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ID PMID Title PublicationDate abstract
8371202 Pancytopenia associated with low dose methotrexate therapy. A regional survey. 1993 Jul OBJECTIVE: To determine which risk factors are associated with serious pancytopenia associated with low dose methotrexate (MTX) therapy. METHODS: All Ottawa area rheumatologists, hematologists and dermatologists were surveyed to obtain cases of pancytopenia associated with low dose MTX therapy between 1981 and 1991. Pancytopenia was defined as white blood cells < 3.5 x 10(9)/l and platelets < 140 x 10(9)/l and hemoglobin < 100 g/l. A case control method was used to evaluate risk factors. RESULTS: Fifteen cases of pancytopenia were identified from returned questionnaires (93% response rate) and from reviewing the medical records of 2 major teaching hospitals. All patients were hospitalized, had MTX therapy discontinued and were treated: 12 patients received transfusions, 8 leucovorin therapy, and 4 folic acid. Two patients died, only 1 directly due to MTX therapy. Identified risk factors were (1) elevated BUN or creatinine levels, (2) increasing mean corpuscular volume values, (3) increased age and (4) concomitant trimethoprim-sulfamethoxazole therapy. CONCLUSIONS: Pancytopenia associated with low dose MTX therapy is a life threatening adverse effect often associated with known risk factors. A change in monitoring guidelines and patient education are suggested as means of risk reduction.
8149645 A one-step sandwich enzyme immunoassay for human matrix metalloproteinase 2 (72-kDa gelati 1993 Nov 30 A one-step sandwich enzyme immunoassay (EIA) for human matrix metalloproteinase 2 (MMP-2, 72-kDa gelatinase/type IV collagenase, EC 3.4.24.24) was established with a pair of monoclonal antibodies prepared against the precursor form of MMP-2 (proMMP-2) purified from the conditioned medium of human skin fibroblasts or against a synthetic peptide corresponding to the N-terminal domain of proMMP-2. ProMMP-2 in samples was allowed to simultaneously react with both solid-phase and peroxidase-labeled antibodies. Sensitivity of this EIA system was 2.4 pg/assay (0.24 microgram/l) and linearity was obtained between 10 and 5,000 pg/assay (1.0-500 micrograms/l). The EIA system recognized both the free form of proMMP-2 and its complex form with TIMP-2 with the same degree of immunoreactivity. ProMMP-2 levels in human sera from patients in various disease states were analyzed. In sera from patients with hyperthyroidism (12), primary biliary cirrhosis (8) and hepatocellular carcinoma (11), 749 +/- 166, 716 +/- 135 and 686 +/- 236 micrograms/l of proMMP-2 were detected, respectively and these were significantly higher than that observed in 213 normal human sera (570 +/- 118 micrograms/l). In contrast, the levels in sera from 33 patients with osteoarthritis (449 +/- 72 micrograms/l), 45 with rheumatoid arthritis (408 +/- 139 micrograms/l), 13 with stomach cancer (427 +/- 103 micrograms/l) and 10 with pancreatic cancer (422 +/- 130 micrograms/l) were significantly lower than that found in normal sera. Immunoblot and gel filtration analyses showed that human sera contain several MMP-2 species in addition to proMMP-2 which exist in a complex form with TIMP-2.
