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Biomedical subjects

F C Breedveld

Publications and source records attributed to F C Breedveld.

At least 289 records · Page 16Linked to original sources

Relative bioavailability of a new oral form of cyclosporin A in patients with rheumatoid arthritis.

The relative bioavailability of cyclosporin A (CsA) from a new microemulsion oral formulation (NEO) and the currently used soft gelatine capsule (SGC) was determined at steady state in 12 patients with rheumatoid arthritis. The AUC(0,12 h) values of cyclosporin A were significantly greater after NEO than SGC (2873 +/- 848 ng ml-1 h (mean +/- s.d.) vs 2355 +/- 1128 ng ml-1 h; P = 0.02, 95% CI (confidence interval of the difference: 81 to 955 ng ml-1 h). Cmax values were significantly higher after NEO than after SGC (811 +/- 244 ng ml-1 vs 495 +/- 291 ng ml-1, P < 0.0001, 95% CI of the difference: 209 to 422 ng ml-1).

Aged↗

The influence of tetracyclines on T cell activation.

Minocycline has been shown to have an anti-inflammatory effect in patients with rheumatoid arthritis (RA). Since there is evidence that RA is a T cell-mediated disease, we investigated the effect of minocycline on human T cell clones derived from the synovium of an RA patient. The T cells, when activated via the T cell receptor (TCR)/CD3 complex, were suppressed functionally by minocycline, resulting in a dose-dependent inhibition of T cell proliferation and reduction in production of IL-2, interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha). Besides an inhibition of IL-2 production, minocycline exerted its effect on T cell proliferation by induction of a decreased IL-2 responsiveness. We showed that the chelating capacity of minocycline plays a crucial role in the inhibitory effect on T cell function, since the inhibitory effect on T cell proliferation could be annulled by addition of exogenous Ca2+. However, minocycline did not markedly influence the typical TCR/CD3-induced intracellular Ca2+ mobilization. Taken together, the results clearly indicate that minocycline has immunomodulating effects on human T cells.

Anti-Bacterial Agents↗

Chloroquine inhibits T cell proliferation by interfering with IL-2 production and responsiveness.

Chloroquine (Chl) is an anti-rheumatic drug that is widely used in the treatment of rheumatoid arthritis (RA). It seems that T cells are important in the pathogenesis of RA, but it is not known whether Chl acts via inhibition of T cell function. We here present evidence that Chl, just like cyclosporine A (CsA), inhibits T cell proliferation as induced with immobilized alpha CD3 MoAb in a concentration-dependent manner, at least partly through interfering with the production of IL-2 protein and the induction of IL-2 mRNA. Furthermore, Chl impedes the responsiveness of T cell clones to IL-2 since (1) the inhibition of alpha CD3 MoAb-induced proliferation by Chl could not be reversed by rIL-2 and (2) Chl directly blocks IL-2-driven proliferation of cloned T cells. Chl appeared to interfere with the internalization (50% inhibition) and degradation (total blockade) of rIL-2. Finally, the combination of Chl and CsA synergistically inhibited T cell proliferation. We conclude that Chl may inhibit functional properties of human T cells, although the drug is 100- to 1000-fold less potent than CsA in inhibiting T cell proliferation and IL-2 production, respectively. It is speculated that the in vitro effects of Chl might be relevant in explaining the anti-rheumatic effect of this drug in patients with RA.

Antibodies, Monoclonal↗

Subclass distribution of IgA and IgG antibodies against Clq in patients with rheumatic diseases.

