Isolation of reovirus-like agents from patients with Crohn's disease

Chlamydia Trachomatis and Inflammatory Bowel Disease - a Coincidence?

Serological tests of 35 patients suffering from inflammatory bowel disease were compared to those of 35 healthy controls. The tests were performed using the indirect immunoperoxidase assay. Ninety-three per cent of 15 patients with Crohn's disease had IgG antibodies against Chlamydia, compared to 26% in the control group. In the 20 patients with ulcerative colitis, 45% had IgG antibodies against Chlamydia, compared to 10% in the control group. High serum titres of IgG antibodies were found in most of the patients with inflammatory bowel disease, mainly with Crohn's disease, while weak reactions appeared in most of the controls in which antibodies were detected. These results suggest a high incidence of Chlamydia infection in the studied patients with inflammatory bowel disease, especially in those with Crohn's disease. The possible association between Chlamydia trachomatis and inflammatory bowel disease is discussed.

Enteropathogenic viruses: triggers for exacerbation in IBD? A prospective cohort study using real-time quantitative polymerase chain reaction

BACKGROUND

While the role of bacteria as an etiological factor triggering relapse in inflammatory bowel disease (IBD) has been studied extensively, little is known of the role of enteric viruses. We aimed to prospectively study the prevalence and risk factors for common enteropathogenic viruses in IBD patients in relation to disease activity.

METHODS

IBD patients visiting the outpatient clinic of the Maastricht University Medical Center were included in a prospective cohort with a follow-up of 1 year. Every 3 months and during relapses, fecal samples, demographic, and clinical data were collected and disease activity was scored. A fecal sample from patients at baseline (Crohn's disease [CD] n = 170, ulcerative colitis [UC] n = 116) and an additional sample from a subgroup with changing disease activity during follow-up (CD n = 57, UC n = 31) were analyzed for the presence of rotavirus, norovirus GI and GII, human astrovirus, and adenovirus using quantitative polymerase chain reaction (qPCR).

RESULTS

Overall viral pathogen detection, defined by the detection of at least one of the studied viruses, at baseline was 5.2% and differed neither between CD (6.5%) or UC patients (3.4%) (P = 0.20), nor between active disease (4.7%) and remission (5.5%) (P = 0.79). Within the subgroup of patients with changing disease activity no association was found between overall viral pathogen detection and disease activity (P = 0.39). Using multivariate logistic regression, age, gender, disease subtype, disease activity, medication, and season of sampling were not associated with overall viral pathogen detection.

CONCLUSIONS

Enteropathogenic viruses are not frequently observed in a consecutive cohort of IBD patients and are not a common trigger for active disease in daily clinical practice.

Current knowledge and systematic review of viruses associated with Crohn's disease

The aetiology of Crohn's disease (CD) is currently unknown. A viral trigger was proposed more than 40 years ago and has been the focus of many investigations. We summarised the current literature surrounding the association between viruses and CD and conducted a systematic review of all studies investigating this association quantitatively. Studies were identified by searching for 13 specific virus names or the general term 'virus' and 'Crohn's disease' in search engines PubMed and OVID. A total of 1315 studies were identified, of which 78 studies had a laboratory result. Of the 78, 46 case-control studies met all the inclusion criteria for forest plot analysis. The most common viruses studied were EBV, CMV and measles virus (MV). Forest plot analysis for each virus was carried out (fitted using random effects) and identified evidence of an association between CD and CMV (risk ratio [RR] 1.602, 95% confidence interval [CI] 1.069 to 2.400) with some suggestion that EBV may also be associated with CD (RR 1.366, 95% CI 0.996 to 1.873). However, there was evidence of large heterogeneity in the results from the identified studies for EBV. There was little evidence of an association with CD for MV, human herpes virus 6, human herpes virus 8, human simplex virus, varicella-zoster virus, mumps virus, Rubella virus, rotavirus, norovirus and adenovirus. There is still some question around whether CD is associated with the presence of a currently known virus.

Detection of immunoreactive antigen, with a monoclonal antibody to measles virus, in tissue from a patient with Crohn's disease

Using immunofluorescence (IF), we investigated reactive antigens present in Crohn's disease patients with monoclonal antibodies derived from cells infected with measles virus, but not with the subacute sclerosing panencephalitis virus. During immunoblotting, one monoclonal antibody (mAb 86) reacted with a polypeptide with a molecular weight of 36,000 dalton (M; matrix protein) in measles virus-infected cells. This monoclonal antibody displayed a positive reaction only with tissues from patients with Crohn's disease by the IF test. It did not react with samples from patients with other chronic inflammatory bowel diseases, such as ulcerative colitis. Other monoclonal antibodies to the measles virus protein, and monoclonal antibodies to Herpes simplex virus type 1 did not react with the same tissue samples. The role of measles virus infection and/or a viral antigen (possibly the M protein) as a causative agent in Crohn's disease poses a challenging avenue for further research.