8921439 Induction of Fas-dependent apoptosis in synovial infiltrating cells in rheumatoid arthriti 1996 Oct Apoptosis is a feature of the synovium of rheumatoid arthritis (RA). We have recently shown that RA synoviocytes were susceptible to anti-Fas mAb and undergo apoptosis in vitro. To investigate whether infiltrating mononuclear cells also undergo Fas-dependent apoptosis, double-labeling techniques combined with immunohistochemical examination with anti-CD3 mAb and the TdT-mediated dUTP-blotin nick end labeling (TUNEL) method to detect apoptotic cells, or in situ RT assay to detect Fas mRNA, were performed using frozen tissue sections. We also examined the in vitro induction of Fas-dependent apoptosis in freshly isolated synovium infiltrating mononuclear cells (SIM), synovial stromal cells (SSC) and peripheral blood lymphocytes (PBL) using tissues from nine patients with RA and three with osteoarthritis (OA). The results showed expression of Fas antigen and apoptotic cells in a number of CD3-bearing cells in RA synovial tissues. In vitro treatment with anti-Fas mAb produced a significant apoptosis of RA SIM and SSC, while none of PBL, and neither SIM nor SSC from OA exhibited apoptosis. Moreover, approximately 50% of CD4+, CD3+ and CD45RO+ cells, and > 90% of Fas-expressing cells of RA SIM underwent apoptosis in response to anti-Fas mAb, as detected by flow cytometry. Our results suggest that RA synovial infiltrating lymphocytes acquire high susceptibility to anti-Fas mAb and undergo apoptosis. Such a phenomenon of infiltrating T cells in RA synovium may play an important pathophysiological role and suggest a possible therapeutic effect for anti-Fas mAb in RA.
8607894 Limited heterogeneity of rearranged T cell receptor V alpha and V beta transcripts in syno 1996 Mar OBJECTIVE: The identification of activated T cells in synovial fluid and synovium, and the association of rheumatoid arthritis (RA) with specific HLA-DR restriction elements, strongly suggest that these T cells play a critical role in the etiology and pathogenesis of RA. Analysis of the T cell receptor (TCR) repertoire in the early stages of RA might be an approach to identify those T cells involved in the initiation and/or perpetuation of the disease. METHODS: TCR V alpha and V beta transcripts of synovial T cells, sampled at the early stages of RA, were amplified by reverse transcriptase-polymerase chain reaction. HLA-DR subtyping was determined by serologic analysis and dot-blot hybridization of polymerase chain reaction amplification products using digoxigenin-labeled, sequence-specific oligonucleotide probes. RESULTS: Our findings showed a limited heterogeneity of V alpha and V beta TCRs in synovial fluid T cells, and a preferential usage of TCR V alpha 17 in early RA. In contrast, in the later stages of RA, a more polyclonal TCR V alpha and V beta gene usage was observed. CONCLUSION: Our results support the view that induction of RA is driven by an oligoclonal immune response to an unknown antigen. These findings also suggest a pathogenetic role for V alpha 17 T cells in the early stages of RA.
8245017 Human cartilage gp-39, a major secretory product of articular chondrocytes and synovial ce 1993 Dec 5 One of the major secreted proteins of human articular chondrocytes in monolayer or explant culture and of synovial fibroblasts is a glycoprotein with an apparent molecular weight of approximately 39,000, referred to as human cartilage glycoprotein-39 (HC gp-39). The protein was purified, and its complete cDNA sequence was determined. It contained an open reading frame coding for a 383-amino acid long peptide. Comparison of the deduced amino acid sequence with known sequences revealed that HC gp-39 contained regions displaying significant homology with a group of bacterial and fungal chitinases and a similar enzyme found in the nematode, Brugia malayi. In addition significant homologies were observed with three mammalian secretory proteins of as yet unknown function, suggesting that a related protein family exists in mammals. The human protein does not possess any glycosidic activity against chitinase substrates, arguing against any function as an endoglycosidase with specificity for N-acetylglucosamine. Analysis by Northern blotting and by reverse transcription/polymerase chain reaction showed mRNA for HC gp-39 to be present in human articular chondrocytes as well is in liver, while mRNA was undetectable in muscle tissues, lung, pancreas, mononuclear cells, or fibroblasts. Neither the protein nor mRNA for HC gp-39 was detectable in normal newborn or adult human articular cartilage obtained at surgery, while mRNA for HC gp-39 was detectable both in synovial specimens and in cartilage obtained from patients with rheumatoid arthritis. These observations suggest that the expression of HC gp-39 may be related to a response of these cells to an altered tissue environment.
