Studies on type II collagen-induced polyarthritis in rats. Effect of antiinflammatory and antirheumatic agents

Soluble complement receptor one (sCR1) inhibits the development and progression of rat collagen-induced arthritis

We set out to determine whether inhibition of complement using sCR1 could influence the development and progression of collagen arthritis in the Lewis rat. Collagen arthritis was successfully established in the Lewis rat, using a novel immunization schedule. In separate experiments, cobra venom factor (CVF) and sCR1 were used to achieve systemic complement inhibition. Their respective effects on disease onset and on the progression of established disease compared with saline-treated control animals was explored. Arthritis was assessed by measurement of clinical score, paw diameter and paw volume. Complement inhibition using either CVF or sCR1, prior to the onset of clinical signs of inflammation, delayed the development of disease. CVF was ineffective in the treatment of established disease, whereas sCR1 delayed the progression of disease in affected joints and prevented the recruitment of further joints while the animals were complement-depleted. In the control saline-treated groups the disease continued to progress relentlessly. We conclude that complement activation is important in the initiation and maintenance of inflammation in collagen arthritis. The potent disease-modulating effect of sCR1 provides persuasive evidence that specific complement inhibiting agents may be an effective approach to the treatment of inflammatory joint diseases

Anti-inflammatory effects of a new tumour necrosis factor-alpha (TNF-alpha) inhibitor (CNI-1493) in collagen-induced arthritis (CIA) in rats

A recently developed compound, a multivalent guanylhydrazone (CNI-1493) that inhibits TNF-alpha production by suppressing TNF-alpha translational efficiency, was administered in an experimental model of collagen type II-induced arthritis in DA rats. CNI-1493 was injected daily intraperitoneally either before the onset of arthritis or after the establishment of clinical disease. Prophylactic treatment with CNI-1493 significantly prevented or delayed the onset and suppressed the severity of arthritis in a dose-dependent manner. Therapeutic intervention with CNI-1493 in established joint disease also resulted in a significant reduction of clinical signs of arthritis in treated animals. No severe side-effects were noted when animals were treated with daily CNI-1493 doses up to 5 mg/kg. An immunohistochemical study was performed which demonstrated that CNI-1493 led to a reduced expression of TNF-alpha at the site of disease activity. Thus, CNI-1493 with documented inhibitory effects on TNF-alpha synthesis, has proven successful in ameliorating the course of arthritis in CIA. We believe that the use of a compound such as CNI-1493 with a defined mode of action provides a useful tool for dissecting and understanding important pathogenic mechanisms operating in the development of chronic arthritis.

Pharmacological effects of SA96 (bucillamine) and its metabolites as immunomodulating drugs--the disulfide structure of SA-96 metabolites plays a critical role in the pharmacological action of the drug

SA96 (generic name, bucillamine) is a disease-modifying anti-rheumatoid arthritis (RA) drug with immunological effects. This compounds has two sulfhydryl groups in its molecule, and the differences and similarities between this drug and D-penicillamine, which is also a sulfhydryl group-containing anti-rheumatic drug, have frequently been discussed. To clarify the pharmacological differences between these two drugs, we examined the concentrations of the compounds and its metabolites in serum and synovial fluid, paying special attention to the metabolites of SA96 produced in vivo. SA96 was metabolized in a very short time to SA981 which is a disulfide compound formed by intramolecular binding of two sulfhydryl groups, and transferred to synovial fluid. In addition SA981 had significant suppressive effects on IL-6 and IL-8 production by synovial cells in vitro. These results demonstrate that SA96, which has two sulfhydryl groups, exhibits anti-rheumatic effects via a pharmacological action clearly different from that of D-penicillamine.

Immunomodulating effects of the new anti-rheumatic drug tenidap on collagen-induced arthritis

We investigated the in vivo action of the newly developed anti-rheumatic agent tenidap, CP-66,248 (Pfizer Inc., New York), on arthritis in collagen-induced arthritic mice. The inhibitory effect of tenidap on the development of arthritis was statistically more significant than piroxicam. The serum anti-type II collagen antibody titer was markedly inhibited in the mice treated by tenidap. These results suggest that, unlike NSAIDs, tenidap inhibits the progress of collagen-induced arthritis through its immunomodulating effect.

Effects of cyclosporin on serum hyaluronan levels in collagen arthritis

Serum hyaluronan (HA) levels were measured in a rat model of collagen arthritis using a sandwich enzyme-linked immunosorbent assay. Values became elevated as the arthritis developed, correlating with its severity. Daily subcutaneous treatment with cyclosporin at the dose of 25 mg/kg per day for fourteen days completely prevented anti-type II collagen antibody production and the serum HA increase as well as development of collagen arthritis. HA in the blood may thus provide a good quantitative marker for joint disease in rat collagen arthritis with potential as a tool for evaluation of drug efficacy in this experimental model.

Measurement of radiographic changes in adjuvant-induced arthritis in rats by quantitative image analysis

OBJECTIVE

To apply quantitative analytical methods to the evaluation of radiographic images in experimental arthritis.

METHODS

Adjuvant was used to induce arthritis in rats. Arthritis progression was followed by conventional methods. In addition, digitized images of radiographs of the calcaneus were examined for changes in the mean and in the distribution pattern of gray values. Periosteal new bone formation was measured as an increase in image area of the calcaneus.

