Do non-steroidal anti-inflammatory drugs influence chronic inflammation? The effects of piroxicam on chronic antigen-induced arthritis in rats.

OBJECTIVE: The effects of non-steroidal anti-inflammatory drugs (NSAIDs) on acute inflammation have been thoroughly investigated. NSAIDs are, however, also prescribed for patients with chronic inflammation, such as rheumatoid arthritis (RA), and objective improvement suggestive of anti-inflammatory action from NSAIDs has not been convincingly shown in chronic RA. An antigen-induced arthritis (AIA) model was used to investigate the effects of piroxicam on chronic inflammation. METHODS: AIA was induced by injecting methylated bovine serum albumin (mBSA) into the knee joints of previously immunized rats that were treated orally with the NSAID piroxicam or with saline. This treatment was started either before AIA was induced or after it had reached a chronic phase. The findings were recorded by clinical and histological assessment of the joints. RESULTS: The piroxicam group developed significantly less acute and subsequent chronic knee joint inflammation but this was only evident if the drug was administered prior to the intra-articular mBSA injections. Piroxicam treatment that was initiated during the chronic inflammation did not have any clinical effect, whereas short-term corticosteroid treatment abolished the chronic inflammation. Moreover, histological analysis of the chronic inflammation revealed significantly more inflammatory changes in the piroxicam group compared with the control group. CONCLUSIONS: Piroxicam treatment had no beneficial effects on the chronic stable inflammation in this model and might even delay histological resolution. As the anti-inflammatory effect of piroxicam is restricted to acute inflammation, the use of NSAIDs during periods of chronic stable arthritis in humans, such as in RA, may need to be investigated.

In vitro and in vivo immunomodulating effects of traditionally prepared extract and purified compounds from Cetraria islandica.

Cetraria islandica (Iceland moss) has been used for centuries in folk medicine in many countries against a number of conditions, including inflammatory conditions, mainly as an aqueous extract. C. islandica contains many compounds, such as polysaccharides and secondary metabolites, some of which have established biological activity. However, very little is known about their effect on the immune system. Human monocyte-derived immature dendritic cells were cultured with an aqueous extract from C. islandica quantified with regard to the polysaccharides lichenan and isolichenan and secondary metabolites protolichesterinic and fumarprotocetraric acids. The purified compounds were also tested individually. Their effect on the maturation of the dendritic cells was assessed by measuring secretion of IL-10 and IL-12p40 and expression of surface molecules. In addition, the effect of the aqueous extract on antigen-induced arthritis in rats was investigated. The aqueous extract caused upregulated secretion of both IL-10 and IL-12p40, with IL-10 secretion being more prominent. Lichenan had similar effects, whereas isolichenan and the secondary metabolites were inactive, suggesting that the effect observed by the aqueous extract was mainly mediated by lichenan. Significantly less arthritis was observed for rats treated by the aqueous extract, administered subcutaneously, compared with rats treated with saline alone. These results suggest that the aqueous extract of C. islandica has anti-inflammatory effect, possibly by changing the cytokine secretion bias from IL-12p40 towards IL-10.

Septic arthritis in Iceland 1990-2002: increasing incidence due to iatrogenic infections.

OBJECTIVES: To assess the impact of increased number of diagnostic and therapeutic joint procedures on the incidence and type of septic arthritis (SA). METHODS: All cases of SA in Iceland from 1990-2002 were identified by thorough review of the available medical information. The results of synovial fluid cultures from every microbiology department in Iceland were checked and positive culture results reviewed, as well as patient charts with a discharge diagnosis of septic arthritis (International Statistical Classification of Diseases and Related Health Problems (ICD) code M009). RESULTS: A total of 253 cases of SA (69 children and 184 adults) were diagnosed in Iceland in 1990-2002, giving an average incidence of 7.1 cases/100,000 inhabitants. The incidence of SA increased from 4.2 cases/100,000 in 1990 to 11.0 cases/100,000 in 2002. This rise in SA was primarily observed in adults where the incidence rose by 0.61 cases/100,000 per year (p<0.001). SA was iatrogenic in 41.8% of adults and the number of iatrogenic infections increased from 2.8 cases/year in 1990-1994 to 9.0 cases/year in 1998-2002 (p<0.01). The annual number of arthroscopies increased from 430 in 1990-1994 to 2303 in 1998-2002 (p<0.001) and there was a correlation between the total usage of intra-articular drugs in Iceland and the incidence of SA (p<0.01). The frequency of post-arthroscopy SA was 0.14% and post-arthrocentesis SA 0.037%. CONCLUSIONS: The incidence of SA has increased in recent years due to an increased number of arthroscopies and joint injections. Although the frequency of SA per procedure has not changed, these results emphasise the importance of sterile technique and firm indications for joint procedures.

