaneously at Weeks 0, 2, and 4 (12.6 +/- 4.7 Week 0 versus 6.2 +/- 4.4 Week 6, P < 0.001). Response and remission rates at Week 6 were 54% and 40%, respectively. We identified 8/11 CD patients undergoing a 50% fistula response (P = 0.021). The frequency of adverse drug reactions attributed to CZP was 6%. CZP was continued in 80% of patients beyond Week 6. CONCLUSIONS: In a population of CD patients with complicated disease behavior, CZP induced a response and remission in 54% and 40% of patients, respectively. This series provides the first evidence of the effectiveness of CZP in perianal fistulizing CD.

Use of the abdominal rectus fascia as a nonvascularized allograft for abdominal wall closure after liver, intestinal, and multivisceral transplantation.

INTRODUCTION: Abdominal wall closure management has become an important challenge during recipient candidate selection, at the time of donor to recipient matching and during the planning of the surgical procedure for intestinal or multiorgan transplantation. Different strategies have been proposed to overcome the lack of abdominal domain: to reduce the graft size or to increase the abdominal domain. Based on the recent concept of using an acellular dermis matrix (Alloderm) and the availability of abdominal wall tissues from the same organ donor, we conceived the idea of using the fascia of the rectus muscle (FoRM) as a nonvascularized tissue allograft. MATERIALS AND METHODS: This is a retrospective report of a series of 16 recipients of FoRM as part of a liver, intestinal, or multiorgan transplant procedure performed between October 2004 and May 2008 at three different transplant centers. RESULTS: Of the 16 recipients of FoRM, all but one case was performed during their transplantation (four multivisceral, two modified multivisceral, three isolated intestine, and two livers). Five patients underwent a retransplant surgery (two livers, two multivisceral, and one isolated intestine). Abdominal wall infection was present in 7 of 16 cases. Nine patients are still alive. No deaths were related to wound infection. Long-term survival showed complete wound healing and only one ventral hernia. DISCUSSION: The use of a nonvascularized FoRM is a novel and simple surgical option to resolve complex abdominal wall defects in liver/intestinal/multivisceral transplant recipients when it can be covered with the recipient skin.

Regression of hepatic fibrosis after intestinal transplantation in total parenteral nutrition liver disease.

BACKGROUND & AIMS: Hepatic fibrosis may occur in patients with intestinal failure requiring total parenteral nutrition, leading to liver dysfunction necessitating combined intestinal and liver transplantation. The decision to perform combined transplantation as opposed to an isolated intestinal transplant is based on the presence of hyperbilirubinemia, portal hypertension, and advanced hepatic fibrosis. METHODS: We identified 4 patients who underwent isolated intestinal transplantation having significant liver fibrosis. A novel image analysis technique was applied to serial liver biopsies to more precisely quantitate posttransplantation fibrosis regression separately within both portal and centrilobular areas. RESULTS: All patients were found to have significant portal and centrilobular fibrosis regression, which occurred more rapidly in the former. Two patients had improvement in fibrosis despite infections and continuation of total parenteral nutrition, suggesting that hepatic fibrosis associated with intestinal failure may in part be related to adequate anatomic and functional bowel length. CONCLUSIONS: Significant hepatic fibrosis and liver dysfunction may regress after intestinal transplantation and fibrosis regresses more rapidly in portal areas. This suggests that some patients with intestinal failure and associated liver disease may safely undergo isolated intestinal transplant without the need for concurrent liver transplantation and its attendant higher morbidity and mortality.

Pretransplant immunomodulation of highly sensitized small bowel transplant candidates with intravenous immune globulin.