Crohn's disease: ancient and modern

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Rotaviruses: immunological determinants of protection against infection and disease

Although studies of rotavirus immunity in experimental animals and humans have often yielded conflicting data, a preponderance of evidence supports the following answers to the questions initially posed. 1. What is the importance of virus serotype in formulating an optimal vaccine? Both vp4 and vp7 induce virus-neutralizing antibodies after either natural infection or immunization; the capacity of vp4 to induce rotavirus-specific neutralizing antibodies is probably greater than that of vp7. However, protection against disease after immunization of infants and young children is induced by strains heterotypic to the challenge virus (e.g., immunization with WC3 induces protection against disease induced by serotypically distinct human G1 strains). In addition, oral inoculation of infants with primate or bovine reassortant rotaviruses containing genes that encode human vp7 has not consistently induced a higher level of protection against challenge than that induced by parent animal rotaviruses (see Table I). Therefore, although vp4 or vp7 or both are probably important in inducing protection against challenge, it has not been clearly demonstrated that inclusion of the epidemiologically important human (as distinct from animal) P or G type is important in protection against human disease. 2. Which immunological effector arm most likely protects against rotavirus disease? No immunological effector arm clearly explains protection against heterotypic challenge. Protection against disease is not predicted by rotavirus-specific neutralizing antibodies in serum. Rotavirus-specific, binding sIgA in feces [detected by enzyme-linked immunosorbent assay (ELISA)] induced after natural infection does correlate with protection against disease induced by subsequent infection. However, protection after immunization with WC3 may occur in the absence of a detectable fecal sIgA response. The relationship between rotavirus-binding sIgA and sIgA-mediated neutralizing activity directed against the challenge virus remains to be determined. Binding rotavirus-specific sIgA in feces detected by ELISA may only be a correlate of other events occurring at the intestinal mucosal surface. The presence of broadly cross-reactive, rotavirus-specific CTLs at the intestinal mucosal surface of mice acutely after infection is intriguing. It would be of interest to determine the degree to which the presence of cross-reactive, rotavirus-specific CTLs in the circulation is predictive of the presence of virus-specific CTLs among intestinal lymphocytes and protection against challenge. Unfortunately, studies of virus-specific CTLs are difficult to perform in children. 3. By what means is virus antigen best presented to the host to elicit a protective immune response? Oral inoculation may not be necessary to induce a protective, virus-specific immune response at the intestinal mucosal surface.(ABSTRACT TRUNCATED AT 400 WORDS)

Etiology of inflammatory bowel diseases: where have we been? Where are we going?

The cause or causes of Crohn's disease and of ulcerative colitis remain uncertain. In spite of extensive investigations, searching for immunologic or infectious causes, clear evidence suggesting an underlying etiology is lacking. Recent studies involving mycobacteria suggest that occasional patients thought to have Crohn's disease may indeed be infected with a mycobacterium. However, clear cause-and-effect relationships have not been established. Future efforts at trying to establish the relationship between environmental factors, including infectious agents, and immunologic mediators seem appropriate on the basis of available data. For the present, the causes or cause of these diseases remains obscure.

Crohn's disease and the mycobacterioses: a review and comparison of two disease entities

Crohn's disease is a chronic granulomatous ileocolitis, of unknown etiology, which generally affects the patient during the prime of life. Medical treatment is supportive at best, and patients afflicted with this disorder generally live with chronic pain, in and out of hospitals, throughout their lives. The disease bears the name of the investigator who convincingly distinguished this disease from intestinal tuberculosis in 1932. This distinction was not universally accepted, and the notion of a mycobacterial etiology has never been fully dismissed. Nevertheless, it was 46 years after the distinction of Crohn's disease and intestinal tuberculosis before research attempting to reassociate mycobacteria and Crohn's disease was published. Recently, there has been a surge of interest in the possible association of mycobacteria and Crohn's disease due largely to the isolation of genetically identical pathogenic Mycobacterium paratuberculosis from several patients with Crohn's disease in the United States, the Netherlands, Australia, and France. These pathogenic organisms have been isolated from only a few patients, and direct evidence for their involvement in the disease process is not clear; however, M. paratuberculosis is an obligate intracellular organism and strict pathogen, which strongly suggests some etiologic role. Immunologic evidence of a mycobacterial etiology, as assessed by humoral immune determinations, has been conflicting, but evaluation of the more relevant cellular immunity has not been performed. Data from histochemical searches for mycobacteria in Crohn's disease tissues have been equally conflicting, with acid-fast bacilli detected in 0 to 35% of patients. Animal model studies have demonstrated the pathogenic potential of isolates as well as elucidated the complexity of mycobacterial-intestinal interactions. Treatment of Crohn's disease patients with antimycobacterial agent has not been fully assessed, although case reports suggest efficacy. The similarities in the pathology, epidemiology, and chemotherapy of Crohn's disease and the mycobacterioses are discussed. The issue is fraught with controversy, and the data generated on the association of mycobacteria and Crohn's disease are in their infantile stages so that a general conclusion on the legitimacy of this association cannot be made. While no firm evidence clearly implicates mycobacteria as an etiologic agent of Crohn's disease, the notion is supported by suggestive and circumstantial evidence and a remarkable similarity of Crohn's disease to known mycobacterial diseases.

