Role of thrombotic vascular risk factors in inflammatory bowel disease

Therapeutic strategies of thromboembolic events in patients with inflammatory bowel diseases: Two case reports

RATIONALE

Inflammatory bowel disease (IBD), including Crohn disease (CD) and ulcerative colitis (UC), is characterized by chronic inflammatory condition and immunological abnormalities, which probably develop into venous thromboembolic events (VTEs). VTE in IBD patients mostly occurs at deep venous thrombosis (DVT) and pulmonary embolism (PE). The complications are extremely important in clinical practice considering the high mortality rate. Hence, an early diagnosis of IBD and the control of complications play an important role in therapy of thromboembolic events (TEEs).

PATIENT CONCERNS

Case 1 was a 31-year-old man with chronic UC who presented with signs of thromboembolism. Case 2 was a 43-year-old woman with CD complicated by fistulas.

DIAGNOSES

Computed tomography (CT) and digital subtraction angiography (DSA) of the patient (case 1) suggested a thrombus in cerebral vein. The patient (case 2) developed acute ischemia of her right arm; B ultrasonography revealed a thrombus in the distal of the right subclavian artery accompanied by stenosis.

INTERVENTIONS

To lower blood viscosity and overcome the risk of deep thrombosis, the patient (case 1) was treated with a combination of low-molecular-weight heparin and dextran as anticoagulation. For the patient (case 2), anticoagulation treatment with 75 mg qd clopidogrel (plavix) and 1.25 mg qd warfarin was performed.

OUTCOMES

In both patients, no further TEE occurred during follow-up 1 year and one and a half years, respectively.

LESSONS

It is important to pay attention to IBD patients especially those with high coagulation state.

Budd-Chiari syndrome: a rare and life-threatening complication of Crohn's disease

Budd-Chiari syndrome (BCS) is characterised by obstruction of hepatic venous outflow and may be triggered by the prothrombotic state associated with inflammatory bowel disease (IBD). We reported a case of Crohn's disease (CD) that presented with anasarca, ascites, symptomatic hepatomegaly, elevated liver enzymes, increased prothrombin time and low albumin. Oesophagogastroduodenoscopy and colonoscopy confirmed active CD. Abdominal CT showed hepatic vein thrombosis. Liver biopsy revealed severe perivenular sinusoidal dilation with areas of hepatocyte dropout, bands of hepatocyte atrophy and centrizonal fibrosis, suggestive of BCS. The patient was treated with steroids for CD and systemic anticoagulants for BCS. His liver function and enzymes normalised, and he reported symptomatic improvement. The precise mechanism responsible for increased hypercoagulability in IBD remains unclear. Early recognition and treatment for possible thrombotic complications of CD is critical to prevent potentially fatal events like pulmonary embolism or liver failure.

Overview of venous thrombosis in inflammatory bowel disease

Thrombosis in inflammatory bowel disease (IBD) is an increasingly noted extraintestinal manifestation with high morbidity and mortality. While controlling the activity of the disease with the appropriate therapy, thromboembolism prophylaxis should be applied to all patients. All common risk factors for thromboembolism are also valid for patients with IBD; however, it is clear that uncontrolled disease and hospitalization are major disease-specific risk factors for venous thromboembolism in patients with IBD. Pharmacological thromboprophylaxis with currently available anticoagulants does not increase the risk of further bleeding in patients with IBD with mild-to-moderate bleeding. In severe bleeding or with increased risk of further bleeding due to other comorbid conditions, thromboprophylaxy with mechanical methods should be the treatment option. Whether thrombosis is the cause or the result of intestinal inflammation remains to be elucidated, and other issues in the etiology, such as the role of intestinal flora in thrombosis pathogenesis, will be the subject of future studies.

Thrombosis in inflammatory bowel diseases: what's the link?

