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M De Vos

Publications and source records attributed to M De Vos.

At least 73 records · Page 4Linked to original sources
PubMed1996

The role of gut inflammation in the pathogenesis of spondyloarthropathies.

The concept of spondyloarthropathy (SpA) gathers together a group of chronic diseases with common clinical, biological, genetic and therapeutic characteristics. The concept forms a distinct entity, different from other rheumatic diseases. The target organs are not only the joint, but also the axial skeleton, the enthesis, the eye, the gut, urogenital tract, the skin and sometimes the heart. The prevalence of this entity in the general population is estimated 1%, equal to the prevalence of rheumatoid arthritis. Genetical predisposition (HLA-B27) is one of the clues to the pathogenesis of the disease. Since reactive arthritis is induced by specific urogenital or enterogenic bacteriae, and since the gut is implicated in different forms of spondyloarthropathies, especially in IBD, it was clear that the gut could play an important role by permitting exogenous factors to enter the body. This hypothesis was the rationale for investigating the gut in the spondyloarthropathies by performing ileocolonoscopies. In the first ileocolonoscopic studies of SpA patients, histological signs of gut inflammation were found in a relatively great number of patients, mostly without any clinical intestinal manifestations. These lesions were not seen in other inflammatory joint diseases. Further ileocolonoscopic studies confirmed the strong relationship between gut and joint inflammation. In patients in whom a second ileocolonoscopy was performed, remission of the joint inflammation was always connected with a disappearance of the gut inflammation, whereas persistence of locomotor inflammation was mostly associated to the persistence of gut inflammation. The hypothesis was proposed that some patients with a spondyloarthropathy had a form of subclinical Crohn's disease in which the locomotor inflammation was the only clinical expression. This hypothesis was confirmed in prospective long-term studies in which the ileocolonoscoped patients were reviewed 2 to 9 years later: about 6% of SpA patients not presenting any sign of Crohn's disease at first investigation but demonstrating gut inflammation on biopsy, developed full-blown Crohn's disease. The discovery of subclinical gut inflammation in the SpA had therapeutic consequences. Sulphasalazine (SASP) has been proven to be an active drug in the treatment of IBD. Since the gut could play a crucial role in SpA, it was logic to use this drug in the treatment of this disease. Multiple open and double-blind studies have proven the effectiveness of this drug in SpA; recent studies concluded that the beneficial effect of the drug in this disease entity is more prominent on the peripheral arthritis than on the axial disease.

Anti-Inflammatory Agents↗
PubMed1995

Gut inflammation in psoriatic arthritis: a prospective ileocolonoscopic study.

OBJECTIVE: Some forms of psoriatic arthritis (PsA) are classified as spondylarthropathy, and subclinical gut inflammation is found in spondylarthropathies. Our study was designed to determine if inflammatory gut lesions were also present in PsA, and if the prevalence of subclinical gut involvement was different in the subgroups of this disease. The relationship with HLA subtypes was also determined. METHODS: Ileocolonoscopy was performed on 64 patients with PsA (37 men, 27 women). RESULTS: Inflammatory gut lesions were found in 10 of the 64 patients (16%): in 3 of the 15 patients (20%) with oligoarthritis and in 7 of the 23 patients (30%) with axial involvement. None of the 26 patients with polyarthritis showed these lesions. The prevalence of HLA-B27, Bw62, and B17 was significantly raised in our total group of patients with PsA. HLA-B27 and Bw62 were significantly more prevalent in patients with gut inflammation, 60 and 50%, respectively. CONCLUSION: Gut inflammation is only present in PsA subgroups that belong to the spondylarthropathy concept. This suggests that the gut plays a role in the pathogenesis of locomotor inflammation in these subgroups. The prevalence of gut inflammation in psoriatic spondylarthropathy is significantly lower than in nonpsoriatic spondylarthropathies. Consequently, not only the gut but also the skin may be a portal of entry for causative antigens in PsA.

Adolescent↗
PubMed1995

The evolution of spondyloarthropathies in relation to gut histology. I. Clinical aspects.

