Hepatobiliary manifestations of inflammatory bowel disease

Cutaneous Manifestations of Crohn Disease

Awareness of the extraintestinal manifestations of Crohn disease is increasing in dermatology and gastroenterology, with enhanced identification of entities that range from granulomatous diseases recapitulating the underlying inflammatory bowel disease to reactive conditions and associated dermatoses. In this review, the underlying etiopathology of Crohn disease is discussed, and how this mirrors certain skin manifestations that present in a subset of patients is explored. The array of extraintestinal manifestations that do not share a similar pathology, but which are often seen in association with inflammatory bowel disease, is also discussed. Treatment and pathogenetic mechanisms, where available, are discussed.

Pediatric ulcerative colitis associated with autoimmune diseases: a distinct form of inflammatory bowel disease?

BACKGROUND

The pathogenesis of inflammatory bowel disease (IBD) is multifactorial, with some patients presenting additional autoimmune symptoms. Inflammatory colitis associated with autoimmune (AI) liver disease appears to have clinical features different from those of "classical" ulcerative colitis (CUC). The aim of this study was to describe these features, in order to differentiate a subgroup of colitis associated with autoimmunity (CAI) from CUC.

METHODS

Twenty-eight consecutive children with inflammatory colitis associated with primary sclerosing cholangitis (PSC), celiac disease, or AI hepatitis were compared with a matched control group of 27 children with isolated UC. Clinical course, histology, as well as inflammatory profile in the colonic mucosa based on real-time polymerase chain reaction (PCR) were analyzed.

RESULTS

In CAI the main digestive symptoms at disease onset were abdominal pain (12/28) and bloody strings in the stool (12/28), along with a high prevalence of autoimmune diseases in relatives, as compared with bloody diarrhea in the CUC group (26/27). At diagnosis, pancolitis was seen in 18/28 CAI patients compared with 8/27 in UC. In CAI, the pathological findings were different from CUC: 1) major lesions predominantly located in the right colon; 2) pseudo-villous appearance of the mucosa, and strong infiltration with eosinophils; 3) mild glandular lesions; and 4) differing inflammatory infiltrate with reduced FOXP3, interleukin (IL)-2, and thymic stromal lymphopoietin (TSLP) levels. Evolution in CAI was less aggressive, requiring less corticosteroids/immunomodulators.

CONCLUSIONS

Precise clinical, histological, and molecular analyses reveal marked differences between patients with CUC and those with associated AI phenomena, supporting the hypothesis of a distinct AI presentation of IBD.

Hepatobiliary complications of inflammatory bowel disease

Several hepatobiliary abnormalities have been described in association with inflammatory bowel disease (IBD), including primary sclerosing cholangitis (PSC), small duct PSC, chronic hepatitis, cryptogenic cirrhosis, cholangiocarcinoma, and cholelithiasis. PSC is the most common biliary condition in patients with IBD, with an incidence ranging from 2.5% to 7.5%. PSC usually progresses insidiously and eventually leads to cirrhosis independent of inflammatory bowel disease activity. There is a very high incidence of cholangiocarcinoma and an elevated risk for developing colon cancer in patients with PSC. Medical therapy has not proven successful in slowing disease progression or prolonging survival. Treatment of symptoms due to cholestasis, such as pruritis and steatorrhea, is an important aspect of the medical care of patients with PSC. Our preferred treatment of pruritis due to cholestasis is with bile acid binding exchange resins, such as cholestyramine or colestipol. Endoscopic manipulation is recommended for treating complications of recurrent cholangitis or worsening jaundice in the setting of a dominant stricture, but endoscopic approaches have not been conclusively demonstrated to improve survival or decrease the need for liver transplantation. Liver transplantation remains the only effective treatment of advanced PSC, and should be considered in patients with complications of cirrhosis or intractable pruritis or fatigue.

