Retention rate of abatacept in rheumatoid arthritis patients in a real-life setting: results from a monocentric cohort.

OBJECTIVE: Data from trials demonstrated that abatacept (ABA) has a good safety and efficacy profile in treating rheumatoid arthritis. We have studied the retention rate of ABA in a real-life cohort of patients with rheumatoid arthritis. METHODS: This is a monocentric, retrospective study including patients with rheumatoid arthritis classified by the American College of Rheumatology/European League Against Rheumatism 2010 criteria who started treatment with ABA. The Kaplan-Meier method was applied to evaluate the ABA retention rate. RESULTS: This analysis was conducted on 161 patients [male/female 21/140, median age 65 years, interquartile range (IQR) 18.7, median disease duration 169 months, IQR 144.0]. 111 patients (68.9%) received ABA subcutaneously. ABA was associated with methotrexate in 61.9% of patients and was the first biological disease-modifying antirheumatic drug in 41%. We observed a median ABA survival of 66 months [95% confidence interval (CI) 57.3-74.7], with a retention rate of 88% at 6 months and 50.9% at 5 years. Drug survival was significantly higher in patients treated with ABA subcutaneously and in male patients (p=0.039 and p=0.018, respectively). Adjusted for main confounders, female gender was the main predictor of withdrawal (hazard ratio 5.1, 95% CI 1.2-21.3). CONCLUSIONS: Our study shows that better survival is associated with subcutaneous administration and male gender, confirming ABA effectiveness.

Anti-tumor necrosis factor α: originators versus biosimilars, comparison in clinical response assessment in a multicenter cohort of patients with inflammatory arthropathies.

OBJECTIVE: To compare etanercept and adalimumab biosimilars (SB4 and ABP501) and respective bioriginators in terms of safety and efficacy in a real-life contest. METHODS: We consequently enrolled patients affected by rheumatoid arthritis, psoriatic arthritis, and ankylosing spondylitis, treated with SB4, and ABP501, or with corresponding originators, belonging to the main biological prescribing centers in the Lazio region (Italy), from 2017 to 2020. Data were collected at recruitment and after 4, 8, 12, and 24 months of therapy. RESULTS: The multicenter cohort was composed by 455 patients treated with biosimilars [SB4/ABP501 276/179; female/male 307/146; biologic disease-modifying anti-rheumatic drug (b-DMARD) naïve 56%, median age/ interquartile range 55/46-65 years] and 436 treated with originators (etanercept/adalimumab 186/259, female/ male 279/157, b-DMARD naïve 67,2%, median age/interquartile range 53/43-62 years). No differences were found about safety, but the biosimilar group presented more discontinuations due to inefficacy (p<0.001). Female gender, being a smoker, and being b-DMARD naïve were predictive factors of reduced drug survival (p=0.05, p=0.046, p=0.001 respectively). The retention rate at 24 months was 81.1% for bioriginators and 76.5% for biosimilars (median retention time of 20.7 and 18.9 months, respectively) (p=0.002). Patients with remission/low disease activity achievement at 4 months showed a cumulative survival of 90% to biosimilar therapy until 24 months (p=0.001); early adverse reactions instead represented a cause of subsequent drug discontinuation (p=0.001). CONCLUSIONS: Real-life data demonstrated a similar safety profile between biosimilars and originators, but a reduced biosimilar retention rate at 24 months. Biosimilars could be considered a valid, safe, and less expensive alternative to originators, allowing access to treatments for a wider patient population.

Porphyromonas gingivalis in the tongue biofilm is associated with clinical outcome in rheumatoid arthritis patients.