Presence of preformed lymphocytotoxic antibodies may represent a barrier to isolated intestinal transplantation (IITx). We developed an intravenous immunoglobulins (IVIg) based desensitization protocol for candidates with high panel-reactive antibodies (PRA). Six patients with a mean PRA of 72+/-22% were included in a four-level (L) protocol with escalating doses of IVIg (L1, L2), addition of mycophenolate mofetil (MMF) or plasmapheresis (L3); and anti-CD20 (Rituximab) (L4). Four of six candidates improved their PRAs (from a mean of 66.2% to 25.5%; P=0.01) and were successfully transplanted. At a mean follow-up of 8 months, number and severity of rejection episodes of protocol patients did not differ from patients with low PRA transplanted during the same period. These data support the use of IVIg to desensitize patients waiting for IITx. It increases the applicability of IITx, and reduces the waiting time and mortality on the waiting list with outcomes comparable to nonsensitized recipients.

Vascular endothelial growth factor regulates reendothelialization and neointima formation in a mouse model of arterial injury.

BACKGROUND: The rate of reendothelialization is critical in neointima formation after arterial injury. Vascular endothelial growth factor (VEGF), a potent endothelial mitogen, has been advocated for accelerating endothelial repair and preventing intimal hyperplasia after percutaneous coronary interventions. However, the precise mechanism of action of VEGF treatment and the physiologic role of endogenous VEGF after arterial injury are not well described. To better understand the role of VEGF in arterial repair, we overexpressed both VEGF and a soluble, chimeric VEGF receptor (VEGF-trap), which binds free VEGF with high affinity, in a mouse model of arterial injury. METHODS AND RESULTS: Four groups of C57BL/6 mice underwent denuding endothelial injury 1 day after systemic injection of recombinant adenovirus expressing (1) VEGF, (2) VEGF-trap, (3) VEGF plus VEGF-trap, or (4) control adenovirus. Circulating levels of adenovirus-encoded proteins were significantly elevated after gene transfer. VEGF overexpression accelerated reendothelialization and increased luminal endothelial cell proliferation 2 weeks after arterial injury (P<0.05), resulting in decreased neointima formation at 4 weeks compared with control (P<0.01). Cotreatment with VEGF-trap completely sequestered free VEGF and abrogated the beneficial effect of VEGF overexpression. Interestingly, sequestration of endogenous VEGF by VEGF-trap overexpression alone also led to delayed reendothelialization at 2 weeks (P<0.01) and increased neointima formation at 4 weeks (P<0.01). CONCLUSIONS: VEGF overexpression accelerated endothelial repair and inhibited neointima formation after arterial injury. Conversely, sequestration of exogenous and/or endogenous VEGF by VEGF-trap delayed reendothelialization and significantly increased neointima size. This demonstrates the therapeutic potential of VEGF but also emphasizes the important physiologic role of endogenous VEGF in vascular repair.

Caspase-3 and tissue factor expression in lipid-rich plaque macrophages: evidence for apoptosis as link between inflammation and atherothrombosis.

BACKGROUND: Macrophages associated with arterial wall lipid deposition contribute to inflammatory processes. Tissue factor (TF) has been implicated in the thrombogenicity of atherosclerotic plaques. Intimal cells undergoing apoptosis have been postulated as a source for TF. However, there is only limited knowledge of cell type, plaque component, and conditions associated with TF expression and apoptosis. We examined the hypothesis that macrophages exposed to conditions of lipid-rich plaque undergo apoptosis and express TF. METHODS AND RESULTS: In human carotid (n=15) and coronary (n=6) atherosclerotic plaques, TF and caspase-3 mRNA and protein expression (evaluated by in situ hybridization and immunohistochemistry) were increased significantly in lipid-rich compared with fibrous plaque components (P<0.01) and correlated with high macrophage content (P<0.05). Double-labeling studies demonstrated colocalization of TF and active caspase-3. In hyperlipidemic mice, expression of TF and active caspase-3 was observed simultaneously and colocalized in neointimal macrophages after arterial injury. In neointima of normolipidemic animals, TF and active caspase-3 were absent after arterial injury. In monocytes cultured in the presence of oxidized LDL, strong induction and colocalization of TF and active caspase-3 were found compared with baseline (P<0.05). Both antigens were significantly decreased after cotreatment with a caspase inhibitor (P<0.05) and were absent in untreated control cells. CONCLUSIONS: The expression of TF as the primary cell-associated activator of the coagulation pathway proves to be closely related to macrophages undergoing apoptosis in conditions of lipid-rich plaque, pointing to a key role of lipid content and inflammatory cell viability in determining plaque thrombogenicity.