8628979 Review of clinical trials and benefit/risk ratio of meloxicam. 1996 Meloxicam is a new once daily non-steroidal anti-inflammatory drug (NSAID). Double-blind trials in over 5000 patients with osteoarthritis and rheumatoid arthritis have shown that meloxicam 7.5 mg and 15 mg are significantly more effective than placebo and comparable in efficacy to standard NSAIDs such as naproxen 750-1000 mg, piroxicam 20 mg and diclofenac 100 mg slow release. In a global safety analysis, both meloxicam doses produced significantly fewer gastrointestinal (GI) side effects than the comparators (p < 0/05). Severe GI side effects, discontinuations due to GI side effects and less serious events such as dyspepsia and abdominal pain were also significantly less frequent with meloxicam. Perforations, ulcerations and bleedings occurred in 0.1%, 0.2%, 1.2%, 0.6% and 2.1% of meloxicam 7.5 mg, 15 mg, piroxicam, diclofenac and naproxen patients respectively (p < 0.05 for piroxicam and naproxen compared with meloxicam). This improved safety profile is likely to be due to meloxicam's selective inhibition of COX-2 relative to COX-1.
7556649 Induction of vascular endothelial growth factor expression in synovial fibroblasts by pros 1995 Sep 18 Inflammatory mediators such as prostaglandin E2 (PGE2) and interleukin-1 (IL-1) induce angiogenesis by yet undefined mechanisms. We demonstrate that PGE2 and IL-1 induces the expression of vascular endothelial growth factor (VEGF), a selective angiogenic factor by rheumatoid synovial fibroblast cells. Transcripts for the EP1 and EP2 subtypes of PGE receptors are expressed in synovial fibroblasts. Activators of protein kinase A pathway stimulated the expression of VEGF whereas down-regulation of protein kinase C did not influence the PGE effect, suggesting that signalling from the EP2 receptor via the protein kinase A pathway is important. The induction of VEGF expression by PGE2 and interleukin-1 alpha may be an important mechanism in inflammatory angiogenesis.
8706598 Lornoxicam. A review of its pharmacology and therapeutic potential in the management of pa 1996 Apr Lornoxicam (chlortenoxicam), a new nonsteroidal anti-inflammatory drug (NSAID) of the oxicam class with analgesic, anti-inflammatory and antipyretic properties, is available in oral and parenteral formulations. It is distinguished from established oxicams by a relatively short elimination half-life (3 to 5 hours), which may be advantageous from a tolerability standpoint. Data from preliminary clinical trials suggest that lornoxicam is as effective as the opioid analgesics morphine, pethidine (meperidine) and tramadol in relieving postoperative pain following gynaecological or orthopaedic surgery, and as effective as other NSAIDs after oral surgery. Lornoxicam was also as effective as other NSAIDs in relieving symptoms of osteoarthritis, rheumatoid arthritis, ankylosing spondylitis, acute sciatica and low back pain. Lornoxicam has a tolerability profile characteristic of an NSAID, with gastrointestinal disturbances being the most common adverse events. Limited clinical experience to date suggests that, as with a number of other NSAIDs, lornoxicam may provide a better-tolerated alternative or adjuvant to opioid analgesics for the management of moderate to severe pain. It has also demonstrated potential as an alternative to other NSAIDs for the management of arthritis and other painful and inflammatory conditions. These preliminary findings require confirmation in further comparative and long term studies.