[Genetics of Crohn disease: study of the HLA association in 169 patients]

Histocompatibility (HLA) antigen phenotypes have been studied in 169 patients with Crohn's disease. The following results could bei shown: HLA-Aw33, -B45 and -Cw3 showed a positive association and HLA-A26, -DR3 and -DRw8 a negative association with Crohn's disease compared to healthy controls. However, when the p-values were corrected by multiplying them by the number of determined antigens per gen-locus, the differences were not significant. Patients with a late onset of the disease (greater than 25 years) showed a statistical significant negative association with HLA-DR3. Numerous studies revealed no significant association between Crohn's disease and HLA-antigens except Smolen et al. (HLA-B12). The significant association of Crohn's disease and HLA-B12 reported by Smolen et al. could be caused by an increased frequency of HLA-B45 as we found in our patients.

Lymphocytotoxic and microbial antibodies in Crohn's disease and matched controls

Patients with Crohn's disease and age, sex and seasonally matched healthy controls were studied for cold lymphocytotoxic and a variety of microbial antibodies. Lymphocytotoxic antibody titers were increased significantly in the Crohn's patients compared to controls, but did not correlate with any of the microbial titers. Antibodies to a Pseudomonas-like bacterium and Bacteroides vulgatus were also increased in the patients, but titers to Chlamydia trachomatis, rotavirus and Norwalk virus were not elevated above control values. Analysis of microbial antibody within the patient and control groups revealed a significant (P = .001) correlation between antibodies to the Pseudomonas-like bacterium and Bacteroides vulgatus. The elevated titers to the Pseudomonas-like organisms and B. vulgatus are of potential importance, but their significance is not known at this time. There is no evidence of an increased incidence of infection with C. trachomatis, rotavirus or Norwalk virus in Crohn's disease.

Crohn's disease: transmission electron microscopic studies. III. Target tissues. Proliferation of and injury to smooth muscle and the autonomic nervous system

Transmission electron microscopy was done on surgical specimens from 12 patients with Crohn's disease and three control subjects. Nonulcerated involved areas of ileum as well as proximal, grossly uninvolved resection margins were chosen for study. Specimens for transmission electron microscopy were prepared by a variety of techniques and 112 blocks were examined by electron microscopy. The study was concentrated on two target tissues of the gut: the autonomic nervous system and the smooth muscle. Proliferative and injurious changes were found in each. Proliferation, myofibroblastic transformation, hypercontraction, and necrosis characterized the smooth muscle changes seen in Crohn's disease of the ileum. Autonomic nervous system changes included proliferation of axons containing dense core granules (catecholamines) and axonal necrosis. The possible pathogenetic significance of these changes is discussed here and in the accompanying article beginning on page 606 of this issue.

Crohn's disease in an isolated rectal stump

A case is reported which illustrates the development of Crohn's disease in an isolated rectal stump occurring four-and-a-half years after subtotal colectomy for multiple polyposis coli. There was no evidence of more proximal small-bowel or colonic Crohn's disease. To our knowledge no similar occurrence has been reported in the literature.