OBJECTIVE: To study prospectively the clinical evolution of different forms of spondyloarthropathy (SpA) (excluding inflammatory bowel disease, IBD): reactive arthritis, undifferentiated SpA, and ankylosing spondylitis (AS). METHODS: Ileocolonoscopy was performed on 217 patients with SpA (149 men, 68 women). They also underwent clinical, laboratory, and radiological examinations. Two to 9 years later, 123 patients (84 men, 39 women) who had been regularly monitored were reviewed and given the same examinations. For the remaining 94 patients clinical data were obtained by telephone. RESULTS: At the time of clinical review, 53 (43%) of the regularly monitored patients were in clinical remission. The remission rate was higher in patients with non-ankylosing spondylitis SpA (non-As-SpA) than in patients with AS (19%). Fourteen patients with non-AS-SpA had developed AS; 4 of them also had IBD. IBD was also found in 4 patients with AS and in 3 patients from the telephone group. The prevalence of HLA-B27 was significantly higher in all SpA subgroups, while HLA-BW62 was elevated in the undifferentiated SpA. At review, HLA-B27 was significantly more prevalent in patients with persistent locomotor inflammation compared to patients in clinical remission, while HLA-BW62 was predominant in the latter group. CONCLUSION: Patients with SpA, especially those with non-AS-SpA, have a good longterm prognosis. However, patients with non-AS-SpA may develop AS. Six percent of the patients with SpA in whom manifestations of IBD are absent will develop this disease. This confirms the hypothesis that some of these patients with SpA initially have a form of subclinical Crohn's disease, of which locomotor inflammation is the only clinical expression. HLA-B27 positivity predisposes to a more severe course of locomotor inflammation, while HLA-BW62 has a protective effect but is associated with gut inflammation.

Adolescent↗
PubMed1995

The evolution of spondyloarthropathies in relation to gut histology. II. Histological aspects.

OBJECTIVE: To study prospectively the clinical evolution of different forms of spondyloarthropathy (SpA) in relation to the type of gut histology in ileocolonoscopic biopsy specimens. METHODS: Ileocolonoscopy was performed in 217 patients with SpA (149 men, 68 women). Three types of gut histology (normal gut histology and acute and chronic inflammatory gut lesions) were found. Clinical, laboratory, and radiological examinations were performed at start and 2 to 9 years later in 123 patients who were regularly monitored. For the remaining 94 patients clinical data were obtained by telephone. RESULTS: Of the 123 patients monitored regularly, 40 (32%) had normal gut histology, and 28 (23%) had acute and 55 (45%) chronic inflammatory gut lesions. Acute lesions were preferentially found in patients with non-ankylosing spondylitis SpA (non-AS-SpA). In the groups with normal gut histology and with chronic gut inflammation, patients with ankylosing spondylitis (AS) and non-AS-SpA were present in equal numbers. At review, clinical evolution was identical in the 3 histological subgroups. Eight patients developed idiopathic inflammatory bowel disease (IBD), one with initially acute gut inflammation, 7 with initially chronic gut inflammation. All had active AS at review. Fourteen patients with non-AS-SpA developed AS; 13 of them had initially presented inflammatory gut lesions. Three patients in the telephone group also developed IBD; all had active AS at review and initially presented chronic inflammatory gut lesions. Persistently high inflammatory serum variables, HLA-B27 negativity in the presence of sacroiliitis or AS, and inflammatory gut lesions at the first ileocolonoscopy indicate patients with SpA are at risk for developing IBD. CONCLUSION: Gut inflammation, mainly subclinical, could be demonstrated in 68% of patients with SpA. Acute gut inflammation was predominant in patients with reactive arthritis (ReA). The evolution to clinical remission was not influenced by the presence or the type of gut inflammation at start. Patients with non-AS-SpA with inflammatory gut lesions have greater risk of developing AS. One patient with Yersinia induced ReA developed AS and IBD. In total, 11 patients (66%) developed IBD, all initially presenting inflammatory gut lesions. Ten had chronic gut lesions, suggesting this type of gut inflammation is related to the inflammation of Crohn's disease. This type of gut inflammation, the persistence of high inflammatory serum variables, and the absence of HLA-B27 in patients with AS are risk factors for developing IBD.

Adolescent↗
PubMed1995

The evolution of spondyloarthropathies in relation to gut histology. III. Relation between gut and joint.