RESULTS

Significant changes in the gray value profile and increases in periosteal bone formation occurred in arthritic rats. More extensive changes occurred in Lewis rats than in Sprague-Dawley rats. Analysis of serial radiographs revealed an initial decrease in the density of juxtaarticular bone, followed by progressive increases in gray value variation due to concurrent bone loss and bone formation. Eventually, bone formation in arthritic rats resulted in increased gray values above those in nonarthritic rats.

CONCLUSION

Image analysis represents a sensitive, quantitative method for detecting radiographic changes in experimental arthritis.

Comparative inhibitory effects of bucillamine and D-penicillamine on the function of human B cells and T cells

OBJECTIVE

Clinical trials have suggested that the efficacy of bucillamine (BUC) in rheumatoid arthritis (RA) may be superior to that of D-penicillamine (DP), although the basis of the differences remains unclear. Previous studies have revealed that BUC has unique immunomodulatory effects that depend upon its capacity to form an intramolecular disulfide (BUC-ID). We therefore examined the effects of BUC-ID on the in vitro function of human B cells and T cells compared with those of DP, at their pharmacologically attainable concentrations.

METHODS

IgM production was induced in highly purified B cells from healthy donors by stimulation with Staphylococcus aureus Cowan 1 (SAC) plus interleukin-2 (IL-2) or with immobilized anti-CD3-activated CD4+ T cells. Interferon-gamma (IFN gamma) production was induced in CD4+ T cells by stimulation with immobilized anti-CD3.

RESULTS

BUC-ID suppressed IgM production induced by SAC+IL-2 as well as that induced by immobilized anti-CD3-activated CD4+ T cells, whereas DP suppressed the latter more markedly than the former. DP (3 micrograms/ml) significantly suppressed IFN gamma production by immobilized anti-CD3-stimulated CD4+ T cells, but not IgM production induced by SAC + IL-2 stimulation. By contrast, BUC-ID (0.3 microgram/ml) significantly suppressed IgM production induced by SAC + IL-2, but not T cell IFN gamma production. Of note, BUC-ID did not suppress IL-6 production by SAC-activated B cells.

CONCLUSION

These results indicate that the target cells of BUC and DP in vivo might be different, with the former inhibiting the function of B cells and the latter that of T cells. The data suggest the possibility that BUC may have a different effect in RA patients compared with the effect of DP, and may be effective in patients who do not respond to DP.

Animal models for osteoarthritis: processes, problems and prospects

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Effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis in rats

The prophylactic and therapeutic effects of gold sodium thiomalate, cyclosporin A, cyclophosphamide, and placebo on collagen-induced arthritis (CIA) were evaluated in DA rats. Prophylactic treatment with cyclosporin A and cyclophosphamide suppressed the arthritis incidence, clinical inflammation, destructive bone changes, and development of anti-collagen antibody in DA rats subsequently injected with porcine type-II collagen. Therapeutic treatment with cyclosporin A and cyclophosphamide had a definite suppression on established CIA when started 21 days after the initial collagen injection, but the suppression was less marked than that of prophylactic treatment. Gold had no impact on CIA in DA rats when administered either prophylactically or therapeutically.

Disease-modifying anti-rheumatic drugs: strategies for screening

Rheumatoid arthritis, a disease of unknown aetiology, has a multifactorial pathogenesis which may result in irreversible connective tissue destruction and loss of joint function. The search for drugs which offer more than symptomatic relief is a long term, largely unachieved aim of many pharmaceutical companies. This review briefly outlines those features of the aetiopathogenesis which appear to offer targets for therapeutic intervention and the structured strategy and test systems that can be used to detect drugs which may be capable of halting disease progression.

Pharmacological aspects of arthritis induced by a muramyl dipeptide analogue in rats

Fourteen consecutive daily subcutaneous injections of 4 mg/kg of the muramyl dipeptide analogue MDP-Lys(L18) into rats caused arthritis characterized by swelling of the tarsal joint, increases in lymphocytes and monocytes in the peripheral blood, and elevated serum immunoglobulin G (IgG). The present study was performed to evaluate the effects of indomethacin, phenylbutazone, dexamethasone, D-penicillamine, aurothioglucose, cyclophosphamide and cyclosporin A on this arthritis. Administration of indomethacin, phenylbutazone or dexamethasone inhibited the development of the tarsal joint swelling, suggesting that prostaglandins may be involved in the pathogenesis of the arthritis. Cyclophosphamide reduced the arthritis, together with decreases in the lymphocyte count and the serum IgG level. Cyclosporin A worsened the arthritis in a dose-dependent manner and increased the neutrophil count without raising the serum IgG level, but inhibited the induction of adjuvant arthritis in rats with Mycobacterium bacilli. MDP-Lys(L18) may therefore induce arthritis differing in mechanism from adjuvant arthritis.

