Cathepsin k is a critical protease in synovial fibroblast-mediated collagen degradation.

Synovial fibroblasts (SFs) play a critical role in the pathogenesis of rheumatoid arthritis (RA) and are directly involved in joint destruction. Both SF-resident matrix metalloproteases and cathepsins have been implicated in cartilage degradation although their identities and individual contributions remain unclear. The aims of this study were to investigate the expression of cathepsin K in SFs, the correlation between cathepsin K expression and disease severity, and the contribution of cathepsin K to fibroblast-mediated collagen degradation. Immunostaining of joint specimens of 21 patients revealed high expression of cathepsin K in SFs in the synovial lining and the stroma of synovial villi, and to a lesser extent in CD68-positive cells of the synovial lining. Cathepsin K-positive SFs were consistently observed at sites of cartilage and bone degradation. Expression levels of cathepsin K in the sublining and vascularized areas of inflamed synovia showed a highly significant negative correlation with results derived from the Hannover Functional Capacity Questionnaire (r = 0.78, P = 0.003; and r = 0.70, P = 0.012, respectively) as a measure of the severity of RA in individual patients. For comparison, there was no correlation between Hannover Functional Capacity Questionnaire and cathepsin S whose expression is limited to CD-68-positive macrophage-like synoviocytes. The expression of cathepsin K was also demonstrated in primary cell cultures of RA-SFs. Co-cultures of SFs on cartilage disks revealed the ability of fibroblast-like cells to phagocytose collagen fibrils whose intralysosomal hydrolysis was prevented in the presence of a potent cathepsin K inhibitor but not by an inhibitor effective against cathepsins L, B, and S. The selective and critical role of cathepsin K in articular cartilage and subchondral bone erosion was further corroborated by the finding that cathepsin K has a potent aggrecan-degrading activity and that cathepsin K-generated aggrecan cleavage products specifically potentiate the collagenolytic activity of cathepsin K toward type I and II collagens. This study demonstrates for the first time a critical role of cathepsin K in cartilage degradation by SFs in RA that is comparable to its well-known activity in osteoclasts.

[Current prescription practice of CSE inhibitors at clinic discharge after acute myocardial infarct]. / Aktuelle Verordnungspraxis von CSE-Hemmern bei Entlassung aus der Klinik nach akutem Myokardinfarkt.

We investigated the use of statins in clinical practice in patients with acute myocardial infarction in Germany in 17,732 consecutively included patients of the registries MIR-1 and MITRA-1. A clinical follow-up has been performed in the MITRA-1 study after a mean period of 18 months. In total 30% of all patients with acute myocardial infarction received statins at discharge. From 1994 to 1998 the use of statins increased from 6% to 44%; however in 1998 still less than half of the patients with acute myocardial infarction received statins at discharge. In a logistic regression model, concomittant diseases as renal failure (OR 0.7), heart failure (OR 0.7) and diabetes mellitus (OR 0.9) were associated with a lower use of statins. Age > 70 years (OR 0.5) was also associated with a lower use of statins at hospital discharge. Patients with statins at discharge had a lower long-term mortality of 5.8% versus 12.9% in patients without statins. After adjustment to age and comorbidity, use of statins at discharge was associated with a borderline significant reduction of long-term mortality (multivariate OR 0.7, 95% CI 0.4-1.0). In a subgroup analysis of therapeutic benefit, measured by the "number needed to treat" (NNT), the number of patients to treat with statins to save one life, patients with cardiovascular risk factors, as heart failure (NNT 7.5), diabetes mellitus (NNT 7.8) and age > 70 years (NNT 13.8) had a larger therapeutic benefit as patients without these risk factors (NNT 345). However, these high-risk patients received less often statins than patients without risk factors (use of statins 11.8% versus 19.8%).

Loss of functional capacity caused by a delayed onset of DMARD therapy in rheumatoid arthritis. Long-term follow-up results of the Keitel function test. Brief definite report.

The aim of this analysis was to investigate the impact of the postponement of DMARD therapy on the functional outcome of rheumatoid arthritis after 10 years of disease. 321 individuals with a disease duration of at least ten years were selected out of a cohort of more than 1800 patients. Two groups were analysed separately: patients who started DMARD therapy within the first year of their disease, and patients who received their first DMARD not earlier than five years after the onset of RA. The Keitel functional index was determined in every patient after 10 years of RA. After 10 years of disease, the swollen joint count and the ESR had decreased in both groups to a comparable degree. However, patients with early treatment performed significantly better in the Keitel test compared to the group with delayed therapy. Although patients with seropositive RA or rheumatoid nodules had a worse outcome in general, the benefit of early treatment was also significant in these subgroups.