Doenças inflamatórias intestinais no Hospital Universitário da Universidade Federal de Sergipe: manifestações extraintestinais

A doença inflamatória intestinal idiopática (DII) representa um grupo de condições inflamatórias crônicas, resultantes de ativação persistente e inadequada do sistema imune mucoso. Além dos sintomas intestinais característicos, as DII podem se manifestar através de uma série de manifestações extraintestinais (MEI). Objetivos: Avaliar a incidência das MEI das doenças inflamatórias intestinais no Hospital Universitário da Universidade Federal de Sergipe; diagnosticar as MEI das DII; instituir o tratamento adequado dos pacientes portadores dessas manifestações. Métodos: Foi aplicado um protocolo para diagnóstico das MEI; quando necessário os pacientes foram encaminhados para as respectivas especialidades. Resultados: Foram catalogados 49 pacientes portadores de DII; destes, 41 (83,6%) apresentaram MEI. As MEI reumatológicas foram as mais frequentes, acometendo 35 pacientes. O restante das MEI foram assim distribuídas: um caso de MEI dermatológica; um caso de MEI urológica; um caso MEI pneumológica; quatro casos de MEI oftalmológicas; oito casos de MEI hepáticas. Conclusões: As MEI têm alta incidência (I=83,6%) entre os pacientes portadores de DII; as MEI tiveram incidência semelhante entre os pacientes portadores de retocolite ulceratica idiopática e de Crohn; o início das MEI foi mais comum após o diagnóstico da DII; a classe de MEI mais prevalente foi a reumatológica (P=71,4%).

Serum bile acid profiling reflects enterohepatic detoxification state and intestinal barrier function in inflammatory bowel disease

AIM: To determine free and conjugated serum bile acid (BA) levels in inflammatory bowel disease (IBD) subgroups with defined clinical manifestations.

METHODS: Comprehensive serum BA profiling was performed in 358 IBD patients and 310 healthy controls by liquid chromatography coupled to electrospray ionization tandem mass spectrometry.

RESULTS: Serum levels of hyodeoxycholic acid, the CYP3A4-mediated detoxification product of the secondary BA lithocholic acid (LCA), was increased significantly in Crohn’s disease (CD) and ulcerative colitis (UC), while most other serum BA species were decreased significantly. Total BA, total BA conjugate, and total BA glycoconjugate levels were decreased only in CD, whereas total unconjugated BA levels were decreased only in UC. In UC patients with hepatobiliary manifestations, the conjugated primary BAs glycocholic acid, taurocholic acid, and glycochenodeoxycholic acid were as significantly increased as the secondary BAs LCA, ursodeoxycholic acid, and tauroursodeoxycholic acid compared to UC patients without hepatobiliary manifestations. Finally, we found that in ileocecal resected CD patients, the unconjugated primary BAs, cholic acid and chenodeoxycholic acid, were increased significantly compared to controls and patients without surgical interventions.

CONCLUSION: Serum BA profiling in IBD patients that indicates impaired intestinal barrier function and increased detoxification is suitable for advanced diagnostic characterization and differentiation of IBD subgroups with defined clinical manifestations.

Computer-assisted quantitative analysis of Ki-67 antigen in dysplasia--associated lesions or masses in ulcerative colitis

BACKGROUND/AIM

The aim of this study was to apply computer-assisted methodology in assessment of Ki-67 positivity in "adenoma-like" dysplasia associated lesions or masses (DALMs), and carcinoma in ulcerative colitis (UC), and to determine a new approach to grading of Ki-67 staining intensity.

METHODS

Immunohistochemical slides were quantitatively analyzed for estimation of proportion and intensity of Ki-67 positive-stained cells in a total of 50 "adenoma-like" DALMs (27 with low-grade dysplasia and 23 with high-grade dysplasia), and 17 adenocarcinomas associated with UC. The four grades of immunohistochemical staining intensity were established by an automated classification of nuclear optical densities.

RESULTS

The Ki-67 labeling index (LI) in low-grade dysplasia was significantly lower than in high-grade dysplasia, and carcinoma (p < 0.001). The Ki-67 LI of carcinomas was not significantly different from the value obtained in high-grade dysplasia (p > 0.05), however having the difference in percentage values of the moderate stained nuclei (p < 0.05). The overall average values of chromogene nuclear optical density, showed statistically significant differences between DALMs and carcinoma (p < 0.05), although not between normal mucosa and low-grade dysplasia (p > 0.05).

CONCLUSION

The obtained results imply, according to the overall percentage of labeled nuclei, that high-grade dysplasia is very close to carcinoma, while there is the difference in the percentage of moderately stained nuclei. We showed that Ki-67 positivity have a different internal distribution which could be useful in analysing these lesions. These findings also, indicate the important biological differences between low-grade dysplasia and carcinoma in UC, and a low proliferative potential of the former. Automated image analysis permits an objective [corrected] estimation of Ki-67 immunohistochemical staining in UC-associated dysplasia and carcinoma.