7875581 An abundantly secreted glycoprotein from Drosophila melanogaster is related to mammalian s 1995 Feb 14 An abundantly secreted 47-kDa glycoprotein, DS47, was purified from Drosophila melanogaster (Dm) Schneider line-2 cells, a line exhibiting macrophage-like properties. DS47 is also secreted from several Dm cell lines resembling S2 but not from lines that are morphologically distinct. A cDNA cline was isolated from an S2 cell cDNA library using oligodeoxyribonucleotide probes based on the DS47 amino acid (aa) sequence and found to encode a novel secretory glycoprotein of 452 aa. Analysis of DS47 protein production and mRNA expression during fly development indicates that both are present throughout the entire Dm life cycle, suggesting that DS47 may be important at all developmental stages. In larvae, the DS47 message is made in the fat body and by hemocytes, and secreted into the hemolymph. DS47 is related to a human cartilage glycoprotein, HC gp-39, that is secreted from cell types associated with the arthritic joint, such as synovial cells and activated macrophages. Interestingly, the HC gp-39 message is most readily detected in the human liver, an organ that is somewhat analogous to the Dm fat body. DS47 also shares homology to a mouse secretory glycoprotein, YM-1, identified in activated macrophages. These homologies extend to the chitinase gene family and include a conserved cysteine aa motif, as well as two blocks of aa within the enzymatic active site, although neither DS-47 nor HC gp-39 exhibit chitinase activity. Potential functions of this conserved protein family are discussed.
7799345 The prevalence of Sjögren's syndrome in Behçet's syndrome. 1994 Sep OBJECTIVE: The role of autoimmune mechanisms in Behçet's syndrome (BS) is debated. Sjögren's syndrome (SS) accompanies most autoimmune diseases. Thus we investigated the prevalence of SS in BS in a formal protocol. METHODS: The study was conducted in 2 phases. During the first phase subjective symptoms of dryness were blindly assessed by questionnaires and Schirmer I and Saxon tests were done in 67 patients with BS and 100 healthy and diseased controls. During the 2nd phase 30 patients with BS and 19 with rheumatoid arthritis (RA) had salivary gland biopsies along with rose bengal dye, Schirmer I and tear breakup time tests. RESULTS: During the first phase only patients with primary SS had significantly abnormal findings. However during the 2nd phase pathologic changes in salivary gland biopsies and positive RB tests were highly significantly more prevalent among patients with RA. CONCLUSION: SS is not a feature of BS.
1302560 Type IV collagenase/gelatinase (MMP-2) is not increased in plasma of patients with cancer. 1992 Sep We have developed a sensitive and specific sandwich-type enzyme-linked immunosorbent assay to detect M(r) 72,000 type IV collagenase [matrix metalloproteinase 2 (MMP-2)] in human plasma. As a result of the linkage between MMP-2 production by cancer cells and the metastatic phenotype, we undertook this study to compare plasma MMP-2 levels in healthy individuals, patients with various types of cancer, and hospitalized patients with chronic diseases other than cancer. The results demonstrate that MMP-2 levels are not increased in cancer patients regardless of the extent of disseminated malignancy. In an effort to explain this data, we compared MMP-2 secretion by human umbilical vein endothelial cells and lung cancer cells passaged as cell lines. Endothelial cells secreted higher levels of MMP-2 than did lung cancer cells propagated in vitro. We propose that blood vessel lining cells make a sizable contribution to plasma levels of MMP-2 and may thereby obfuscate the detection of increased levels of MMP-2 originating from extravascular sources such as solid tumors.
8410097 Moderate to high intensity conditioning leisure time physical activity and high cardioresp 1993 Oct A reduction of plasma fibrinogen has been suggested as one mechanism through which physical activity would protect against coronary heart disease (CHD). Therefore, we investigated the association of conditioning leisure time physical activity (CLTPA), assessed quantitatively by a 12-month history, and maximal oxygen uptake (VO2max) with plasma fibrinogen concentration in eastern Finnish men aged 42-60 years. A high mean intensity of CLTPA (standardized multivariate regression coefficient beta -0.059, p = 0.020) and a high maximal oxygen uptake (beta -0.163, p < 0.001) were associated with reduced plasma fibrinogen when adjusting for the strongest covariates. The adjusted relative difference in plasma fibrinogen concentration was 6.6% between men with a mean CLTPA intensity of < 4 and > 8 METs and 9.1% between the extreme quartiles of VO2max (< 2.21 vs > 2.961/min). The association between the mean intensity of CLTPA (p = 0.030 for interaction) and VO2max (p = 0.033) and plasma fibrinogen was stronger for smokers than for non-smokers. These data indicate that a reduction of plasma fibrinogen concentration may be one mechanism through which moderate to high intensity CLTPA and high cardiorespiratory fitness reduce the risk of CHD.