Interleukin 1 mediated acceleration of type II collagen-induced arthritis: effects of anti-inflammatory or anti-arthritic drugs

We previously demonstrated that treatments with rIL-1 beta accelerated the onset and progression of CIA in mice. In the present study, it was observed that IL-1 also enhanced the development of CIA in rats. Like the mouse model, maximal incidence (80-100%) of arthritis occurred within 7 days after the first treatment with IL-1 in rats. Thus, the acceleration of CIA by IL-1 (IL-1 CIA) may be an improved model for the rapid screening of anti-inflammatory and/or anti-arthritic drugs. As a first step to determining the utility of the IL-1 CIA model as a drug screen, we examined the ability of various known anti-inflammatory and anti-arthritic drugs to modify the IL-1 mediated enhancement of CIA in both rats and mice. The results of these studies showed that when analyzed in the IL-1 CIA model, rats and mice exhibited differences in their responses to several of these drugs. For example, dexamethasone, cyclophosphamide, azathioprine, various non-steroidal anti-inflammatory drugs (NSAIDs) as well as methotrexate were found active in the IL-1 CIA of rats. By contrast, the NSAIDs were found to be less effective in suppressing the IL-1 accelerated disease in mice. In both rats and mice, cyclosporine A and several disease modifying anti-arthritic drugs failed to the prevent the development of CIA that was potentiated by IL-1. Thus, in the IL-1 CIA model NSAIDs appeared to be less active in mice than rats. In conclusion, because of the shorter latent period required for the development of arthritis in the IL-1 treated animals, the IL-1 accelerated CIA model in both mice and rats may be useful for screening anti-inflammatory or anti-arthritic compounds.

Protective effect of transforming growth factor beta 1 on experimental autoimmune diseases in mice

Interleukin 1 (IL-1) and tumor necrosis factor alpha are thought to contribute to the inflammatory response associated with autoimmune diseases. Transforming growth factor beta 1 (TGF-beta 1) counteracts many effects of these cytokines and has various immunosuppressive properties. In the present study, it is shown that microgram amounts of TGF-beta 1, injected daily for 1-2 weeks, protect against collagen-induced arthritis (CIA) and relapsing experimental allergic encephalomyelitis (REAE), the animal models for rheumatoid arthritis and multiple sclerosis, respectively. When administered during induction of the disease, TGF-beta 1 prevents CIA but only delays the onset of REAE by 2-3 days. However, when administered during a remission. TGF-beta 1 prevents the occurrence of relapses in REAE. The results suggest that TGF-beta 1 has powerful anti-inflammatory effects, mimicking in some respects the beneficial effects of immunosuppressive drugs in these experimental models of autoimmune disease, but without discernable adverse effects.

Osteoporosis associated with rheumatoid arthritis: pathogenesis and management

Rheumatoid arthritis is associated with both localized and generalized osteoporosis. Localized osteoporosis can be considered to be caused by local disease mechanisms, including the generation of factors from activation of the cytokine pathway. The etiology of generalized osteoporosis has been difficult to elucidate, particularly because of the lack of sensitive techniques to measure bone mineral density. The introduction of single- and dual-photon absorptiometry and quantitative computed tomography has allowed more accurate assessment of bone mineral density. In general, bone mineral density loss at appendicular sites does not correlate well with axial bone density loss. Corticosteroid treatment exaggerates the development of osteoporosis in up to 40% of patients with rheumatoid arthritis. Sex hormone status, physical activity, disease duration, and functional class are all significant predictors for the development of osteoporosis. Current therapy for prevention and treatment is based largely on theoretical considerations. Physical activity should be encouraged once acute joint inflammation has settled. Postmenopausal women and amenorrheic premenopausal women will benefit from cyclical estrogen replacement. Patients with low serum 1,25-dihydroxy vitamin D3 levels, and males with low serum testosterone levels, are candidates for replacement therapy with the appropriate hormones. In patients who are receiving corticosteroids the dose should be limited, and oral calcium supplements are of benefit. The use of the newer corticosteroid deflazacort, and disease-modifying immunosuppressive drugs, are discussed. Other therapeutic options which should be considered, although published trials are scarce, are calcitonin and the diphosphonates. Further studies are awaited concerning the optimum prevention and treatment of osteoporosis associated with rheumatoid arthritis.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition by FK506 of established lesions of collagen-induced arthritis in rats

We investigated the superior potency of the immunosuppressive agent FK506 on collagen-induced arthritis in rats. In our initial studies, we demonstrated that only one shot administration of FK506 at a dose of 10 mg/kg on the same day as type II collagen immunization suppressed the incidence of arthritis completely as well as humoral and delayed-type hypersensitivity (DTH) skin test responses to type II collagen. Yet no major side effects were observed in the rats treated with such a high dose of FK506. Additional studies demonstrated that pretreatment with FK506 on day -7 or day -3 was effective in suppressing the severity of arthritis and immune responses to type II collagen. The immunosuppressive effect of a single high-dose administration of FK506 continued for at least 1 week in this animal model of arthritis. A single administration of FK506 at a dose of 10 mg/kg on day 12 or 15, after the clinical onset of arthritis, was also effective in suppressing the severity of arthritis and immune response to type II collagen. We conclude that FK506, in this model, possesses an important, curative action when applied therapeutically. The outlook of FK506 treatment in clinical autoimmunity is promising at present.

Effects of indomethacin, cyclosporin, cyclophosphamide, and placebo on collagen-induced arthritis of mice

The long term effects of indomethacin, cyclosporin, cyclophosphamide, and placebo on collagen-induced arthritis in mice were tested under two different treatment protocols. A prophylactic experiment examined the effects of the daily drug administration for 180 days beginning one day before the first collagen injection. Under this dosage schedule, cyclophosphamide and cyclosporin decreased the severity of arthritis, while indomethacin did not. A therapeutic protocol examined the effects of these same drugs when daily administration was delayed until the animals had active disease at 78 days after the first collagen injection. Under this protocol, all three drugs reduced the progression of disease. In both protocols, the most significant suppression of arthritis was seen in animals receiving cyclophosphamide which was associated with a decrease in anti-collagen antibody levels. Collagen-induced arthritis in mice should be further investigated as a model to study the long term effects of "slow-acting" anti-rheumatic drugs.