Removal of immunoglobulins by a protein A versus an antihuman immunoglobulin G-based system: evaluation of 602 sessions of extracorporeal immunoadsorption.

Elimination of IgG can be achieved by extracorporeal immunoadsorption (IA) based on specific binding to either staphylococcal protein A (Excorim) or sheep polyclonal antibodies directed against human IgG (Therasorb). In 602 analyzed sessions of IA, elimination of IgG was 60% through 80% depending on the treated plasma volume, with no significant difference between the mentioned systems. However, the decrease of IgM and IgA was approximately 50% in the anti-IgG compared to 20-40% in the protein A system. Plasma albumin concentration decreased by 20% in the anti-IgG system compared to 15% in the protein A system, and hemoglobin values increased by 2% in the anti-IgG system and decreased by 6% in the protein A system. In conclusion, a clinical relevance for these findings cannot be ruled out, and the individual choice might depend on the clinical situation and laboratory findings.

Long-term application of disease modifying antirheumatic drugs (DMARD). A single-center, observational study of 1681 patients with rheumatoid arthritis (RA).

OBJECTIVE: To study the long-term efficacy and safety of methotrexate (MTX), intramuscular gold, azathioprine (AZA), chloroquine (CQ), sulphasalazine (SASP), and D-penicillamine (DPA) in rheumatoid arthritis (RA) patients. METHODS: Between 1979 and 1994, clinical data were prospectively gathered in a single center. 1681 patients were followed-up for at least 4 years. A 50% reduction of the swollen joint count was required to continue therapy. In addition, a modified Lansbury index, the Keitel function test, and laboratory parameters were determined every six months. Side effects leading to the discontinuation of treatment were recorded as well. RESULTS: After an observation period of more than four years, 39.6% and 28.3% of patients were taking MTX and AZA, respectively; 18.2% were receiving gold, 16.9% remained on DPA. SASP and CQ were still applied in 13.5% and 6.6%. MTX, AZA and SASP had a drop-out rate due to toxicity of 15.9%, 15.3% and 17.7%, whereas 34.8% had to discontinue CQ (gold: 27.4%, DPA: 26.9%). The majority of dropouts occurred within the first year of treatment. Subgroups of seropositive patients and patients with rheumatoid nodules had a poorer treatment efficacy irrespective of the DMARD. CONCLUSION: In the long-term application, MTX was the most efficient compound, followed by AZA, whereas CQ had the poorest drug survival. Our results underline the value of long-term observations under the conditions of clinical practice as a supplement to controlled clinical trials.

Efficacy and safety of a combination therapy of methotrexate, chloroquine and cyclophosphamide in patients with refractory rheumatoid arthritis: results of an observational study with matched-pair analysis.

The efficacy and safety of a combination of methotrexate (MTX), chloroquine (CQ) and cyclophosphamide (CYC) were studied in patients with refractory rheumatoid arthritis. A single-centre, matched-pair observational study with prospectively gathered data was performed. Fifty-six patients who had previously failed with MTX were treated with 15 mg MTX per week, 50 mg CYC three times a week and 250 mg CQ per day (group A). A 50% improvement of the swollen joint count was required to continue therapy. Data were compared with the results of the previous MTX therapy in the same group and with a matched-patient cohort receiving MTX monotherapy for the first time (group B). In group A, the combination therapy resulted in a significant decline of the swollen joint count after 1 year, in contrast to the previous MTX monotherapy in the same group. Complete remission of joint swelling was achieved in 13 patients (23%), compared with 26 patients in group B (47%). The median duration of effective combination treatment in group A was significantly longer than preceding therapies with MTX alone (19 vs 13 months, p<0.05). However, patients in group B could be treated for a median of 57.5 months (p<0.0001 compared with group A). Side-effects were comparable in both groups. The applied DMARD combination is safe and beneficial in a significant proportion of patients if MTX monotherapy is ineffective.

