A shared and unique epitope(s) on human colon, skin, and biliary epithelium detected by a monoclonal antibody

Anti-neutrophil antibodies in primary sclerosing cholangitis

Anti-neutrophil specific antibodies are detected in up to 88% of patients with PSC. The labelling pattern of neutrophils produced by these antibodies when examined by indirect immunofluorescence microscopy is distinct from that produced by anti-neutrophil cytoplasmic antibodies (ANCA) in vasculitic diseases. The antigen(s) recognized by anti-neutrophil antibodies in PSC is not yet known but appears to be localized to the periphery of the nucleus. Accordingly, the term peripheral anti-neutrophil nuclear antibodies (p-ANNA) is more appropriate than the frequently used p-ANCA. As the titre of p-ANNA in PSC does not correlate with disease-specific clinical parameters, they are not useful markers for the management of patients. However, the high prevalence of p-ANNA in PSC makes them a reasonable diagnostic marker if used in conjunction with other standard diagnostic tests. The role of anti-neutrophil antibodies in the pathogenesis of PSC, if any, remains to be established.

Mechanisms of tissue damage in inflammatory bowel disease

Crohn disease and ulcerative colitis are caused by an excessive immune-inflammatory reaction in the intestinal wall. Analysis of the types of immune response ongoing in the inflamed intestine has revealed that in Crohn disease there is predominantly a T helper cell type 1 response, with exaggerated production of interleukin (IL)-12 and interferon-gamma, whereas in ulcerative colitis the lesion seems to be more of an antibody-mediated hypersensitivity reaction. Despite these differences, downstream inflammatory events are probably similar in both conditions. In both Crohn disease and ulcerative colitis there is an increased synthesis of proinflammatory cytokines, including IL-1beta, IL-6, IL-8, IL-16, and tumor necrosis factor-alpha accompanying the influx of nonspecific inflammatory cells into the mucosa. These cytokines contribute to the tissue damage either directly or indirectly by enhancing the production of matrix metalloproteinases and growth factors, which produce ulceration as well as mucosal repair.

Recent advances in inflammatory bowel disease

The last decade has seen tremendous advances in our knowledge, which has led to genuine improvements in our understanding of the pathogenesis and management of inflammatory bowel disease (IBD). The combined power of cellular and molecular biology has begun to unveil the enigmas of IBD, and, consequently, substantial gains have been made in the treatment of IBD. Refinements in drug formulation have provided the ability to target distinct sites of delivery, while enhancing the safety and efficacy of older agents. Simultaneous progress in biotechnology has fostered the development of new agents that strategically target pivotal processes in disease pathogenesis. This article addresses our current understanding of the pathogenesis of IBD, including the latest developments in animal models and covers agents currently used in the treatment of IBD as well as emerging therapies.

Manipulation of cytokines in the management of patients with inflammatory bowel disease

In recent years, new concepts have been formulated for the therapeutic management of the intractable forms of Crohn's disease and ulcerative colitis, the two major forms of inflammatory bowel disease. These advances are based largely on new insights into the immune-inflammatory events occurring in the gut of these patients. Analysis of the types of immune response ongoing in the inflamed intestine has revealed that in Crohn's disease there is predominantly a T-helper cell type 1 response, with exaggerated production of interleukin (IL)-12 and interferon (IFN)-gamma, whereas in ulcerative colitis the lesion seems more of an antibody-mediated hypersensitivity reaction. Despite these differences, downstream inflammatory events are the same in both conditions. In both Crohn's disease and ulcerative colitis mucosa, IL-1gamma, IL-6, IL-8 and tumour necrosis factor (TNF)-alpha are produced in excess, and the production of free radicals accompanying the influx of nonspecific inflammatory cells into the mucosa is above the normal range. Strategies aimed at inhibiting T-cell responses are therefore more relevant in Crohn's disease, whereas, in theory at least, inhibition of downstream inflammatory processes should be therapeutic in both Crohn's disease and ulcerative colitis. This review seeks to summarize studies in which anticytokine antibodies, cytokines or cytokine-modifying agents have been used in the treatment of either Crohn's disease or ulcerative colitis.

Chronic cholestatic diseases

Chronic cholestatic diseases, whether occurring in infancy, childhood or adulthood, are characterized by defective bile acid transport from the liver to the intestine, which is caused by primary damage to the biliary epithelium in most cases. In this article, approaches to diagnosis and management of the main specific disorders are provided and some of the recent developments in this field are discussed. Major advances in the understanding of the cellular and molecular physiology of bile secretion have led to identification of genetic defects responsible for the different types of progressive familial intrahepatic cholestasis (PFIC). The potential role of the genes involved in PFIC in some adult cholestatic disorders remains to be determined. The majority of adult patients with chronic cholestasis have primary biliary cirrhosis (PBC) or primary sclerosing cholangitis (PSC). Recently, variant forms of PBC have been described. The term autoimmune cholangitis is used to describe patients having chronic non-suppurative cholangitis with negative antimitochondrial antibodies (AMA) but positive antinuclear and/or antismooth muscle antibodies. Autoimmune cholangitis and AMA-positive PBC are quite similar in terms of clinical presentation, survival and response to ursodeoxycholic acid (UDCA) therapy. In contrast, autoimmune cholangitis must be distinguished from PBC-autoimmune hepatitis (AIH) overlap syndrome in which biochemical and histological characteristics of both PBC and AIH coexist. Combination of UDCA and corticosteroids is required in most patients with overlap syndrome to obtain a complete clinical and biochemical response. Long-term UDCA treatment improves survival without liver transplantation in PBC patients. Among the putative mechanisms of the beneficial effects of UDCA, description of anti-apoptotic properties and effect on endotoxin disposal in biliary cells have provided new insights. In patients with incomplete response to UDCA, combination of UDCA with antiinflammatory or immunosuppressive drugs is under evaluation. Variant forms of PSC have also been described, including PSC-AIH overlap syndrome, especially in children or young adults, and small-duct PSC, which is characterized by normal cholangiogram in patients having chronic cholestasis, histologic features compatible with PSC and inflammatory bowel disease. Development of cholangiocarcinoma (CC) is a major feature of PSC, occurring in 10-15% of patients. Early diagnosis of CC is a difficult challenge, although positron emission tomography seems a promising tool. Unlike PBC, effective medical therapy is not yet available in PSC, reflecting the lack of knowledge about the exact pathogenesis of the disease. Currently, liver transplantation is the only effective therapy for patients with advanced disease, although recurrence of PSC in the graft may occur.