Antiarthritic synergism of combined oral and parenteral chrysotherapy. I. Studies in adjuvant-induced arthritis in rats

In comparative clinical studies of auranofin (AF, oral gold) and parenteral gold in the treatment of rheumatoid arthritis, no difference in efficacy was detected. Since the pharmacologic profiles of these compounds are different, we studied their combined effect on adjuvant arthritis (AA). The effect of AF alone and combined with gold sodium thiomalate (GTM) or gold sodium thiosulfate (GTS) on the excretion of urinary hydroxyproline (UHP) and urinary calcium (UCa), and the articular index of arthritic rats was followed during five weeks of treatment. The excretion of UHP and UCa was significantly inhibited (P less than 0.005) in rats treated with AF combined with GTM or GTS as compared with animals treated with the individual gold compounds. However, the articular index only decreased significantly (P less than 0.02) in the group of rats treated with AF + GTS. The present studies open the possibility that combined treatment with oral and injectable gold provide a new approach for chrysotherapy with an increased antiarthritic potency.

Immunosuppressive effect of FK506 on collagen-induced arthritis in rats

FK506, a new immunosuppressive agent, was given intramuscularly to rats for 12 days, starting on the day of type II collagen immunization. FK506 in doses of 0.32 mg/kg or more suppressed arthritis and also suppressed humoral and skin test response to type II collagen. FK506 suppressed arthritis only when given during the afferent limbs of immune response (0-4 days), whereas the drug was only marginally effective when treatment was started during the efferent limbs of immune response (7-11 days). FK506-induced immunosuppression continued and/or was maintained throughout the experiments (50 days). These rats immunized with type II collagen and treated with FK506 failed to develop arthritis even following a secondary immunization 50 days later but were fully capable of developing experimental allergic encephalomyelitis. This result suggest that FK506-treated rats develop specific unresponsiveness toward the type II collagen. It is concluded that FK506 is a strong immunosuppressive drug on collagen-induced arthritis.

Inhibitory effects of anti-inflammatory drugs on type II collagen induced arthritis in rats

The effects of steroidal and non-steroidal anti-inflammatory drugs on the established lesion of type II collagen induced arthritis in rats were evaluated by measuring the hind paw oedema and anti-type II collagen antibody titre. Dexamethasone, a steroidal anti-inflammatory drug, reduced the anti-type II collagen antibody titre and markedly suppressed the established lesion of type II collagen induced arthritis in rats. A rebound of the arthritis, i.e., a rapid recovery of the hind paw swelling took place after withdrawal of the treatment with steroidal anti-inflammatory drugs, including dexamethasone, prednisolone, and hydrocortisone. On the other hand, indomethacin, benoxaprofen, piroxicam, and tiflamizole, which are cyclo-oxygenase inhibitors in prostaglandin synthesis, had no effect on anti-type II collagen antibody titre, but suppressed the established lesion of the arthritis without causing an apparent rebound of the arthritis after withdrawal of the drug treatment. These results suggest that the level of anti-type II collagen antibodies has no relation to the intensity of hind paw swelling in the established lesion of the arthritis, though the antibodies contribute to the incidence of the arthritis. It also indicates that non-steroidal anti-inflammatory drugs having inhibitory action on cyclo-oxygenase are useful antiarthritic drugs without causing the rebound phenomenon, an untoward side effect after withdrawal of steroidal anti-inflammatory drugs.

Effect of cyclophosphamide and its analogs on collagen arthritis in rats

The effects of cyclophosphamide (CY) and its structurally related analogs, ifosfamide (Ifo), sufosfamide (Sufo), and mafosfamide (Mafo), on collagen arthritis in Sprague-Dawley rats were examined. Prophylactic treatment with 7.5-10 mg/kg/day of CY. 15 mg/kg/day of Ifo, and 10-15 mg/kg/day of Sufo for the first 10 days starting on the same day as the type II collagen immunization suppressed arthritis induction as well as humoral immune response to type II collagen. Prophylactic treatment with Mafo at doses ranging from 10 to 40 mg/kg/day for 10 days was ineffective in suppressing the disease development. When drug treatment was started only during the immediate preclinical phase of arthritis, the development of arthritis was suppressed in the animals treated with 10 mg/kg/day of CY and 15 mg/kg/day of Ifo from Day 5 to Day 14. Additional studies demonstrated that treatment with 10 mg/kg/day of CY and 15 mg/kg/day of Ifo started at the time of disease onset significantly suppressed the severity of arthritis compared with the control group. These results show the effectiveness of Ifo and CY on this animal model of polyarthritis and suggest the possibility of clinical use of Ifo for the treatment of human arthritides similar to CY.

Modulation of cartilage destruction by select nonsteroidal antiinflammatory drugs. In vitro effect on the synthesis and activity of catabolism-inducing cytokines produced by osteoarthritic and rheumatoid synovial tissue

Non-enzymatic factors produced by synovial tissue can potentially mediate cartilage destruction by inducing the synthesis and release of matrix-degrading proteinases from chondrocytes. Pharmacologic control of this process is of potential clinical relevance. The in vitro effect of therapeutic concentrations of select nonsteroidal antiinflammatory drugs on the synthesis and activity of catabolism-inducing cytokines produced by 6-day explant cultures of osteoarthritic and rheumatoid synovial tissue was studied. Piroxicam regularly suppressed such factor synthesis by both types of tissue without significantly affecting total protein synthesis. This did not occur using sodium salicylate or indomethacin in osteoarthritis tissue cultures and was observed only occasionally in rheumatoid arthritis cultures. None of the nonsteroidal antiinflammatory drugs studied consistently blocked catabolism-inducing activity in osteoarthritis tissue, whereas piroxicam more consistently inhibited activity produced by rheumatoid arthritis tissue. Results suggest that the catabolism-inducing factors produced by the 2 tissue sources may differ.