Circulating levels of matrix metalloproteinases MMP-3 and MMP-1, tissue inhibitor of metalloproteinases 1 (TIMP-1), and MMP-1/TIMP-1 complex in rheumatic disease. Correlation with clinical activity of rheumatoid arthritis versus other surrogate markers.

OBJECTIVE: To investigate whether plasma levels of matrix metalloproteinases 3 (MMP-3, stromelysin), MMP-1 (collagenase), tissue inhibitor of metalloproteinases 1 (TIMP-1), and MMP1/TIMP-1 complex (MT complex) are specifically elevated in erosive joint diseases compared to nonerosive rheumatic diseases, and to assess how these markers reflect the clinical activity of rheumatoid arthritis (RA) compared to circulating cytokines and markers of connective tissue turnover as well as established variables [C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor titer]. METHODS: Plasma levels of MMP-3, MMP-1, TIMP- 1, and MT complex were determined by ELISA. One hundred fifteen patients with RA, 20 with osteoarthritis (OA), 28 with psoriasis arthritis (PsA), 24 with ankylosing spondylitis (AS), 3 groups with systemic autoimmune diseases, and 30 healthy controls were analyzed. In patients with RA routine laboratory variables, circulating inflammatory cytokines [interleukin 1 (IL-1), tumor necrosis factor-alpha (TNF-alpha), and IL-6], collagen degradation products, and markers of bone formation were determined in parallel and were correlated to 4 variables of clinical activity. RESULTS: MMP-3 levels were markedly elevated in RA compared to controls and OA, but also in all other groups, including 26 patients with systemic lupus erythematosus (SLE). MMP-1 levels were significantly elevated in RA, but also in OA, PsA, SLE, and mixed connective tissue disease. In contrast, MT complex was elevated in RA only. TIMP-1 was not different from controls. CRP levels, MMP-3, and ESR correlated best with clinical activity of RA. In contrast, there was no correlation of IL-1 and TNF-alpha and only a weak correlation of IL-6 with clinical measures. Among variables of connective tissue turnover, only pyridinoline and deoxypyridinoline crosslinks were weakly correlated with disease activity. CONCLUSION: Elevated MMP-3 and MMP-1 levels are not specific for RA or for erosive joint diseases in general. In contrast, elevated MT complex levels were observed in patients with RA. However, the correlation of MT-1 with clinical data was weaker than that of MMP-3. Elevated MMP-3 levels reflected disease activity of RA better than cytokine levels or markers of connective tissue turnover. However, MMP-3 levels do not exceed the association of CRP with clinical activity.

Treatment of refractory rheumatoid arthritis with low-dose cyclophosphamide. Long-term follow-up of 108 patients.

Although cyclophosphamide (CYC) is an effective drug in the treatment of refractory rheumatoid arthritis (RA), the application of this drug in RA has largely been abandoned, due to potentially life-threatening adverse events such as myelosuppression and cancer development. However, the question remains open, whether it is possible to balance the toxicity and the efficacy of CYC with low-dose therapy. 108 patients with refractory RA or with vasculitic organ involvement were treated with 50 mg CYC per day. Joint indices and laboratory parameters were gathered prospectively and the occurrence of serious side effects was monitored over a median of 10 years. The efficacy was surveyed in six months intervals. A 50% improvement of the swollen joint count was required to continue therapy. A long-term follow-up was performed to survey the incidence of malignancies. 85 patients dropped out within the first year. Only four patients were treated for longer than 4 years. In the total cohort, 50 patients were withdrawn due to the lack of efficacy, 34 patients had to discontinue because of adverse events, and 9 patients dropped out for both reasons. Gastrointestinal intolerance was the most frequent adverse event that led to the discontinuation of the drug, followed by myelosuppression. Five patients suffered from 6 malignancies occurring after a median of 4.5 years after cessation of treatment. Treatment of RA patients with 50 mg CYC per day resulted in a more favorable rate of serious adverse events and a markedly lower incidence of tumors compared to the treatment with 75 to 150 mg per day described in the literature. However, the long-term efficacy of this regimen was poor in our cohort.

Matrix metalloproteinases, but not cathepsins B, H, and L or their inhibitors in peripheral blood of patients with rheumatoid arthritis are potentially useful markers of disease activity.