1532618 Alterations in tryptophan metabolism in the toxic oil syndrome and in the eosinophilia-mya 1992 Jan The eosinophilia-myalgia syndrome (EMS) was associated with ingestion of L-tryptophan containing products and was accompanied by altered metabolism of L-tryptophan during the active phase. Many patients with EMS exhibited clinical and histopathological features similar to another epidemic, the toxic oil syndrome (TOS), associated with ingestion of adulterated rapeseed oil. We hypothesized that patients with TOS, like patients with EMS, may have had altered metabolism of L-tryptophan during the acute phase of the illness. Therefore, we quantitated the tryptophan metabolites, L-kynurenine and quinolinic acid, and we measured neopterin, a marker of interferon-gamma (IFN-gamma), in blood obtained during the acute phase of each syndrome. Patients with TOS or EMS had significantly higher L-kynurenine and quinolinic acid than healthy control subjects or rheumatic disease control subjects. Neopterin was also elevated in patients with untreated TOS and EMS, and correlated strongly with L-kynurenine and quinolinic acid. Our data suggest that indoleamine-2,3-dioxygenase (IDO), the rate limiting enzyme of the kynurenine pathway of L-tryptophan metabolism, was activated in both syndromes by cytokines including IFN-gamma, and that perhaps products of tryptophan metabolism played a role in the pathogenesis of EMS and TOS.
8730142 Resolution of the neutropenia of Felty's syndrome by longterm administration of recombinan 1996 Apr Felty's syndrome is characterized by neutropenia, splenomegaly, and recurrent infection in patients with rheumatoid arthritis. We used recombinant granulocyte colony stimulating factor (rGCSF) in a patient with Felty's syndrome and recurrent sepsis. rGCSF induced a statistically significant increase in the patient's absolute neutrophil and total white blood cell counts. During 14 months of followup taking rGCSF, disseminated varicella zoster was the only infectious complication. Except mild thrombocytopenia and a transient flare of arthritis, no serious adverse effects occurred. rGCSF may be a safe and effective therapy for Felty's syndrome in selected patients.
7684808 Collagen-induced arthritis suppressed with monoclonal anti-idiotypic antibody. 1993 In foregoing work, we identified at least 5 distinct epitopes on human type II collagen (CII), using 8 murine monoclonal antibodies (mAb) against human CII, and suggested that a species-nonspecific epitope on CII recognized by anti-CII mAb termed 1-5 is an arthritogenic epitope. We also found that antibody response against a selected epitope of human CII could be induced by immunization with rabbit anti-idiotypic (Id) antibody against anti-CII mAb. The author developed and characterized monoclonal anti-Id antibodies against 1-5 mAb recognizing a putative arthritogenic epitope. The author also investigated whether the anti-Id mAb could regulate antibody response directed against a selected epitope recognized by 1-5 mAb, and the induction of collagen-induced arthritis in DBA/1J mice. DBA/1J mice intravenously preinjected with anti-Id mAb to 1-5, did not produce anti-CII antibody expressing 1-5 Id upon immunization with human CII. Furthermore, as the development of collagen-induced arthritis (CIA) in DBA/1J mice pretreated with anti-Id mAb to 1-5 was significantly suppressed, anti-Id mAb will be a useful tool for studying the regulation of antibody response to a selected epitope. This study lends support to our hypothesis that the 1-5 epitope is an arthritogenic epitope.