To obtain insight into the immunoregulatory mechanisms in patients with different rheumatic diseases, the occurrence and the subclass distribution of IgA and IgG antibodies against Clq (anti-ClqAb) was determined. In patients with systemic lupus erythaematosus (SLE) the highest frequency of increased serum levels of IgG anti-ClqAb were found, whereas IgA anti-ClqAb were predominantly present in patients with ankylosing spondylitis (AS) and patients with rheumatoid arthritis complicated by vasculitis (RV). In all the IgA anti-ClqAb positive AS and RV patients the antibody reactivity involved the IgA1 subclass while the IgA2 subclass was found in 47% of the patients. Further characterization of the IgA anti-Clq binding activity in sera of AS patients revealed that both subclasses of IgA anti-ClqAb were predominantly polymeric; the binding of both IgA subclasses with solid phase Clq was inhibitable by aggregated fluid phase Clq; we found no detectable interference of rheumatoid factor in the test system for the measurement of IgA anti-ClqAb. In patients with SLE the IgG anti-ClqAb reactivity was mainly of the IgG2 and IgG3 subclass, whereas in the same patients the IgG anti-tetanus toxoid response was not restricted to these subclasses. The predominance of IgG2 and IgG3 subclass of anti-ClqAb in sera of SLE patients, suggests a skewing of the anti-ClqAb response. The observation that the IgA anti-ClqAb of both subclasses is predominantly polymeric in nature and the notion that polymeric IgA is associated with activation of inflammation cascades, suggests that IgA anti-ClqAb may contribute to tissue damage.

Antibodies, Monoclonal↗

Tenidap, but not nonsteroidal anti-inflammatory drugs, inhibits T-cell proliferation and cytokine induction.

T-lymphocytes are involved in the inflammatory response that occurs in affected joints of patients with rheumatoid arthritis (RA). Some second-line disease modifying anti-rheumatic drugs used in the treatment of patients with RA are known to block T-cell activation. The present study assessed whether tenidap, an investigational anti-rheumatic drug, affects in vitro T-cell responses such as proliferation and cytokine production. It was found that tenidap, in contrast to several nonsteroidal anti-inflammatory drugs, inhibits anti-CD3 or IL-2 driven proliferative responses of cloned human T-cells. Furthermore, tenidap was found to inhibit IFN-gamma production as well as the induction of mRNA encoding IFN-gamma or TNF-alpha. The results indicate that tenidap may exert at least part of its anti-inflammatory activity via inhibition of T-cell function and cytokine production.

Anti-Inflammatory Agents, Non-Steroidal↗

Therapeutic regulation of T cells in rheumatoid arthritis.

TCR repertoire studies in RA have yielded conflicting data. These studies were initiated on the premise that clonal expression of T cells at the site of inflammation could serve as a target for immune therapies designed on the basis of the option to inactivate or eliminate the presumed pathogenic T cells. These analyses have demonstrated the existence of a highly diverse overall TCR repertoire on the basis of extensive usage of TCR V genes both in synovial fluid and tissue. However, clusters of RA patients can be recognized who share increased usage frequencies of defined TCR V genes among synovial fluid or synovial tissue lymphocytes. Subsequent analysis of the CDR3 regions among diverse overall TCR repertoires have revealed the presence of conserved amino acid sequences in the CDR3 regions of the variable portions of TCRs in T lymphocytes derived from the site of inflammation. These findings suggest that a selective, antigen-driven expansion of T lymphocytes is occurring in the inflamed joints. Parallel to the TCR-repertoire studies, we investigated whether vaccines prepared from synovial T cells could modulate T-cell reactivity. The studies were based on previous work on TCV in animals, revealing that attenuated non-specific T-cell lines could serve as a vaccine. The results obtained in 13 RA patients showed no clear indication for a cellular or humoral immune response. Our experience with TCV in RA patients showed that this technique is feasible and safe. We found some evidence for a modulated T-cell reactivity both in vivo and in vitro. These results show at least some immunomodulatory effect af T-cell vaccination, although the antigen specificity of the effect of this intervention remains to be shown. Because of the convincing studies in animals and MS patients, further studies in RA should focus on the effect of vaccination using vaccines prepared from disease-inducing cells. In this respect, determination of the CDR3 regions of synovial T cells could lead to the identification of those T cells that are relevant for the disease.

Arthritis, Rheumatoid↗

Teenager with an irritable hip, anaemia and malaise.