OBJECTIVE: The clinical activity of rheumatoid arthritis (RA) is not reliably reflected by laboratory measures. Proteolytic enzymes involved in the cascade of joint destruction are potentially useful parameters to monitor the extent of joint inflammation in RA. This study compares the validity of two classes of proteolytic enzymes, matrix metalloproteinases (MMP) and lysosomal cysteine proteinases (cathepsin B, H, and L) as well as their respective inhibitors to serve as parameters of RA disease activity. METHODS: The proteolytic activity of cathepsin B, H, and L was determined by fluorometry in sera of 20 patients with active RA and of 20 healthy donors. In addition, the concentrations of cathepsin B and L as well as of cathepsin inhibitors stefin A, stefin B, and cystatin C were measured by ELISA. The plasma concentrations of MMP-1 (collagenase), MMP-3 (stromelysin), tissue inhibitor of metalloproteinases 1 (TIMP-1), and of MMP-1/TIMP-1 complex (MT complex) were analyzed by ELISA as well. RESULTS: A significant increase of MMP-1, MMP-3, and MT complex was observed in RA plasma, compared to normal controls, whereas TIMP-1 concentrations did not differ. In contrast, neither serum activity nor protein concentration of any of the cathepsins or cathepsin inhibitors were elevated in RA. CONCLUSION: Despite ample evidence in the literature that cathepsin activity contributes to the pathogenesis of inflammatory joint disease, this is not reflected by the conditions in peripheral blood. In contrast to the cysteine proteinases, MMP-1 and MMP-3 as well as MT complex are elevated in RA. In the context of findings in the literature, this stresses the importance of MMP as disease activity markers, compared to cysteine proteinases or their inhibitors.

Comparative analysis of cathepsin L, cathepsin D, and collagenase messenger RNA expression in synovial tissues of patients with rheumatoid arthritis and osteoarthritis, by in situ hybridization.

OBJECTIVE: To compare the expression of cathepsin L, cathepsin D, and collagenase messenger RNA (mRNA) in synovial specimens from patients with rheumatoid arthritis (RA) and osteoarthritis (OA). METHODS: The expression of cathepsins L and D as well as collagenase mRNA in synovial tissues from 8 patients with RA, 6 patients with OA, and 2 patients with noninflamed joints was evaluated using in situ hybridization with digoxigenin-labeled RNA probes. RESULTS: Both RA and OA synovial tissue expressed cathepsins L and D as well as collagenase mRNA. The expression of the cathepsins was markedly higher in interstitial regions and, to some extent, in perivascular infiltrates of RA synovial tissue compared with OA specimens. CONCLUSION: Cathepsins L and D mRNA are expressed differently in RA and OA synovial tissues, supporting the concept that these enzymes may contribute to the influx of mononuclear cells into RA synovium. Moreover, the data reveal that the expression of collagenase and cathepsins in RA and OA synovial lining is otherwise largely similar, and suggest that the adhesion of synovial cells to cartilage mediates the invasive destructive process in RA.

[Therapy of rheumatoid arthritis with azathioprine--results of an open long-term study of at least 4 years with 528 patients]. / Therapie der Rheumatoid-Arthritis (RA) mit Azathioprin--Ergebnisse einer offenen Langzeitstudie über mindestens 4 Jahre bei 528 Patienten.

In an open study 528 patients affected with rheumatoid-arthritis were treated with azathioprine, then observed for a period of at least 4 years and assessed according to Steinbrocker's therapeutic criteria. In 178 of them (33.7%) the therapy was still effective even after that time, which corresponds to grade I and II according to Steinbrocker. The therapy was cancelled in 211 patients due to ineffectiveness and in 85 patients due to side-effects. The side-effects are represented in detail. Owing to the favorable relationship between benefit and risk, azathioprine proves to be a means of first choice in all cases with a high process activity and an unfavorable prognosis.

[HLA-antigens in patients with rheumatoid arthritis]. / HLA-Antigene bei Patienten mit Rheumatoid-Arthritis.

109 patients with rheumatoid arthritis (RA) from the north of the GDR were HLA typed and the antigen frequencies compared with those of a control group. Even in our patients the HLA-DR4 association was demonstrable. But in all studies DR4 association is not strong enough for taking HLA typing as a diagnostic test for RA. There was an immunogenetic heterogeneity in correlation to side effects of therapy with sodium aurothiomalate or D-penicillamine. HLA-DR5 was significantly increased in patients with side effects in comparison to patients without side effects in therapy. Before recommending HLA-DR typing for selection of high risk patients in D-penicillamine therapy these results should be proven in a large patient group or in a second study.

