Influence of interferon-gamma on isolated chondrocytes from human articular cartilage. Dose dependent inhibition of cell proliferation and proteoglycan synthesis

The effect of human recombinant interferon-gamma (IFN-gamma) on cultured human cartilage cells was studied by 2 variables: cell proliferation and proteoglycan synthesis. Cell proliferation was determined from 3H-thymidine incorporation rates in monolayer cultured chondrocytes. Proteoglycan synthesis was determined from 35S incorporation rates in monolayers and in chondrocytes cultured in agarose gel. IFN-gamma concentrations used in these experiments ranged from 10(-6) micrograms/ml (0.025 U/ml) to 10(-2) micrograms/ml (250 U/ml). The lowest concentrations are comparable with the synovial fluid levels in inflamed joints of patients with rheumatoid arthritis. At these concentrations, IFN-gamma was found to induce a dose dependent decrease of cell proliferation and of proteoglycan synthesis in monolayer cultured human chondrocytes. The decrease of proteoglycan synthesis was ascribed both to an inhibition of the proteoglycan protein core production and to a downregulation of the glycosaminoglycan chain elongation.

Juvenile spondyloarthropathies in 1992

There is some evidence that patients with late onset pauciarticular juvenile chronic arthritis (JCA) should be included among those with spondyloarthropathies, at least during the course of their disease, even if at the onset of the disease we prefer to label them as patients with JCA. The clinical symptoms which could allow us to classify them as spondyloarthritic are frequently absent at the onset of the disease. The gut seems to play a role in the pathogenesis of this form of JCA, though the exact mechanisms must be elucidated further.

Interlaboratory variability of the antiperinuclear factor (APF) test for rheumatoid arthritis

The antiperinuclear factor (APF) test is as sensitive and specific for rheumatoid arthritis as the classical rheumatoid factor tests. Five European laboratories decided to perform a consensus study on the interlaboratory variability of the APF test. They used different donor cells, different conjugates and different criteria for positivity. However, the results differed by not more than one two-fold dilution step, when expressed in international units using WHO reference rheumatoid arthritis serum as the standard.

Development of immortalized human articular cartilage cell lines

Human articular cartilage cells were transfected with the t.-sensitive polyomavirus large T antigen of SV40. Several immortalized chondrocyte cell lines were obtained. The types of acidic polysaccharides and of collagen synthesized suggest dedifferentiation in the in vitro culture system used afterwards to obtain large numbers of cells.

Simultaneous occurrence of diffuse idiopathic skeletal hyperostosis and ankylosing spondylitis in the same patient

Diffuse idiopathic skeletal hyperostosis (DISH) frequently gives rise to some diagnostic confusion, as it may radiologically mimic ankylosing spondylitis (AS). A patient with features of DISH and AS is described and the literature is reviewed. The diagnostic value of sacroiliac computerized tomography is emphasized. The role of spinal mobility in the appearance of the enthesiophytes is discussed since our patient, who underwent a segmental fusion, presented different radiological features in the mobile segment and the fused region.

Evaluation of the involvement of axial entheses and sacroiliac joints in relation to diagnosis: comparison among diffuse idiopathic skeletal hyperostostis (DISH), osteoarthrosis and ankylosing spondylitis

Since diffuse idiopathic skeletal hyperostosis (DISH) is frequently difficult to differentiate radiologically from the axial involvement of ankylosing spondylitis and osteoarthrosis, some features of these 3 different diseases were compared. The predominantly horizontal nature of the enthesiophyte in DISH and its right preponderance in the thoracic region were demonstrated. This right preponderance was due to the presence of the thoracic aorta located in the left thoracic side. A midthoracic notch was described in DISH which seemed to be confined to noninflammatory conditions, but was not found in ankylosing spondylitis. The importance of sacroiliac computerized tomography to differentiate sacroiliac joint abnormalities associated with DISH from the sacroiliitis of spondylarthropathies was stressed.

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.

Intra-articular injection pentosanpolysulphate results in increased hyaluronan molecular weight in joint fluid

The influence of an oversulphated glycosaminoglycan, pentosanpolysulphate, on hyaluronan metabolism of the synovial lining cell was studied in vivo in human volunteers. Significant increases in the mean degree of polymerisation of the hyaluronan chains were observed after a series of four to six intra-articular injections of this glycosaminoglycan. No increases in hyaluronan synthesis rates were observed. Repeated administration of the drug did not cause any inflammation or bleeding in the joint cavity.

