Cytokine and chemokine receptor profile of peripheral blood mononuclear cells during treatment with infliximab in patients with active rheumatoid arthritis

OBJECTIVES: To analyse immunological changes during treatment with a monoclonal anti-tumour necrosis factor alpha (TNFalpha) antibody, infliximab, in patients with rheumatoid arthritis (RA). METHODS: 25 patients with RA and 5 patients with other arthritides were studied during the first 6 weeks of treatment with infliximab. At the start of treatment and after 2 and 6 weeks, spontaneous expression of CCR3 and CCR5 on peripheral blood T cells and monocytes was studied by flow cytometry. The secretion and mRNA expression of interferon gamma (IFNgamma), interleukin (IL)4, IL5, and TNFalpha from phytohaemagglutinin (PHA) stimulated peripheral blood mononuclear cells was measured with an ELISA and RT-PCR. Plasma levels of C reactive protein, serum amyloid protein A, rheumatoid factor, and antibodies to filaggrin and citrullinated cyclic peptide were measured with an ELISA. RESULTS: The number of CD4 T cells and CD14 monocytes expressing CCR3 (p = 0.013, p = 0.009, respectively) and CD8 T cells expressing CCR5 (p = 0.040) as well as PHA stimulated secretion of IL4 and IFNgamma (p<0.05) increased during treatment in patients with RA. 15 (60%) patients with RA achieved clinical response (at least ACR20) during the first 2 weeks. The number of T cells expressing CCR3 and CCR5 was higher before treatment in non-responders than in responders (p<0.05). The number of T cells increased in responders. CONCLUSION: Increase in secretion of Th1 and Th2 cytokines together with induced expression of chemokine receptors on T cells and monocytes suggest restoration of peripheral cell mediated immunity and blockade of the accumulation of inflammatory cells in joints as response to treatment.     

B cell activation in rheumatoid arthritis patients under infliximab treatment

OBJECTIVE: To determine whether anti-TNF alpha (infliximab) treatment affects B cell activation in patients with rheumatoid arthritis (RA) METHODS: B cell activation was analyzed in fifteen anti-TNF-treated RA patients. CD23 expression was used as a B cell activation marker and was studied before and after three months of infliximab treatment. PBMC were stimulated with anti-CD3 mAb during 18 h and were separated by rosseting into E+ and E-cells. B cells were assessed in E-population by double staining with CD19 and CD23. ELISA assays were used to assess both soluble TNF alpha and circulant immune complexes (CIC) containing TNF alpha. We also used B cells from tonsils to establish the relationship between B cell activation and TNF alpha CIC. RESULTS: The proportion of B cells expressing CD23 was higher before infliximab exposure than after treatment (48.3 +/- 16.7 versus 29.5 +/- 12.5, p = 0.007). T-B cell interactions were assessed by means of blocking antibodies to CD154, CD40, CD69, and CD18; these interactions were not specially affected by infliximab treatment. We could demonstrate CIC containing TNF alpha after infliximab treatment, these CIC, similarly to others IgG-containing immune complexes, were capable to downregulate CD23 on B cells. CONCLUSIONS: Infliximab treatment in RA downregulates CD23 expression on T-cell activated B cells. This downregulation is connected with the presence of CIC containing TNF alpha. Presumably, the Fc gamma RIIb1 endows IgG-containing immune complexes, as TNF alpha-anti-TNF alpha, with the capacity to regulate B cells and inflammatory cells.     

Proliferation of peripheral blood mononuclear cells from rheumatoid arthritis patients to mycobacterial antigens

Summary Proliferation of rheumatoid and control peripheral blood mononuclear cells (PBMC) to an antigenic acetone-precipitable extract from mycobacterium tuberculosis (MTa) was investigated. Cells were also stimulated with the recall antigen tuberculin PPD (purified protein derivative) and the mitongen OKT3. Controls had a significantly higher response to both MTa and tuberculin PPD than RA patients. However, lymphocytes from patients who had had their disease for 3–10 years profliferated more vigorously to MTa than did PBMD from patients with longer disease duration. There was no difference in the proliferation to OKT3 between patients and controls. We were not able to confirm a previously found correlation between the HLA-DR4 phenotype and lymphocyte transformation to MTa.     