Inflammatory bowel disease affects more than 2 million people in Europe, with almost 20% of patients being diagnosed in pediatric age. Patients with inflammatory bowel disease are at increased risk of thromboembolic complications which may affect patients’ morbidity and mortality. The risk of the most common thromboembolic events, such as deep venous thrombosis and pulmonary embolism, are estimated to be three-fold increased compared to controls, but many other districts can be affected. Moreover, patients with ulcerative colitis and Crohn’s disease experience thromboembolic events at a younger age compared to general population. Many factors have been investigated as determinants of the pro-thrombotic tendency such as acquired risk factors or genetic and immune abnormalities, but a unique cause has not been found. Many efforts have been focused on the study of abnormalities in the coagulation cascade, its natural inhibitors and the fibrinolytic system components and both quantitative and qualitative alterations have been demonstrated. Recently the role of platelets and microvascular endothelium has been reviewed, as the possible link between the inflammatory and hemostatic process.

Postoperative portomesenteric venous thrombosis: lessons learned from 1,069 consecutive laparoscopic colorectal resections

BACKGROUND

Portomesenteric venous thrombosis (PVT) is a known complication after open and laparoscopic colorectal (LCR) surgery. Risk factors and the prognosis of PVT have been poorly described.

METHODS

This study is a retrospective analysis of a prospectively collected database. Patients with new-onset postoperative abdominal pain were evaluated with a computed tomography scan of the abdomen. Patients found to have PVT were analyzed. A multivariate analysis was performed to identify predictors of PVT.

RESULTS

A total of 1,069 patients undergoing LCR surgery for inflammatory bowel disease (IBD) or nonmetastatic cancer between June 2002 and June 2012 were included. Altogether, 37 (3.5 %) patients experienced symptomatic postoperative PVT. On univariate analysis, IBD (p < 0.001), ulcerative colitis (p = 0.016), preoperative therapy with steroids (p = 0.008), operative time ≥220 min (p = 0.004), total proctocolectomy (TPC) (p < 0.001), ileoanal pouch anastomosis (p = 0.006), and postoperative intraabdominal septic complications (p < 0.001) were found to be significant risk factors. By multivariate analysis, TPC (p = 0.026) and postoperative intraabdominal septic complications (p < 0.001) were independent predictors of PVT. In the PVT group, postoperative length of stay was longer (14.8 vs. 7.4 days, p < 0.001). Of the patients evaluated with a hematologic workup, 72.7 % were found to have a hypercoagulable condition. All patients were managed with oral anticoagulation for at least 6 months. No death or complications related to PVT occurred.

CONCLUSIONS

PVT is a potentially serious complication that is more likely to occur after TPC and in the presence of postoperative intraabdominal septic complications, particularly in patients with a coagulation disorder. Prompt diagnosis and treatment with oral anticoagulation are recommended to avoid long-term sequelae.

Inflammatory bowel disease: epidemiology, pathology and risk factors for hypercoagulability

Hypercoagulability observed in patients with inflammatory bowel diseases (IBD) may lead to thromboembolic events (TE), which affect the venous and arterial systems alike and are an important factor in patients' morbidity and mortality. The risk of TE in IBD patients has been demonstrated to be approximately three-fold higher as compared to the general population. The pathogenesis of thrombosis in IBD patients is multifactorial and not fully explained. The most commonly listed factors include genetic and immune abnormalities, disequilibrium between procoagulant and anticoagulant factors, although recently, the role of endothelial damage as an IBD-triggering factor is underlined. Several studies report that the levels of some coagulation enzymes, including fibrinogen, factors V, VII, VIII, active factor XI, tissue factor, prothrombin fragment 1 + 2 and the thrombin-antithrombin complex, are altered in IBD patients. It has been demonstrated that there is a significant decrease of tissue plasminogen activator level, a marked increase of plasminogen activator inhibitor type 1 and thrombin-activable fibrinolysis inhibitor, a significantly lower level of antithrombin III and tissue factor pathway inhibitor. IBD patients have been also observed to produce an increased amount of various anticoagulant antibodies. Hyperhomocysteinemia, which is a potential risk factor for TE was also observed in some IBD patients. Further studies are necessary to assess the role of coagulation abnormalities in IBD etiology and to determine indications for thromboprophylactic treatment in patients at high risk of developing TE.