Gut inflammation in the spondyloarthropathies: clinical, radiologic, biologic and genetic features in relation to the type of histology. A prospective study

Ileocolonoscopy was performed on 354 patients with spondyloarthropathies. Histologically, the population could be divided into 145 patients with normal gut histology, 88 patients with acute inflammatory lesions and 121 patients with chronic inflammatory lesions. A number of clinical, biologic, radiologic and genetic variables were determined before ileocolonoscopy. Chronic gut lesions were associated with a family history of ankylosing spondylitis (AS) and Crohn's disease, several episodes of diarrhea, an increased stool frequency, elevated inflammatory serum variables, reduced axial mobility, the presence of sacroiliitis, bamboo spine, destructive joint lesions, a diagnosis of AS and HLA-Bw62 positivity. As the frequency of HLA-Bw62 is also increased in proven Crohn's disease, this would suggest that chronic gut lesions are related to this disease. Acute inflammatory lesions were related to a higher fecal carriage of specific bacteria and to the diagnosis of undifferentiated spondyloarthropathy, especially the enterogenic forms of reactive arthritis. Consequently, these lesions also appear to be related to a bacterially induced gut inflammation. Gut histology was normal in urogenital inflammation and urogenital reactive arthritis, suggesting a different portal of entry for antigens. The 3 histologic pictures of the gut (normal, acute and chronic) inflammation seem to correlate with different clinical, biologic and radiologic manifestations of the disease concept of spondyloarthropathies.

Influence of human recombinant interleukin-1 beta on human articular cartilage. Mitotic activity and proteoglycan metabolism

The effects of human recombinant interleukin-1 beta (IL-1 beta) were investigated on recently isolated (1 to 3 weeks) and on well-established (older than 3 weeks) monolayer cultured human articular chondrocytes. IL-1 beta was found to depress 35S-proteoglycan synthesis rates and to enhance prostaglandin E2 (PGE2) production in these monolayer cultured chondrocytes. Induction of 35S-proteoglycan-degradative activity by these cells also occurred in IL-1 beta treated cultures. These "catabolin" -IL-1 activities were observed in recently isolated as well as in well-established "old" cultures. IL-1 beta increased 3H-thymidine incorporation rates in the "old" cultures. However, in recently isolated chondrocytes a dose-dependent reduction of the 3H-thymidine incorporation occurred. The depression of mitotic activity in these cells was partially abolished by indomethacin, indicating that this depression was a PGE2 effect. However, supplementing IL-1 beta with indomethacin did not raise the 3H-thymidine incorporation rates above the control levels. It can be concluded that IL-1 beta in itself is unable to induce proliferation in recently isolated cartilage cells. Our results suggest the possible existence of two different receptors for the different IL-1 beta activities. Hence, human articular chondrocytes respond differently to in vitro IL-1 beta exposure at different stages of differentiation.

Osteomyelitis in a patient with a chronically infected arterial graft and longstanding hypertrophic osteoarthropathy of the leg

A patient is reported with hypertrophic osteoarthropathy of the right leg who developed an osteomyelitis; this appeared to be related to an infected aortic bifurcation prosthesis with increased uptake on leukocyte scan and chronic gas formation at the proximal aortic anastomosis on computed tomography. There have been previous reports of hypertrophic osteoarthropathy as a sign of arterial prosthesis infection. In this patient antibiotic therapy was successful in controlling the osteomyelitis but eradication of the arterial prosthesis infection could not be confirmed and an elective arterial operation involved too great a risk.

Sulfasalazine treatment in juvenile chronic arthritis: an open study

In an open study, the effect of sulfasalazine was evaluated in the treatment of juvenile chronic arthritis (JCA). Forty-one patients, i.e., 27 boys and 14 girls with JCA under 16 years of age, were included in the study. In all of them, treatment with nonsteroidal antiinflammatory drugs (NSAID) had been unable to control the disease. The patients were divided in 4 subgroups depending on the mode of onset and evolution (Type I = systemic onset, Type II = polyarticular form. Type IIIa and Type IIIb = pauciarticular form). Remission was achieved in 21 patients, significant improvement in 12. Status was unchanged in 4 patients and worsened in 3. In 5 patients side effects were observed, which forced interruption of treatment in 4. Sulfasalazine was stopped in 7 patients: for toxicity in 4 and for inefficacy in 3. In 7 other patients the treatment was terminated after a prolonged remission. These promising results must be confirmed in a double blind versus placebo study, preferably restricted to type III JCA.

Intestinal mucosal permeability in inflammatory rheumatic diseases. II. Role of disease

Gut permeability as measured by the 51Cr-EDTA resorption test was determined in 56 patients with rheumatoid arthritis (RA), 73 patients with spondyloarthropathies (SpA), 18 patients with inflammatory bowel disease (IBD) and 97 controls (42 patients with no inflammatory rheumatic diseases and 55 healthy controls). Gut permeability was found to be increased in the 3 patient groups, partially due to the intake of antiinflammatory drugs. When only patients not taking these drugs were considered, an increased gut permeability was found in patients with SpA and IBD. In patients with RA gut permeability could not be evaluated as they were all taking antiinflammatory medication. Ileocolonoscopy with biopsies of the gut was performed in 62 of the 73 patients with SpA and disclosed subclinical gut inflammation in 21. No difference in gut permeability was found between patients with or without gut inflammation. However, when the type of gut inflammation was considered, a significant increase of gut permeability was found in patients with chronic gut inflammation compared with patients presenting acute lesions. Our findings again suggest that the chronic gut inflammation seen in SpA is fundamentally different from acute gut inflammation and possibly related to the gut inflammation of IBD.

