Antibodies to Mycobacterium paratuberculosis and nine species of environmental mycobacteria in Crohn's disease and control subjects.

Cultural and serological studies have provided limited, often conflicting, evidence of a role for mycobacteria in the pathogenesis of Crohn's disease. Interest has focussed on Mycobacterium paratuberculosis, previously considered to be common in the environment with no major role as a human pathogen. Whether a specific serum antibody response to mycobacteria occurs in Crohn's disease or ulcerative colitis was investigated. Sera from patients with Crohn's disease (n = 38), ulcerative colitis (n = 15), and a healthy control population (n = 30) were assayed in an enzyme linked immunosorbent assay (ELISA) using eight filtered sonicate mycobacterial preparations and a purified protein derivative made from the bovine tubercle bacillus. In addition, IgG, IgM, and IgA levels to M paratuberculosis were determined in sera from patients with active (n = 24) or inactive (n = 29) Crohn's disease and the control populations. There was strong evidence of contact with environmental mycobacteria in all patients and control populations, with the greatest responses to preparations of M avium, M tuberculosis, and M kansasii. A large proportion of patients with Crohn's disease had antibodies that bound most antigens tested but there were no statistical differences between these values and those of the control population. Similarly, there were no differences in antibody levels to M paratuberculosis in patient and control groups. Although a subset of patients with active Crohn's disease (25%) had IgG concentrations that exceeded the control mean by more than 2 SD, this phenomenon may not be specific to Crohn's disease: 20% of a small group of patients with coeliac disease had similarly raised IgG levels to M paratuberculosis. These findings do not provide serological evidence of a role for this organism in the pathogenesis of Crohn's disease.     

克隆产现与副结核杆菌

分支杆菌、尤其是副结核杆菌长期被疑为克隆病的致病菌。采用聚合酶链反应技术对手术及内镜活检的７４例石蜡包埋组织中的副结核杆菌ＤＮＡ进行检测。扩增的靶ＤＮＡ为副结核杆菌染色体特异重复插入序列ＩＳ９００１上４００ｂｐ的片段。其产笺特异性通过生物素杆主民的副结核杆菌全染色体探针Ｓｏｕｔｈｅｒｎ杂交证实。     

Mycobacterial aetiology of Crohn's disease: serologic study using common mycobacterial antigens and a species-specific glycolipid antigen from Mycobacterium paratuberculosis.

Crohn's disease is a granulomatous form of enteritis superficially similar to Johne's disease (paratuberculosis) of ruminants. Recently, a Mycobacterium sp closely related to Mycobacterium paratuberculosis was cultured from tissues of patients with Crohn's disease suggesting that M paratuberculosis may be the aetiologic agent in some cases. In addition, greater seroreactivity to M paratuberculosis has been reported in patients with Crohn's disease. In the present study, we have evaluated the serum antibody response to disrupted M paratuberculosis using ELISA and serum specimens from 33 people with Crohn's disease, 21 with ulcerative colitis, and 12 non-inflammatory bowel disease controls. We failed to find a consistent IgG, IgM, or IgA antibody response to Mycobacterium paratuberculosis. The results indicate that, as in bovine paratuberculosis, serum seroreactivity is not a reliable tool for examining the relationship between human intestinal disease and mycobacteria.     

Mycobacterium paratuberculosis and Crohn''s disease.

The possible aetiological role of Mycobacterium paratuberculosis in Crohn's disease was investigated. The immunological response was studied using an enzyme-linked immunosorbent assay (ELISA), Western blotting, and immunocytochemistry. The antibody response to two protoplasmic antigen preparations of M paratuberculosis in the sera of patients with inflammatory bowel disease was measured by ELISA. IgG and IgM antibodies to these antigens were measured in serum samples from 52 patients with Crohn's disease, 15 patients with ulcerative colitis, and 41 control patients without inflammatory bowel disease. Although there was wide variation in the concentrations of antibody detected, patients with Crohn's disease had concentrations that were not significantly different from those of the other two groups. In addition, mycobacterial antigens were separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis and the immune response to each antigen was then examined separately and assayed for IgG and IgM in 10 patients from each of the three groups. An indirect peroxidase test was also used to detect M paratuberculosis in sections of tissue from 18 patients with Crohn's disease and 10 with ulcerative colitis. The results were negative in all cases. This study does not support a role for M paratuberculosis in Crohn's disease.     