Passive transfer of collagen arthritis: heterogeneity of anti-collagen IgG

Using a combination of affinity chromatography procedures, anticollagen IgG was fractionated into three distinct populations. One population reacted only to conformational determinants, another population reacted only to structural determinants, and the third population reacted to both conformation and structural determinants. When these populations were tested for their arthritogenicity, only those fractions that reacted to conformational and to conformational and structural determinants were active in inducing clinical arthritis. Immunofluorescence analysis of the hind paw of recipient rats indicated that antibodies directed only to conformational and to both conformational and structural determinants bound to articular cartilage and activated the complement system. Antibodies directed strictly to structural determinants did not bind to articular cartilage and were nonarthritogenic.

Murine type II collagen arthritis. Association of an acute-phase response with clinical course

The acute-phase reactant, C-reactive protein, is a good index of disease activity in patients with rheumatoid arthritis. We examined the murine acute-phase reactant, serum amyloid P, as an index of disease in type II collagen-induced arthritis in 3 mouse strains. The onset of type II collagen-induced arthritis, which is characterized by paw swelling, is associated with a significant, but transient, elevation of serum amyloid P. Anticollagen antibody titers are not temporally associated with the onset of disease. Although murine type II collagen arthritis fails to show the chronic acute-phase reactant elevation that is characteristic of arthritis in humans, the transient elevation of the acute-phase reactant is a reliable indicator of the onset of disease.

Studies on type II collagen induced arthritis in mice

A consistent and reproducible polyarthritis was induced in mice by immunizing them with type II collagen in Complete Freunds adjuvant (CFA) and Bacillus Calmette-Guerin (BCG) vaccine. Several inbred strains of mice were investigated for the ability to develop collagen induced arthritis (CIA). DBA/1 mice (H-2q) produced the highest incidence and the most severe arthritis of all the strains examined. Viable BCG vaccine was essential for the induction of a reproducible disease in this strain. The effects of some anti-inflammatory and anti-rheumatic compounds were examined on the developing and established lesions of CIA. These effects were determined by assessing the paw inflammation using a subjective scoring system and measuring foot weight. Furthermore, levels of serum amyloid P component (SAP) were also determined. Benoxaprofen, cyclophosphamide, indomethacin and prednisolone inhibited the paw inflammation in the developing disease whilst the anti-rheumatic compounds auranofin and D-penicillamine exacerbate the paw inflammation. Cyclophosphamide and prednisolone inhibited the established lesions but only prednisolone prevented the development of further lesions in the established disease. The SAP levels in the prednisolone treated group were also reduced. Auranofin treatment exacerbated the inflammation of both the established and the developing lesions in the same animal. D-penicillamine was inactive in the established disease.

Rat haptoglobin: method of quantitation and response to antiarthritic therapy in collagen arthritis

Concentrations of the acute phase reactant haptoglobin were quantitated in the serum of rats using a commercially available antihuman haptoglobin radial immunodiffusion kit. That this antiserum reacted with rat haptoglobin was shown through the techniques of Ouchterlony immunodiffusion and immunoelectrophoresis. Haptoglobin levels were increased seven days after immunization of rats with type II collagen plus incomplete Freund's adjuvant (ICFA) and peaked on day 14. However, even six weeks post-immunization the concentration of haptoglobin was elevated in arthritic rats. A significant correlation was observed between the concentration of serum haptoglobin and the severity of disease (arthritic index) in rats immunized six weeks previously with type II collagen plus ICFA. The effects of antiinflammatory and antirheumatic therapy on arthritic index and serum haptoglobin concentration were determined using a therapeutic dosing protocol. Under these conditions, the known antiarthritic effects of nonsteroidal antiinflammatory drugs, steroids and immunosuppressive agents in this model were confirmed. Of these agents, only the nonsteroidal drugs reduced serum haptoglobin; hydrocortisone, cyclophosphamide and azathioprine elevated haptoglobin. Aurothioglucose, auranofin, and chloroquine, members of the class of disease-modifying antirheumatic drugs, had a general tendency to exacerbate disease, but had minimal effect on serum haptoglobin. D-Penicillamine had little effect on arthritic index and haptoglobin. These results suggest that, while haptoglobin levels do correlate with the intensity of hindpaw swelling, measurement of haptoglobin may not be an accurate indicator of the underlying disease processes in the collagen arthritis model.

Effects of cyclosporin on collagen induced arthritis in mice

We have studied the effect of the immunosuppressive agent cyclosporin on collagen induced arthritis in mice. Cyclosporin, when given prophylactically, was capable of suppressing the development of collagen induced arthritis and the immunological response to native type II collagen in a dose dependent manner. Furthermore, treatment with cyclosporin, started on the same day as the booster injection with type II collagen, also resulted in inhibition of development of arthritis and of immunity to collagen. These findings suggest that the time of a booster injection, three weeks after the initial immunisation, might be still within the induction phase of arthritis since reinoculation is required to produce a high incidence of arthritis in mice. In addition, therapeutic treatment with cyclosporin did not affect the clinical course of the disease or the immune response to collagen.