Pediatric inflammatory bowel disease

Inflammatory bowel disease is an important cause of gastrointestinal pathology in children and adolescents. The incidence of pediatric inflammatory bowel disease is increasing; therefore, it is important for the clinician to be aware of the presentation of this disease in the pediatric population. Laboratory tests, radiology studies, and endoscopic procedures are helpful in diagnosing inflammatory bowel disease and differentiating between Crohn’s disease and ulcerative colitis. Once diagnosed, the goal of medical management is to induce remission of disease while minimizing the side effects of the medication. Specific attention needs to be paid to achieving normal growth in this susceptible population. Surgical management is usually indicated for failure of medical management, complication, or malignancy. Algorithms for diagnostic evaluation and treatment of pediatric inflammatory bowel disease are presented. The specific psychosocial issues facing these patients are also discussed in this review as are the future goals of research in the complex problem of pediatric inflammatory bowel disease.

Inflammatory bowel disease characteristics among African Americans, Hispanics, and non-Hispanic Whites: characterization of a large North American cohort

OBJECTIVES

Inflammatory bowel disease (IBD), comprising primarily of Crohn's disease (CD) and ulcerative colitis (UC), is increasingly prevalent in racial and ethnic minorities. This study was undertaken to characterize racial differences in disease phenotype in a predominantly adult population.

METHODS

Phenotype data on 830 non-Hispanic white, 127 non-Hispanic African American, and 169 Hispanic IBD patients, recruited from six academic centers, were abstracted from medical records and compiled in the NIDDK-IBD Genetics Consortium repository. We characterized racial differences in family history, disease location and behavior, surgical history, and extraintestinal manifestations (EIMs) using standardized definitions.

RESULTS

African American CD patients were more likely than whites to develop esophagogastroduodenal CD (OR = 2.8; 95% CI: 1.4-5.5), colorectal disease (OR = 1.9; 95% CI: 1.1-3.4), perianal disease (OR = 1.7; 95% CI: 1.03-2.8), but less likely to have ileal involvement (OR = 0.55; 95% CI: 0.32-0.96). They were also at higher risk for uveitis (OR = 5.5; 95% CI: 2.3-13.0) and sacroiliitis (OR = 4.0; 95% CI: 1.55-10.1). Hispanics had higher prevalence of perianal CD (OR = 2.9; 95% CI: 1.8-4.6) and erythema nodosum (3.3; 95% CI: 1.7-6.4). Among UC patients, Hispanics had more proximal disease extent. Both African American and Hispanic CD patients, but not UC patients, had lower prevalences of family history of IBD than their white counterparts.

CONCLUSIONS

There are racial differences in IBD family history, disease location, and EIMs that may reflect underlying genetic variations and have important implications for diagnosis and management of disease. These findings underscore the need for further studies in minority populations.

The Deafness of Ludwig Van Beethoven: an Immunopathy

OBJECTIVE

To analyze and discuss the deafness of Ludwig van Beethoven (1770-1827) and to offer a logical theory for its etiology.

METHOD

The study will carefully review the composer's symptoms as described in his letters to friends and acquaintances and also will review a large body of source material, particularly publications by his contemporaries, some of which were generously loaned by Beethoven-Haus, Bonn, Germany, where necessary translations were made directly from the original German. We will also study publications on Inflammatory Bowel Disease (IBD) and its associated extraintestinal manifestations and personal discussions with experienced gastroenterologists.

RESULTS

Beethoven's abdominal symptoms that began in his teens are highly suggestive of IBD, which we believe to be a correct diagnosis. IBD is an umbrella term that includes a number of named entities such as ulcerative colitis and Crohn's Disease. IBD is now considered to be a problem of immune regulation with extra intestinal manifestations that include sensorineural hearing loss and primary sclerosing cholangitis (PSC). PSC eventually causes cirrhosis and failure of the liver. A diagnosis of IBD therefore provides a single entity that explains most of the composer's symptoms and was finally the cause of his death. Our conclusion is that Beethoven's sensorineural hearing loss was an immunopathy associated with IBD.