OBJECTIVE: To study prospectively the clinical evolution of different forms of spondyloarthropathy (SpA) in relation to the evolution of gut histology in consecutive ileocolonoscopic biopsy specimens. METHODS: Ileocolonoscopy was performed in 49 patients with SpA (34 men, 15 women). They also underwent clinical, laboratory, and radiological examinations. Two to 9 years later, a 2nd and sometimes a 3rd or 4th ileocolonoscopy was performed, and the other examinations were repeated. RESULTS: At first ileocolonoscopy, 34 patients (69%) showed inflammatory gut lesions. At the 2nd ileocolonoscopy, 16 patients (32%) were in clinical remission; none were found to have inflammatory gut lesions. Of the 33 patients with persistent locomotor inflammation, 14 had persistent inflammatory gut lesions, predominantly the chronic type. Of these 14 patients, 6 had developed inflammatory bowel disease (IBD). None of the 15 patients with an initially normal gut histology had gut inflammation at 2nd examination. Of the 9 with initially acute lesions, 3 developed chronic lesions (1 Crohn's disease). Initial chronic lesions in 25 patients persisted in 9, of whom 5 had developed IBD. Seven of the 19 patients with non-SpA ankylosing spondylitis (non-AS-SpA) developed ankylosing spondylitis (AS); all had initially presented inflammatory gut lesions, which persisted at 2nd examination. In the 11 patients with more than 2 consecutive ileocolonoscopies, clinical remission was always associated with normal gut histology, and flares of the joint disease were related temporally to the reappearance of gut inflammation. CONCLUSION: This study demonstrates the close relationship between gut and locomotor inflammation in SpA. Clinical remission was always associated with normal gut histology, whereas active locomotor inflammation was usually associated with the presence of gut inflammation. Absence of gut inflammation in the SpA is a good prognostic indicator, since gut inflammation or IBD never develops in these patients. Evolution of non-AS-SpA to full blown AS or of uncomplicated SpA to a form of IBD was always associated with gut inflammation at disease onset.

Adolescent↗
PubMed1994

M-cells are damaged and increased in number in inflamed human ileal mucosa.

Ileocolonoscopy and biopsies of patients with spondylarthropathy reveal gut inflammation in 62% of cases. In order to better understand the pathogenetic mechanisms of spondylarthropathy-related gut inflammation, the follicle-associated epithelium was examined. Biopsies from nine controls and 18 patients with spondylarthropathy were studied by electronmicroscopy. Membranous (M) cells were investigated in normal and inflamed ileum. In normal mucosa, M-cells were scarce whereas in inflamed mucosa their number was increased (up to 24% of follicle-associated epithelial cells). They showed a thin rim of cytoplasm covering groups of lymphocytes. In chronic ileitis, necrotic M-cells, rupture of M-cells and lymphocytes entering the gut lumen were observed. The bursting of M-cells at the top of the lymphoid follicles leads to interruption of the gut epithelial lining and gives the luminal content access to the lymphoid tissue. This pathogenetic mechanism may cause aphthoid ulcers.

Adolescent↗
PubMed1993

Results of extracorporeal shock wave lithotripsy of gall bladder stones in 693 patients: a plea for restriction to solitary radiolucent stones.

During a period of 24 months 693 consecutive patients with symptomatic gall bladder stones (526 males, 167 females; mean age 51 years, range 18-89) were treated by extracorporeal shock wave lithotripsy with a Piezolith 2300. The procedure was carried out on an out-patient basis without analgesics or sedatives. Concomitant chemolitholytic treatment (ursodeoxycholic and chenodeoxycholic acid 7.5 mg/kg/day each) was administered until three months after total fragment clearance for a maximum therapy period of 1.5 years. In 601 patients with radiolucent stones complete clearance of all fragments was obtained after three, six, 12, and 18 months in respectively 20, 41, 64, and 78%. Actuarial analysis of the subgroups according to the stone mass (size and number) selected an ideal patient population with solitary stones less than 20 mm diameter (84% stone free after one year). The results are significantly less good when the greater the number of stones or their maximal diameter increases. Treatment was interrupted in 3.6% of the patients. In 90 sludge or fragments remain present. Twenty five patients were lost to follow up for non-biliary reasons. Stone recurrence was 5.7% at one year and was observed both in patients with solitary and multiple stones. A cost effectiveness analysis suggests that laparoscopic cholecystectomy is the most effective and economic solution, although extracorporeal shock wave lithotripsy for solitary radiolucent stones less than 2 cm is cheaper than conventional cholecystectomy. Extracorporeal shock wave lithotripsy for multiple stones is the most expensive and least effective option.

Adolescent↗
PubMed1993

Gut inflammation in children with late onset pauciarticular juvenile chronic arthritis and evolution to adult spondyloarthropathy--a prospective study.