Evaluation of the effects of various anti-arthritic drugs on type II collagen-induced mouse arthritis model

A battery of drugs which are commonly used as therapeutic agents for arthritis was tested for effects on the inflammatory and immunological responses of DBA/1J mice, after immunization with type II collagen. All the drugs were tested at more than one dosage. The mice were protected from the development of arthritis by treatment with paramethasone (0.25 mg/kg/day) or cyclophosphamide (5 mg/kg/day). The nonsteroidal anti-inflammatory drugs used in these studies, viz. aspirin (200 mg/kg/day), benoxaprofen (100 mg/kg/day) and naproxen (200 mg/kg/day), had no significant effect on the joint involvement, although naproxen and benoxaprofen at these high doses caused some reduction of immune responses of mice to collagen. Chloroquine (100 mg/kg/day), levamisol (50 mg/kg/day) and gold chlorophosphene (5 mg/kg/day) had no effect on the inflammatory or humoral response, while treatment with D-penicillamine (100 mg/kg/day) led to an early onset of arthritis in mice. These data suggest that the type II collagen-induced mouse arthritis model may not be highly suitable for detection of the traditional nonsteroidal anti-inflammatory class of drugs or the anti-rheumatic drugs, although the possibility remains that some new and novel immunosuppressive agents may be detected with this model.

Inhibition of collagen II arthritis by simultaneous administration of concanavalin A and other substances with antigen emulsion

Several pharmacological agents, some of which are known to have effects on the immune system, decrease the incidence of collagen II-induced arthritis when added to the antigen emulsion. Concanavalin A, which has been reported to exert suppressive effects on the immune system in vivo, consistently reduced the immune response to the collagen antigen. These effects were dose and time dependent. The suppressive effects of pokeweed mitogen, tilorone and carrageenan on anti-collagen II responses were somewhat variable. Suppressive activity could be observed with concanavalin A and levamisole when the drugs were injected at a site distant from the collagen emulsion. These studies indicate that local administration of drugs is an effective approach for demonstrating the activity of some agents that may alter the course of collagen II disease through an effect on the immune system.

Comparison of inflammatory changes in established type II collagen- and adjuvant-induced arthritis using outbred Wistar rats

Type II collagen- and adjuvant-induced arthritis in outbred Wistar rats were compared using parameters that measured the inflammatory response, cellular and humoral immunity, blood protein changes, drug metabolism and histopathological and bony changes of the inflamed paws. There was a lesser incidence (40-70%) and severity of collagen disease than the adjuvant model (incidence approximately 100%). The use of MDP increased the incidence and severity of collagen arthritis. The acute phase protein response (plasma fibrinogen) was similar in both models during the peak of inflammatory response. Drug metabolism was inhibited in both type II collagen boosted with MDP or M. butyricum sensitized rats with arthritis; however, arthritic rats sensitized with collagen alone produced no inhibition. Only collagen arthritic rats produced type II collagen antibody and exhibited delayed hypersensitivity to type II collagen. Bony changes as assessed by radiographic evaluation were more severe in adjuvant arthritic rats than in the collagen arthritic model; histopathological findings from these animals confirmed this observation. The primary lesions in both models were periosteal reaction of the bone and ankylosis. Several classes of antiarthritic drugs were compared in both models using paw edema measurements and bony changes by radiographic evaluation. Drugs with inhibitory activity in both models were indomethacin, methylprednisolone, D-penicillamine and gold sodium thiomalate. Levamisole, chloroquine and auranofin were inactive in both models.

Passive transfer of collagen arthritis: studies with affinity-purified anticollagen IgG prepared in rabbits

Affinity-purified rabbit anticollagen IgG failed to transfer arthritis to rats when it was injected intravenously. Immunofluorescence examination of the joints of the hind paws of recipient rats showed the deposition of rabbit IgG on the articular surfaces; however, C4 or C3 deposition was not detected. In recipient rats injected intravenously with equivalent amounts of rat anticollagen IgG, arthritis occurred within 48 hr; IgG, C4, and C3 could be detected on the articular surface. Rats given Type II collagen intravenously accumulated inflammatory cells in the pleural cavity in response to a subsequent challenge with intrapleural rat anticollagen IgG; with rabbit anticollagen IgG significantly fewer cells accumulated. Rabbit anticollagen IgG did not promote the lysis of Type II collagen coated sheep red blood cells that were incubated with rat serum. In parallel control experiments, lysis of cells occurred when rat serum was added to either sheep cells coated with Type II collagen and incubated with rat anticollagen IgG or sheep cells coated with bovine serum albumin and incubated with rabbit anti-bovine serum albumin. These observations suggest that the failure of rabbit anticollagen IgG to transfer arthritis to rats is, at least in part, due to its inability to activate rat complement.

Anticollagen antibodies and immune response gene products in rheumatoid arthritis

Circulating antibodies to native and denatured types I and II human and bovine collagens were assayed in patients with rheumatoid arthritis (RA), patients with other rheumatic diseases, and normal individuals. A subgroup of this population was also assayed for reactivity with typing reagents which detect determinants (MT and HLA-DR) present in human immune response gene products. The mean titers of antibodies to each collagen tested were not significantly higher in RA patients when compared with patients who had other rheumatic diseases. Although both MT3 and MT4 were significantly associated with RA, there was no significant association between the anticollagen antibodies and any MT type or HLA-DR4. These studies raise a question concerning the role of collagen antibodies in the pathogenesis of RA and suggest that genes distinct from those coding for HLA-DR may play a role in the expression of the disease.