Molecular evidence for Mycobacterium avium subspecies paratuberculosis (MAP) in Crohn''s disease correlates with enhanced TNF-α secretion

BACKGROUND: Support for a role of Mycobacterium avium subspecies paratuberculosis in Crohn's disease is largely based on epidemiological evidence, as no data on mechanisms linking the presence of M. avium subspecies paratuberculosis with gut damage is available. AIMS: To determine whether the presence of M. avium subspecies paratuberculosis contributes to the pathogenesis of Crohn's disease by promoting cytokine secretion within gut mucosa. PATIENTS AND METHODS: A total of 235 subjects were recruited: 63 with Crohn's disease, 53 with ulcerative colitis, 45 with irritable bowel syndrome and 74 normal controls. M. avium subspecies paratuberculosis status was defined by nested PCR using IS900 sequence. Gut mucosal organ cultures were established to detect cytokine secretion patterns. RESULTS: Significantly higher tumour necrosis factor-alpha concentrations were found in culture supernatants for Crohn's disease compared to ulcerative colitis (p<0.05), irritable bowel syndrome (p<0.01) and controls (p<0.0001). When tumour necrosis factor-alpha levels were correlated with the presence of M. avium subspecies paratuberculosis, significantly greater concentrations were only found in M. avium subspecies paratuberculosis-positive Crohn's disease patients (p<0.05). Tumour necrosis factor-alpha levels in M. avium subspecies paratuberculosis-positive Crohn's disease were significantly higher than in M. avium subspecies paratuberculosis-positive ulcerative colitis (p<0.01), M. avium subspecies paratuberculosis-positive irritable bowel syndrome (p<0.05) and M. avium subspecies paratuberculosis-positive controls (p<0.01) and all M. avium subspecies paratuberculosis-negative specimens. CONCLUSIONS: The data link M. avium subspecies paratuberculosis with a pathogenic mechanism in Crohn's disease and is consistent with abnormal macrophage handling of M. avium subspecies paratuberculosis.     

Specific detection of Mycobacterium paratuberculosis DNA associated with granulomatous tissue in Crohn's disease.

The role of mycobacteria, specifically Mycobacterium paratuberculosis, in Crohn's disease has aroused considerable controversy for many years. Using the ultra sensitive polymerase chain reaction some studies have reported detection of M paratuberculosis DNA in as many as 65% of Crohn's disease patients but also in patients without disease. Other studies have been negative for both groups. We therefore designed a double blind control trial to investigate the presence of mycobacterial DNA in age, sex, and tissue matched paraffin wax embedded tissues from 31 Crohn's disease tissues, 20 diseased gut control tissues, and 10 ulcerative colitis tissues. The specimens were coded and analysed blind with three separate polymerase chain reactions (PCR) based on DNA sequences specific for M paratuberculosis (IS900), M avium (RFLP type A/1) (IS901), and the Mycobacterium genus (65 kDa gene, TB600). The number of granulomata and presence of acid fast bacilli in each Crohn's disease tissue was also investigated. The sensitivity of the system was determined using similarly prepared gut tissue from an animal infected with M paratuberculosis. Four of 31 Crohn's disease tissues and none of the 30 control and ulcerative colitis derived tissues amplified M paratuberculosis DNA. Crohn's disease tissues containing granulomata were significantly more likely to amplify M paratuberculosis specific DNA on PCR than the non-Crohn's disease tissues (p = 0.02). All the positive Crohn's disease tissues contained granulomata, and none contained acid fast bacilli. Equivalent numbers of Crohn's and non-Crohn's disease tissues amplified the region of the 65 kD gene on PCR for non-specific mycobacterial DNA (11/31 and 9/30 respectively). No sections produced an amplified product with the IS901 PCR. These results suggest that few Crohn's disease gut biopsy sections contain M paratuberculosis DNA in association with granulomata. The absence of such DNA in any control and ulcerative colitic tissue strengthens the case for it having a specific association, which may be pathogenic, with Crohn's disease in this minority of patients.     

Mycobacterium paratuberculosis DNA in Crohn''s disease tissue.