Sonographic detection of perihepatic lymphadenopathy is an indicator for primary sclerosing cholangitis in patients with inflammatory bowel disease

AIM

Primary sclerosing cholangitis (PSC) is a frequent complication in patients with inflammatory bowel disease (IBD). While hyperplasia of the perihepatic lymph nodes has been described in patients with PSC, its prevalence and cause in IBD patients remains obscure. In the present study we address the question of whether ultrasound (US) examination is useful to detect perihepatic lymphadenopathy and improve the diagnostic accuracy for PSC in patients with underlying IBD.

METHODS

A total of 310 consecutive IBD patients were prospectively evaluated by US for enlarged perihepatic lymph nodes, as well as serologic testing for cholestasis-indicating enzymes. In patients with positive test results, viral or autoimmune liver disorders were excluded by serum testing. Next, the presence of PSC was confirmed/excluded by endoscopic retrograde cholangiography (ERC).

RESULTS

Perihepatic lymphadenopathy was detected by US in 27 of 310 (9%) patients. In 9 (33%) of those, serologic testing identified an underlying autoimmune or viral hepatitis. In the remaining 18 patients, ERC confirmed PSC in 17 (94%) and excluded it in 1. Elevated cholestasis parameters were found in 43 of 310 (14%) patients and 5 (12%) of those were diagnosed with autoimmune or viral hepatitis. In the remaining 38 patients, ERC confirmed PSC in 15 (39%) and excluded it in 23 (61%). Therefore, when autoimmune or viral hepatitis was excluded, enlarged lymph nodes in US predicted PSC more accurately than conventional serum parameters alone (PPV 94 and 39%, respectively [ P<0.001]), and the sensitivity ratio increased by a factor of 1.13 in favor of the US examination.

CONCLUSION

In patients with IBD, detection of enlarged perihepatic lymph nodes is a highly predictive indicator for the presence of PSC. Alternative causes of perihepatic lymphadenopathy have to be excluded.

Noninfectious liver disorders: assessment and diagnosis

Infectious hepatitis is often the initial suspect when abnormal serum liver function test results are discovered in primary care settings. However, noninfectious liver disorders may also present with altered liver function tests. Noninfectious liver disorders require careful assessment of patient history, physical findings, and serum laboratory tests to distinguish among entities that have varying clinical implications and treatments.

Inflammatory bowel disease emergencies

Emergency complications of IBD are rare, but may be life-threatening, require surgery, and result in permanent end organ damage. The most common complications associated with UC are fulminant colitis, toxic megacolon, and bleeding. Each of these complications may resolve with aggressive medical therapy but often result in a total proctocolectomy. The most common complications associated with CD are abscesses and intestinal obstruction. Although initial treatment includes medical treatment, these Crohn's-related complications usually require a surgical intervention and intestinal resection. Finally, the most common extraintestinal manifestations that present as an emergency include thromboembolic events, ocular complications, and hepatobiliary disease. Some of these complications may parallel the course of the underlying disease and respond to IBD treatment, but thromboemboli, uveitis, and PSC do not. In the last decade there has been an explosion of knowledge and discovery into the pathogenesis of IBD. These findings have led to better and earlier treatment of IBD that it is hoped will alter the natural course of disease and prevent many of the complications outlined in this article.

Kupffer-cell depletion attenuates colonic and extracolonic granulomatous inflammation in chronic colitis

Intramural injection of peptidoglycan-polysaccharide polymers into the distal colon in rats induces granulomatous colitis associated with extracolonic manifestations. We sought to clarify the effects of Kupffer-cell depletion induced by the intravenous administration of gadolinium on colonic and extracolonic inflammation in this model. The effects of Kupffer-cell depletion on acute and chronic inflammation were evaluated 3 days and 3 weeks after injection of peptidoglycan-polysaccharide, respectively. We assessed the effects of gadolinium on colonic cytokine levels in vivo and the viability of elicited peritoneal macrophages and peptidoglycan-polysaccharide-induced production of nitrite, an indirect index of nitric oxide production, by these cells in vitro. A single injection of gadolinium caused a marked decrease in the number of Kupffer cells stained with antibodies within 3 days. Gadolinium treatment did not alter acute inflammation at 3 days. Repeated treatment with gadolinium dramatically attenuated grossly observed chronic inflammation, including thickening of colon wall, hepatic and splenic nodules, and swelling of foot joints; and significantly reduced the proportional areas occupied by granulomas in the colon, liver, and spleen at 3 weeks. These protective effects were reflected in significant reduction in colon and liver weights; gross scores; colonic myeloperoxidase activity, an indirect quantitative index of granulocyte infiltration; colonic interleukin-1beta levels; plasma nitrite and nitrate levels; and decreased tendency toward arthritis. Although gadolinium did not cause injury in elicited peritoneal macrophages in vitro, the compound dose-dependently attenuated peptidoglycan-polysaccharide-induced production of nitrite by these cells. Chronic Kupffer-cell depletion attenuates peptidoglycan-polysaccharide-induced granulomatous inflammation in the colon, liver, and spleen and reduces the incidence of arthritis, possibly by suppressing the production of interleukin-1beta and nitric oxide.