We have described a boy with a juvenile spondyloarthropathy who also showed inflammatory changes in the gut. Gastrointestinal symptoms initially indicated the presence of an inflammatory bowel disease, but this was excluded histopathologically.

Anemia, Iron-Deficiency↗

Joint-derived T cells in rheumatoid arthritis proliferate to antigens present in autologous synovial fluid.

The histopathological features of rheumatoid joint-inflammation suggest that an antigen-driven activation of T cells plays a central role in the onset and/or perpetuation of the inflammatory process. However, the disease-associated antigens responsible for the activation of T cells in the joint are unknown. In this project we study the response of IL-2 expanded T-cell lines from the synovial fluid (SF) of rheumatoid arthritis (RA) patients against autologous SF in a proliferation assay. Sixteen out of 32 RA patients were found to have CD4+ T cells that proliferate in response to autologous SF. The presence of T cells able to respond to SF antigens in inflamed joints suggests that these T cells play an active role in the pathogenesis of RA. T cell clones reactive to autologous SF were isolated from SF-derived T-cell lines of two RA patients. All clones were of the CD4+, CD8-, alpha/beta+ phenotype. SF-reactivity of T-cell clones from the DR4/DR12-positive RA patient was restricted via the Dw4 subtype of DR4. SF reactivity of T cells of the DR12/DR15 patient was DP-restricted. Some of the T-cell clones responded specifically to autologous and not to allogeneic SF, whereas others revealed responsiveness against a limited number of allogeneic SF samples. The (restricted) specificity of T cells towards autologous SF antigens is indicative for heterogeneity of the epitopes recognized and argues against ubiquitous nonpolymorphic joint constituents as the relevant antigens recognized by the SF-autoreactive T cells.

Arthritis, Rheumatoid↗

Rheumatoid factor production in the joint.

Mononuclear cells derived from bone marrow, synovium and peripheral blood of patients with rheumatoid arthritis (RA) were examined for their capacity to produce rheumatoid factor (RF) in order to investigate the origin of circulating RF. The results demonstrate that mononuclear cells derived from bone marrow are able to produce IgG-, IgA- and IgM-RF and that the amounts of RF produced by bone marrow cells are not significantly different from that by dissociated synovial cells. Since circulating immunoglobulins are mainly derived from the bone marrow this observation suggests that also RF circulating in RA patients mainly originates from the bone marrow.

Arthritis, Rheumatoid↗

Technetium-99m labelled polyclonal human IgG scintigraphy before and 26 weeks after initiation of parenteral gold treatment in patients with rheumatoid arthritis.

OBJECTIVE: To determine effectiveness of technetium-99m labelled polyclonal human immunoglobulin G (99mTc-IgG) scintigraphy to monitor variation in arthritis activity in patients with rheumatoid arthritis (RA). METHODS: The results of semiquantitative 99mTc-IgG scintigraphy were compared with those of examination before and 26 weeks after initiation of parenteral gold treatment in 19 patients with RA. RESULTS: Clinical and laboratory variables of arthritis activity as well as the scores of 99mTc-IgG scintigraphy were significantly lower after gold treatment compared to the scores before treatment. However, the difference between the mean scores of 99mTc-IgG scintigraphy before and after treatment was statistically significant for more joints than such difference in scores for joint pain and joint swelling. CONCLUSION: 99mTc-IgG scintigraphy is able to reflect variations in arthritis activity in patients with RA.

Adult↗

Antimalarial drug induced decrease in creatinine clearance.