Crohn's disease has long been suspected of having a mycobacterial cause. Mycobacterium paratuberculosis is a known cause of chronic enteritis in animals, including primates, but may be very difficult to detect by culture. IS900 is a multicopy genomic DNA insertion element highly specific for M paratuberculosis. A polymerase chain reaction (PCR) based on the 5' region of IS900 and capable of the specific detection of a single M paratuberculosis genome was developed. This was applied to DNA extracts of full thickness samples of intestine removed at surgery from 40 patients with Crohn's disease, 23 patients with ulcerative colitis, and 40 control patients without inflammatory bowel disease. Stringent precautions were taken that excluded contamination artefact. M paratuberculosis was identified in 26 of 40 (65%) Crohn's disease, in 1 of 23 (4.3%) ulcerative colitis, and in 5 of 40 (12.5%) control tissues. Positive samples from Crohn's disease were from both the small intestine and colon, those from control tissues were from the colon those from control tissues were from the colon only. All PCR internal control reactions were negative. The presence of M paratuberculosis in a small proportion of apparently normal colonic samples is consistent with a previously unsuspected alimentary prevalence in humans. The presence in two thirds of Crohn's disease tissues but in less than 5% of ulcerative colitis tissues is consistent with an aetiological role for M paratuberculosis in Crohn's disease.     

Polymerase chain reaction detection of Mycobacterium paratuberculosis and Mycobacterium avium subsp silvaticum in long term cultures from Crohn''s disease and control tissues.

Thirty one cultures were established in MG3 medium from the intestinal tissues of 29 patients, including 18 with Crohn's disease, five with ulcerative colitis, and six non-inflammatory bowel disease controls. All cultures grew either acid fast bacilli or uncharacterized spheroplasts. Pellets from these cultures were coded and assayed blind for M paratuberculosis and M avium subsp silvaticum using IS900- and IS902-PCR (polymerase chain reaction) assays, respectively. IS900 and IS902 are multicopy DNA insertion elements specific for these two organisms. Six Crohn's disease cultures and a single non-inflammatory bowel disease control were positive for M paratuberculosis. A further six cultures were positive for M avium subsp silvaticum, of which two each were from Crohn's disease, ulcerative colitis, and non-inflammatory bowel disease controls. The intensity of the IS900-PCR signals indicated very low numbers of M paratuberculosis organisms and bore no relation to visible spheroplastic or bacillary mycobacterial growth. The results suggest that M paratuberculosis isolated from man exists in a form which hardly replicates if at all when cultured in MG3 medium in vitro, and are consistent with the involvement of this known animal enteric pathogen in a proportion of chronic enteritis in man.     

Agglutinins to bacteria in Crohn's disease.

Sera from patients with Crohn's disease were tested for antibodies against organisms which are thought to cause inflammatory bowel disease in animals, or have been implicated in human Crohn's disease. Control sera were collected from healthy individuals and patients with ulcerative colitis. Sera from Crohn's disease and controls failed to agglutinate Clostridium colinum or Campylobacter sputorum subsp. mucosalis and two strains of Mycobacterium paratuberculosis (M26 and M27). Most of the sera agglutinated a Citrobacter freundii variant, Mycobacterium paratuberculosis (M28) and Mycobacterium avium (M41) but Crohn's disease sera did not differ from controls. A complement fixation test against Chlamydia gave more positive reactions in patients with Crohn's disease and colitis than in healthy controls. There was a clear difference between the sera from patients with Crohn's disease and other sera, including ulcerative colitis, in agglutination tests with the commensal coccoid rods of the genera Eubacterium and Peptostreptococcus; in these tests 54% of sera from Crohn's disease were positive compared with 11% in ulcerative colitis and none of the sera from healthy controls. All the results were essentially negative with the exception of those from Eubacterium and Peptostreptococcus and these bacteria merit investigation.     

Mycobacterium paratuberculosis DNA not detected in Crohn's disease tissue by fluorescent polymerase chain reaction.

The role of mycobacteria in the aetiology of Crohn's disease has been a contentious subject for many years. Mycobacterium paratuberculosis is known to cause a chronic granulomatous enteritis in animals (Johne's disease) and has been implicated as a possible infectious cause of Crohn's disease. However this fastidious organism is only rarely detected by conventional microbiological techniques. This study used oligonucleotide primers to the species-specific M paratuberculosis IS900 DNA insertion element and the polymerase chain reaction to amplify any M paratuberculosis DNA from intestinal tissue DNA extracts. One oligonucleotide primer was fluorochrome-labelled and the presence of fluorescent amplified product was determined using an automated DNA sequencer with a computerised gel-scanning laser. This method was shown capable of detecting 1-2 mycobacterial genomes. Intestinal tissue samples were obtained from 68 patients with histologically confirmed Crohn's disease, 49 patients with histologically confirmed ulcerative colitis, and 26 non-inflammatory bowel disease controls. In no case was M paratuberculosis detected in any of the inflammatory bowel disease tissue samples and only one non-inflammatory bowel disease case was positive. These results do not support the hypothesis that M paratuberculosis has an aetiological role in Crohn's disease.     