Sclerosing pancreatitis presenting as a periampullary tumour

BACKGROUND

Sclerosing lesions of the pancreatic duct are rare and may be secondary to primary sclerosing cholangitis (PSC) or the result of a primary sclerosing process (the recently described lymphoplasmacystic sclerosing pancreatitis, LSP). Occasionally this process may present as a mass lesion.

CASE OUTLINE

A 21 -year-old man presented with abdominal pain and jaundice, giving a high index of suspicion for a periampullary malignancy. There were minimal symptoms suggestive of PSC. The resected head of the pancreas demonstrated changes of chronic pancreatitis with a fibro-inflammatory process of the pancreatic duct suggesting an underlying ductal sclerosing process.

DISCUSSION

Clinical presentation and imaging characteristics of PSC involving the pancreas are often misleading and may suggest a neoplasm as the underlying disorder. Conclusive diagnosis is usually not determined until after surgical intervention. Although racial differences in pancreatic duct involvement have been suggested, the underlying histopathology is the same as in PSC involving the biliary ducts.

Appendectomy protects against the development of ulcerative colitis but does not affect its course

OBJECTIVES

Appendectomy has been shown to protect against the development of ulcerative colitis. The objective of this study was to examine the effect of appendectomy on the clinical features and natural history of colitis.

METHODS

A total of 259 consecutive adults patients with ulcerative colitis were studied. Of the patients, 20 had undergone appendectomy (12 before onset of colitis and eight after diagnosis).

RESULTS

The frequency of appendectomy was significantly less than in a group of 280 controls, which comprised partners of the patients and a group from the community (OR = 0.25; 95% CI = 0.14-0.44). This was even more significant if only the 12 patients who underwent surgery before the onset of colitis were considered (OR = 0.15; 95% CI = 0.07-0.28). Patients with prior appendectomy developed symptoms of ulcerative colitis for the first time at a significantly later age than those without appendectomy (42.5 +/- 6.5 vs 32.1 +/- 0.8 yr; p < 0.01) or those who had appendectomy after the onset of colitis (24.6 +/- 3.4 yr; p < 0.05). Appendectomy did not influence disease extent, need for immunosuppressive treatment with azathioprine or 6-mercaptopurine (as a marker of resistant disease), or the likelihood of colectomy. Five patients in the appendectomy group had clinical evidence of primary sclerosing cholangitis (25%). This was more common than in those without appendectomy (8%; OR = 4.09; 95% CI = 1.04-13.60).

CONCLUSIONS

These results indicate that although appendectomy may delay onset of colitis, it does not influence its course. However, it is associated with the development of primary sclerosing cholangitis. Appendectomy is unlikely to be of benefit in established ulcerative colitis.

Pancreatic and biliary tract disorders in inflammatory bowel disease

Hepatobiliary disorders occur frequently in patients with IBD, with PSC and cholangiocarcinoma being the most clinically significant for endoscopists. Endoscopic therapy for PSC is effective in improving symptoms, biochemical parameters, and radiographic abnormalities. Endoscopic therapy may also confer survival benefit, but this has yet to be confirmed in randomized, controlled trials. Treatment should be restricted to those individuals with a rapid decline in liver function testing or those with recurrent cholangitis. Cholangiocarcinoma is a serious complication of PSC and carries an extremely poor prognosis. ERCP with brush cytology has a relatively low sensitivity and the diagnosis is usually made after the disease has become metastatic. Malignant biliary obstruction can be palliated by endoscopic stenting. Photodynamic therapy is a promising experimental technique that may confer symptomatic and survival benefit in patients with nonresectable, advanced cholangiocarcinoma. IBD patients also have an elevated risk for developing acute and chronic pancreatitis as well as pancreatic insufficiency. The majority of cases of acute pancreatitis are likely due to medication side effects and local structural complications of IBD. The remainder may possibly represent true extraintestinal manifestations of IBD. Chronic pancreatitis is frequently subclinical, but may be accompanied by clinically relevant exocrine insufficiency. ERCP is the test of choice for the diagnosis of chronic pancreatitis, but the role of endoscopy in the therapeutic management of IBD-associated chronic pancreatitis remains to be defined.