The effects of tobacco smoking and rheumatoid factor seropositivity on disease activity and joint damage in early rheumatoid arthritis.

OBJECTIVE: To study the effect of tobacco smoking and rheumatoid factor (RF) isotypes on disease activity and joint damage in early rheumatoid arthritis (RA). METHODS: One hundred early RA patients were followed prospectively for 2 yr. They were evaluated at recruitment and at 6 and 24 months. Sociodemographic information included smoking history, and radiographs of hands and feet were obtained. RF was monitored by IgM- and IgA-specific RF enzyme-linked immunosorbent assay and by agglutination, and serial measurements were also obtained for C-reactive protein. The influence of tobacco smoking and RF positivity on disease outcome was evaluated using multivariate analysis. Covariates for the regression analysis included sex, age, coffee consumption and IgA-RF positivity. RESULTS: A gradient of increase in disease activity was observed from never smokers to former smokers to current smokers during the 2 yr of observation, defined by number of swollen joints (SJC), tender joints (TJC) and visual analogue scale for pain (P<0.001, P=0.02 and P=0.005, respectively), but smoking status did not influence radiological progression. Ever smokers were more often IgA RF positive (P<0.05). IgA RF-positive patients had more active disease (SJC P=0.002, TJC P=0.01) and showed more radiological progression (P<0.0001) compared with IgA RF-negative patients. Of the RF-positive patients 22% had elevated IgM RF without IgA RF and these patients showed similar disease activity and radiological joint progression to the RF-negative patients. None of these associations were explained by possible confounders. CONCLUSION: Tobacco smoking has an adverse effect on patients with early RA and this is possibly immunologically mediated. IgM RF does not predict poorer prognosis in RA unless it is associated with a concomitant elevation of IgA RF.

The inheritance of rheumatoid arthritis in Iceland.

OBJECTIVE: Rheumatoid arthritis (RA) is the most common form of inflammatory arthritis. Although there is a large body of evidence suggesting that RA is immune mediated, the etiology remains unresolved. Twin studies have shown disease concordance rates of approximately 15% in monozygotic twins and 4% in dizygotic twins, while the estimated risk ratio for siblings of RA patients ranges from 5 to 8. Our goal was to use genealogic data from Iceland to further investigate the genetic component of RA. METHODS: Data were obtained from a population-based, computerized genealogy database that was developed to examine multigenerational relationships among individuals in the relatively homogeneous population of Iceland. Using an algorithm, the minimum founder test, we calculated the least number of founders required to account for a list of RA patients, and compared it with 1,000 sets of same-sized matched control groups. In addition, we estimated the kinship coefficient and risk ratios for relatives of the RA patients. RESULTS: Several familial clustering tests demonstrated that the RA patients were more related to each other than were the average control set of Icelanders. A significantly fewer number of founders was necessary to account for our patient list than for the random sets of matched controls (P < 0.001), and the average pairwise identity-by-descent sharing was greater among the patients than among the control sets (P < 0.001). In addition, there was an increased risk of RA in first- and second-degree relatives of the patients; e.g., for siblings, the risk ratio was 4.38 (95% confidence interval 3.26-5.67), and for uncles/aunts, the risk ratio was 1.95 (95% confidence interval 1.52-2.43). CONCLUSION: The familial component of RA is shown to extend beyond the nuclear family, thus providing stronger evidence for a significant genetic component to RA.

Low mannose binding lectin predicts poor prognosis in patients with early rheumatoid arthritis. A prospective study.