Possible role of Mycobacteria in inflammatory bowel disease

An unclassified Mycobacterium species has been isolated from two patients with Crohn's disease (CD). Antibodies to the unclassified mycobacteria cross-reacted with Mycobacterium paratuberculosis. Because of this cross-reactivity, an enzyme-linked immunosorbent assay (ELISA) was used to examine the sera of inflammatory bowel disease (IBD) patients, both CD (N = 56), and ulcerative colitis (UC) (N = 34), for antibodies to M. paratuberculosis, Mycobacterium kansasii, and Mycobacterium tuberculosis. Controls consisted of healthy, PPD-negative individuals (N = 67), and from PPD-positive patients (N = 41). Eighteen resected CD patients were also examined. CD patients had a statistically significant increase in antibody titer (P = 0.0003) to M. paratuberculosis compared to healthy controls. Although patients with positive PPD had elevated titers to this organism, the positive response of CD patients was not related to PPD responsiveness, area of involvement in the gut, nor to activity of the disease process.     

Mycobacteria and inflammatory bowel disease. Results of culture

We have been able to isolate mycobacteria from intestinal specimens obtained by surgical resection or endoscopic biopsy from patients with Crohn's disease, ulcerative colitis, and noninflammatory bowel diseases. Nineteen slow-growing (Runyon groups I and III) and 17 rapid-growing (Runyon group IV) mycobacterial isolates were obtained. Slow-growing mycobacteria were recovered from approximately one-third of intestinal biopsy specimens from Crohn's disease, one-quarter of ulcerative colitis biopsies, and 40% of biopsies from noninflammatory bowel disease patients. Isolates were most commonly members of the Mycobacterium avium-complex. One isolate (from an ulcerative colitis patient) was biochemically similar to the Mycobacterium strain previously associated with Crohn's disease, and one from a Crohn's disease patient was Mycobacterium kansasii. The rapid-growing organisms were members of the Mycobacterium fortuitum-complex. In addition to conventional mycobacteria, spheroplasts (cell wall-defective forms) were isolated from 12 patients with Crohn's disease (most often from surgically resected colon) and 3 patients with ulcerative colitis; none were isolated from non-inflammatory bowel disease patients. We have been unable to identify a consistent relationship between the presence, or the species, of Mycobacterium and Crohn's disease. Our results do not support the proposed role of a specific mycobacterium in the pathogenesis of Crohn's disease. The cause of Crohn's disease remains unclear.     

Serum antibodies to cow's milk proteins in ulcerative colitis and Crohn's disease

Serum antibodies of immunoglobulin G, immunoglobulin M, and immunoglobulin A isotypes to five major proteins of cow's milk, casein, bovine serum albumin, alpha-lactalbumin, beta-lactoglobulin A, and beta-lactoglobulin B, were measured using enzyme-linked immunosorbent assay in 51 patients with ulcerative colitis, 49 with Crohn's disease, and 20 age-matched controls. Immunoglobulin G and immunoglobulin M antibodies to cow's milk proteins were significantly elevated in patients with inflammatory bowel disease as compared to controls. In contrast, no significant increase in immunoglobulin A antibodies to 3 of 5 proteins was noted. The increased titers of antibodies to milk proteins seem to be specific and not due to a polyclonal immunoglobulin activation, as naturally occurring blood group antibodies were not elevated in patients with ulcerative colitis and Crohn's disease. A good correlation of disease activity, as measured by serum alpha 1-acid glycoprotein concentrations, and immunoglobulin G and immunoglobulin A antibody titers against certain cow's milk proteins could be demonstrated in Crohn's disease, but not ulcerative colitis. These findings suggest that production of antibodies to cow's milk proteins reflects specific immunization with these antigens. The study of antibody isotypes and correlation with disease activity may provide better insight into the immune response to dietary antigens and its possible role in the pathogenesis of inflammatory bowel diseases.     