[Model of complex medical rehabilitation of rheumatoid arthritis--possibilities and problems, exemplified by the Rostock district]. / Modell der komplexen medizinischen Rehabilitation der Rheumatoid-Arthritis--Möglichkeiten und Probleme, dargestellt am Beispiel des Bezirkes Rostock.

The complex rehabilitation of the patients suffering from rheumatoid arthritis requires an interdisciplinary cooperation and a reasonable coordination of all involved persons of the territory. Taking an example of the Rostock county the possibilities and problems hereby arising are illustrated.

[Wound infection following surgical intervention for rheumatism and its relationship to preoperative basic therapy]. / Wundinfektionen nach rheumachirurgischen Eingriffen und ihre Beziehungen zur präoperativen Basistherapie.

Theoretically, slow acting antirheumatic drugs are capable of affecting the body's infection resistance. We have therefore analyzed the records of all 558 RA-patients hospitalized and operated on at our department from 1985-1987 with respect to the incidence of post-surgical wound infections and possible links to previous treatment with slow acting antirheumatic drugs. A total of 2456 operations were performed, or 4.4 per patient. Severe complications due to infection occurred in 24 patients (0.98%). The slow acting drugs had no effect on the complications rate.

Diclofenac and piroxicam in a double-blind trial results and methodological problems. Working Party of the Society for Rheumatology of the GDR for the Testing of Anti-rheumatic Drugs.

Diclofenac (150 mg/d) and piroxicam (20 mg/d) were compared in a cross-over trial with 12-day periods of double-blind treatment and 3-day wash-out periods. The following open phase of the trial lasted for two months and served to assess the tolerance. For this the dosage of diclofenac was reduced to 100 mg/d. 134 volunteers from 5 departments of rheumatology participated in the study. Statistical analysis showed that the two groups were of homogenous composition and that--with certain limitations--the necessary assumptions for the evaluation as a cross-over experiment were fulfilled. All tests used to determine the efficacy showed approximately parallel improvement with both formulations and in the wash-out phase this was followed by marked deterioration. The sum of the parameters for individual improvement showed a tendency in favour of piroxicam. However, clear superiority of one trial formulation over the other with respect to efficacy or tolerance could not be demonstrated by the statistical analysis.

[Behavior of the heparinocytes after gold therapy]. / Verhalten der Heparinozyten nach Goldtherapie

A reduction of the total leukocytes as well as a significant decrease of heparinocytes and BAI (basophilic age index) can be observed in rheumatoid arthritis in the course of a gold therapy. As some coagulation parameters simultaneously speak in favour of an enhancement of the intravasal coagulation, a partial blocking of the endogenous heparin caused by gold may be supposed. A combined heparin or heparinoid therapy in a low dosage is being recommended for risk patients of the vascular and coagulation system.

[Fibrinolysis before and after gold therapy in rheumatoid arthritis]. / Zur Fibrinolyse vor und nach Goldtherapie bei Rheumatoidarthritis

In 12 patients with chronic rheumatoid arthritis the immunoglobulins IgG, IgA and IgM were determined according to Mancini and the fibrinolytic split products according to Nilehn before and after a gold treatment of 3 to 6 months. The IgG values were always increased and even after the treatment there was only little regression. The fibrinolytic split products found in 5 cases speak in favour of an enhanced intravasal coagulation, which increased still further after the gold therapy. In spite of clinical improvement the immunological processes and latent actions of coagulation seem to pass almost undiminished.

[Effect of gold therapy in rheumatoid arthritis on leukopoiesis and granulocyte phagocytosis]. / Die Beeinflussung der Leukopoese und der Granulozytenphagozytose vor und nach Goldtherapie bei Rheumatoidarthritis

In 12 patients with rheumatoid arthritis the investigations of leukopoiesis and granulocytic phagocytosis were carried out before and after a gold therapy. A marked reduction of granulocytic phagocytosis could be observed here which decreased after the gold therapy, yet remained below the values of a normal collective. Partly contrary informations are discussed. The disturbance of the phagocytosis capacity of granulocytes may possibly be due to a rheumatic factor.