Colorectal disease in liver allograft recipients -- a clinicopathological study with follow-up

OBJECTIVE

To determine the spectrum and outcome of colorectal diseases occurring in adult liver allograft recipients.

DESIGN

A retrospective cohort analysis of clinical, microbiological and histopathological data regarding colorectal disease.

PATIENTS

Forty three out of 302 adult primary liver allograft recipients were transplanted and followed up (at median 42 months) at a tertiary referral centre/teaching hospital.

RESULTS

Out of 302 patients, 43 (14%) were investigated (by endoscopy and/or laparotomy) for symptoms of colorectal disease after orthotopic liver transplantation. The symptoms were: diarrhoea (n = 31); per-rectal bleeding (n = 5); and symptoms relating to pre-transplant ulcerative colitis (n = 7). Among the patients without known ulcerative colitis, per-rectal bleeding occurring early after orthotopic liver transplantation was most commonly caused by cytomegalovirus colitis and carried a poor prognosis. Excluding ulcerative colitis, the commonest causes of diarrhoea were Clostridium difficile, cytomegalovirus infection and medications, particularly during the first 2 months after orthotopic liver transplantation. No cases of colorectal graft-versus-host disease, cryptosporidiosis, amoebiasis, atypical mycobacterial infection or post-transplant lymphoproliferative disease were demonstrated. The activity of pre-transplant ulcerative colitis was unchanged or increased after orthotopic liver transplantation. Two further patients developed new-onset ulcerative colitis after orthotopic liver transplantation.

CONCLUSIONS

Ulcerative colitis, C. difficile, cytomegalovirus infection and medications are the commonest colorectal causes of morbidity after orthotopic liver transplantation. Adult liver allograft recipients are, however, unlikely to show certain large bowel diseases encountered in other immunosuppressed groups. Amongst non-ulcerative colitis patients, those presenting with diarrhoea show a good outcome with appropriate management, whereas those with per-rectal bleeding have a more guarded prognosis.

Hepatobiliary disease in inflammatory bowel disease

Many hepatobiliary diseases are seen in IBD. PSC is the most common, occurring in 7.5% of patients with UC. The cause of PSC is not well understood, but PSC seems to be associated with genetic susceptibility, sharing some immunologic abnormalities with UC. A characteristic cholangiogram in a patient with abnormal liver function tests usually establishes the diagnosis. Liver biopsy is not essential but can help make the diagnosis of small duct PSC in patients with a normal cholangiogram. There are no medications that treat PSC effectively. Endoscopic dilation of dominant strictures reduces the frequency of cholangitis and may improve survival. OLT remains the only proven treatment of advanced PSC. Cholangiocarcinoma is a feared complication of PSC that is difficult to diagnose. Cholelithiasis, PBC, portal vein thrombosis, and hepatic abscess are hepatobiliary disorders that occur less frequently in IBD patients.

Homing of mucosal lymphocytes to the liver in the pathogenesis of hepatic complications of inflammatory bowel disease

Primary sclerosing cholangitis is strongly linked to inflammatory bowel disease, but any model to explain the development of primary sclerosing cholangitis must take into account the fact that it usually runs a course independent from inflammation in the bowel, illustrated by the fact that this disease can develop many years after proctocolectomy. Thus, liver disease can develop in the absence of a diseased colon and cannot be explained solely by release of toxic factors from the inflamed gut. We propose the existence of an enterohepatic circulation of lymphocytes, whereby some mucosal lymphocytes generated in the gut during active inflammatory disease subsequently persist as longlived memory cells capable of recirculation through the liver. Under the right conditions, these dual-homing lymphocytes might become activated in the liver resulting in hepatic inflammation that is independent from inflammation in the gut. Recent reports that some lymphocyte homing-receptors are shared by the liver and gut provide a molecular basis for this hypothesis and explain the distribution of extraintestinal disease in inflammatory bowel disease.