Immune status in Crohn's disease. 4. In vitro antibody dependent cell mediated cytotoxicity in peripheral blood

In Crohn's disease (CD) a potential etiopathogenetic role of the antibody dependent cell mediated cytotoxicity (ADCC) has been discussed. By means of a 51Cr release assay with an established human lymphoblastoid cell line as target, the in vitro ADCC activity was studied in the peripheral blood of 34 patients with CD. 11 patients with inflammatory bowel disease other than CD or ulcerative colitis (group D) and 45 sex and age matched healthy people served as controls. In unseparated mononuclear cell suspensions, we found a significantly lower ADCC activity in CD patients and in group D than in normals. Depletion of both phagocytic and plastic adherent cells, i.e. macrophages, resulted in complete normalisation of the ADCC activity in all patients of group D and also two-thirds of the CD patients. However, the remaining one third CD patients still exhibited ADCC activity below 1 standard deviation of normal. Most of these latter CD patients had highly active disease. Thus, this study showes that the general ADCC per se is normal in CD, except for a decrease in patients with high activity of disease. However, the normal general ADCC activity per se is significantly suppressed by phagocytic, plastic adherent cells. In this regard similar results were found in group D.

New concepts in viral gastroenteritis

The use of negative contrast electronmicroscopy of stool suspension in the investigation of the aetiology of childhood gastroenteritis has led to the recognition of a number of candidate viral agents. There is convincing evidence that rotavirus is the single most important cause of community acquired gastroenteritis, and is responsible for some nosocomial outbreaks. The epidemiology of rotavirus acqusition, differential clinical susceptibilities of young and older infants, pathogenesis of disease, mechanisms of immunity and breast milk protection, and the role of different viral serotypes are aspects as yet poorly understood; and attempts to propagate human rotavirus in tissue culture have met with only limited success. Moreover, the aetiologically unaccountable one third of cases of infantile diarrhoea, and the association of enteritis with up to six other virus-like particles add to the complexity of the problem. This review considers the available data from human and animal studies, and based on the experience of ourselves and others comments on the present state of knowledge and trends in continuing research.

Crohn disease lymph node homogenates produce murine lymphoma in athymic mice

To study the putative agent(s) related to Crohn disease, we intraperitoneally in injected mesenteric lymph node homogenates from four patients with active Crohn disease into 10-week-old athymic (nu/nu) mice. Control mice (nu/nu) were injected with homogenates of mesenteric lymph nodes from two patients with ulcerative colitis and four patients undergoing elective cholecystectomy, and with a homogenate of a cervical lymph node containing sarcoid granuloma. Thirty-four mice received filtered or unfiltered homogenates from Crohn disease lymph nodes. Thirty-two mice received homogenates or filtrates from lymph nodes of control patients. Four mice from the group injected with Crohn disease homogenates from four different patients developed generalized lymphadenopathy due to lymphoma 10-28 weeks after th injection. Two additional mice developed lymphadenopathy due to plasma cell hyperplasia. None of the control mice developed lymphomas or lymphadenopathy. Two lymphomas were homogenized, filtered, and injected intraperitoneally into a second group of nu/nu mice, which also developed lymphoma within 8 weeks of injection. Two lymphomas were cultured in vitro and B cell sur?ACE MARKERS WERE IDENTIFIED. Indirect immunofluorescence studies in two lymphomas showed cytoplasmic staining of lymphoma cells with sera from 10 patients with active Crohn disease but not with sera from 13 control subjects, including 6 with ulcerative colitis and 7 with other gastrointestinal disorders. These results suggest that a transmissible factor present in Crohn disease lymph nodes produces lymphoma in nu/nu mice. Furthermore, sera of Crohn disease patients contain an antibody that recognizes an "antigen(s)" in the murine lymphoma.

Low frequency of chlamydial antibodies in patients with Crohn's disease and ulcerative colitis

Serum samples from 55 patients with Crohn's disease and from 23 patients with ulcerative colitis were tested for antibodies to Chlamydia trachomatis immunotypes by a micro-immunofluorescence technique. Antibody titres of 1:8 or greater against several immunotypes were detected in 14.5% of patients with Crohn's disease and in 21.7% of those with ulcerative colitis. These figures resemble the incidence in a healthy, non-venereal-disease population. Furthermore, there was no correlation between the presence of antibody and such factors as duration of symptoms, localisation of disease, or disease activity. These findings indicate that there is no reason to believe that Crohn's disease involves chlamydiae or that examination for chlamydial antibody is helpful in diagnosis.

Search by immunofluorescence for antigens of Rotavirus, Pseudomonas maltophilia, and Mycobacterium kansasii in Crohn's disease

Crohn's-disease tissue was tested by indirect immunofluorescence for antigens of rotavirus, Pseudomonas maltophilia, and Mycobacterium kansasii. No reactions were obtained with anti-serum to P. maltophilia and M. kansasii, and a granular fluorescence seen with rotavirus antibody was probably non-specific.

Crohn's disease in a husband and wife

The case-histories of a husband and wife in whom Crohn's disease developed after more than 30 years of marriage are described.