Treatment of experimental colitis by oral tolerance induction: a central role for suppressor lymphocytes

OBJECTIVE

Inflammatory bowel diseases (IBD) are immune-mediated disorders wherein an imbalance between proinflammatory (Th1) and antiinflammatory (Th2) cytokines is thought to play a role in the pathogenesis. The aim of this study was to test whether induction of oral tolerance to proteins extracted from inflammatory colon alleviates experimental colitis, and whether oral tolerization mediated by suppressor cells can induce immune tolerance.

METHODS

Colitis was induced in rats by intracolonic instillation of trinitrobenzenesulfonic acid (TNBS). Rats received five oral doses of colonic proteins extracted from TNBS-colitis colonic wall. Splenocytes harvested from tolerized and control rats were transplanted into irradiated naive rats.

RESULTS

Feeding of colitis-extracted proteins ameliorated colonic inflammation, as shown by reduction of colonic ulcerations, as well as decreased diarrhea, intestine and peritoneal adhesions, wall thickness, and edema. A marked reduction of the fraction of injured colonic area and colon weight, and decrease in colon weight, were observed in tolerized rats versus controls. Histological parameters for colitis were markedly improved in tolerized animals that showed significant reduction in inflammatory response and mucosal ulcerations. Tolerized rats developed an increase in TGFbeta1 and a decrease in IFNgamma serum levels. TNBS-induced colitis was significantly attenuated in naive recipients of splenocytes from tolerized rats, compared with rats that received splenocytes from control donors.

CONCLUSIONS

Induction of oral tolerance to colitis-extracted proteins downregulates the anticolon immune response, thereby ameliorating experimental colitis. Suppressor lymphocytes mediate the tolerance by induction of a shift from a proinflammatory to an antiinflammatory immune response.

Externalization of tropomyosin isoform 5 in colon epithelial cells

Ulcerative colitis (UC) is associated with autoantibody response to a cytoskeletal protein, human tropomyosin (hTM) isoform-5 (hTM5). Because hTM5 is an intracellular protein, it may remain inaccessible to the autoantibodies. Therefore, we have investigated the possibility of externalization of hTM5 in colon epithelial cells. Freshly isolated colonic and small intestinal epithelial cells and LS-180 colon cancer cell line were examined for surface expression of hTM5 by flow cytometric analysis using hTM isoform-specific MoAbs. The extracellular release of hTM5 was determined by Western blot and radioimmunoprecipitation analyses. Physical association of hTM5 with a membrane-associated colon epithelial protein (CEP) was examined by co-immunoprecipitation of hTM5 with anti-CEP MoAb, and CEP with anti-hTM5 MoAb. Cell surface expression of hTM5 was observed in colonic epithelial and LS-180 cells but not in small intestinal epithelial cells. LS-180 cells spontaneously released hTM5 as well as CEP into the culture medium that was significantly stimulated by a calcium ionophore, A23187, but inhibited by phorbol-12-myristate-13-acetate, monensin and methylamine. Co-immunoprecipitation experiments revealed that hTM5 forms a complex with CEP. We conclude that hTM5 is externalized in colon but not in small intestinal epithelial cells. The physical association of hTM5 with CEP suggests a possible chaperone function of CEP in the transport of hTM5, a putative target autoantigen in UC.

Hepatobiliary manifestations of inflammatory bowel disease

PSC is the most common of the clinically significant hepatobiliary diseases seen in association with IBD, with an incidence that varies from 2.5% to 7.5%. Conversely, 50% to 75% of patients with PSC have IBD. This high degree of association suggests a common pathogenetic mechanism; however, no causal relationship has been established. The etiopathogenesis of PSC remains poorly understood, despite a large number of studies looking at differing hypotheses. The diagnosis is usually established by cholangiography. Liver biopsy can sometimes be helpful in diagnosing pericholangitis. There is a significant overlap of the histology with chronic hepatitis. Serum markers have been studied for diagnosing PSC, particularly for early diagnosis of cholangiocarcinoma, but none have shown the high sensitivity and specificity needed to use them clinically. PSC usually progresses insidiously and eventually leads to cirrhosis. Despite progress in early recognition, optimal management of patients with PSC remains a challenge requiring a multidisciplinary approach among hepatologists, endoscopists, surgeons, and interventional radiologists. Colectomy for ulcerative colitis does not alter the natural history of PSC. There is a high (10% to 15%) incidence of cholangiocarcinoma in patients with PSC. This incidence along with the risk of colon cancer in patients with ulcerative colitis makes it necessary to follow these patients closely. A number of pharmacologic therapies have been evaluated, but none has proven successful in slowing the progression of PSC or prolonging survival. Endoscopic therapy has a proven utility in treating complications of recurrent cholangitis or worsening jaundice in the setting of a dominant stricture, but endoscopy has not been shown to improve survival or decrease the need for liver transplantation. Liver transplantation is life-saving for patients with advanced PSC. Pericholangitis, gallstones, and chronic hepatitis are additional disorders noted in association with IBD, but they are much less common and easier to manage than PSC.

The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder and prostate

OBJECTIVE

To determine if the monoclonal antibody 7E12H12, which reacts with a 40 kDa protein in normal human enterocytes and has been shown to be a marker for intestinal metaplasia and adenocarcinoma arising in the bladder, could assist in distinguishing prostatic, urachal and vesical adenocarcinoma, using a sensitive immunohistochemical assay.

MATERIALS AND METHODS

Fifteen primary prostatic adenocarcinomas and five adenocarcinomas of the urinary bladder were selected for a retrospective evaluation. The monoclonal antibody 7E12H12 (IgM isotype) was used in an immunoperoxidase assay to survey formalin-fixed, paraffin-embedded archival tissue specimens.

RESULTS

All vesical adenocarcinomas reacted positively with the antibody, regardless of grade; none of the 15 prostatic specimens reacted positively in either the benign or malignant glandular epithelium.

CONCLUSION

The monoclonal antibody 7E12H12 can differentiate primary adenocarcinoma of the bladder from secondary adenocarcinoma arising in the prostate and may be a useful tool in diagnostic pathology.