OBJECTIVE: To confirm the antimalarial drug induced increase of creatinine to determine the factors contributing to this effect. METHODS: Patients with rheumatoid arthritis (RA) (n = 118) who have used or still use antimalarials (chloroquine or hydroxychloroquine). Serum creatinines prior to antimalarials and serum creatinines during antimalarials were recorded and the creatinine clearance was estimated. RESULTS: The mean creatinine clearance decreased from 99 ml/min to 92 ml/min (p < 0.001) after the start of antimalarial drugs. Fifty-five percent of the patients with chloroquine compared to 15% of the patients with hydroxychloroquine (chi 2 = 17.8; p < 0.001) had more than 10% decrease of the creatinine clearance. Age (beta = 0.004; p = 0.0002) and the kind of antimalarial (beta = 0.095; p = 0.0002) were strong independent predictors of the decrease of the creatinine clearance in the multiple regression analysis. For patients using chloroquine the mean age adjusted decrease of creatinine clearance was 11.2%. CONCLUSION: Antimalarials cause a significant reduction of the creatinine clearance. The use of chloroquine and older age were associated with decreased creatinine clearance. Whether antimalarials affect glomerular filtration or tubular excretion of creatinine remains to be investigated.

Adult↗

Activated gelatinase-B (MMP-9) and urokinase-type plasminogen activator in synovial fluids of patients with arthritis. Correlation with clinical and experimental variables of inflammation.

OBJECTIVE: To evaluate the occurrence of gelatinase-B (matrix metalloproteinase 9, MMP-9) in synovial fluids (SF) of patients with arthritis to investigate the possible role of this neutral MMP in joint destruction. METHODS: In paired (series I) and unpaired SF (series II) we examined the occurrence of gelatinase-B, prostromelysin-1, and urokinase-type plasminogen activator (u-PA). RESULTS: In the paired SF a parallelism between the presence of activated gelatinase-B and the local arthritis activity scores of the knees was observed. Activated gelatinase-B correlated well with the presence of stromelysin-1 and u-PA, 2 enzymes probably involved in the activation process of gelatinase-B. In the 2nd series, activated gelatinase-B was found in 56 SF samples, whereas 82 samples did not exhibit activated gelatinase-B. The SF samples with the activated form of gelatinase-B showed a significantly higher ability to induce permeability changes in cultured monolayers of human endothelial cells, had more myeloperoxidase activity--secreted by infiltrated leukocytes--and had higher u-PA antigen concentrations, compared to SF samples without the activated form of gelatinase-B. CONCLUSION: Our data suggest that the presence of gelatinase-B is a reflection of the inflammatory condition of the joints of patients with arthritis, and that the activation of gelatinase-B in the joints, which may occur in a u-PA/plasmin dependent and/or a stromelysin dependent way, contributes to the progression of arthritis.

Adult↗

Minocycline in the treatment of rheumatoid arthritis: relationship of serum concentrations to efficacy.

OBJECTIVE: To assess the relationships between serum concentrations of minocycline and clinical efficacy and toxicity during the treatment of patients with rheumatoid arthritis (RA) with minocycline. METHODS: Forty patients with active RA were administered minocycline (maximal oral dose 100 mg twice a day) for 26 weeks. At 3 time points during the treatment, serum samples were collected for measurement of minocycline activity using a microbiological assay. An analysis of variance was performed to estimate an extrapolated concentration at time = 0 (C0) for each patient separately and this value of C0 was regarded to be proportional to the average serum concentration in each patient. The relation between C0 and clinical response and between C0 and the occurrence of adverse effects was evaluated. RESULTS: Minocycline was detected in 96 serum samples from 37 patients. Eighty-two percent of the variance in serum concentrations was accounted for by a model incorporating patient, dose, and time effects. A weak correlation between C0 and clinical response, as expressed by a Ritchie articular index and number of swollen joints, was demonstrated. No correlation was seen between C0 and toxicity, including gastrointestinal or vestibular adverse effects. CONCLUSION: Results suggest a relationship between the serum concentrations of minocycline and the clinical response, including Ritchie articular index and number of swollen joints, in the treatment of patients with RA. No relationship was seen between the serum concentrations of minocycline and its toxicity.

Adult↗

Randomised double-blind comparison of chimeric monoclonal antibody to tumour necrosis factor alpha (cA2) versus placebo in rheumatoid arthritis.