Several studies have suggested a link between human microbiome and rheumatoid arthritis (RA) development. Porphyromonas gingivalis seems involved in RA initiation and progression, as supported by the high occurrence of periodontitis. In this case-control study, we analysed tongue P. gingivalis presence and quantification in a large healthy and RA cohort. We enrolled 143 RA patients [male/female (M/F) 32/111, mean ± standard deviation (s.d.), age 57·5 ± 19·8 years, mean ± s.d. disease duration 155·9 ± 114·7 months); 36 periodontitis patients (M/F 11/25, mean ± s.d., age 56 ± 9·9 years, mean ± s.d. disease duration 25·5 ± 20·9 months); and 57 patients (M/F 12/45, mean ± s.d., age 61·4 ± 10·9 years, mean ± s.d. disease duration 62·3 ± 66·9 months) with knee osteoarthritis or fibromyalgia. All subjects underwent a standard cytological swab to identify the rate of P. gingivalis/total bacteria by using quantitative real-time polymerase chain reaction. The prevalence of P. gingivalis resulted similarly in RA and periodontitis patients (48·9 versus 52·7%, P = not significant). Moreover, the prevalence of this pathogen was significantly higher in RA and periodontitis patients in comparison with control subjects (P = 0·01 and P = 0·003, respectively). We found a significant correlation between P. gingivalis rate in total bacteria genomes and disease activity score in 28 joints (DAS28) (erythrocyte sedimentation rate) (r = 0·4, P = 0·01). RA patients in remission showed a significantly lower prevalence of P. gingivalis in comparison with non-remission (P = 0·02). We demonstrated a significant association between the percentage of P. gingivalis on the total tongue biofilm and RA disease activity (DAS28), suggesting that the oral cavity microbiological status could play a role in the pathogenic mechanisms of inflammation, leading to more active disease.

Distribution of interleukin-10 family cytokines in serum and synovial fluid of patients with inflammatory arthritis reveals different contribution to systemic and joint inflammation.

Evidence exists that interleukin (IL)-10 family cytokines may be involved in the pathogenesis of rheumatoid arthritis (RA). We sought to determine whether or not these cytokines are involved in psoriatic arthritis (PsA). We conducted a prospective study on patients with PsA, RA and osteoarthritis (OA); healthy controls (HC) were also included. We analysed IL-20, IL-24 and IL-19 serum and synovial fluid (SF) levels and change of serum levels following treatment with biological agents. IL-20 serum levels were increased in PsA and RA compared with OA patients and HC and with matched SF levels. IL-24 serum levels in PsA, RA and OA patients were higher than those in HC and also with respect to matched SF in PsA. IL-19 serum levels were higher in HC and OA compared with PsA and RA patients; IL-19 SF levels were higher in PsA and RA compared with OA patients, and in PsA compared with RA patients. PsA and RA patients showed a reduction of IL-19 serum levels after biological treatment. Therefore, IL-19 seems to be involved mainly in the joint inflammation, whereas IL-20 and IL-24 appear to participate mainly in the systemic responses. These findings may further the comprehension of the contribution of these cytokines to the inflammatory response involved in chronic arthritis, as well as to the development of novel therapeutic strategies.

Multi-functional flow cytometry analysis of CD4+ T cells as an immune biomarker for latent tuberculosis status in patients treated with tumour necrosis factor (TNF) antagonists.

Although monitoring tuberculosis (TB) infection during long-term treatment with tumour necrosis factor (TNF) antagonists is of great importance, no monitoring strategy has yet proved successful. Indeed, even the newly proposed interferon-gamma release assays (IGRAs) are known to produce dynamic changes in IFN-γ plasma levels, making them unreliable indicators of patients' pathological/clinical status. We used intracellular cytokine flow cytometry (ICCFC) to investigate the performance of multi-functional CD4(+) T cells producing IFN-γ, interleukin (IL)-2 and/or TNF in response to Mycobacterium tuberculosis-specific antigens in subjects treated with TNF antagonists. Patients were classified into three groups based on their TB status before commencement of treatment and on IFN-γ level fluctuations evaluated by IGRA during a 36-month follow-up period. The cytokine profile of M. tuberculosis-specific CD4(+) T cells showed that latent tuberculosis infection (LTBI) subjects had a higher frequency of double-positive IFN-γ(+) IL-2(+) CD4(+) T cells and triple-positive IFN-γ(+) IL-2(+) TNF(+) CD4(+) T cells compared to those without LTBI, who showed IFN-γ-level fluctuations over time. In contrast, this latter group of patients showed similar proportions of cells producing IFN-γ alone, IL-2 alone and IL-2 in combination with TNF in response to M. tuberculosis-specific antigens. It therefore appears that patients with and without LTBI infection are characterized by different intracellular cytokine profiles. This is the first study evaluating ICCFC in patients treated with TNF antagonists, and suggests that multi-functional analysis of CD4(+) T cells could be useful for ruling out TB infection in patients classified at screening as LTBI-negative but who show IGRA fluctuations under long-term TNF antagonist treatment.

Biological therapies in rheumatic diseases.