Serum levels of interleukins 8 and 10, interferon gamma, granulocyte-macrophage colony stimulating factor and soluble CD23 in patients with primary sclerosing cholangitis

The presence of auto-antibodies and hypergammaglobulinaemia in patients with primary sclerosing cholangitis (PSC) suggest an overactive humoral immune system. Serum cytokines, measured using in-house double monoclonal sandwich ELISA, were used to assess the state of cellular and humoral immunity in this condition by comparison with sex and age matched normal controls and patients with alcoholic cirrhosis (AC). Soluble CD23 (sCD23) as a marker of humoral immunity was significantly elevated in PSC (N = 31) relative to patients with AC (N = 12) and the control group (N = 20) (P < 0.0001 and P < 0.001 respectively). Serum interleukin (IL) 10, as an anti-inflammatory cytokine and IL8, as a marker of neutrophil activation were significantly elevated in patients with PSC relative to those with AC and the controls (P < 0.001 and P < 0.05 respectively). Interferon gamma, as a marker of cellular immunity, and granulocyte-macrophage colony stimulating factor, a marker of monocyte/macrophage function were similar in all the groups. Cytokines and sCD23 were no different between patients with AC and the control group. While more than two thirds of the patients with PSC were positive for ANCA, there was no correlation between the presence of ANCA or ANCA titre and serum levels of either IL8, IL10 and sCD23. These results suggest exaggerated humoral immunity in PSC. The raised levels of IL10 and IL8 in PSC are discussed in the context of inflammatory bowel disease and liver dysfunction.

Primary sclerosing cholangitis: a clinical review

Primary sclerosing cholangitis (PSC) is a cholestatic liver disease characterized by fibro-obliterative inflammation of the entire biliary tree. It is a slowly progressive disease with an undulating course, resulting in terminal biliary cirrhosis after a median period of about 12 years after diagnosis. The etiology of the disease is unknown and there is no effective therapy that can halt disease progression. Around 8% of PSC patients develop cholangiocarcinoma, which, by the time it is diagnosed, cannot be treated curatively. The purpose of this article is to review the current knowledge about primary sclerosing cholangitis and to speculate on future strategies to address the issues of etiology and therapy.

Autoimmune (Hashimoto's) thyroiditis associated with Crohn's disease

We report the occurrence of autoimmune (Hashimoto's) thyroiditis in three patients with Crohn's disease. Previously, thyroid disease has been described only in association with ulcerative colitis. We review the pertinent literature on thyroid disease in inflammatory bowel disease (IBD) and suggest that this association supports the hypothesis that autoimmunity is involved in the pathogenesis of IBD. Early diagnosis and treatment of thyroid dysfunction in patients with IBD is desirable because thyroid dysfunction worsens the symptoms and course of IBD.

Adenocarcinoma of the urachus and bladder expresses a unique colonic epithelial epitope: an immunohistochemical study

PURPOSE

Primary adenocarcinoma of the bladder is a rare neoplasm whose histogenesis is poorly understood. Current data support the concept that adenocarcinoma of the bladder and urachus evolves from zones of intestinal metaplasia that become dysplastic and invasive. To address this hypothesis further we determined the immunoreactivity of benign and malignant epithelial tissue from the bladder and urachus with a monoclonal antibody that is reactive with colonic epithelium to evaluate the presence of a common reactive epitope.

MATERIALS AND METHODS

The monoclonal antibody 7E12H12 (IgM isotype), developed against a colonic epithelial protein, was used in an immunoperoxidase assay to survey formalin fixed, paraffin embedded archival tissue specimens. A total of 26 specimens obtained by endoscopic biopsy or extirpative surgery, including benign and malignant bladder and urachal epithelial abnormalities, was chosen for retrospective evaluation.

RESULTS

All adenocarcinoma reacted positively regardless of the histological variant, differentiation, or bladder or urachal origin. In contrast, transitional cell and squamous cell carcinomas were nonreactive. Also, the pattern of reactivity in tissues that contained benign epithelial proliferations suggested a stepwise transition with no reactivity in normal urothelium or Brunn's epithelial nests, rare staining of cystitis cystica, and uniformly positive reactivity in cystitis glandularis and frank colonic intestinal metaplasia of the bladder and urachus.

CONCLUSIONS

The shared, aberrant phenotypic expression of a unique colonic epitope in benign epithelial metaplasia, and adenocarcinoma of the bladder and urachus suggests a common underlying pathway toward adenocarcinoma in cystic and urachal adenocarcinoma. The implications for diagnostic pathology are discussed.

Ulcerative colitis: an immunological disease?

Ulcerative colitis is an inflammatory disease of the large intestine of unknown aetiology. The nature of the inflammatory infiltrate together with the response to corticosteroids suggests that an abnormal immune response is at work. The key question of whether the immune system is responding to an abnormal breach in the mucosa due to another primary abnormality or whether the primary defect lies within the immune response itself has not been answered. Thus far, it is clear that both T and B cell compartments are involved in the persistence of inflammation but the initial interactions that take place in the mucosa in terms of antigen processing and presentation have not been adequately investigated. Those critical steps and potential defects that push T cells and B cells into a heightened state of activation need to be identified.

Patients with psoriasis have elevated levels of serum eosinophil cationic protein and increased numbers of EG2 positive eosinophils in the duodenal stroma

The occurrence of EG2-positive (EG2+) eosinophils and IgE in biopsy specimens of duodenal mucosa and skin from 39 psoriasis patients was studied, with emphasis on the relation to serum eosinophil cationic protein (ECP), serum IgE and the presence or absence of serum IgA and IgG antigliadin antibodies. Psoriasis patients had significantly elevated serum levels of ECP even after exclusion of five of 37 sera which were Phadiatop positive. The elevated serum ECP was not associated with the presence of IgA or IgG antibodies to gliadin. After exclusion of Phadiatop positive sera the serum IgE values did not differ from those of a group of healthy blood donors. Patients with psoriasis had a pronounced increase of EG2+ cells in their duodenal stroma. Patients without antibodies to gliadin tended to have even more EG2+ cells than those with such antibodies and those with increased duodenal intraepithelial lymphocytes. IgE+ cells were present in most duodenal specimens, and in some specimens there were > 100 IgE+ cells/section. The number of EG2+ cells was increased in lesional skin and, in some patients, also in non-involved skin, but there was a more pronounced increase in EG2 reactivity in the duodenal than in the skin specimens. IgE reactivity was increased both in non-involved and involved skin and was significantly related to the number of IgE-positive cells in the duodenal stroma. The results of this study indicate that the gastrointestinal tract and the eosinophil granulocyte might be involved in psoriasis in a hitherto unknown way.