Venous and arterial disease in inflammatory bowel disease

Awareness is increasing that risk of venous thromboembolism and development of atherosclerosis is elevated in patients with some chronic inflammatory diseases. This review aimed to examine the risk of vascular disease in patients with inflammatory bowel disease (IBD) and to identify potential pathogenic mechanisms and therapeutic approaches. An extensive literature search was conducted using MEDLINE database, Cochrane Library and international conference abstracts for studies pertaining to venous and arterial thromboembolism in adult IBD patients. There is a 1.1-3.6 fold risk of venothromboembolism in IBD, affecting 0.55-6.15% of patients. Risks are increased during a flare or with chronically active inflammation. Evidence is building that there may be a modestly increased risk of arterial disease overall, despite evidence that traditional risk factors may be reduced. Multiple pathogenic factors have been identified including endothelial dysfunction, inflammation-mediated calcium deposition in the media of arteries, hyperhomocysteinemia, platelet activation, and altered coagulation and fibrinolysis. The key to active and preventive therapy is to effectively treat inflammation. Recommendations for prophylaxis of venothromboembolism have followed guidelines where they exist and have been extrapolated from studies of other at-risk conditions, as have those for arterial disease, where screening for risk factors and actively treating abnormalities is encouraged. In conclusion, patients with IBD are at considerably increased risk of venothromboembolism and probably of arterial disease, in particular mesenteric ischemia and ischemic heart disease. Increased penetration of gaps between this knowledge and clinical therapeutic action to prevent thromboembolic events into IBD clinical practice is needed.

Protective effect of magnesium lithospermate B against dextran sodiumsulfate induced ulcerative colitis in mice

Anti-platelet drugs have been used to treat inflammatory bowel disease. In this study, we observed the therapeutic effects of magnesium lithospermate B, a main component of salvianolate, on colitis induced by dextran sodiumsulfate (DSS). Colitis was induced by 5% DSS oral administration in BALB/C male mice. Magnesium lithospermate B (60-240mg/kg) was given by subcutaneous injection for 2 weeks. Then, mice were sacrificed; serum and colon tissues were collected for biomarker assay, histological examination, immunohistochemical study and real-time quantitative polymerase chain reaction. DSS induced gross bleeding, inflammation, crypt damage and mucosal damage in colon. Treatment with magnesium lithospermate B could reduce colon inflammation induced by DSS. Magnesium lithospermate B could reverse the high CD40/CD40L expression and hypercoagulable state induced by DSS in colon. This study showed that magnesium lithospermate B could be used to treat colitis. The protective effects of magnesium lithospermate B may be due to its effects on CD40/CD40L expression and blood clotting status.

Venous thrombotic events in hospitalized children and adolescents with inflammatory bowel disease

BACKGROUND

Adults with inflammatory bowel disease (IBD) have an increased risk of venous thrombotic events (TEs). We sought to evaluate the risk for TE in children and adolescents with IBD using a large population database.

METHODS

The triennial Healthcare Cost and Utilization Project Kids' Inpatient Database was used in a retrospective cohort study of hospitalized children in the United States across 1997, 2000, 2003, 2006, and 2009. Billing codes were used to identify discharges with Crohn disease, ulcerative colitis, pulmonary embolism, deep vein thrombosis, thrombophlebitis, thrombosis of intracranial venous sinus, Budd-Chiari syndrome, and portal vein thrombosis. A logistic regression model was fitted to quantify the increased risk of TE in children with IBD, while adjusting for other risk factors of thrombosis.

