Expression of chemokines and matrix metalloproteinases in early rheumatoid arthritis

OBJECTIVE: To compare macrophage infiltration and expression of chemokines and matrix metalloproteinases (MMPs) in synovial tissue between patients with early and long-standing rheumatoid arthritis (RA). METHODS: Knee synovial biopsies were taken from 22 patients with early (<1 yr) and 22 patients with long-standing (>5 yr) RA and immunostained with antibodies specific for CD68; macrophage inflammatory protein (MIP)-1alpha and monocyte chemoattractant protein (MCP)-1; MMP-1 and -3 and the tissue inhibitors of metalloproteinases (TIMP)-l and -2. Immunostaining was quantified using a colour video image analysis system. RESULTS: CD68+ macrophage infiltration and the expression of MIP-1alpha, MCP-1, MMP-1, MMP-3, TIMP-1, and TIMP-2 were observed in synovial tissue of patients with early RA. In long-standing RA, there was a further increase in CD68+ macrophage infiltration and MIP-1alpha expression in the synovial lining layer. CD68 expression correlated with MIP-1alpha (R=0.39, P=0.01), but not with MCP-1 expression. CONCLUSION: Macrophage accumulation, and the expression of chemokines and MMPs in synovial tissue occur in early RA. Targeting chemokines which play a role in the migration of macrophages into the joints may be of therapeutic benefit in RA patients.     

The effects of interferon-beta treatment of synovial inflammation and expression of metalloproteinases in patients with rheumatoid arthritis

OBJECTIVE: Interferon-beta (IFNbeta) treatment is emerging as a potentially effective form of therapy in various immune-mediated conditions. This study evaluated the effects of IFNbeta therapy on the cell infiltrate, cytokine profile, and expression of metalloproteinase 1 (MMP-1) in synovial tissue from patients with rheumatoid arthritis (RA). To further assess the mechanism of action, in vitro experiments were conducted to determine the effects of IFNbeta on the production of MMP-1, MMP-3, tissue inhibitor of metalloproteinases 1 (TIMP-1), and prostaglandin E2 (PGE2) by human fibroblast-like synoviocytes (FLS). METHODS: Eleven patients were treated for 12 weeks with purified natural fibroblast IFNbeta (Frone; Ares-Serono, Geneva, Switzerland) subcutaneously 3 times weekly with the following dosages: 6 million IU (n = 4), 12 million IU (n = 3), and 18 million IU (n = 4). Synovial biopsy specimens were obtained by needle arthroscopy at 3 time points: directly before and at 1 month and 3 months after initiation of treatment. Immunohistologic analysis was performed using monoclonal antibodies specific for the following phenotypic markers and mediators of joint inflammation and destruction: CD3, CD38, CD68, CD55, tumor necrosis factor alpha (TNFalpha), interleukin-1beta (IL-1beta), IL-6, MMP-1, and TIMP-1. In addition, we measured the production of MMP-1, MMP-3, TIMP-1, and PGE2 by RA FLS and dermal fibroblasts in the presence and absence of IFNbeta. RESULTS: A statistically significant reduction in the mean immunohistologic scores for CD3+ T cells and the expression of MMP-1 and TIMP-1 at 1 month, CD38+ plasma cells and the expression of IL-6 at 3 months, and the expression of IL-1beta at both 1 and 3 months was observed in synovial tissue after IFNbeta treatment. The scores for CD68+ macrophages and TNFalpha expression also tended to decrease, but the differences did not reach statistical significance. The in vitro experiments revealed inhibition of MMP-1, MMP-3, and PGE2 production by RA FLS, whereas TIMP-1 production was only slightly decreased. These effects were more consistent in RA FLS than in dermal fibroblasts. CONCLUSION: The changes in synovial tissue after IFNbeta treatment and the in vitro data support the view that IFNbeta therapy has immunomodulating effects on rheumatoid synovium and might help to diminish both joint inflammation and destruction. Larger well-controlled studies are warranted to show the efficacy of IFNbeta treatment for RA.     