Relationships between sclerosing cholangitis, inflammatory bowel disease, and cancer in patients undergoing liver transplantation

BACKGROUND

Liver transplantation has emerged as the definitive treatment for primary sclerosing cholangitis (PSC). Its relationships to inflammatory bowel disease and cholangiocarcinoma were evaluated in this series.

METHODS

Fifty-three liver transplantations were performed in 41 patients with PSC at the University of Wisconsin from 1986 through 1994. Fourteen of the patients underwent colectomies for inflammatory bowel disease, eight before transplantation and six after transplantation. Five patients had cholangiocarcinoma on the hepatectomy specimen, and another two had been diagnosed before transplantation.

RESULTS

Patient survival for PSC without cholangiocarcinoma was 85% and 62% at 2 and 9 years, respectively. No patient with PSC and cholangiocarcinoma has survived 2 years, although two patients were free of disease 11 and 20 months after transplantation. Despite maintenance immunosuppression seven patients with liver transplants had reactivation of inflammatory bowel disease and colon carcinoma developed in three after liver transplantation.

CONCLUSIONS

Liver transplantation should be performed early in the course of PSC to avoid the lethal complications of cholangiocarcinoma. Careful colonoscopic follow-up is necessary in patients undergoing transplantation for PSC because immunosuppressive therapy does not necessarily cause inflammatory bowel disease to be quiescent, nor does it reduce the risk of colon carcinoma developing.

Antibodies to colonic epithelial cells from the serum and colonic mucosal washings in ulcerative colitis

It has been suggested that antibodies to a colonocyte protein of 40 kD (an intestinal isoform of tropomyosin) are specifically found in the serum and mucosa of patients with ulcerative colitis, which has important pathogenic implications. This study isolated and purified tropomyosin from the colonic mucosa, but no specific binding to this protein has been detected in serum samples or immunoglobulins isolated from mucosal washings of 20 ulcerative colitis (UC) patients by enzyme linked immunosorbent assay (ELISA) compared with 21 controls or 17 Crohn's disease (CD) patients. Samples from a further 12 patients with UC and primary sclerosing cholangitis (it is proposed that cross reactivity against the intestinal tropomyosin isoform accounts for the extraintestinal disease) also did not show binding to tropomyosin, whereas monoclonal antitropomyosin antisera bound both ELISAs and western blots. This study also examined the proteins in the normal colonic biopsy specimens on western blots that are bound by both serum samples and mucosal immunoglobulin preparations from these patients groups; there was no specific IgG or IgA binding to patients with UC or UC/primary sclerosing cholangitis, whereas binding to mitochondrial proteins of 70,000 and 45,000 was seen in samples from 12 primary biliary cirrhosis positive controls. This work does not support the hypothesis that autoimmune activity against the intestinal isoform or tropomyosin is important in the pathogenesis of ulcerative colitis.

Expression of a unique protein on colon cancer cells that reacts with a novel monoclonal antibody and ulcerative colitis serum

We earlier developed a MoAb, 7E12H12 (IgM isotype), against a protein present in normal colonic epithelial cells. To examine if 7E12H12-reactive protein is expressed in colon cancer cells and is recognized by ulcerative colitis (UC)-associated autoantibody, we investigated several colon cancer cell lines. 7E12H12 reactivity against the cells was examined by indirect immunofluorescence assay and whole cell ELISA against six colon cancer cell lines HT-29, LoVo, COLO 205, DLD-1, LS 180 and SW 1116. A competitive ELISA was developed using 7E12H12 MoAb and patients' serum to examine the cross-reactive antibodies in the serum. Among the six colon cancer cell lines only LS 180, DLD-1 and SW 1116 reacted with 7E12H12 MoAb, while others did not. The mean (+/- s.e.m.) inhibition of the binding of 7E12H12 MoAb to LS 180 cells by UC serum (n = 51) was 42 +/- 2.1%, whereas in normal subjects (n = 17) it was 14 +/- 2.6%, in Crohn's disease (n = 19) it was 15.3 +/- 2.5%, in infectious diarrhoea (n = 10) it was 11% +/- 3%, and in systemic lupus erythematosus (n = 10) it was 2% +/- 0.6%. The inhibition by the UC group was significantly (P < 0.001 - < 0.0001) higher than any of the non-UC groups, and this inhibition was mainly by IgG1 antibody. The protein in the specific colon cancer cells recognized by the 7E12H12 MoAb cross-reacts with UC-IgG1 antibody and may provide an in vitro system to examine the autoimmune mechanisms in UC.

Ulcerative colitis associated with preceding systemic lupus erythematosus

We report a 50-year-old female patient who developed ulcerative colitis 31 after years being diagnosed with systemic lupus erythematosus. The overall clinical evaluation of her SLE activity differentiated ulcerative colitis from lupus colitis. Since the association of idiopathic systemic lupus erythematosus with ulcerative colitis has rarely been reported, the combination of these two diseases may be coincidental.

Autoimmunity in ulcerative colitis: tropomyosin is not the major antigenic determinant of the Das monoclonal antibody, 7E12H12

Ulcerative colitis (UC) has a proposed autoimmune pathogenesis. A 40-kD antigen (P40) has been isolated from UC colon, bound to immunoglobulin. Tropomyosin has been reported as the target antigen of a MoAb (7E12H12) raised against P40. We set out to investigate whether tropomyosin is the major antigenic determinant for 7E12H12. Formalin-fixed, paraffin-processed and cryostat sections of fresh frozen colon from patients with UC, Crohn's disease and normals, were immunostained with 7E12H12 and commercial anti-tropomyosin antibodies. In addition, the immunoreactivity of 7E12H12 with cytoskeletal components was examined on human endothelial cells (HUVEC) using anti-tropomyosin as a positive control. Con-focal microscopy was used to determine the subcellular localization of signal. An extract of total colonic protein from UC colon was prepared. Using a combination of Western and immunoblotting (dot-blots), the immunoreactivities of both tropomyosin (porcine and chicken) and colon protein extract with either 7E12H12 or commercial anti-tropomyosin were examined. Immunocytochemically, 7E12H12 localized to the apical and basolateral regions of plasma membrane, and to the supranuclear cytoplasm in colonic epithelium. Using anti-tropomyosin antibody it was not possible to identify the cytoskeleton in colonic epithelium. Cytoskeletal components were identifiable in HUVEC cultures with anti-tropomyosin antibody but not with 7E12H12. P40 antigen was identified in the colon protein extract by immunoblotting with 7E12H12. There was clear immunoreactivity between anti-tropomyosin antibody and both chicken and porcine tropomyosin, and the colon protein extract. 7E12H12 did not bind to either chicken or porcine tropomyosin in appropriately controlled systems. We conclude that the pattern of immunostaining with 7E12H12 is not cytoskeletal, and there is no reactivity in immunoblots, between tropomyosin and 7E12H12. Tropomyosin is not the major target antigen of this antibody in ulcerative colitis.