RESULTS

The total weighted number of pediatric discharges was 7,448,292, and 68,394 (0.92%) were identified with IBD. The incidence of any TE in a hospitalized child or adolescent with IBD was 117.9/10,000 with a relative risk (95% confidence interval) of 2.36 (2.15-2.58). The adjusted odds ratio for any TE in a patient with IBD without surgery was 1.22 (1.08-1.36). Risk factors for TE among patients with IBD include older age, central venous catheter, parenteral nutrition, and an identified hypercoagulable condition. There is an increasing trend of TE in both the IBD and non-IBD patients.

CONCLUSIONS

Hospitalized children and adolescents with IBD are at increased risk for TE. Conservative methods of TE prevention including hydration, mobilization, or pneumatic devices should be considered in hospitalized patients with IBD.

B-vitamin deficiency is protective against DSS-induced colitis in mice

Vitamin deficiencies are common in patients with inflammatory bowel disease (IBD). Homocysteine (Hcys) is a thrombogenic amino acid produced from methionine (Met), and its increase in patients with IBD indicates a disruption of Met metabolism; however, the role of Hcys and Met metabolism in IBD is not well understood. We hypothesized that disrupted Met metabolism from a B-vitamin-deficient diet would exacerbate experimental colitis. Mice were fed a B(6)-B(12)-deficient or control diet for 2 wk and then treated with dextran sodium sulfate (DSS) to induce colitis. We monitored disease activity during DSS treatment and collected plasma and tissue for analysis of inflammatory tissue injury and Met metabolites. We also quantified Met cycle activity by measurements of in vivo Met kinetics using [1-(13)C-methyl-(2)H(3)]methionine infusion in similarly treated mice. Unexpectedly, we found that mice given the B-vitamin-deficient diet had improved clinical outcomes, including increased survival, weight maintenance, and reduced disease scores. We also found lower histological disease activity and proinflammatory gene expression (TNF-α and inducible nitric oxide synthase) in the colon in deficient-diet mice. Metabolomic analysis showed evidence that these effects were associated with deficient B(6), as markers of B(12) function were only mildly altered. In vivo methionine kinetics corroborated these results, showing that the deficient diet suppressed transsulfuration but increased remethylation. Our findings suggest that disrupted Met metabolism attributable to B(6) deficiency reduces the inflammatory response and disease activity in DSS-challenged mice. These results warrant further human clinical studies to determine whether B(6) deficiency and elevated Hcys in patients with IBD contribute to disease pathobiology.

Mortality in inflammatory bowel disease in the Netherlands 1991-2002: results of a population-based study: the IBD South-Limburg cohort

BACKGROUND

The aim was to evaluate overall and disease-specific mortality in a population-based inflammatory bowel disease (IBD) cohort in the Netherlands, as well as risk factors for mortality.

METHODS

IBD patients diagnosed between 1 January 1991 and 1 January 2003 were included. Standardized mortality ratios (SMRs) were calculated overall and with regard to causes of death, gender, as well as age, phenotype, smoking status at diagnosis, and medication use.

RESULTS

At the censoring date, 72 out of 1187 patients had died (21 Crohn's disease [CD], 47 ulcerative colitis [UC], and 4 indeterminate colitis [IC] patients). The SMR (95% confidence interval [CI]) was 1.1 (0.7-1.6) for CD, 0.9 (0.7-1.2) for UC and 0.7 (0.2-1.7) for IC. Disease-specific mortality risk was significantly increased for gastrointestinal (GI) causes of death both in CD (SMR 7.5, 95% CI: 2.8-16.4) and UC (SMR 3.4, 95% CI: 1.4-7.0); in CD patients, especially in patients <40 years of age at diagnosis. For UC, an increased SMR was noted in female patients and in patients <19 years and >80 years at diagnosis. In contrast, UC patients had a decreased mortality risk from cancer (SMR 0.5, 95% CI; 0.2-0.9).