Homocysteine enhances cytokine production in cultured synoviocytes from rheumatoid arthritis patients

OBJECTIVE: Hyperhomocysteinemia is commonly observed in Rheumatoid Arthritis (RA) patients, thus putatively accounting in part for the high rate of cardiovascular events in these subjects. Homocysteine (Hcy) is known to exert a pro-inflammatory effect putatively contributing to the progression of atherosclerotic lesions by cytokine production from several vascular cell-types. In order to evaluate the possibility that Hcy may play a direct pro-inflammatory activity also in the joints of RA patients, we investigated: (i) the joint concentration of Hcy, and (ii) the effect of Hcy on cytokine production by unstimulated and IL-1beta-stimulated human RA cultured synoviocytes. METHODS: In 5 RA and 5 controls subjects, Hcy was measured in the blood and knee synovial fluid, and specimens of synovial tissue were taken to obtain cell cultures. Cultures were incubated with Hcy (10-100 micromol/l) +/- IL-1beta, and IL-6 and IL-8 concentrations were evaluated in the supernatants (ELISA) together with the activation of nuclear factor-kB (NF-kB) (immunocytochemistry). RESULTS: Hcy was present in synovial fluids, with a mean concentration significantly higher in RA patients than in controls (9.0 +/- 1.1 vs 5.9 +/- 1.2 micromol/l). Hcy enhanced IL-6 and IL-8 production in RA synoviocytes only (up to 35%). Moreover, Hcy produced a clear-cut activation of NF-kB in rheumatoid cells only. CONCLUSION: Hcy enhances IL-1-dependent cytokine production by rheumatoid synoviocytes at a concentration measurable in RA joints in vivo. Thus, in RA patients, Hcy may not only represent an important risk factor for the progression of cardiovascular diseases, but it may also contribute to the joint damage.     

Clinical impact of switching from infliximab to etanercept in patients with rheumatoid arthritis

We assessed the disease activity in patients with rheumatoid arthritis (RA) after switching from infliximab to etanercept according to the reason of infliximab discontinuation. At Helsinki University Central Hospital during the period 1999 to 2003, 49 patients with RA were switched from infliximab to etanercept. The reasons for infliximab discontinuation were: 42% for failure to respond by >American College of Rheumatology 50% criteria; 12% for adverse events; 46% responded to infliximab and were switched for non-medical reasons. Clinical outcome after the switch was compared between the groups according to the reason of infliximab discontinuation. Disease activity was measured with the 28-joint count Disease Activity Score (DAS28). In patients in the non-medical reasons group, the disease activity was suppressed effectively both during infliximab and etanercept. Furthermore, the one-year drug survival of etanercept in this group was the highest of 77% (95% confidence interval (CI), 62 to 97) among the three groups. In patients in the infliximab failure and adverse event groups, DAS28 values improved significantly during etanercept therapy. The 1-year drug survival of etanercept was 43% (95% CI, 26 to 70) and 50% (95% CI, 33 to 100), respectively. For RA patients who discontinued taking infliximab because of non-medical reasons experienced similar treatment efficacy during both biological agents. The treatment with etanercept provided sufficient disease control also for patients with infliximab failure or adverse event. Therefore, etanercept can be suggested when infliximab has failed or discontinued for other reasons.     

Peripheral neuropathy in two patients with rheumatoid arthritis receiving infliximab treatment

Antitumor necrosis alpha agents have been successfully used for the treatment of rheumatoid and seronegative arthritis, Crohn’s disease, psoriasis, and severe cases of vasculitis. Several side effects have been observed in patients receiving these agents including hypersensitivity reactions, infections, drug-induced lupus, or demyelinating syndromes. The presence of peripheral neuropathy has been reported only in isolated cases. We describe two cases of peripheral neuropathy which occurred in patients with rheumatoid arthritis receiving infliximab treatment, one with multifocal motor neuropathy with conduction block and another with axonal sensory polyneuropathy, reversed upon discontinuation of infliximab and intravenous gammaglobulin treatment.     