Variability of neoplastic parameters in colon tumours, and its significance in diagnostic practice

We have reviewed the value of individual variability in the reaction of tissues to treatment with carcinogens, and the manifestation of this variability in different morphological (histological, morphometric, and ultrastructural), histochemical and immunohistochemical parameters generated in tumorous tissues. Moreover, we also reviewed data in the literature on individual variability in the manifestation of some biochemical and immunochemical markers which are accumulated in the serum of tumour-bearing patients and which are characteristic for the different phases of tumourigenesis. The high variability of different tumorous parameters suggests that none can be utilized alone as a conclusive marker of neoplasia and that only their combined use can give objective information. We also reviewed the impact of this variability in the evaluation of various pathological methods to detect different stages of neoplastic transformation in the colon. It has been concluded that none of the present approaches can be absolutely conclusive and without false results, and that objective information regarding early cancerous changes may be obtained only by use of combined analyses utilizing several laboratory methods. The diagnostic procedures should be based on the complex utilization of all appropriate methods using the quantitative interpretation of the obtained data. Multivariate analysis of many parameters should be very effective for the prediction of therapeutic results.

Circulating granulocyte antibodies in first attacks of colitis

BACKGROUND

Antineutrophil cytoplasmic antibodies (ANCA) have recently been demonstrated in the sera of patients with inflammatory bowel disease (IBD).

METHODS

The presence of ANCA was studied in 107 sera obtained during 1 year from 48 patients with a first attack of IBD and in 33 such sera from 19 patients with infectious or infectious-type colitis (non-relapsing colitis (NRC)).

RESULTS

In 65% (31 of 48) of the IBD patients positive immunofluorescence reactivity against granulocytes was observed, compared with in 5% of the NRC patients. No significant difference in granulocyte reactivity was found either between patients with colonic Crohn's disease and those with ulcerative colitis or between active and inactive phases of the disease. Most of the sera showed a perinuclear immunofluorescence staining pattern (68%), in contrast to the classical cytoplasmic staining pattern seen in Wegener's granulomatosis. In sera obtained at the first visit from the 31 IBD patients with positive granulocyte reactivity a hitherto unknown antibody against beta-glucuronidase was found in 42%, whereas in 45% the specificity was not identified. Other antibodies, rarely seen, were directed against myeloperoxidase, lactoferrin, elastase, and cathepsin G. No antibody directed against lysozyme was detected.

CONCLUSIONS

Positive granulocyte reactivity practically excluded NRC and was seen in more than half of IBD patients. Antibodies against beta-glucuronidase were common, but still almost half of the antibodies remained unknown.

Circulating immunoglobulin G1 antibody in patients with ulcerative colitis against the colonic epithelial protein detected by a novel monoclonal antibody

Autoimmunity has been implicated in the pathogenesis of ulcerative colitis (UC). Several studies have shown amplified immunoglobulin G1 (IgG1) antibody response in UC; however the immunoreactive antigen(s) is unknown. To study this antigen(s), mucosal colonic extract was prepared by sonication, ultracentrifugation followed by ion exchange chromatography in fast protein liquid chromatography. The fraction (enriched colonic peptide), that was most reactive to a novel monoclonal antibody, 7E12H12 (IgM isotype), was isolated and used to examine the immunoreactivity against the patients' serum samples. Two hundred and thirteen coded samples from 111 patients with UC (symptomatic and untreated (63), symptomatic and treated (26), remission (22)); 47 with Crohn's disease (CD) (40 were symptomatic and untreated, and 30 had colonic disease); 29 with acute diarrhoea caused by specific pathogen(s); 10 with systemic lupus erythematosus, and 16 normal subjects were examined against the enriched colonic peptide by IgG subtype specific enzyme linked immunosorbent assays (ELISAs). Total IgG antibody reactivity was significantly (p < 0.01) higher only in symptomatic and untreated UC patients compared with each of the non-UC group, but the sensitivity was only 50%. IgG2 and IgG3 reactivities were not different among various groups. The IgG1 antibody reactivity against the enriched colonic peptide, however, differentiated UC patients from CD and each of the other non-UC groups. Seventy nine per cent of the patients with UC, treated or untreated, symptomatic or in remission, had significantly (p < 0.0001) higher IgG1 antibody against the enriched colonic peptide when compared with each of the other non-UC groups. Only 12% of CD serum samples and none of the other control serum samples reacted. Using purified serum IgG1 and 7E12H12-IgM, by 7E12H12 reactive peptide indeed reacts with UC-IgG1 antibody but not with control IgG1.

Hepatobiliary manifestations of inflammatory bowel disease

Several hepatobiliary disorders may be associated with inflammatory bowel disease (IBD). These various disease states can be diagnosed before, concomitant with, or after the diagnosis of IBD is made. This article describes these disorders, clinical features, evaluation, and possible treatment.

Current concepts in primary sclerosing cholangitis

OBJECTIVE

To describe primary sclerosing cholangitis (PSC) and its associated complications, as well as medical and surgical treatment.

DESIGN

A review of PSC and its associated etiopathologic factors is presented; numerous studies of agents that are used to treat patients with PSC are discussed.