CONCLUSIONS

In this population-based IBD study, mortality in CD, UC, and IC was comparable to the background population. The increased mortality risk for GI causes might reflect complicated disease course, with young and elderly patients at diagnosis needing intensive follow-up. Caution in interpreting the finding on mortality risk from cancer is needed as follow-up was probably to short to observe IBD-related cancers.

Thrombophilic Risk Factors in Patients With Inflammatory Bowel Disease

Background

Inflammatory bowel disease (IBD) patients have an increased risk for thromboembolism. The aim of this study was to assess the presence of thrombophilic risk factors in IBD patients and to assess the associations of these factors with disease activity.

Methods

Forty-eight patients with IBD (24 ulcerative colitis, 24 Crohn’s disease) and 40 matched healthy control individuals were enrolled. In addition to routine biochemical analysis, fasting blood samples were studied for prothrombin time (PT), activated partial thromboplastin time (aPTT), fibrinogen, protein-C, protein-S, antithrombin III, factor VII, factor VIII, D-dimer, vitamin B₁₂, folic acid and homocysteine.

Results

Levels of erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), fibrinogen, D-dimer and the number of platelets were significantly higher in patients with IBD. When compared to control group, in patients with Crohn’s disease serum homocystein levels were significantly higher (p = 0.025) while serum folic acid levels were significantly lower (p < 0.019). Levels of fibrinogen, D-dimer, protein C, factor VIII, total homocystein and the number of platelets were found to be significantly higher in Crohn’s disease patients who were in active period of the disease.

Conclusions

Thrombophilic defects are multifactorial and might be frequently seen in IBD patients. They might contribute to thrombotic complications of this disease.

Pulmonary abnormalities in inflammatory bowel disease

Extraintestinal manifestations of inflammatory bowel disease (IBD) is a common clinical problem affecting up to half of all IBD patients; pulmonary disease, however, ranks among less common extraintestinal manifestations of IBD. Pulmonary disease in patients with IBD is most frequently drug induced due to treatment with sulfasalazine or mesalamine leading to eosinophilic pneumonia and fibrosing alveolitis or due to treatment with methotrexate leading to pneumonitis. Recently, various opportunistic infections have been shown to be a further important cause of pulmonary abnormalities in those IBD patients who are treated with immunosuppressants such as anti TNF-α monoclonal antibodies, methotrexate, azathioprine or calcineurin antagonists. In not drug related pulmonary disease a wide spectrum of disease entities ranging from small and large airway dysfunction to obstructive and interstitial lung disorders exist. Patients with lung disorders and inflammatory bowel disease should be evaluated for drug-induced lung disease and opportunistic infections prior to considering pulmonary disease as an extraintestinal manifestation of inflammatory bowel disease.

Portal vein thrombi after ileal pouch-anal anastomosis: its incidence and association with pouchitis

PURPOSE

Portal vein thrombi (PVT) have recently been linked to ileal pouch-anal anastomosis (IPAA). We assessed the rate of PVT in patients who underwent IPAA and attempted to identify the associated features.

METHODS

We reviewed all patients who underwent IPAA at our hospital between 1997 and 2002, noting demographic, operative, and clinical data. Computed tomography (CT) scans were independently re-reviewed by two radiologists blinded to patient data. Scans were designated as positive, negative, or indeterminate for PVT.

RESULTS

A total of 112 patients underwent IPAA for ulcerative colitis, 28 (25%) of whom had a CT scan done within 8 weeks postoperatively. The indications for CT included prolonged ileus (32.1%), abdominal pain (28.6%), and fever (17.9%). On examining the CT scans, 39% were positive, 14% were indeterminate, and 46% were negative for PVT. There was no association between PVT and pelvic sepsis. Within a mean follow-up of 36.2 months, 15.4% patients without PVT had suffered pouchitis compared with 25% of those with indeterminate scans and 45.5% of those with PVT.

CONCLUSIONS

Portal vein thrombi are a common finding in the subset of patients who require a CT scan after IPAA. Patients who suffer PVT have a higher incidence of postoperative pouchitis. Thus a prospective evaluation of the risk of PVT and its association with pouchitis is warranted.