Serum Antibodies to Mycobacterium paratuberculosis in Patients with Crohn's Disease

Mycobacterium paratuberculosis has beensuggested as a causative organism of Crohn's disease.Despite a long-term debate to prove this possibility,the role of this bacteria in the pathogenesis of Crohn's disease is still a subject of controversy. Inthe present study, serum antibodies (IgG, IgA, and IgM)to the protoplasmic antigen of M. paratuberculosis werequantified in patients with Crohn's disease and in control subjects by using anenzyme-linked immunosorbent assay whose specificity wasincreased by preabsorbing the sera with cell extracts ofMycobacterium phlei . As compared to normal controls (1/20; 0.062 ± 0.022), a significantdifference was seen in the antibody-positive prevalencerate and mean values of the serum IgG titer in patientswith Crohn's disease (5/13; 0.102 ± 0.039) (P< 0.05), but not in patients with ulcerativecolitis (2/20; 0.065 ± 0.035) and tuberculosis(0/4; 0.053 ± 0.008). No significant differenceswere seen in the antibody-positive prevalence rate andmean values of the serum IgA and IgM titers amongthe four study groups. These results indicate the uniqueimmune response to M. paratuberculosis in patients withCrohn's disease, suggesting that this organism may play some role in the pathogenesis ofCrohn's disease.     

The evidence for Mycobacterium paratuberculosis in Crohn's disease.

PURPOSE OF REVIEW: Though long hypothesized, the putative link between Mycobacterium avium paratuberculosis and Crohn's disease remains neither confirmed nor refuted. This article reviews published contributions that directly or indirectly address this question. RECENT FINDINGS: Epidemiologic studies, looking for M. avium paratuberculosis DNA in Crohn's tissue, show a strong association between the agent and this disease. Supporting data, however, are presently inconclusive on a causal role. Genetic studies provide indirect support for a role of mycobacteria in Crohn's disease, by identifying susceptibility genes that encode proteins implicated in innate immunity to intracellular bacteria. Clinical trial data support at least a short-term benefit for antimycobacterial therapy in Crohn's disease, but the microbial specificity of this response is presently unknown. SUMMARY: There appears to be a strong association between M. avium paratuberculosis and Crohn's disease, but the causality of this association is unknown. Consequently, the therapeutic implications of this association require further study. A number of critical questions about the biology of M. avium paratuberculosis remain unanswered. Data from studies of this organism, and its interaction with the immune system, can help address proposed reasons for or against a role of M. avium paratuberculosis in the etiology of Crohn's disease.     

Detection of Mycobacterium avium subspecies paratuberculosis in Crohn's diseased tissues by in situ hybridization

OBJECTIVES: Reports about the association between Crohn's disease (CD) and cell wall-deficient (CWD) forms of Mycobacterium avium subspecies paratuberculosis (M. paratuberculosis) are controversial. This may be due to the heterogeneous nature of CD where only about 50% of the patients show granulomatous inflammation. Detection of CWD forms of M. paratuberculosis in tissues from patients with CD would support its association with the disease. To help identify these forms in inflamed tissues, a previously developed and optimized nonradioactive in situ hybridization method was applied on well-defined tissue materials obtained from patients with CD, ulcerative colitis (UC), and controls. METHODS: Specimens from 37 patients with CD (15 with epitheloid cell granulomas and 22 without granulomas), 21 UC, and 22 noninflammatory bowel disease (IBD) patients were analyzed by the in situ hybridization method based on the digoxigenin-labeled M. paratuberculosis IS900 fragment, previously shown to be species specific. Samples were counterstained with hematoxylin and eosin to show the location of the positive signal. Positive controls made of beef cubes injected with CWD and acid-fast M. paratuberculosis and negative controls were included in each experiment to monitor for nonspecific hybridization or staining. RESULTS: Six of 15 (40%) patients with CD and granulomas showed positive signals in myofibroblasts and macrophages. Interestingly, no positive signals were observed within granulomas. Only 4.5% of 22 CD samples from patients with nongranulomatous disease, 9.5% of 21 UC, and remarkably, none of the 22 non-IBD patients were M. paratuberculosis positive. CONCLUSION: The demonstration of DNA from CWD forms of M. paratuberculosis in this limited number of CD tissues further supports and confirms previous reports of its association with the granulomatous type of the disease.     