RESULTS

PSC, a slowly progressive disease that often involves autoimmune damage to the biliary tree, is frequently associated with inflammatory bowel disease, usually chronic ulcerative colitis. Long-term follow-up of patients with PSC has revealed a high incidence of colon cancer and bile duct cancer, both of which are most likely related to the chronic inflammation involving these two organs. Although PSC is an unusual disease, it is now diagnosed with approximately the same frequency as is primary biliary cirrhosis. The histopathologic evolution of PSC results in irreversible damage to bile ducts, which ultimately leads to cholestasis, cirrhosis, liver failure, and premature death from liver failure unless liver transplantation is performed. Therefore, the best chance of achieving success is to treat patients with early-stage disease rather than those with irreversible end-stage cirrhotic disease. Although several medical therapies for PSC have been evaluated, only D-penicillamine, cyclosporine, methotrexate, and, most recently, ursodeoxycholic acid have been studied in controlled clinical trials. Furthermore, several surgical therapies for PSC and its associated complications have been assessed.

CONCLUSION

Currently, no therapy achieves a complete clinical, biochemical, or histologic remission in this disease. Until the etiopathogenesis of PSC is further defined, effective therapy is unlikely to be found. Thus, liver transplantation will continue to be an important therapeutic intervention for the management of patients with end-stage PSC.

A shared and unique peptide in the human colon, eye, and joint detected by a monoclonal antibody

BACKGROUND/AIMS

Extraintestinal manifestations of inflammatory bowel disease include involvement of the eye and joint. However, the pathogenesis of ocular and joint complications is unknown. The aim of the current study is to examine the presence of cross-reactive peptide in the colon and ocular and joint tissue.

METHODS

Using a murine monoclonal antibody (7E12H12; immunoglobulin M isotype) developed against a colon epithelial protein, various parts of the eyes (n = 10) and joints (n = 8) were examined. A sensitive immunoperoxidase assay was used.

RESULTS

In the ocular and joint tissues, the reactivity of 7E12H12 monoclonal antibody was exclusively present in the nonpigmented epithelial cells of the ciliary processes and chondrocytes, respectively. Other structures of the eyeball, such as the sclera, cornea, iris, and retina, and the synovium of the joints did not react with 7E12H12 monoclonal antibody. Colonic epithelial cells examined in parallel also reacted with the monoclonal antibody.

CONCLUSIONS

The colon epithelial cells share a unique peptide with the nonpigmented ciliary epithelial cells and chondrocytes. Future studies of the peptide(s) expressing this common epitope shared by the colon and extracolonic organs known to be involved in colitis may provide further understanding of the pathogenesis of extraintestinal complications in patients with ulcerative colitis.

Aetiology and pathogenesis of chronic inflammatory bowel disease

While Crohn's disease and ulcerative colitis are both conditions characterized by intestinal inflammation, with some overlap in their clinical and histological features, they are essentially different in pathogenesis. Crohn's disease appears to be primarily a condition of chronic T-lymphocyte activation, with tissue damage induced by secondary macrophage activation. What activates the T-cells is unknown. In this chapter we look at the evidence for and against cell-wall deficient mycobacteria species, viral infection of vascular endothelium and luminal contents as potential mechanisms of chronic activation. In ulcerative colitis, by contrast, there is no strong evidence for T-cell activation, and humoral mechanisms predominate. While the finding of atypical anti-neutrophil cytoplasmic antibodies (P-ANCAs) may be useful in screening, the only novel pathogenetic discovery is the co-localization of a 40 kD colonic autoantibody with immunoglobulins and complement on the apical enterocyte surface. Despite the fundamental differences in initiating mechanisms, the two conditions have many 'downstream' inflammatory processes in common. We discuss the evidence for local production of cytokines, arachidonic acid metabolites and reactive oxygen and nitrogen radicals, highlighting the potential adverse consequences for intestinal vascular integrity.

Systemic lupus erythematosus in association with ulcerative colitis: related autoimmune diseases

We report a patient who developed urticaria, angio-oedema and polyarthropathy secondary to the hypocomplementaemic urticarial vasculitis syndrome, a year prior to the onset of ulcerative colitis. Ten years later, primary sclerosing cholangitis and the antiphospholipid syndrome developed concomitantly. We believe this patient represents only the second reported case of idiopathic systemic lupus erythematosus (SLE) occurring in association with ulcerative colitis.

Autoantibodies in sclerosing cholangitis against a shared peptide in biliary and colon epithelium

BACKGROUND/AIMS

A strong association exists between ulcerative colitis and primary sclerosing cholangitis (PSC). Previously, the presence of a unique epitope shared by colon and biliary epithelial cells was shown by using the novel monoclonal antibody (MAb) 7E12H12 developed against a colonic epithelial protein. In the present study, the presence of circulating autoantibody in PSC against this peptide was examined.

METHODS

Sera from 16 patients with PSC, 13 with primary biliary cirrhosis, 6 with secondary biliary stricture, and 6 with chronic liver diseases and 10 normal subjects were used. An inhibition immunoperoxidase assay using the 7E12H12 MAb was developed against sections of bile duct and gallbladder. Sera were also examined in an enzyme-linked immunosorbent assay (ELISA) against the gallbladder extract enriched in 7E12H12-reactive protein.

RESULTS

About two thirds of the sera from patients with PSC blocked the binding of 7E12H12 MAb on the bile duct and gallbladder, whereas non-PSC sera did not. In the ELISA, 93% of PSC sera had circulating immunoglobulin G antibodies against the enriched gallbladder extract. The reactivity of sera from the PSC group was significantly (P < 0.01 to P < 0.0001) higher than in each of the non-PSC groups.

CONCLUSIONS

Sera from patients with PSC contains autoantibodies against a cross-reactive peptide shared by colon and biliary epithelial cells.

Etiology and pathogenesis in primary sclerosing cholangitis

The etiology and pathogenesis of the inflammatory and fibrotic bile duct lesions characteristic of primary sclerosing cholangitis (PSC) is unknown, but several lines of evidence support the contention that genetic and immunologic factors are involved. There is an association with human leukocyte antigens (HLA) with an increased frequency of DR3, DR6, and DR2 positive haplotypes. DRB3*0101(DR52a) is the most strongly associated allele in some studies, but the HLA gene conferring the primary HLA associated susceptibility to PSC remains to be established. There is an aberrant expression of HLA class II antigens (DR and DP) on bile duct epithelial cells, with the potential to present antigens to the surrounding T-lymphocytes. A defective suppressor T-cell function has been suggested in some studies. The patients may have elevated levels of circulating immune complexes, immunoglobulins, and non-organ-specific autoantibodies. Antibodies to perinuclear antigens (pANCA) are present in about 80% of cases. Increased metabolism of complement C3, reduced clearance of immune complexes, and increased concentration of biliary immune complexes have been found. The strong association between PSC and ulcerative colitis (UC) has not been explained. The detection of circulating IgG antibodies against a specific epitope shared by epithelial cells in the bile ducts and colon in about two-thirds of PSC patients may be of importance. Portal bacteremia secondary to a diseased bowel may possibly contribute to development of liver disease in UC. Viral infections and toxic and ischemic factors have also been implicated in the pathogenesis of PSC. In conclusion, PSC seems to occur in genetically predisposed individuals, mediated by immunologic mechanisms. The primary event triggering the disease development is, however, unknown.