Systemic thromboembolism in inflammatory bowel disease: mechanisms and clinical applications

Systemic thromboembolism is an extraintestinal manifestation of inflammatory bowel disease (IBD), and an important cause of patient morbidity and mortality. The underlying basis for the hypercoagulable state in IBD is complex, and involves altered activity of all three components that govern hemostasis: platelets, fibrinolysis, and the coagulation cascade. Currently, there are no distinct guidelines for treating or preventing thromboembolic (TE) events in IBD patients compared with the general population. However, the prothrombotic state in IBD stems, at least in part, from several modifiable factors, such as hyperhomocysteinemia and an active inflammatory state. In this review we summarize the mechanisms that favor thrombosis in IBD, and the principles that need to be applied for the primary and secondary prevention of TE in this selected group of patients.

Therapy insight: Vascular complications in patients with inflammatory bowel disease

Inflammatory bowel disease (IBD) is associated with an increased risk of vascular complications. The most important of these complications are arterial and venous thromboembolism, which represent a significant cause of morbidity and mortality in IBD patients. Recent data suggest that thromboembolism is a disease-specific extraintestinal manifestation of IBD. The most common thrombotic manifestations in IBD are deep vein thrombosis of the leg and pulmonary emboli. It has been suggested that disease activity and the extent of colonic localization are correlated with the risk of developing thromboembolism. The occurrence of thrombosis in patients with IBD is partially attributed to the existing hypercoagulable state in IBD. Both coagulation and fibrinolysis are activated in patients with IBD; this is especially true for those with active disease. The most common risk factors for thrombophilia in IBD patients with venous thromboembolism are Leiden mutation in the gene encoding factor V, hyperhomocysteinemia, and antiphospholipid antibodies. The main genetic defects that have been established as risk factors for venous thrombosis are rather uncommon in IBD, but when present increase the risk of thromboembolism. Screening for coagulation defects seems justified only in IBD patients with a history of thrombosis or a family history of venous thromboembolic events. Antithrombotic treatment of IBD patients with venous thromboembolism is similar to that of thrombotic non-IBD patients.

Prevalence of hyperhomocysteinaemia, activated protein C resistance and prothrombin gene mutation in inflammatory bowel disease

BACKGROUND

Thromboembolic disease is a significant cause of morbidity and mortality in patients with inflammatory bowel disease (IBD). A hypercoagulable state exists in IBD that may involve many components of haemostasis and is closely linked to the disease pathogenesis. It has been proposed that microvascular thrombosis and infarction may trigger the underlying inflammatory process.

AIM

To determine the prevalence of prothrombotic factors including hyperhomocysteinaemia, activated protein C (APC) resistance and prothrombin gene mutations as well as vitamin levels in the local IBD population.

METHOD

A total of 68 patients (37 men and 31 women) attending the IBD clinic were enrolled into the study. Citrated and ethylenediamine tetraacetic acid blood samples were collected from all patients as well as from 30 controls. Homocysteine levels were measured using the IMX immunoassay. APC resistance was measured using an unmodified activated partial thromboplastin time-based clotting assay. Prothrombin mutations were determined using polymerase chain reaction with the HB-gene factor II detection system.

RESULTS

Mean homocysteine levels were significantly higher and APC resistance ratios significantly lower in IBD patients compared with controls. No significant difference was detected between patients with ulcerative colitis or Crohn's disease. There was no significant increase in the incidence of prothrombin mutation in IBD patients. IBD patients had lower vitamin B12 and higher serum folate levels than controls.

CONCLUSION

High homocysteine and high serum folate may be associated with low vitamin B12 levels in IBD patients. We did not find any association between a low APC ratio and the factor V Leiden mutation or high factor VIII levels. Both hyperhomocysteinaemia and a low APC ratio may contribute to an increased risk of thromboembolic disease in IBD patients.