Ileocolonoscopy with biopsy of the colon and terminal ileum was performed prospectively on 12 patients under age 16 with late onset juvenile chronic arthritis (JCA). Inflammatory gut lesions were seen in 9 of these 12 patients; 4 were of the acute type, 5 of the chronic type. Chronic gut inflammation was related to axial inflammatory complaints, inflammatory serum variables, thrombocytosis and sacroiliac radiological abnormalities. A 2nd ileocolonoscopy was performed on 5 of the 12 patients, and a 3rd ileocolonoscopy on 2 of these with persistent synovitis. Gut inflammation and joint inflammation were related; moreover, all 5 patients had chronic inflammatory lesions by the time of the last investigation, one presented with Crohn's disease. The 12 patients were reviewed 3 to 9 years after the first ileocolonoscopy. Four patients were in remission, including the 3 patients with initial normal gut histology. Five patients had developed ankylosing spondylitis (AS), a 6th patient possible AS. Axial inflammatory complaints, a family history of spondyloarthropathies, HLA-B27 positivity, early sacroiliac and peripheral joints radiographic changes, persistence of inflammatory serum variables, thrombocytosis and chronic inflammatory lesions on gut biopsy, are predictive factors in juveniles for evolution to AS. Late onset pauciarticular JCA represents a form of spondyloarthropathy similar to adolescent forms. Persistent gut inflammation could play a role in the pathogenesis of the disease and persistent synovitis.

Adolescent↗
PubMed1993

A prospective study of patients with spondyloarthropathy with special reference to HLA-B27 and to gut histology.

Ileocolonoscopy was performed on 357 patients meeting the European Spondylarthropathy Study Group criteria for spondyloarthropathy. HLA loci A, B and C were determined in all patients; HLA-B27 was detected in 196 and was absent in the 161 remaining patients. A number of clinical, laboratory and radiological variables were determined before ileocolonoscopy and compared between the HLA-B27+ and HLA-B27- patients. The HLA-B27+ patients were mainly men, with significantly more family members with spondyloarthropathies. Clinical evidence of tendinitis and uveitis was more frequently found in these patients. Like several authors, we found that these patients were more severely affected since they presented more severe radiological involvement of the sacroiliac joints. Syndesmophytes, bamboo spine and erosive joint lesions were more frequent in this group, the hip involvement being of the concentric type. In HLA-B27+ patients ankylosing spondylitis was more prevalent, while in the B27- patients enterogenic, urogenital or undifferentiated spondyloarthropathy was diagnosed. The HLA-B27- patients experienced more episodes of diarrhea, and Crohn-like inflammatory gut lesions were more frequently seen on ileocolonoscopy. In this group a number of patients probably had a form of subclinical Crohn's disease of which the locomotor symptoms were the only clinical expression.

Adolescent↗
PubMed1992

Brain abscess after esophageal dilatation for stenosis.

The case is presented of a 28-year-old female with a brain abscess after esophageal dilatation for stricture, secondary to an acute necrotizing esophagitis. Other causes of brain abscess were excluded. To our knowledge this is the first documented case of brain abscess after dilatation for esophageal stricture in adult life. Some reports in the pediatric literature have been published previously.

Adult↗
PubMed1992

A theoretical perspective on population policy in South Africa.

The author describes the goals of South Africa's Population Development Programme, which works to enact the government's population policy. The primary objective is to achieve a balance between population size and natural and socioeconomic resources in the country. "The Population Development Programme promotes specific fertility-inhibiting programmes, projects and actions in the socio-economic fields of education, manpower training, health, the economy and housing. Population information, education and communication programmes are also directed at people with high fertility to facilitate the change of fertility perceptions in favour of a small family norm."

Africa↗
PubMed1992

Expression of T cell receptors alpha beta and gamma delta in the ileal mucosa of patients with Crohn's disease and with spondylarthropathy.

The expression of the alpha beta and gamma delta heterodimer of the T cell receptor (TCR) was studied in normal human ileal mucosa or in ileal biopsies featuring Crohn's disease or acute and chronic spondylarthropathy-related gut inflammation. With an immunohistochemical technique we demonstrated that the increase of mucosal lymphocytes per mm mucosa in Crohn's disease and spondylarthropathy-related ileitis is exclusively due to expansion of the alpha beta + T cell compartment. In Crohn's disease and chronic ileitis observed in some spondylarthropathy patients the alpha beta + T cells were increased amongst intraepithelial lymphocytes (IEL). The lamina propria lymphocytes (LPL) were augmented in all studied inflammatory conditions. The gamma delta + T cells showed no changes in IEL or LPL and their proportions were not altered. They were evenly dispersed throughout the ileal mucosa and did not seem to participate in the inflammatory process. This study confirms that gamma delta T cells are a distinct subset in the intestinal mucosa. The increase in alpha beta + T cells suggests augmented mucosal antigen handling and involvement of the major histocompatibility complex in the pathogenesis of spondylarthropathy-related gut inflammation and Crohn's disease.