Stress proteins in colorectal mucosa. Enhanced expression in ulcerative colitis

Stress (heat shock) proteins are ubiquitous intracellular proteins that can be induced in vitro by physiological stress events that occur during inflammation. We have used an indirect immunoperoxidase method to locate 60-kDa stress proteins in biopsies taken from normal and inflamed colorectal mucosa. An anti-60-kDa monoclonal antibody (ML30) produced specific staining of surface epithelial cells localized to the site of the Golgi apparatus. In ulcerative colitis, there was an increased concentration of this stress protein compared with controls (P < or = 0.002) and also with a small group of active Crohn's colitis (P < or = 0.01), but no relationship between its concentration and disease activity. All biopsies also showed staining of goblet cells by ML30, suggesting a possible cross-reaction with mucin; electroblotting of crude but not purified mucin showed a faint 60-kDa band with ML30. We conclude that the 60-kDa stress protein is present in normal colorectal epithelial cells and is markedly induced in vivo in ulcerative colitis. Further, we suggest that since the 60-kDa protein functions as a molecular chaperone, it may associate with colonic mucin aiding in its synthesis and/or secretion.

Neutrophil cytoplasmic autoantibodies after liver transplantation in patients with primary sclerosing cholangitis

The immunopathogenic importance of neutrophil cytoplasmic autoantibodies in ulcerative colitis and primary sclerosing cholangitis is unknown. These autoantibodies were investigated before and after liver transplantation in 9 patients with primary sclerosing cholangitis. Sera from 10 patients transplanted for metabolic disorders or hemangioma served as controls. Before liver transplantation neutrophil cytoplasmic autoantibodies, producing a perinuclear pattern by indirect immunofluorescence on ethanol fixed neutrophils, were present in all patients with primary sclerosing cholangitis. A decline in titer was noted in the first months after liver transplantation. During long-term follow up, the autoantibodies remained present and most often the titer did not differ from before transplantation. They were not directed against proteinase 3, myeloperoxidase, elastase or lactoferrin. All but one of the control patients were negative for the autoantibody. No relation was seen, before or after transplantation, with ulcerative colitis or proctocolectomy. There was no recurrence of primary sclerosing cholangitis in any of the patients as judged by liver histology. We conclude that neutrophil cytoplasmic autoantibodies remain present after liver transplantation for primary sclerosing cholangitis and that its synthesis is not related to the presence of the diseased organ(s). The primary disease process in primary sclerosing cholangitis and ulcerative colitis may well be a disturbance of the immune system.

Epithelial deposits of immunoglobulin G1 and activated complement colocalise with the M(r) 40 kD putative autoantigen in ulcerative colitis

The intestinal expression pattern and general tissue distribution of the M(r) 40 kD putative epithelial autoantigen in ulcerative colitis were re-examined by in situ two and three colour immunofluorescence staining including the murine monoclonal antibody 7E12H12. The intestinal distribution was also compared with the epithelial codeposition of IgG1 and activated complement (C3b and terminal complement complex) seen selectively in ulcerative colitis. The M(r) 40 kD antigen was found for the first time in goblet cells of normal terminal ileum and proximal colon but not in rectal goblet cells. By contrast, colonic enterocytes expressed this antigen apically with increasing intensity in a distal direction, expanding to intense cytoplasmic expression in rectal enterocytes. The antigen was also expressed by the epithelium of the fallopian tubes, major bile ducts, gall bladder, and epidermis but not by proximal gastrointestinal tract epithelium or 13 other extra-gastrointestinal organs. Activated complement and IgG1 often colocalised with the M, 40 kD antigen apically on the surface epithelium in active ulcerative colitis but not in Crohn's disease. Our results support the idea that an autoimmune response to this antigen, leading to complement activation mediated by IgG1, is a possible pathogenetic mechanism for epithelial damage and persistent inflammation in ulcerative colitis.

Serum antineutrophil cytoplasmic autoantibodies in inflammatory bowel disease are mainly associated with ulcerative colitis. A correlation study between perinuclear antineutrophil cytoplasmic autoantibodies and clinical parameters, medical, and surgical treatment

Perinuclear antineutrophil cytoplasmic antibodies have recently been demonstrated in the sera of patients with inflammatory bowel disease. Three hundred and sixty six sera obtained from 120 patients with ulcerative colitis, 105 patients suffering from Crohn's disease and 49 non-inflammatory bowel disease controls were tested in two laboratories, using an indirect immunofluorescence assay. In addition, a fixed-neutrophil enzyme linked immunoadsorbent assay (ELISA) was evaluated in one of the two laboratories. The results in the immunofluorescence test showed a high degree of correlation between the two laboratories (Kappa coefficient = 0.8). Ninety five of the 120 (79%) ulcerative colitis patients had a positive test whereas only 14 of the 105 (13%) patients with Crohn's disease were positive. Sera from four patients suffering from primary sclerosing cholangitis were positive as well as four of the 45 control sera (9%). The sensitivity of the perinuclear antineutrophil cytoplasmic antibody immunofluorescence test for the diagnosis of ulcerative colitis was 0.75 with a specificity of 0.88 and a positive predictive value of 0.88 (all sera). In the ELISA technique 37 of 94 ulcerative colitis sera and one of the 68 Crohn's disease sera were positive. In the control group only one of the patients suffering from primary sclerosing cholangitis reacted positively (32 non-inflammatory bowel disease sera tested). The ELISA technique had a high specificity (0.97), but a low sensitivity (0.39). There was no relation of perinuclear antineutrophil cytoplasmic antibodies in ulcerative colitis patients or in Crohn's disease patients with disease activity, duration of illness, localisation, extent of disease, previous bowel operations or medical treatment. The clinical significance of perinuclear antineutrophil cytoplasmic antibody positive and negative subsets in both groups of patients thus remains unexplained. Our study confirms that determination of serum antineutrophil cytoplasmatic antibodies in patients with inflammatory bowel disease may differentiate ulcerative colitis from Crohn's disease. Further immunological studies are needed to explain the absence of these antibodies in a subset of ulcerative colitis patients and their role in the pathogenesis of the disease.