The efficacy of switching from etanercept to infliximab in patients with rheumatoid arthritis

OBJECTIVE: To describe the degree of clinical benefit in patients with rheumatoid arthritis (RA) who receive infliximab therapy after lack of efficacy with etanercept. METHODS: In a retrospective study among 6 centers primarily designed to assess the safety of infliximab in combination with leflunomide, a standardized chart review form was used to collect data on 93 patients with RA. During that study, it was noted that some of these patients had switched from etanercept to infliximab. In this study, we compared the response of subjects switching from etanercept to infliximab (n = 20) to that of subjects receiving infliximab with no prior tumor necrosis factor (TNF) therapy (n = 73). RESULTS: The swollen and tender joint count, patient and physician global assessments, morning stiffness, and C-reactive protein all improved substantially in both groups, with no statistical difference in the degree of benefit between the groups. At the time of chart review, switchers had received a statistically higher dose of infliximab than controls (4.4 vs 3.19 mg/kg; p = 0.006) with a total of 5.7 and 5 infusions, respectively. CONCLUSION: In this retrospective study, previous lack of efficacy with etanercept did not predict lack of efficacy with infliximab. Indeed, the degree of clinical improvement was similar in both groups, although switchers were receiving a higher dose of infliximab at the time of chart review. Our findings suggest that clinical response may differ between anti-TNF agents, and lack of response to one agent may not predict a lack of response to another.     

Enhanced phospholipase activity in peripheral blood monocytes from patients with rheumatoid arthritis

Peripheral blood monocytes (PBM) from patients with rheumatoid arthritis (RA) produce greater amounts of prostaglandins (PG) than do control cells. To further explore the reasons for the increased PG production, we assessed the phospholipase activities in these cells. We found that PBM from patients with severe RA expressed greater phospholipase A2 (PLA2) and phospholipase C (PLC) activities than did the control cells. Enhanced PLA2 activities were observed in RA patient cells when phosphatidylcholine (PC) or phosphatidylethanolamine (PE) were used as substrates. Enhanced PLC activities also were seen when PC, PE, and phosphatidylinositol (PI) were used as labeled substrates. Increased PLC activity was observed whether linoleic acid or arachidonic acid was esterified to the 2 position of the phospholipid substrate used. Because all patients with RA were treated with nonsteroidal antiinflammatory drugs, we examined the effects of aspirin ingestion on phospholipase activities. Aspirin had no consistent effect on PLA2 activities but markedly inhibited PLC activities against PC, PI, and PE with arachidonic acid in the R2 position. That aspirin enhanced PLC activities against PC and PI with linoleic acid in the R2 position, suggests that PLC activity may be regulated in part by the R2 fatty acid. Our results indicate that increased phospholipase activities exhibited by PBM from RA patients may help explain the increased PG production by these cells. The increased phospholipase activities in PBM from RA patients do not appear to be due solely to nonsteroidal antiinflammatory drug therapy.     

Titration of infliximab treatment in rheumatoid arthritis patients based on response patterns

OBJECTIVES: To observe the course of the disease activity in rheumatoid arthritis (RA) patients treated with the standard infliximab dosing regimen and to adjust treatment guided by the pattern of disease activity. METHODS: All RA patients starting infliximab treatment were included and observed for at least 37 weeks. At infusion 4 (week 14), European League Against Rheumatism response was assessed. In moderate responders the dose was unchanged and the disease activity was carefully observed. In case of stable disease activity, the dose was increased at infusion 5 (week 22). In case of a temporary response the interval was reduced. Paired t-testing was applied to the disease activity score with 28-joint counts (DAS28) at week 22 and study endpoint. RESULTS: A total of 76 patients were included. Response after 14 weeks: good 22 (29%) patients, moderate 26 (34%) patients, and non-response in 21 patients. Seven patients (9%) dropped out before week 14 due to adverse events (5) or patients' initiative (2). In patients with moderate response, the following disease course between infusion 4 and 5 was observed: improvement to good response 6, temporary response 6, stable disease activity 6, drop out 8. In moderate responders, interval reduction and dose increase resulted in a decrease in mean DAS28 from 5.1 to 3.6 [P = 0.005, mean interval 5.6 weeks, mean infliximab dose 4.8 mg/kg/8 week (endpoint)] and from 4.1 to 3.6 [P = 0.04, mean infliximab dose 7.3 mg/kg/8 week (endpoint)], respectively. CONCLUSION: Three different patterns of disease activity were observed in moderate responders after 14 weeks of infliximab treatment, i.e. further improvement, no change in disease activity or a temporary response. Both interval reduction and dose increase significantly reduced disease activity, however, with different mean infliximab dosages. In good responders the response was often sustained over follow-up, whereas non-responders showed modest or no improvement despite dose adjustments.     