Nonsteroidal anti-inflammatory drugs and modulation of cartilaginous changes in osteoarthritis and rheumatoid arthritis. Clinical implications

Nonsteroidal anti-inflammatory drugs have a potential for modifying the complex pathophysiologic events leading to cartilage destruction in various forms of arthritis. Following an evaluation of basic mechanisms in the pathogenesis of cartilaginous destructive lesions, the effects of nonsteroidal anti-inflammatory drugs on normal chondrocyte metabolism are discussed. Their capacity to modulate cartilage and bone lesions in experimental forms of arthritis is addressed, as is the manner in which they may modify the pathophysiology of cartilage destruction in human forms of arthritis. Different classes of nonsteroidal anti-inflammatory drugs produce different effects in certain in vivo or in vitro settings.

Suppression of type II collagen-induced arthritis by the intravenous administration of type II collagen or its constituent peptide alpha 1 (II) CB10

Intravenous administration of Type II collagen to rats prior to immunization with Type II collagen suppresses hind paw inflammation, humoral response to Type II collagen, and the severity of the arthritic lesion. Suppression of inflammation and its severity as well as the humoral response can also be induced by the prior intravenous administration of alpha 1 (II) CB10 a cyanogen bromide peptide derived from Type II collagen. Suppression of arthritis is disease specific; intravenous administration of either Type II collagen or alpha 1 (II) CB10 does not have an effect on adjuvant-induced arthritis. These studies indicate that structural determinants of alpha 1 (II) CB10 (Mr 30,000), a peptide located near the carboxy terminus of the collagen molecule, can induce suppression and suggest that these determinants may be responsible for the suppression of arthritis when Type II collagen is administered intravenously.

Effect of gold salts, D-penicillamine and benoxaprofen on type II collagen-induced arthritis in rats

We investigated the therapeutic effect of two gold salts, gold sodium thiomalate (GST, i.m.) and auranofin (p.o.), D-penicillamine (p.o.) and benoxaprofen (p.o.) in rat collagen-induced arthritis using type II collagen from fetal bovine articular cartilage. GST, but not auranofin, reduced hind paw edema and bone pathology. However, auranofin reduced serum copper and zymosan-induced prostaglandin production from peritoneal macrophages. In contrast, GST increased both serum copper and macrophage prostaglandin production by zymosan. Benoxaprofen reduced both hind paw edema and pathology, whereas D-penicillamine was without effect. None of these treatments influenced the circulating level of antibody to type II collagen.

In vitro synthesis of anticollagen IgG by sensitized lymph node cells derived from type II collagen-induced polyarthritic rats

Using lymph node cells from Type II collagen-induced polyarthritic rats, the present studies describe an in vitro system that is active in the synthesis of anticollagen IgG. Synthesis of anticollagen IgG by these cells is blocked by the addition of cycloheximide, indicating a requirement for de novo protein synthesis. The predominant anticollagen IgG synthesized is IgG2a; this subclass also represents the major anticollagen IgG present in the serum and the cartilage of polyarthritic rats. Synthesis of anticollagen IgG is inhibited by a mixture of D-penicillamine and copper sulfate. These latter observations suggest that the in vitro system described is responsive to pharmacologic intervention.

Humoral and cellular immunologic responses in collagen-induced arthritis in rats: their correlation with severity of arthritis

Collagen arthritis in rats has a well defined humoral and cellular immunologic response to type II collagen, the inciting antigen. Like other chronic models of inflammation, considerable variation exists in terms of severity and incidence. We have attempted to correlate the inflammatory response as measured by paw volume, with serum type II collagen antibody and skin delayed hypersensitivity (DH) to type II collagen. Surprisingly, the incidence and severity of collagen arthritis, induced in the presence of MDP to increase incidence of the disease, are neither correlated with type II collagen antibody nor DH to type II collagen. However, tarsometatarsal bone erosion is significantly correlated with paw edema. Further studies will be necessary to elucidate the role of both humoral and cellular immune responses in the development of type II collagen arthritis in the rat.

Effect of D-penicillamine pre- and post-implantation treatment on formation of sponge-induced granulation tissue in rats

DNA, collagen and sulfated glycosaminoglycans (GAGs) of rat sponge granulation tissue were studied after 42 days of D-penicillamine (D-pen) treatment at 100, 250 or 500 mg/kg/day, starting 10 days before or 28 days after induction of granulation tissue formation. The effects were compared with those observed when the same dosage was started at the onset of the granulation tissue formation and with pair-fed controls. D-pen stimulated the cell invasion into the sponge implants, as manifested by an increased DNA content, particularly with pre-treatment. Pre-treatment reduced the net deposition of of collagen per cell as assessed by the lower hydroxyproline/DNA ratio, at the lower dose leading to reduced collagen concentration. The total amount of granulation tissue collagen remained essentially unaffected within the observation period. Salt-soluble collagen was augmented in a dose-dependent manner, irrespective of treatment protocol, signifying decreased collagen cross-linking. Both pre- and post-implantation treatment enhanced the radiosulfate incorporation into sulfated GAGs, regardless of dose, whereas treatment from the day of sponge implantation had no effect. It is concluded that D-pen enhances the early connective tissue response to injury. Reduction of collagen cross-linking and net collagen deposition, concomitant with stimulation of the proteoglycan metabolism, may pertain to the antirheumatoid activity of D-pen. The observations suggest that long-term administration of D-pen, starting before new attacks of arthritis, may be most effective in controlling developing articular fibrosis.