Tumour necrosis factor alpha (TNF alpha) is a critical inflammatory mediator in rheumatoid arthritis, and may therefore be a useful target for specific immunotherapy. In support of this hypothesis, we previously observed beneficial responses in patients with active rheumatoid arthritis after open-label administration of a chimeric monoclonal antibody to TNF alpha (cA2). We now report the results of a four-centre, randomised double-blind trial of a single infusion of 1 or 10 mg/kg cA2 compared with placebo in 73 patients with active rheumatoid arthritis. The primary endpoint of the study was the achievement at week 4 of a Paulus 20% response, an amalgam of six clinical, observational, and laboratory variables. Intention-to-treat analysis of data from individual patients showed only 2 of 24 placebo recipients responding at this time, compared with 11 of 25 patients treated with low-dose cA2 (p = 0.0083) and 19 of 24 patients treated with high-dose cA2 (p < 0.0001). Over half of the high-dose cA2 patients responded by the more stringent 50% Paulus criteria at this time (p = 0.0005). The magnitude of these responses was impressive, with maximum mean improvements in individual disease-activity assessments, such as tender or swollen-joint counts and in serum C-reactive protein, exceeding 60% for patients on high-dose treatment. There were two severe adverse events. 1 patient on 1 mg/kg cA2 developed pneumonia ("possibly" treatment-related) and 1 on 10 mg/kg had a fracture ("probably not" treatment-related). The results provide the first good evidence that specific cytokine blockade can be effective in human inflammatory disease and define a new direction for the treatment of rheumatoid arthritis.

Adolescent↗

Minocycline in active rheumatoid arthritis. A double-blind, placebo-controlled trial.

OBJECTIVE: To determine the efficacy of minocycline in the treatment of rheumatoid arthritis (RA). METHODS: Minocycline (maximal oral daily dose 200 mg) or placebo was administered in a 26-week, randomized, double-blind study to 80 patients with active RA, who were treated or had previously been treated with at least one disease-modifying antirheumatic drug. RESULTS: There were 15 premature discontinuations: 6 (5 taking minocycline) because of adverse effects, 8 (all taking placebo) because of lack of efficacy, and 1 (taking placebo) because of intercurrent illness. There was a statistically significant improvement in the minocycline group over the placebo group. There was a pronounced improvement in laboratory parameters of disease activity; however, improvement in clinical parameters was less impressive. The observed adverse effects attributable to minocycline were mainly gastrointestinal symptoms and dizziness. CONCLUSION: The results of the present study suggest that minocycline is beneficial and relatively safe in RA patients.

Adult↗

A randomized, double-blind, 24-week controlled study of low-dose cyclosporine versus chloroquine for early rheumatoid arthritis.

OBJECTIVE: To investigate whether low-dose cyclosporin A (CSA) is safe and effective in comparison with chloroquine (CQ) in patients with early rheumatoid arthritis (RA). METHODS: We performed a randomized, double-blind study comparing CSA with CQ in patients with early RA (duration < 2 years) who had had active disease for at least 3 months. Forty-four RA patients with a mean disease duration of 6 months were randomly allocated to receive CSA (initial dosage 2.5 mg/kg/day, maintenance dosage 3.6 mg/kg/day) or CQ (initial dosage 300 mg/day, maintenance dosage 100 mg/day) for 24 weeks. RESULTS: Five patients (2 taking CSA and 3 taking CQ) discontinued the study prematurely. Intention-to-treat analysis disclosed a decrease in the swollen joint count by 7 in both groups. The erythrocyte sedimentation rate and C-reactive protein level did not change significantly. CSA and CQ were tolerated equally well, although mild paraesthesia occurred more frequently in the CSA-treated group. The serum creatinine level increased by 13 mumoles/liter (95% confidence interval [95% CI] 4, 22) in the CSA group and by 6 mumoles/liter (95% CI 1, 11) in the CQ group (difference not statistically significant). CONCLUSION: Both CSA and CQ are effective in alleviating the symptoms of active early RA. There is only slightly impaired renal function after 24 weeks of drug administration of either drug in patients with early RA.

Adult↗