Pulmonary manifestations of inflammatory bowel disease

Extraintestinal manifestations of both Crohn's disease and ulcerative colitis (UC) have been well described, although pulmonary findings are often overlooked. We summarize the experience of more than 400 cases of pulmonary manifestations of inflammatory bowel disease (IBD). These manifestations will be categorized by disease mechanism into drug-induced disease, anatomic disease, over-lap syndromes, autoimmune disease, physiologic consequences of IBD, pulmonary function test abnormalities, and nonspecific lung disease. We intend to provide the clinician with a practical working update on the spectrum of pulmonary dysfunction associated with IBD.

Effects of chronic inflammatory bowel diseases on left ventricular structure and function: a study protocol

BACKGROUND

Experimental evidences suggest an increased collagen deposition in inflammatory bowel diseases (IBD). In particular, large amounts of collagen type I, III and V have been described and correlated to the development of intestinal fibrotic lesions. No information has been available until now about the possible increased collagen deposition far from the main target organ. In the hypothesis that chronic inflammation and increased collagen metabolism are reflected also in the systemic circulation, we aimed this study to evaluate the effects on left ventricular wall structure by assessing splancnic and systemic collagen metabolism (procollagen III assay), deposition (ultrasonic tissue characterization), and cardiac function (echocardiography) in patients with different long standing history of IBD, before and after surgery.

METHODS

Thirty patients affected by active IBD, 15 with Crohn and 15 with Ulcerative Colitis, submitted to surgery will be enrolled in the study in a double blind fashion. They will be studied before the surgical operation and 6, 12 months after surgery. A control group of 15 healthy age and gender-matched subjects will also be studied. At each interval blood samples will be collected in order to assess the collagen metabolism; a transthoracic echocardiogram will be recorded for the subsequent determination of cardiac function and collagen deposition.

DISCUSSION

From this study protocol we expect additional information about the association between IBD and cardiovascular disorders; in particular to address the question if chronic inflammation, through the altered collagen metabolism, could affect left ventricular structure and function in a manner directly related to the estimated duration of the disease.

Increased levels of lipoprotein (a) in Crohn's disease: a relation to thrombosis?

OBJECTIVE

Lipoprotein (a) is recognized as a risk factor for arterial and venous thrombosis, a property that might be related to its structural similarity to plasminogen. Since patients with inflammatory bowel disease frequently suffer from thromboembolic events, we studied the role of lipoprotein (a) in conjunction with lipids and apolipoproteins in Greek patients with ulcerative colitis and Crohn's disease.

METHODS

Lipoprotein (a), total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, triglycerides, apolipoprotein A-1 and apolipoprotein B-100 were determined in sera from 129 consecutive fasting Greek patients with inflammatory bowel disease (66 with ulcerative colitis and 63 with Crohn's disease) and from 66 matched healthy controls.

RESULTS

In Crohn's disease patients, the mean serum lipoprotein (a) level was significantly higher than in control patients (41.2 mg/dl vs 22.9 mg/dl; P = 0.005). Mean apolipoprotein A-1 and apolipoprotein B-100 levels were significantly lower in Crohn's disease patients than in the controls. In ulcerative colitis patients the mean levels of lipoprotein (a) and apolipoprotein A-1 were not significantly different to the controls, but the levels of apolipoprotein B-100 were significantly lower. Raised levels of lipoprotein (a) of > 30 mg/dl were found in 29 Crohn's disease patients (46%), 15 ulcerative colitis patients (23%) and 11 control patients (17%). Patients with active Crohn's disease had significantly higher mean lipoprotein (a) and lower apolipoprotein A-1 than patients with non-active disease.

CONCLUSIONS

Our results suggest that Crohn's disease patients have different lipoprotein (a) and apolipoprotein patterns compared to ulcerative colitis patients and healthy controls. These changes in Crohn's disease patients may possibly expose them to a higher risk of thrombosis.