Clinical aspects and pathophysiology of inflammatory bowel disease

The chronic inflammatory bowel diseases (IBD), Crohn's disease and ulcerative colitis, are recognized as important causes of gastrointestinal disease in children and adults. In this review we delineate the clinical manifestations and diagnostic features of IBD. In addition, we summarize important recent advances in our understanding of the immune mediators of intestinal inflammation. This information has led to new therapeutic approaches in IBD. Further, we discuss the considerable data that point to the significance of genetic factors in the development of IBD and the genetic loci which have been implicated through genome-wide searches. The commensal bacterial flora also appears to be a critical element, particularly in regards to Crohn's disease, although the precise role of the bacteria in the disease manifestations remains unclear. Current investigations promise to yield fresh insights in these areas.

Colorectal neoplasia in ulcerative colitis-recent advances

It is recognized that ulcerative colitis (UC) predisposes to the development of colorectal adenocarcinoma (CRC), and the molecular pathway for this process differs from that for sporadic CRCs. However, several important details regarding the risk factors for and the molecular changes underlying UC-related colorectal carcinogenesis have only come to light lately. First, recent data suggest environmental factors related to long-standing inflammation contribute more to this increased cancer risk than an inherited susceptibility. Second, molecular changes that may represent the first steps in the development of neoplasia are being increasingly identified in non-dysplastic, colitic mucosa. Third, there is now good evidence suggesting that UC-related CRC may develop along more than one molecular pathway. These emerging data will hopefully contribute to attempts to prevent the development of UC-related CRC, e.g. through refining surveillance programmes. Details of the molecular heterogeneity of UC-related dysplasia and CRC may also help develop reliable tools for diagnosing the former and for predicting the behaviour of the latter. Finally, there is increasing awareness of non-epithelial colorectal malignancies which are associated with UC and may potentially increase in incidence with changes in the medical management of this inflammatory disease.

The epidemiology and the pathogenesis of inflammatory bowel disease

The etiology of inflammatory bowel disease (IBD) is still unknown. However, a satisfactory solution cannot be far away. IBD actually encompasses two diseases, i.e. Crohn's disease (CD) and ulcerous colitis (UC). These diseases resemble each other so closely that they cannot be distinguished even pathologically, but differ from each other sufficiently to regard them as independent entities. Epidemiological observations may be helpful in identifying the true causative factors of this evasive disease. Geographically, the prevalence of the disease has a slope from North to South and, to a lesser degree, from West to East. The Western-Eastern discrepancy can be attributed to a difference in Western life styles. The incidence of the disease has been increasing world-wide of late, but its spread has been slowing down in highly affected countries. Racial and ethnic relations in different populations and immigration studies offer interesting data which can reflect genetic, inherited, environmental and behavioural factors. The disease seems to have a characteristic racial-ethnic distribution: the Jewish population is highly susceptible everywhere, but its prevalence in that population nears that of the domestic society in which they live. In Hungary, the Roma (Gypsies) have a considerably lower prevalence than the average population. This can be attributed to a genetic or environmental influence. According to age, the onset of the disease occurs more often in the second or the third decade of life, but there also is another peak in the 60s. Regarding sexual distribution, there is a slight preponderance of colitis ulcerosa in men and of Crohn's disease in women. It may correspond to the stronger auto-immune affection in the process of Crohn's disease. Environmental factors and behavioural influences also are investigated. Diet, the role of the early ages, smoking habits and the influence of hormonal status and drugs are viewed as useful contributing factors in the manifestation of the disease. Genetic studies show that one-fourth of IBD patients have an affected family member. HLAB27 histocombatibility also plays an important, but not determining role in the development of the disease. Genetic factors seem to have a stronger influence in Crohn's disease than ulcerative colitis. The existence of multiple sclerosis-IBD families may reflect the common genetic background or the similar microbial effect as well. A great number of bacterial and viral factors has been suspected of being infectious factors in IBD, mostly in CD. Mycobacteria, Yersinia, Campylobacter, Clostridium, Clamidias, etc. as well as bacteria and some viruses such as herpes and rotavirus and the primary measles virus. None of them has been proven as a real and exclusively pathogenic factor. Immunological background has an important function in the manifestation of the disease. If an individual has a genetic susceptibility to infections, the down regulation of an inflammation in the bowel wall does not occur in a proper way. This initiates the auto-immune process which is a self-increasing cycle. Extra-intestinal manifestations of IBD are of high importance because they can not only follow intestinal symptoms, but precede them by years. Hepatic and biliary disturbances (primary sclerosing cholangitis), are the most serious complications. Mucocutaneous manifestations can be the first appearance of the main disease (in the mouth). Auto-immune consequences (erythema nodosum) or complications caused even by the therapy can occur. Ocular and musculoskeletal manifestations supposedly have the same genetic background and often precede the intestinal symptoms. Considering the epidemiological, genetic and immunological data, we can conclude that ulcerative colitis and Crohn's disease are heterogeneous disorders of mutifactorial etiology in which hereditary (genetic) and environmental (microbial, behaviour) factors interact to produce the disease.