Increment of Tal positive cells in peripheral blood from patients with rheumatoid arthritis

Recently it was demonstrated that the Tal antigen is a marker for activated T cells and the population of Tal+ cells includes memory T cells. Our study was undertaken to analyze Tal+ cells in peripheral blood from patients with rheumatoid arthritis (RA) and examine the correlation between the proportion of Tal+ cells and disease activity. Using a dual immunofluorescent method, T cell subsets were analyzed in peripheral blood from 46 patients with RA, 10 patients with osteoarthritis (OA) and 10 healthy subjects. Patients with RA had a significantly higher percentage of T cells bearing the Tal antigen than patients with OA and healthy subjects. Furthermore, the percentage of CD3+Tal+ cells in peripheral blood from patients with RA was significantly correlated with disease activity including erythrocyte sedimentation rate, morning stiffness and the Lansbury index, whereas CD3+ HLA-DR+ cells did not correlate. In serial observations in patients with RA, the percentage of CD3+ Tal+ cells decreased in accordance with the improvement of disease activity. Thus, we suggest that the percentage of Tal+ cells may be a marker of the disease activity in patients with RA.     

Clinical outcomes of patients with rheumatoid arthritis after switching from infliximab to etanercept

OBJECTIVE: To assess the efficacy and monitor serious adverse events in patients with rheumatoid arthritis (RA) switching treatment from infliximab to etanercept. METHODS: Adult patients with active RA who were discontinuing treatment with infliximab were eligible to enroll in this prospective, 12-week, open label, single-arm, observational study. Four to 10 weeks after their last infusion of infliximab, patients began treatment with etanercept (twice weekly subcutaneous injections of 25 mg). Clinical assessments using the American College of Rheumatology (ACR) criteria for improvement were performed at baseline and at Weeks 6 and 12, and serious adverse events were monitored throughout the study. RESULTS: Twenty-five patients were enrolled, 18 of whom had discontinued infliximab because of lack of efficacy, and 22 completed 12 weeks of etanercept treatment. After 12 weeks, 14 of 22 patients (64%) achieved at least a 20% improvement in ACR criteria (ACR20), 13 (59%) experienced improvements in physical function that were considered clinically important (> or = 0.22 point decrease in overall Health Assessment Questionnaire score), and mean values of all individual components of the ACR criteria had improved. No serious adverse events were reported during the study and no patient discontinued because of lack of efficacy. CONCLUSION: Etanercept, a soluble tumor necrosis factor (TNF) receptor, provided a well tolerated and effective treatment option for some patients even when infliximab, a monoclonal antibody to TNF, had been ineffective.     

Serum ghrelin in female patients with rheumatoid arthritis during treatment with infliximab

Ghrelin is a gastric hormone that posses multiple functions, including induction of growth hormone release, regulation of proinflammatory cytokines and control of food intake and energy homeostasis. A few reports on serum ghrelin level in chronic inflammatory states revealed contradictory results. The study was undertaken to determine ghrelin in patients with rheumatoid arthritis receiving infliximab, a TNF-α blocking agent. Serum ghrelin was determined in 18 female rheumatoid patients before the treatment with infliximab, 1 week after the first infusion and after 53 weeks of medication and compared with 15 age-matched healthy women. Serum ghrelin level was shown to be increased in the patients. A decrease in serum ghrelin level was found after the first infusion of infliximab and similarly decreased ghrelin level but still higher than in the control was shown in the 53rd week of medication. The obtained results suggest that ghrelin level is related to inflammation, and its serum level in patients with severe rheumatoid arthritis behaves similarly to acute-phase reactants.     