Biopsy↗
PubMed1992

Concentrations of 5-ASA and Ac-5-ASA in human ileocolonic biopsy homogenates after oral 5-ASA preparations.

Intramucosal 5-aminosalicylic acid (5-ASA) and acetylated 5-ASA (Ac-5-ASA) concentrations were determined in ileocolonic biopsy specimens from 61 patients with irritable bowel syndrome treated for one week with near equimolar doses of different slow release preparations of 5-ASA (Claversal, Asacol, or Pentasa) or azo-bound drugs (Salazopyrin, Dipentum). The transit time in these patients was accelerated by a laxative, metoclopramide, and colonic lavage. The presence of 5-ASA in the mucosa was confirmed by autofluorescence. The highest concentrations of 5-ASA were obtained after Asacol (mean (SEM), 298.5 (37.3) ng/mg wet wt), followed by Claversal 500 mg (108.8 (11.7) ng/mg wet wt) and Pentasa (25.7 (2.2) ng/mg wet wt). Very low concentrations only were observed after Claversal 250 mg (0.3 (0.03) ng/mg wet wt), Salazopyrine (1.2 (0.1) ng/mg wet wt), and Dipentum (11.0 (3.2) ng/mg wet wt). The results for Ac-5-ASA were similar but the concentrations were generally lower. Serum concentration-time curves over eight hours were obtained from 34 healthy volunteers after a single oral dose of 400 to 500 mg of the different drugs. For the slow release forms, an apparently inverse relationship was found between the area under the curve of the serum concentrations and the intramucosal concentrations, supporting the importance of the local availability of the drug. This inverse relationship was absent for the azo-bound drugs. Colonic washout induced mechanical removal of intraluminal 5-ASA with a secondary disturbance in absorption resulting in a rapid decline in the serum concentrations. However, only for Dipentum did this result in significantly lower 5-ASA mucosal concentrations. This is the first reported attempt to evaluate the mucosal availability of 5-ASA after different oral preparations. It shows that where transit time is accelerated higher mucosal concentrations occur after slow release preparations (except for Claversal 250 mg) than after azo-bound drugs. Additional studies are necessary to correlate these concentrations with clinical effects.

Administration, Oral↗
PubMed1992

Spondylarthropathy and gut inflammation: immunopathogenetic mechanisms.

In 62% of patients with spondylarthropathy (SpA) we found clinically unsuspected gut inflammation to feature acute or chronic enterocolitis on ileocolonoscopy. A proportion of patients of the latter group had subclinical Crohn's disease as demonstrated clinically, endoscopically, genetically, histologically and immunopathologically. There is a relation between the activity of the gut inflammation and clinical rheumatic symptoms. A pathogenetic mechanism is increased handling of luminal (bacterial or nutritional) antigen, hence inducing T-cell activation and intestinal inflammation. In ileal mucosal biopsies we showed two different cellular events: increased enterocytic expression of class II molecules in active inflammation and an increase of membranous (M) cells overlying lymphocytes in inflamed mucosa. Although the number of intraepithelial lymphocytes was not increased in inflammation, intraepithelial T lymphocytes had protruding processes in close apposition to the tips of epithelial plasma membranes. Lymphocytes crossing the basement membrane were a frequent finding. These features indicate that the intestinal immune response caused by increased antigen processing in the terminal ileum induces an inflammatory immunocascade responsible for the clinical picture of SpA.

Adolescent↗
PubMed1991

High-performance liquid chromatographic assay for the determination of 5-aminosalicylic acid and acetyl-5-aminosalicylic acid concentrations in endoscopic intestinal biopsy in humans.

A high-performance liquid chromatographic method for the simultaneous determination of 5-amino-salicylic acid (5-ASA) and N-acetyl-5-ASA (Ac-5-ASA) concentrations in endoscopic mucosal biopsy homogenates is presented. The mean recoveries of 5-ASA and Ac-5-ASA from spiked blank biopsy homogenates ranged from 95.9 to 120% and from 92.5 to 100%, respectively. The coefficients of variation for 5-ASA and Ac-5-ASA were 0.7-8.6% and 1.4-12.9%, respectively. This method is useful for direct determination of topical availability of 5-ASA and Ac-5-ASA and probably an accurate parameter of drug bioavailability.

Aminosalicylic Acids↗