Clinical features of inflammatory bowel disease

The purpose of this review is to highlight new developments during the past year regarding diagnosis and clinical features of inflammatory bowel disease. Endoscopy remains the cornerstone for diagnosis and evaluation of ileocolonic inflammatory bowel disease. In ulcerative colitis, recent studies have challenged the concept of a continuous and homogeneous inflammatory process with constant rectal involvement: patchy inflammation and rectal sparing were reported in treated ulcerative colitis, and frequent cecum and appendiceal orifice skip lesions were confirmed. Cross-sectional imaging techniques usefully complement endoscopy by assessing whole-bowel thickness and detecting abscesses and fistulae. Furthermore, echo Doppler ultrasound is able to measure mesenteric blood flow, which is increased in active inflammatory bowel disease and seems to parallel inflammatory disease activity. Osteopenia, which affects approximately half of patients with inflammatory bowel disease, can be detected by dual-energy x-ray absorptiometry and prevented. Hyperhomocysteinemia, a predisposing factor for thrombosis, seems to be more frequent in inflammatory bowel disease, and can be corrected by folate supplementation. The concept of an aggressive, penetrating form of Crohn disease with early postoperative recurrence as opposed to a more indolent, nonpenetrating form of the disease, with later recurrence, was recently challenged. The most significant predictor of the risk of malignancy in inflammatory bowel disease remains the presence of dysplasia in colonic biopsy specimens. A dysplastic polypoid lesion or mass is a strong predictor of cancer but should be distinguished from the dysplasia inherent in a coincident sporadic adenoma.

Molecular mechanisms of tumor necrosis factor alpha-stimulated leukocyte recruitment into the murine hepatic circulation

To date, much of the adhesion work in the liver has been restricted to sinusoids and postsinusoidal venules. However, selectins have been localized on the portal (presinusoidal) venules and these vessels have been shown to be important in metastasis of tumors. The purpose of this study was to characterize the leukocyte-endothelial interactions within the 3 compartments of the hepatic microvasculature under baseline conditions and in response to tumor necrosis factor alpha (TNF-alpha). Mice deficient in P-selectin or both E- and P-selectin were compared with wild-type (C57Bl/6, wild type) mice. Animals were injected with murine TNF-alpha (15 microg/kg intraperitoneally [IP]) and the liver was examined by fluorescence intravital microscopy 4 hours later. Under baseline conditions, leukocyte flux in the portal venules was 1.42 +/- 0.42 cells/min. Leukocyte flux in the portal venules of wild-type mice increased 8-fold in response to 4 hours of TNF-alpha stimulation. This was reduced by 50% in the P-selectin-deficient mice but was not reduced further by either the addition of an E-selectin antibody (9A9, 100 microg intravenously [IV]) to these mice or in mice deficient in both E- and P-selectin. In P-selectin-deficient mice, the addition of an antibody against alpha(4)-integrin (R1-2, 75 microg IP) reduced rolling to baseline. But in the E- and P-double-selectin-deficient mice the addition of an antibody against L-selectin (Mel 14, 3 microg/kg IV) had no effect on TNF-alpha-induced recruitment. Similar responses were seen in the central venules, however, in the sinusoids the increased number of stationary leukocytes seen in response to 4 hours of TNF-alpha stimulation in the wild-type mice was not reduced in P-selectin-deficient mice with or without the alpha(4)-integrin antibody. These data suggest that leukocytes can use alpha(4)-integrin independent of the selectins in the venules. Within the sinusoids, however, inhibition of E-selectin, P-selectin, and alpha(4)-integrin was insufficient to reduce leukocyte recruitment.