Paradoxical effects of cyclosporin A on collagen arthritis in rats

The effect of the immunosuppressive agent cyclosporin A (CS-A) on collagen arthritis in Sprague-Dawley rats is investigated. A 14-d course of CS-A treatment at doses of 15 mg/kg per day or more, begun on the same day as type II collagen immunization, suppressed the development of arthritis as well as humoral and delayed-type hypersensitivity (DTH) skin test responses to type II collagen, possibly by interfering with helper T cells. Additional studies demonstrated that CS-A treatment only during the induction phase of immunity proved to be successful. When CS-A treatment was started only during the immediately preclinical phase of arthritis or after the disease onset, a significant enhancement of the disease was obtained in a dose-dependent manner. This enhancement was accompanied by an augmentation of DTH skin reactions, while antibody responses were either suppressed or unaffected. These results appear to be attributable at least in part to a suppressive effect of CS-A on a population of suppressor T cells, thus resulting in a T cell-mediated helper effect. It is therefore reasonable to assume that the paradoxical effects of CS-A on collagen arthritis in rats might be caused by an altering of the sensitive balance of the two regulatory subpopulations of T cells. It is also possible that cell-mediated immune responses may play an important role in influencing the course of the disease.

Passive transfer of arthritis by purified anticollagen immunoglobulin: localization of 125I-labeled antibody

Intravenous administration of purified 125I-labeled anti-type II collagen immunoglobulin results in a polyarthritis in the recipient rats. Whole-animal radioautography indicates that the antibody is present in the various tissues that contain Type II collagen. However, the polyarthritic lesion is limited to the front and hind paws. These observations indicate that effector mechanisms subsequent to antibody binding are involved in the pathogenesis of Type II collagen-induced arthritis.

Pharmacologic properties of fenbufen

Fenbufen (Cinopal) is an orally active nonsteroidal anti-inflammatory drug with analgesic and antipyretic activity. Like clinically used nonsteroidal anti-inflammatory drugs, it shows activity in a wide spectrum of laboratory tests in mice, rats, guinea pigs, and dogs. Fenbufen has a long duration of anti-inflammatory and analgesic activity. Mechanistic studies indicate that fenbufen has no intrinsic effect on cyclooxygenase activity, whereas its major metabolite, biphenylacetic acid, is a potent inhibitor of prostaglandin synthesis. These observations indicate that fenbufen is a pro-drug and account for its low ulcerogenic potential. Anti-inflammatory pro-drugs that are readily metabolized to the biologically active molecule are expected to retain a favorable anti-inflammatory to ulcerogenic ratio because the gastrointestinal tract is not exposed to a large concentration of the active molecule. Comparative studies in the type II collagen arthritis model indicate that the anti-inflammatory properties of fenbufen are more potent than those of a second nonsteroidal anti-inflammatory drug, sulindac.

Does drug therapy slow radiographic deterioration in rheumatoid arthritis?

Many clinicians believe that slow-acting therapeutic agents, such as fold, penicillamine, the antimalarials, and cytotoxic drugs, can retard joint destruction in rheumatoid arthritis. We reviewed 60 published studies employing these drugs to evaluate critically the evidence that drug therapy can slow the radiographic progression of disease. Seventeen studies were found that included radiographic assessment of both treated and control groups; they were analyzed using methodologic criteria known to be important in affecting the results of drug trials. In addition to numerous qualitative methodologic deficiencies, many studies showed inadequacies in sample size and duration of treatment, and the drug dosage used varied from one study to another. We found evidence suggesting that both gold and cyclophosphamide can retard radiographic progression of joint destruction. At present, there are too few technically adequate studies to permit even provisional conclusions concerning other agents.

Type II collagen-induced arthritis. Studies with purified anticollagen immunoglobulin

Immunization of rats with native bovine type II collagen results in a polyarthritis by day 21 in approximately 40% of the rats. Sera of these rats contained anticollagen IgG, principally IgG2a. Small amounts of IgG2b were also detected, but IgG1 and IgG2c were absent. By enzyme-linked immunosorbent assay, the paw tissue of these polyarthritic rats was shown to contain anticollagen IgG, the principal subclass being IgG2a, with minor amounts of IgG2b. Immunofluorescence examination of the paws from polyarthritic rats demonstrated deposition of both IgG and C3 on the articular surface. Passive transfer of disease was accomplished by injection of affinity-purified anticollagen immunoglobulin into naive recipients; paw swelling and histopathologic changes were detected 24 hours after transfer, and by immunofluorescence techniques IgG and C3 deposits were demonstrable on the articular cartilage. On passive transfer, neutrophils invaded the joint space and became juxtaposed to the surface of the articular cartilage. Passive transfer of the disease with anticollagen immunoglobulin was unsuccessful after rats were decomplemented with cobra venom factor; immunofluorescence demonstrated IgG but not C3 on the articular cartilage of these decomplemented rats. In rats decomplemented with cobra venom factor, neutrophils did not accumulate in the joint and erosion of articular cartilage was not detected.