Discriminant function analysis as decision support system for the diagnosis of acute leukemia with a minimal four color screening panel and multiparameter flow cytometry immunophenotyping.

Despite several recommendations for standardization of multiparameter flow cytometry (MFC) the number, specificity and combinations of reagents used by diagnostic laboratories for the diagnosis and classification of acute leukemias (AL) are still very diverse. Furthermore, the current diagnostic interpretation of flow cytometry readouts is influenced arbitrarily by individual experience and knowledge. We determined the potential value of a minimal four-color combination panel of 13 monoclonal antibodies (mAbs) with a CD45/sideward light scatter-gating strategy for a standardized MFC immunophenotyping of the clinically most relevant subgroups of AL. Bone marrow samples from 155 patients with acute myeloid leukemia (AML, n=79), B-cell precursor acute lymphoblastic leukemia (BCP-ALL, n=29), T-cell precursor acute lymphoblastic leukemia (T-ALL, n=12) and normal bone marrow donors (NBMD, n=35) were analyzed. A knowledge-based learning algorithm was generated by comparing the results of the minimal panel with the actual diagnosis, using discriminative function analysis. Correct classification of the test sample according to lineage, that is, BCP-ALL, T-ALL, AML and differentiation of NBMD was achieved in 97.2% of all cases with only six of the originally applied 13 mAbs of the panel. This provides evidence that discriminant function analysis can be utilized as a decision support system for interpretation of flow cytometry readouts.     

Effect of theophylline and enprofylline on bronchial hyperresponsiveness.

The effect of increasing intravenous doses of theophylline and enprofylline, a new xanthine derivative, on bronchial responsiveness to methacholine was studied in eight asthmatic patients. Methacholine provocations were carried out on three days before and after increasing doses of theophylline, enprofylline, and placebo, a double blind study design being used. Methacholine responsiveness was determined as the provocative concentration of methacholine causing a fall of 20% in FEV1 (PC20). The patients were characterised pharmacokinetically before the main study to provide an individual dosage scheme for each patient that would provide rapid steady state plasma concentration plateaus of 5, 10, and 15 mg/l for theophylline and 1.25, 2.5, and 3.75 mg/l for enprofylline. Dose increments in the main study were given at 90 minute intervals. FEV1 showed a small progressive decrease after placebo; it remained high in relation to placebo after both drugs and this effect was dose related. Methacholine PC20 values decreased after placebo; mean values were higher after theophylline and enprofylline than after placebo (maximum difference 2.0 and 1.7 doubling doses of methacholine); the effect of both drugs were dose related. Thus enprofylline and theophylline when given intravenously cause a small dose related increase in FEV1 and methacholine PC20 when compared with placebo.     

Effects of oral prednisolone on biomarkers in synovial tissue and clinical improvement in rheumatoid arthritis

OBJECTIVE: To create greater understanding of the changes in synovial tissue parameters that occur in conjunction with clinical response by using an effective therapy, in order to facilitate the planning of future studies with therapeutic agents for rheumatoid arthritis (RA). METHODS: Twenty-one patients with active RA were randomized to receive either oral prednisolone (n = 10) or placebo (n = 11) for 2 weeks. In all patients, synovial tissue biopsy specimens were obtained by arthroscopy directly before treatment and after 14 days of treatment. Immunohistochemical analysis was performed to characterize the cell infiltrate and vascularity. Stained tissue sections were analyzed by digital imaging. Statistical analysis was performed using an analysis of covariance model. RESULTS: After treatment, the mean Disease Activity Score in 28 joints (DAS28) was 2.0 units lower (95% confidence interval [95% CI] 1.0-3.0) in patients who received prednisolone than in those who received placebo. In the prednisolone group, the mean (+/-SD) DAS28 decreased from 6.27 +/- 0.95 to 4.11 +/- 1.43 after therapy; minimal change was observed in the placebo group. For macrophages, the estimated effect of prednisolone was large. Patients receiving active treatment had fewer (mean 628 cells/mm(2) [95% CI 328-927]) macrophages after therapy compared with those receiving placebo. A reduction in the total number of CD68+ macrophages, from 1,038 +/- 283 cells/mm(2) before treatment to 533 +/- 248 cells/mm(2) after treatment, was observed in the prednisolone group. There were clear trends toward decreased infiltration by T cells, plasma cells, and fibroblast-like synoviocytes after active treatment. We observed a trend toward a reduction in alphavbeta3+ newly formed blood vessels and expression of vascular growth factors after prednisolone therapy. CONCLUSION: Prednisolone therapy in RA is associated with a marked reduction in macrophage infiltration in synovial tissue, suggesting that synovial macrophage numbers could be used as a biomarker for clinical efficacy.     