8947598 Binding specificities of a polyreactive and a monoreactive human monoclonal IgG rheumatoid 1996 Nov The immunological specificites of two human rheumatoid factor-reactive IgG monoclonal antibodies derived from unstimulated rheumatoid synovial lymphocytes have been analysed. A malaria antigen-reactive IgG monoclonal antibody from an immune donor served as a control. Purified IgG monoclonal antibody from one IgG-RF hybridoma (L1), but not from the other IgG-RF hybridoma (D1) or the anti-malaria monoclonal antibody, exhibited dose-dependent binding to multiple self and non-self antigens such as ds-DNA, cytochrome-c, bovine thyroglobulin, transferrin, cellulose and lipopolysaccharide and therefore was considered polyreactive. The immunological specificity was confirmed by inhibition experiments using the same soluble antigens as inhibitors. The polyreactivity of the IgG-RF MoAb was markedly inhibited by absorption with glycoproteins such as thyroglobulin, a commonly used target for xenoreactive natural antibodies, and cytochrome-c, indicating that the monoclonal antibody is reactive with epitopes expressed on these ligands. Since some naturally occurring antibodies are carbohydrate specific, the authors tested the IgG-RF MoAb for possible carbohydrate specificity. Absorption with certain polysaccharides containing only one or two different sugar moieties did not inhibit the binding reactivities to any of the tested antigens. Polyreactivity of the monoclonal antibody, unlike most xenoreactive natural antibodies, was not caused by reactivity with (gal alpha 1-3gal) as indicated by the remaining binding reactivity after alpha-galactosidase treatment of the antigen. Removal of the N-linked glycosylation sites within the Fc portion of target IgG markedly reduced the antibody binding. The findings suggest that the carbohydrate content of the antigen is necessary for binding of the polyreactive IgG-RF MoAb. Reactivity to carbohydrate antigens may readily explain the so-called multispecificity of certain antibodies.
8785461 Polymyositis and Sjögren's syndrome associated with bronchiolitis obliterans organizing p 1996 Mar Bronchiolitis obliterans organizing pneumonia (BOOP) occurred in a 53-year-old woman with well-documented Sjögren's syndrome (SjS) and polymyositis (PM). BOOP has often been reported as a pulmonary manifestation of collagen vascular diseases, mainly rheumatoid arthritis (RA), but the association of BOOP and PM has rarely been documented. A search of the literature showed only 16 case reports of BOOP associated with polymyositis-dermatomyositis (PM-DM). It is interesting that BOOP occurred prior to PM-DM, while it is commonly believed to occur after RA.
7690805 Synovial fluid macrophages and blood monocytes differ in their response to IL-4. 1993 Sep 15 IL-4 has been described as a potential anti-inflammatory molecule because of its ability in vitro to down-regulate human monocyte production of proinflammatory mediators. In this study, the activity of IL-4 on mononuclear cells and CD14+ macrophages from a site of chronic inflammation, namely, the joints of patients with rheumatoid and psoriatic arthritis, was investigated and compared directly with its activity on PBMC and monocytes from the same patients. In contrast to the response by blood monocytes, the response to IL-4 by synovial fluid cells was selective; IL-4 did not significantly suppress LPS-induced TNF-alpha production, but decreased CD14 expression to a similar extent in the two cell populations. IL-4 induction of monocyte/macrophage CD23 expression was investigated as a stimulatory response to IL-4, and although significantly increased on synovial fluid CD14+ cells by IL-4, the induction was considerably reduced compared with that measured for blood cells. Activation and differentiation in vitro of blood monocytes reduced their response to IL-4 for decreased TNF-alpha production and induction of CD23 and suggested that these biologic phenomena may contribute to the decreased responsiveness to IL-4 by synovial fluid monocytes/macrophages. Thus, IL-4 does not have the same anti-inflammatory properties in vitro on synovial fluid cells as on blood monocytes.