Effect of vascular endothelial growth factor on functional recovery after hepatectomy in lean and obese mice.

BACKGROUND/AIMS: Liver regeneration is dependent upon coordinated proliferation of hepatocytes and endothelial cells. Vascular endothelial growth factor (VEGF) promotes angiogenesis. Hepatic steatosis delays regeneration and increases liver resection morbidity. We hypothesized that VEGF overexpression stimulates hepatic regeneration. METHODS: Recombinant adenovirus expressing human VEGF165 or adenovirus control-vector (LacZ) were administered before 2/3 hepatectomy in lean and ob/ob mice. Galactose elimination capacity, a quantitative liver function test, was repeatedly measured before and after hepatectomy. Expression of VEGF receptors (flt1, flk1), endoglin and hypoxia inducible factor-1alpha (HIF-1alpha) was assessed by quantitative RT-PCR and for endoglin also by immunohistochemistry. RESULTS: After 2/3 hepatectomy, VEGF gene transfer increased galactose elimination capacity in lean and ob/ob mice. HIF-1alpha, endoglin and VEGF receptor mRNA increased during regeneration in lean but not in obese mice. Staining of endothelial cells by endoglin immunohistochemistry returned to baseline reactivity in lean mice by day 6 and remained decreased in ob/ob mice. VEGF treatment decreased HIF-1alpha and increased flk1 response in lean mice. CONCLUSIONS: Hepatic resection elicits an angiogenic response in the remnant liver, which is impaired in case of steatosis. Adenovirus-mediated transfer of VEGF hastens functional hepatic recovery in lean, and more importantly also, in obese mice after partial hepatectomy.

Decreased reendothelialization and increased neointima formation with endostatin overexpression in a mouse model of arterial injury.

BACKGROUND: Impaired endothelial regeneration contributes to arterial lesion formation. Endostatin is a specific inhibitor of endothelial cell growth and induces endothelial cell apoptosis. We examined the effect of endostatin overexpression on reendothelialization and neointima formation in a mouse model of arterial injury. METHODS AND RESULTS: Mice underwent femoral arterial denudation and received recombinant adenovirus, expressing either murine endostatin (n=19) or control adenoviral vector (n=12), by jugular vein injection. Endostatin gene transfer resulted in high serum levels of endostatin. Strong adenoviral gene expression of beta-galactosidase-expressing control vector was detected in liver tissue and was absent in the injured arterial wall at 1 week. Deposits of endostatin protein were detected along the denuded arterial wall and were not seen in the noninjured contralateral artery at 1 week. Endostatin deposits were also absent in the injured artery of control vector-treated animals. Overexpression of endostatin led to decreased reendothelialization and increased apoptosis of luminal endothelial cells 2 and 4 weeks after arterial injury (P<0.05). In addition, endostatin overexpression resulted in increased neointima formation (P<0.05). Endothelial apoptosis and neointima area correlated positively with endostatin serum levels, whereas the degree of reendothelialization correlated negatively with endostatin serum levels (P<0.05). Furthermore, poor reendothelialization correlated with increased neointima formation (P<0.05). CONCLUSIONS: In summary, decreased reendothelialization and enhanced endothelial apoptosis, in response to endostatin overexpression, were associated with increased neointima formation. These findings demonstrate that high serum levels of endostatin are capable of inhibiting endothelial regeneration and promoting arterial lesion growth in conditions of endothelial injury.