The development of the biological drugs has revolutionized the therapeutic approach of the chronic inflammatory rheumatic diseases, particularly in patients resistant to standard treatment. These drugs are characterized by an innovative mechanism of action, based on the targeted inhibition of specific molecular or cellular targets directly involved in the pathogenesis of the diseases: pro-inflammatory cytokines (tumor necrosis factor, interleukin-1 and 6), CTLA-4, and molecules involved in the activation, differentiation and maturation of B cells. Their use has indeed allowed for a better prognosis in several rheumatic diseases (such as rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, systemic lupus erythematosus) and to obtain a clinical remission. In the present review we give an overview of the biological drugs currently available for the treatment of the rheumatic diseases, analyzing the different mechanism of action, the therapeutic indications and efficacy data, and adverse events.

Evaluation of QuantiFERON-TB Gold In-Tube in human immunodeficiency virus infection and in patient candidates for anti-tumour necrosis factor-alpha treatment.

SETTING: Cross-sectional study at four out-patient clinics in a single referral centre in Italy. OBJECTIVE: To evaluate the performance of QuantiFERON-TB Gold In-Tube (QFT-GIT) in human immunodeficiency virus (HIV) infected adults and in patients with immune-mediated inflammatory diseases (IMIDs) who are candidates for anti-tumour necrosis factor-alpha (TNF-alpha) treatment. DESIGN: A total of 402 immunocompromised patients were enrolled, including 207 HIV-infected individuals and 195 IMID patients scheduled for anti-TNF-alpha treatment. Tuberculin skin test (TST) and QFT-GIT were performed. For active tuberculosis (TB), test results were compared with microbiological, histopathological and clinical diagnoses. RESULTS: In HIV-infected patients, the level of agreement between the tests was 68% and QFT-GIT sensitivity was 66% (95%CI 47-82). We found a large proportion of indeterminate QFT-GIT results (33.4%), which correlated with CD4 count < 200 cells/microl (P < 0.0001). The degree of agreement with TST was higher in IMID patients (81.6%). Factors associated with discordant positive TST and negative QFT-GIT results were bacille Calmette-Guérin vaccination (P = 0.0001), previous TB (P = 0.0001) and agricultural work (P = 0.0005). CONCLUSION: The performance of QFT-GIT varies between different types of immunocompromised patients. Interferon-gamma release assays should not be used to confirm or rule out a diagnosis of active TB in HIV-infected adults. As there were no cases of active TB in the IMID subgroup, it was difficult to determine which test performs better in this population.

Switching between TNFalpha antagonists in rheumatoid arthritis: personal experience and review of the literature.

OBJECTIVE: To evaluate the clinical response after switching to another TNFalpha antagonist in patients with rheumatoid arthritis (RA) and provide a review of the literature on this topic. METHODS: In this ongoing, longitudinal, observational study we have prospectively collected data of patients starting biological treatments since 2000. The present analysis is restricted to RA patients who switched to another anti-TNFalpha due to lack of efficacy (LaE), loss of efficacy (LoE), or adverse events (AEs) by the end of December 2007. Disease activity score (ESR-based DAS28) was calculated and the clinical response (none, moderate, good) was evaluated according to the European League Against Rheumatism (EULAR) criteria. Clinical remission (DAS28 <2.6) and low disease activity (DAS28

Anti-cyclic citrullinated peptide antibody determination in synovial fluid of psoriatic arthritis.

OBJECTIVE: To assess the role of anti-CCP antibodies in synovial fluid (SF) of psoriatic arthritis (PsA) patients by analysing their association with different clinical patterns of the disease. METHODS: Seventy-five patients with a knee-joint effusion were studied, including 31 PsA patients, 29 rheumatoid arthritis (RA) and 15 osteoarthritis (OA) patients. SF and paired serum samples were stored at -70 degrees C until IgG anti-CCP and total IgG determination. The pattern of PsA articular involvement was defined as mono-, oligo-, polyarticular or axial. RESULTS: Lower levels of IgG anti-CCP antibodies in SF (p < 0.01) and serum (p < 0.005) were found in PsA respect to RA patients without difference with OA. We found a higher SF/serum ratio for anti-CCP compared to the SF/serum ratio for total IgG in PsA (p < 0.0005) as well as in RA and OA. The correction of anti-CCP concentration in SF as IgG anti-CCP (unit) / total IgG revealed lower (p < 0.002) values in PsA patients with respect to RA patients. In PsA group, values of anti-CCP antibodies, SF/serum ratio of anti-CCP and anti-CCP/IgG above the cut-off were found in 5, 6 and 2 SF samples respectively. The presence or absence of anti-CCP antibodies did not discriminate a particular clinical subset. CONCLUSIONS: In conclusion, strengthening the concept of local production of anti-CCP antibodies within the joint space, our results suggest that anti-CCP antibody detection in SF should take into account corrections such as total amount of corresponding immunoglobulin or SF/serum ratio. In our study, the presence or absence of anti-CCP antibodies did not discriminate a particular clinical subset, but further longitudinal studies are required to clarify the clinical role of anti-CCP in PsA.