The interrelation between sclerosing cholangitis and ulcerative colitis in patients undergoing liver transplantation

Thirty-six patients underwent orthotopic liver transplantation (OLT) for primary sclerosing cholangitis under cyclosporine, azathioprine, and steroid immunosuppression. Of these patients, 29 suffered from chronic ulcerative colitis. The purpose of this study is to determine (1) whether replacement of the diseased liver and the altered immunocompetence suppresses the manifestation of chronic ulcerative colitis, and (2) if active colonic disease alters allograft function. Thirty of 36 patients survived OLT. After OLT, seven of 14 patients with symptomatic colon disease at the time of transplantation continue to suffer from active chronic ulcerative colitis, and three of 13 who were asymptomatic developed clinically active disease. Intractable colonic disease was the indication for post-OLT proctocolectomy in three patients, and one refused an indicated colectomy. Despite the long duration of the disease, none developed colonic malignancy. Long-term graft assessment showed good hepatocyte synthetic function in patients suffering from either active or inactive disease. Liver alkaline phosphatase, however, was significantly higher in patients suffering from active colonic disease. Furthermore, the alkaline phosphatase in symptomatic patients was higher than that seen in a matched cohort undergoing OLT for chronic active hepatitis or primary biliary cirrhosis. These results suggest that (1) liver replacement and immunosuppression in patients suffering from sclerosing cholangitis and ulcerative colitis do not alter the course of the colon disease, and (2) active chronic ulcerative colitis does not adversely affect allograft function, although elevation of alkaline phosphatase may be the harbinger of recurrence over the long term.

Expression of the 40 kD protein in DLD-1 colon cancer cells and the effect of cytokines

We recently reported the presence of an organ-specific 40 kD colonic protein which acts as an autoantigen(s) in patients with ulcerative colitis. Using a specific monoclonal antibody directed against 40 kD protein (7E12H12, IgM isotype), in conjunction with immunocytochemistry and flow cytometry, we examined the presence of the 40 kD protein on human colon cancer cells, DLD-1, and also characterized the ability of cytokines, IFN-gamma and tumour necrosis factor, to modulate the expression of this protein on these tumour cells. The presence of the 40 kD protein was localized to the plasma membrane; less was present within the cytoplasm. Following exposure to IFN-gamma (10-1000 U/ml), DLD-1 colon tumour cells showed a dose- and time-dependent increase in 7E12H12 antibody associated immunofluorescence, with the maximum 7E12H12 antibody binding observed with 100 U/ml IFN-gamma at 48 h. In contrast, tumour necrosis factor did not alter the levels of anti-40 kD antibody binding over that of control cells. Since IFN-gamma is also known to induce class II major histocompatibility antigens, we examined the possibility of cross-reactivity of HLA class II antigens and Mr 40 kD epitope. Neither pre-incubation of DLD-1 colon tumour cells with anti-HLA class II antibodies followed by 7E12H12 nor co-incubation of both antibodies altered the amount of 7E12H12 antibody binding. Using a direct ELISA, a highly enriched preparation of Mr 40 kD protein reactive to anti-40 kD antibody did not react with HLA class II antibodies. The present results suggest that 40 kD protein is present on DLD-1 human colon tumour cells and that although the 40 kD protein epitope expression is increased by the lymphocyte-derived cytokine, IFN-gamma, the epitope is separate and distinct from the class II HLA antigens. Further studies on the 40 KD protein may elucidate its autoantigenic role in the pathogenesis of inflammatory bowel disease.

Inflammatory bowel disease. Part I: Nature and pathogenesis

Once regarded as medical curiosities, ulcerative colitis and Crohn's disease have achieved a remarkable change in status recently and today are among the more compelling of all human illnesses. The cause(s) of inflammatory bowel disease (IBD) are not known. Genetic, environmental, microbial, and immunologic factors are involved, but the precise mechanisms are obscure. The incidence of ulcerative colitis is relatively stable, while Crohn's disease continues to increase in frequency. In 10% to 15% of patients, it is hard to differentiate between ulcerative colitis and Crohn's colitis; however, problems with diagnosis usually resolve with time and repeated examinations. In part I of his two-part monograph on IBD, Dr. Kirsner addresses the nature and pathogenesis of the disease. Increased study of ulcerative colitis and Crohn's disease in recent years has generated new knowledge regarding their etiology. Part I focuses on microbial, immunologic, and genetic mechanisms and the inflammatory processes involved in the disease. In part II, which will be presented in next month's issue of Disease-a-Month, Dr. Kirsner deals with the clinical features, course, and management of IBD, based on the author's 55 years of experience with these problems and supplemented by critical examination of the recent (1988-1990) literature. Particular attention is directed to the symptoms and physical findings of ulcerative colitis and Crohn's disease, the laboratory, radiologic, endoscopic, and pathologic features, and the many systemic complications. The IBDs are mimicked by several enterocolonic infections and other conditions, making differential diagnosis necessary. Inflammatory bowel disease in children and the elderly conforms to conventional clinical patterns modified by the health circumstances of the respective age groups. Because the cause of IBD has not been established, current medical therapy is facilitative and supportive rather than curative. The principles of medical treatment are approximately the same for ulcerative colitis and Crohn's disease. Treatment emphasizes a program rather than a drug and also considers the individuality of the therapeutic response. A clearer understanding of dietary and nutritional needs, including hyperalimentation and electrolyte and fluid balance, aids treatment. Antidiarrheal and antispasmodic preparations and sedatives are prescribed for symptom relief. The bowel inflammation is controlled with sulfasalazine or the newer 5-amino salicylic acid (5-ASA) compounds, antibacterial drugs for complications of Crohn's disease and IBD, adrenocortical steroids, and the immunosuppressive compounds 6-mercaptopurine (6-MP), azathioprine, and cyclosporine, as determined in each patient. The surgical procedures available for treatment of ulcerative colitis include total proctocolectomy and ileostomy or ileoanal anastomosis.(ABSTRACT TRUNCATED AT 400 WORDS)