OBJECTIVE: To determine whether low mannose binding lectin (MBL) is associated with poor prognosis in rheumatoid arthritis (RA) and whether patients with RA have increased frequency of MBL deficiency. METHODS: Patients with recent onset symmetric polyarthritis (< 1 year, median 3 mo) were recruited if they had not been treated longer than 2 weeks with disease modifying drugs. They were reevaluated after 6 months and their disease activity and progression were correlated with their MBL concentration, rheumatoid factor (RF) isotypes, and C-reactive protein (CRP). Sixty-three female patients with advanced RA were also analyzed. RESULTS: Sixty-five patients with early arthritis fulfilled American College of Rheumatology criteria for RA and 52 were followed for 6 months or longer. Low MBL was associated with raised RF, IgA RF in particular (p = 0.02). and also with a combined elevation of IgM and IgA RF (p = 0.035). Patients with low MBL (lowest 25th percentile) showed less improvement after 6 months of treatment than patients in the highest MBL quartile. This applied to the Thompson joint score (p = 0.03) and grip strength (p = 0.004). Low MBL was also significantly associated with radiological joint erosions at recruitment and at 6 month followup (p = 0.039); and the group with advanced RA also showed a significant association between low MBL concentration and radiological damage (p = 0.036). However. neither patient group had increased frequency of MBL deficiency compared to healthy controls. CONCLUSION: Low MBL predicts poor prognosis in patients with early RA.

Smoking, rheumatoid factor isotypes and severity of rheumatoid arthritis.

OBJECTIVES: Smokers have an increased incidence of rheumatoid factor (RF) and rheumatoid arthritis (RA) and one report has also indicated that smoking may also adversely influence the severity of RA. METHODS: Sixty-three women with advanced RA answered a structured questionnaire that included detailed information about their smoking history. The women were also evaluated clinically and radiologically. RESULTS: Heavy smoking (>/= 20 pack-yr) was associated with rheumatoid nodules (P: = 0.01), a higher HAQ score (P: = 0.002) and a lower grip strength (P: = 0.01). Smoking was also associated with more radiological joint damage (P: = 0.02). A positive correlation was observed between smoking and RF levels, in particular IgA RF and a combined elevation of IgM and IgA RF. CONCLUSIONS: Smoking has an adverse effect on disease progression in patients with RA. An association was also observed between smoking and those RF types that predispose to RA and have the highest diagnostic specificity for this disease.

Altered kinetics of CD4+ T cell proliferation and interferon-gamma production in the absence of CD8+ T lymphocytes in virus-infected beta2-microglobulin-deficient mice.

CD8+ T cells are the major mediators of cytotoxic T cell activity controlling viral infections in normal mice. CD8+ T cells have also been implicated in regulating the activity of other immune cells. We have examined the possible regulatory role of CD8+ T cells on CD4+ T cells by comparing immune responses in mice expressing normal CD8+ T cell responses and in CD8+ T cell-deficient beta2-microglobulin "knockout" mice. In normal mice, infection with lymphocytic choriomeningitis virus (LCMV) results in a biphasic T cell immune response. First, CD8+ T cells proliferate and produce interferon-gamma (IFN-gamma), and then 2 to 4 days later CD4+ T cells proliferate and produce IFN-gamma. CD8+ T cell activity is not detected during LCMV infection in beta2-microglobulin-deficient mice. However, in beta2-microglobulin-deficient mice the CD4+ T cell expansion is exaggerated and occurs 2 days earlier than observed in normal mice. Furthermore, the CD4+ T cells have substantial cytotoxic activity, which is not observed in the CD4+ T cell population in normal mice. However, CD4+ T cell IFN-gamma production in beta2-microglobulin-deficient mice lags behind the proliferative response, resulting in a relative delay in overall T cell IFN-gamma production compared to normal mice. Taken together, these data suggest that CD8+ T cell activation peaks at an earlier time point than CD4+ T cell activation during the primary immune response to LCMV and that CD8+ T cells may inhibit CD4+ T cell proliferation and the development of CD4+ T cell cytotoxic activity.

Oestrogen influences CD4+ T-lymphocyte activity in vivo and in vitro in beta 2-microglobulin-deficient mice.