Mycobacteria in the Intestine of Japanese Patients with Inflammatory Bowel Disease

Objectives : It is still controversial whether or not a mycobacterial infection may be a cause of Crohn's disease. Mycobaclerium paratuberculosis may be very difficult to detect using routine culture techniques. To clarify this, we delected mycobacterial DNA in patients with inflammatory bowel disease. Methods : IS900 sequences highly specific to M. paratuberculosis and groEL gene encoding a conserved mycobacterial antigen were studied in colonic mucosa using polymerase chain reaction (PCR). PCR products were analyzed by Southern blot hybridization. Results : IS900 sequences were detected in all (100%)of 10 patients with Crohan's disease, in 11 (61.1%) of 18 patients with ulcerative colitis, and in 14 (87.5%) of 16 control patients with noninflammatory bowel disease. All IS900 positive samples had groEL PCR products. Conclusions : Our results, on the basis of the prevalence, do not support the hypothesis that M. paratuberculosis is involved in the pathogenesis of Crohn's disease.     

Partial overlap of anti-mycobacterial, and anti- Saccharomyces cerevisiae mannan antibodies in Crohn＇s disease

AIM： To test whether humoral immune reaction against mycobacteria may play a role in anti- Saccharomyces cerevisiae antibodies （ASCA） generation in Crohn＇s disease （CD） and/or whether it correlates with clinical subtypes.
METHODS： The dominant ASCA epitope was detected by Galanthus nivalis lectin （GNL）-binding assay. ASCA and IgG against mycobacterial lysates （M avium, M smegmatis, M chelonae, M bovis BCG M avium ssp. paratuberculosis （MAP）] or purified lipoarabinomannans （LAM） were detected by ELISA. ASCA and anti-mycobacterial antibodies were affinity purified to assess cross-reactivities. Anti-mycobacterial IgG were induced by BCG-infection of mice.
RESULTS： GNL bound to different extents to mycobacterial lysates, abundantly to purified mannosecapped （Man） LAM from M tuberculosis, but not to uncapped LAM from M srnegrnatis. Fifteen to 45% of CD patients but only 0%-6% of controls were seropositive against different mycobacterial antigens. Anti-mycobacterial IgG correlated with ASCA （r = 0.37-0.64; P = 0.003-P 〈 0.001）. ASCA-positivity and deficiency for mannan-binding lectin synergistically associated with anti-mycobacterial IgG. In some patients, anti-mycobacterial antibodies represent crossreactive ASCA. Vice-versa, the predominant fraction of ASCA did not cross-react with mycobacteria. Finally, fistulizing disease associated with antibodies against M avium, M smegmatis and MAP （P = 0.024, 0.004 and 0.045, respectively）.
CONCLUSION： Similar to ASCA, seroreactivity against mycobacteria may define CD patients with complicated disease and a predisposition for immune responses against ubiquitous antigens. While in some patients anti-mycobacterial antibodies strongly cross-react with yeast mannan; these cross-reactive antibodies only represent a minor fraction of total ASCA. Thus, mycobacterial infection unlikely plays a role in ASCA induction.     

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.     

Ulcerative colitis and Crohn's disease: is Mycobacterium avium subspecies paratuberculosis the common villain?

Mycobacterium avium, subspecies paratuberculosis (MAP) causes a chronic disease of the intestines in dairy cows and a wide range of other animals, including nonhuman primates, called Johne's ("Yo-knee's") disease. MAP has been consistently identified by a variety of techniques in humans with Crohn's disease. The research investigating the presence of MAP in patients with Crohn's disease has often identified MAP in the "negative" ulcerative colitis controls as well, suggesting that ulcerative colitis is also caused by MAP. Like other infectious diseases, dose, route of infection, age, sex and genes influence whether an individual infected with MAP develops ulcerative colitis or Crohn's disease. The apparently opposite role of smoking, increasing the risk of Crohn's disease while decreasing the risk of ulcerative colitis, is explained by a more careful review of the literature that reveals smoking causes an increase in both diseases but switches the phenotype from ulcerative colitis to Crohn's disease. MAP as the sole etiologic agent of both ulcerative colitis and Crohn's disease explains their common epidemiology, geographic distribution and familial and sporadic clusters, providing a unified hypothesis for the prevention and cure of the no longer "idiopathic" inflammatory bowel diseases.