Intestinal mucosal permeability in inflammatory rheumatic diseases. I. Role of antiinflammatory drugs

Using the 51Cr-EDTA resorption test, gut permeability was measured in 129 patients with inflammatory joint diseases and in 97 control patients (42 patients with no inflammatory rheumatic disorders taking antiinflammatory medication and 55 healthy controls). Thirty-two patients (30 arthritis and 2 control patients) taking nonsteroidal antiinflammatory drugs (NSAID) as well as corticosteroids were excluded from statistical analysis. The intake of NSAID significantly increased gut permeability in controls but not in the arthritis groups. The same applied to corticosteroid intake. This could be due to the restricted number of arthritis patients who had never taken antiinflammatory drugs or to a disease related increased permeability. There was no statistically significant difference in altered gut permeability between patients taking NSAID and patients taking corticosteroids. Our findings suggest that drug induced alteration of gut permeability may not only be accounted for by an inhibition of mucosal cyclooxygenase activity, but that other enzymatic pathways in the arachidonic cascade might be implicated.

Onset of symptoms of rheumatoid arthritis in relation to age, sex and menopausal transition

In a population of 564 patients with rheumatoid arthritis (RA), the onset of symptoms has been studied in relation to age, sex and last menstrual period for women. Median age of menopause was 49 years (3rd percentile: 32 years and 97th percentile: 56 years). Median age of first symptoms was 45 years in women and 50 in men. The individual interval between menopause and first symptoms has a Gaussian distribution with mean at time 0, implying that the average woman develops the first symptoms at the time of her menopause. The F:M ratio of all patients was 2.3; with increasing age the F:M ratio decreased from 3.7 before 30 years of age to 1 after the 6th decade of life, with a peak at the age of 40-44 years. A possible effect of age related changes in sex hormone levels on the pathogenesis of RA is suggested.

The synthesis and immobilisation of cartilage-specific proteoglycan by human chondrocytes in different concentrations of agarose

Chondrocytes were cultured in agarose gels of different concentrations. In this in vitro model these cells synthesize tissue-specific proteoglycans. The rate of proteoglycan synthesis was not dependent on the concentration of the surrounding gel. The immobilisation of these macromolecules in monomeric and in aggregated form were studied. 0.5% to 1.0% of agarose failed to retain important amounts of proteoglycan. Proteoglycan monomers and even aggregates diffused to the incubation medium. 2.0% and 4.0% of agarose immobilised the bulk of the aggregates and approximately 50% of the monomeric proteoglycans. Low-molecular proteoglycan species or break-down products freely moved out of the gel. The reproducibility of the variables concerning proteoglycan metabolism was very good.

HLA-B27 positive idiopathic acute anterior uveitis: a unique manifestation of subclinical gut inflammation

Ileocolonoscopy was performed on 2 HLA-B27 positive patients with idiopathic acute anterior uveitis neither of whom had articular or intestinal complaints. Microscopic examination of the biopsy specimens revealed the presence of chronic inflammatory lesions in the ileum. Since these lesions have also been described in other forms of spondyloarthropathy, we postulate the presence of gut inflammation was related to the uveitis.

Proteoglycan metabolism in isolated chondrocytes from human cartilage. Influence of niflumic acid

The effect of niflumic acid on hyaluronic acid and proteoglycan metabolism of human cartilage cells was investigated in vitro. Cartilage cells were obtained from five different donors. Niflumic acid levels used in the test systems ranged from 0 to 22 microgramsr/ml and were comparable to serum concentrations in humans after oral intake. Niflumic acid increased the synthesis rates of proteoglycan in some batches of isolated and monolayer-cultured chondrocytes. The effect on hyaluronate synthesis was less pronounced. The fact that this increase in the synthesis of proteoglycan was restricted to some of the donors whereas isolated cells or tissue samples from other individuals remained unaffected illustrates the heterogeneity of different human donors. Depression of proteoglycan synthesis in the presence of the drug was never observed.

Destructive hip lesions in seronegative spondyloarthropathies: relation to gut inflammation

In the seronegative spondyloarthropathies the hip lesions can be subdivided into a concentric type progressing to ankylosis and an eccentric type leading to joint destruction. Radiologic examination of the hips was performed in 177 of 211 patients suffering from seronegative spondyloarthropathies on whom ileocolonoscopy with biopsies of ileum and colon was performed; in 27 of these 177 patients, hip lesions were demonstrated. The concentric form seems to be radiologically, clinically and genetically more related to axial involvement; moreover, the frequency of subclinical gut inflammation was the same as in the group of patients with ankylosing spondylitis (AS) without peripheral arthritis, and thus significantly lower than in patients with AS with peripheral arthritis. Eccentric, destructive hip lesions seem to be unrelated to axial involvement, but they are associated with the presence of HLA-Bw62 and gut inflammation (100%), mainly of the chronic, Crohn disease-like type.