Oestrogen directly influences autoimmune diseases and the immune response to microbes. We studied the effect of oestrogen on CD4+ T cells specific for lymphocytic choriomeningitis virus (LCMV) using mice genetically engineered to be deficient in beta 2-microglobulin (beta 2m-/-). These mice are deficient in beta 2-microglobulin, class I major histocompatibility complex (MHC) molecules and CD8+ T lymphocytes. Fatal leptomeningitis after intracranial infection with LCMV is mediated by CD8+ cytotoxic T lymphocytes (CTL) in wild-type C57BL/6 mice, and by CD4+ T cells in beta 2m-/- mice. Male and female wild-type C57BL/6 mice showed equal susceptibility to immune meningitis. In contrast, male beta 2m-/- mice were less susceptible to fatal immune meningitis than were females. Orchidectomy and oestrogen treatment of male beta 2m-/- mice in vivo restored susceptibility to meningitis. The classic weight loss seen in beta 2m-/- mice after intracranial infection was also accentuated in females. Further, the in vitro activity of CD4+ T cells from male beta 2m-/- mice, as measured by CTL assays, was shown to be dependent on oestrogen. The natural killer cell activity of spleen cells from beta 2m-/- mice after infection with LCMV was not affected by oestrogen. These data demonstrate the influence of oestrogen on CD4+ T-cell activity both in vivo and in vitro.

Enumeration of IFN-gamma producing lymphocytes by flow cytometry and correlation with quantitative measurement of IFN-gamma.

We describe a flow cytometry method to simultaneously analyze IFN-gamma production and T cell surface phenotype in freshly isolated lymphocytes without requiring prior in vitro stimulation. We show that enumeration of intracytoplasmic IFN-gamma positive T cells correlates with quantitative measurement of IFN-gamma in culture supernatant fluids. This suggests that cytokines can be reliably measured using flow cytometry. Flow cytometry has the added advantage of simultaneous detection of cell surface markers. Furthermore, we suggest that analysis of ex vivo IFN-gamma production at the single cell level may reflect more accurately T cell IFN-gamma production, by avoiding the polyclonal stimulation of IFN-gamma production observed after short term in vitro stimulation.

Rheumatoid arthritis. Importance of early diagnosis in long-term outcome.

Rheumatoid arthritis is a common disorder that does not have the favorable outcome it was once thought to have. A detailed clinical history, thorough physical examination, and judicious use of serologic tests and radiologic studies should allow accurate diagnosis, even at an early stage. Traditional therapy can successfully improve short-term functional status but may not alter long-term outcome. Early, aggressive therapy may improve prognosis, but this approach must be further studied and, if attempted, should be done in consultation with a rheumatologist.

In vivo effects of nonsteroidal antiinflammatory drugs on rat skin and synovial mast cell-induced vasopermeability.

Using our animal model of synovial mast cell-mediated arthritis in rats, we tested the effects of 3 nonsteroidal antiinflammatory drugs (NSAIDs) (aspirin, indomethacin, and ketoprofen) and an H1 and an H2 histamine receptor antagonist (diphenhydramine and cimetidine, respectively) on synovial and dermal mast cell-induced vasopermeability. Drug effects were assessed by quantifying the leakage of radiolabeled albumin into tissues following specific antigen-initiated activation of passively sensitized dermal and synovial mast cells. The 3 NSAIDs tested had different effects on synovial and dermal mast cell-induced vasopermeability. Aspirin and indomethacin significantly increased dermal and synovial plasma exudation (P less than or equal to 0.008). Ketoprofen decreased dermal (P = 0.015), but had no effect on synovial, vascular exudation. Complete histamine H1 and H2 receptor blockade with diphenhydramine and cimetidine, respectively, substantially decreased (P less than or equal to 0.0008), but did not completely inhibit, dermal and synovial mast cell-induced vasopermeability. However, the addition of indomethacin to the combined antihistamine regimen resulted in an increase in the leakage of the radiolabel into skin and synovium (back to control levels), despite the complete blockade of H1 and H2 receptors. Results of experiments with antihistamines and indomethacin suggest that mediators other than histamine are involved in synovial mast cell-induced inflammation. Furthermore, the differential response to ketoprofen indicates that the specific antigen-stimulated mediator release profiles of dermal and synovial mast cells are different. Our finding of enhanced synovial vascular leakage in animals treated with some NSAIDs, and no such effect by other NSAIDs, perhaps explains in part the diverse effects of these agents in humans with arthritis.