8017358 Healing of NSAID-induced gastric ulcers with a synthetic prostaglandin analog (enprostil). 1994 Jul OBJECTIVE: Conventional ulcer therapy has not been proven effective in healing gastric ulcers caused by nonsteroidal anti-inflammatory drugs (NSAIDs) if the NSAIDs are continued. Our objective in this study was to determine whether a prostaglandin analog is an effective treatment for such NSAID-induced lesions. METHODS: To make this determination, we conducted a 9-wk double-blind trial comparing placebo with enprostil 35 micrograms twice daily and three times daily. Use of antacids was not allowed. Three centers entered 145 patients with chronic inflammatory arthritis and osteoarthritis, mean age 63 yr, who required continuous fixed-dose NSAID therapy within the range of therapeutic dosage. The minimum entrance criterion was the presence of either four gastric erosions or one gastric ulcer. Two pretreatment endoscopies within a 2-wk interval were performed to establish the presence of stable baseline gastric lesions. Endoscopy was repeated at wk 6 and 9 during treatment. All groups were similar with regard to age distribution, sex, weight, height, smoking usage, and alcohol consumption. RESULTS: The ulcer healing rates were 14%, 57%, and 68% at 6 wk and 19%, 68%, and 74% at 9 wk for the groups receiving placebo, enprostil twice daily, and enprostil three times daily, respectively (p < 0.01). Complete mucosal healing of all erosions and ulcers at 9 wk occurred in 59% of enprostil-treated patients and in 10% of placebo-treated patients. Additional gastric erosions and gastric ulcers developed in 16% of placebo patients and 4% of the enprostil patients. Eighteen percent of enprostil patients withdrew early from the study due to adverse experiences, such as diarrhea and abdominal pain. CONCLUSION: We concluded that during continued NSAID therapy 1) enprostil 35 micrograms (taken either twice daily or three times daily) heals NSAID-induced gastric ulcers and erosions and protects the mucosa from further NSAID-induced gastric injury; 2) gastric ulcers and erosions rarely heal spontaneously, and 3) enprostil results in a high incidence of diarrhea.
8568271 In vivo blockade of TNF-alpha by intravenous infusion of a chimeric monoclonal TNF-alpha a 1996 Feb 15 Due to the unknown etiology of RA, specific treatment is not available. Recently, in a double-blinded, placebo-controlled clinical trial, in vivo blockade of TNF-alpha by a single infusion of a chimeric TNF-alpha-blocking mAb, cA2, has proven to be highly effective in the treatment of RA. In parallel to this trial, we tested the consequences of cA2 infusion in ex vivo and in vitro experiments. In this paper, we describe an increase in CD4+ and CD8+ T lymphocyte counts on day 1 and a marked decrease in monocyte counts preferentially on day 7 after cA2 treatment, without major changes in B lymphocyte or NK cell counts. In addition, we found an increased responsiveness of PBMC to CD28 mAb/PMA, but not to CD3 mAb, superantigen staphylococcus enterotoxin B, or PHA on day 1 after infusion. The increase in DNA synthesis of PBMC was paralleled by increased IL-2 mRNA and IL-4 mRNA expression and IL-2 protein secretion in culture supernatants after in vitro stimulation of PBMC with CD28 mAb/PMA. In PBMC, we did not find any significant changes in mRNA or protein expression of CD28 Ag or CD28 ligands, B7-1 and B7-2. Serum concentrations of IL-1 beta, IL-6, and soluble CD14 were significantly diminished after in vivo TNF-alpha blockade. We did not see relevant changes in granulocyte function in vitro after cA2 infusion. Finally, we observed a statistically significant decrease in slCAM-1 molecules in the serum of patients treated with verum compared with that in the serum of subjects given placebo. This change in slCAM-1 concentration was evident on days 1 and 7 after the infusion of 10 mg/kg cA2, whereas it occurred only on day 7 in the serum of patients treated with the low dose (1 mg/kg) of cA2.