Antinuclear antibodies following infliximab treatment in patients with rheumatoid arthritis or spondylarthropathy

OBJECTIVE: To investigate the effect of infliximab treatment on antinuclear antibodies (ANAs), anti-double-stranded DNA (anti-dsDNA), antinucleosome, antihistone, and anti-extractable nuclear antigen (anti-ENA) antibodies in rheumatoid arthritis (RA) and spondylarthropathy (SpA) patients. METHODS: Sera from 62 RA and 35 SpA patients treated with infliximab were tested at baseline and week 30 (RA group) or week 34 (SpA group). ANAs were tested by indirect immunofluorescence (IIF) on HEp-2 cells. Anti-dsDNA antibodies were detected by IIF on Crithidia luciliae and by enzyme-linked immunosorbent assay (ELISA) and were further isotyped with gamma, mu, and alpha chain-specific conjugates at various time points. Antinucleosome antibodies were tested by ELISA. Antihistone and anti-ENA antibodies were detected by line immunoassay. RESULTS: Initially, 32 of 62 RA patients and 6 of 35 SpA patients tested positive for ANAs. After infliximab treatment, these numbers shifted to 51 of 62 (P < 0.001) and 31 of 35 (P < 0.001), respectively. At baseline, none of the RA or SpA patients had anti-dsDNA antibodies. After infliximab treatment, 7 RA patients (P = 0.016) and 6 SpA patients (P = 0.031) became positive for anti-dsDNA antibodies. All 7 anti-dsDNA-positive RA patients had IgM and IgA anti-dsDNA antibodies. Three of the 6 anti-dsDNA-positive SpA patients had IgM and IgA anti-dsDNA antibodies, and 2 had IgM anti-dsDNA antibodies alone. In both diseases, the IgM anti-dsDNA antibodies appeared before the IgA anti-dsDNA antibodies. During the observation period, no IgG anti-dsDNA antibodies or lupus symptoms were observed. The development of antinucleosome, antihistone, or anti-ENA antibodies following infliximab treatment was observed in some patients, but the numbers were not statistically significant. CONCLUSION: Infliximab treatment may induce ANAs, and especially IgM and IgA anti-dsDNA antibodies, in RA and SpA patients. However, no anti-dsDNA IgG antibodies or lupus symptoms were observed during the period of observation in this study, and the development of antinucleosome, antihistone, or anti-ENA antibodies was not statistically significant. These observations do not exclude potential induction of clinically significant lupus in the long term, and further followup is therefore mandatory.     

The efficiency of switching from infliximab to etanercept and vice-versa in patients with rheumatoid arthritis

OBJECTIVE: To determine whether it may be successful to try another TNF-alpha antagonist (infliximab or etanercept) when one has failed due to non response or the development of side effects. METHODS: In a cohort of 282 patients with rheumatoid arthritis treated with infliximab or etanercept, we observed 38 patients who had received both agents. RESULTS: Twenty-four patients received infliximab first and 14 received etanercept first. Discontinuation was due to a lack of efficiency for 29 patients and to the occurence of an adverse effect for 9 patients. For 25 out of the 38 patients, the switch was a success according to the global physician's assessment 3 months after switching. This result was correlated to a significant decrease of DAS 28 measurements and CRP values (p < 0.05). The response after switching was recorded as a success for 18 out of the 24 patients who were treated with infliximab first, and for 12 out of the 14 patients who were treated with etanercept first. There was no statistical difference concerning the response after the switch between the two groups. Among the 29 patients who discontinued the first anti TNF-alpha treatment due to lack of efficiency, only 6 did not respond to the second anti TNF-alpha treatment. Only one out of the 9 patients who stopped a first anti TNF-alpha treatment after developing a side effect underwent an adverse event with the second anti TNF-alpha treatment. CONCLUSION: Our study suggests that switching between TNF-alpha antagonists seems to be relevant, regardless of which one was used first. It is legitimate to try to switch TNF-alpha blockers before contemplating other therapeutic strategies.