Discovery of distinctive gene expression profiles in rheumatoid synovium using cDNA microarray technology: evidence for the existence of multiple pathways of tissue destruction and repair

Rheumatoid arthritis (RA) is a heterogeneous disease. We used cDNA microarray technology to subclassify RA patients and disclose disease pathways in rheumatoid synovium. Hierarchical clustering of gene expression data identified two main groups of tissues (RA-I and RA-II). A total of 121 genes were significantly higher expressed in the RA-I tissues, whereas 39 genes were overexpressed in the RA-II tissues. Among the 121 genes overexpressed in RA-I tissues, a relative majority of nine genes are located on chromosome 6p21.3. An interpretation of biological processes that take place revealed that the gene expression profile in RA-I tissues is indicative for an adaptive immune response. The RA-II group showed expression of genes suggestive for fibroblast dedifferentiation. Within the RA-I group, two subgroups could be distinguished; the RA-Ia group showed predominantly immune-related gene activity, while the RA-Ib group showed an additional higher activity of genes indicative for the classical pathway of complement activation. All tissues except the RA-Ia subgroup showed elevated expression of genes involved in tissue remodeling. These results confirm the heterogeneous nature of RA and suggest the existence of distinct pathogenic mechanisms that contribute to RA. The differences in expression profiles provide opportunities to stratify patients based on molecular criteria.     

The effects of interferon beta treatment on arthritis.

OBJECTIVE: To determine whether interferon beta (IFN-beta) therapy might have a beneficial effect on arthritis, we evaluated the effect of IFN-beta on collagen type II-induced arthritis (CIA) in rhesus monkeys and conducted a pilot study in patients with rheumatoid arthritis (RA). METHODS: Four rhesus monkeys with CIA were treated with 10 x 10(6) U (MIU)/kg mammalian cell-derived recombinant IFN-beta (Rebif; Ares-Serono) s.c. daily for 1 week. Subsequently, 12 patients with active RA were treated for 12 weeks with purified natural fibroblast IFN-beta (Frone, Ares-Serono) s.c. 3 times weekly at the following dosages: 6 MIU (n = 4), 12 MIU (n = 4) and 18 MIU (n = 4). RESULTS: Rapid clinical improvement during IFN-beta therapy was observed in three of the four rhesus monkeys with CIA. There was also a marked decrease in serum C-reactive protein (CRP) levels with a subsequent increase after discontinuation of the treatment in all monkeys. The 10 RA patients who completed the study exhibited on average gradual improvement of tender and swollen joint counts, patient's assessment of pain, and patient's and doctor's global assessment (all P < 0.05). The health assessment questionnaire and serum CRP levels also tended to decrease, but this was not statistically significant; 40% of the patients fulfilled the ACR criteria for 20%, improvement, whereas none fulfilled the ACR criteria for 50% improvement 12 weeks after initiation of treatment. There was no clear dose response relationship. CONCLUSION: The data suggest that IFN-beta treatment has a beneficial effect on arthritis.