[Occupational therapy in rheumatoid arthritis: short term prospective study in patients treated with anti-TNF-alpha drugs]. / La terapia occupazionale nell'artrite reumatoide: studio prospettico a breve termine in pazienti in trattamento con farmaci anti-TNF-alfa.

OBJECTIVE: To assess the effect of occupational therapy (OT) in rheumatoid arthritis (RA) patients treated with anti-TNF-alpha drugs in a short-term open controlled prospective study. METHODS: 31 RA subjects [(M/F=5/26; mean age= 56 (range=28-73) years; mean disease duration= 165 (range =15-432) months], treated with anti- TNF-alpha drugs, were allocated to OT (n=15) or control (n=16) group. We evaluated at entry and 12 weeks the following outcome parameters including Health Assessment Questionnaire (HAQ), Short-Form Health Survey (SF-36), Global Health (GH), Ritchie index, number of swollen or tender joints, pain, patient and physician disease activity, Disease Activity Score (DAS28), erythrocyte sedimentation rate (ESR), C-reactive protein CRP) and the correct adherence to items regarding activity daily living (ADL). RESULTS: At baseline, OT and control group had similar demographic and clinical features. After 12 weeks, the changes from baseline of main outcome parameters were not significantly different between the two groups. After 12 weeks, in 7 out of 11 items regarding ADL, the percentage of patients showing a correct adherence was significantly increased in OT group only. Moreover at the end of the study, the OT group showed a correct adherence to 8 out of 11 ADL items in an higher percentage of patients respect to the control group. CONCLUSION: Our study sustains that OT improves self-management but not main parameters of disease activity or functional capacity. Nevertheless educational intervention should be considered as a useful tool in conjunction with pharmacological treatment.

[Usefulness of anti-cyclic citrullinate peptide antibody determination in synovial fluid analysis of patients with rheumatoid arthritis]. / Utilità della determinazione degli anticorpi antipeptidi ciclici citrullinati nell'analisi del liquido sinoviale di pazienti con artrite reumatoide.

OBJECTIVE: To assess the role of anti-cyclic citrullinated peptide (CCP) antibody detection in synovial fluid (SF) of RA patients compared to OA patients. METHODS: We evaluated in 25 RA subjects and 14 OA patients, presenting a knee-joint effusion, the main clinical and laboratory parameters including the number of painful and/or swollen joints, Ritchie index, morning stiffness, ESR, CRP and analysis of SF obtained by therapeutic arthrocentesis. IgG anti-CCP (ELISA), rheumatoid factor (RF) and total IgG (nephelometry method) were measured in SF and paired serum samples. RESULTS: We found anti-CCP antibodies and RF in 64% (16/25) and 60% (15/25) of RA sera, respectively; 72% (18/25) of RA patients were positive for anti-CCP antibodies or RF. We found a higher SF/serum ratio for anti-CCP (p<0.004) compared to that for total IgG. The calculation of anti-CCP concentration as IgG anti-CCP (units)/total IgG (g L-1) revealed higher values in SF than in serum (p<0.046) in RA patients. Among these, correlation analysis showed that anti-CCP/total IgG values in SF correlated with the relative concentration of serum anti-CCP/total IgG (rs=0.842; p<0.00001) and serum anti-CCP antibody levels (rs=0.799; p<0.0001). We did not find any correlation between SF anti-CCP levels and the main characteristics of SF as well as the clinical or laboratory parameters. CONCLUSION: Our study give evidence for a preferential production of anti-CCP antibodies at RA joint level, confirming the pathogenetic role of these autoantibodies. Moreover, SF determination of anti-CCP, corrected for the total amount of the corresponding immunoglobulin, may be helpful as diagnostic tool in selected cases.

[Soluble P-selectin levels in synovial fluid and serum from patients with psoriatic arthritis]. / Livelli di P-selettina solubile nel liquido sinoviale e nel siero di pazienti con artrite psoriasica.

OBJECTIVE: P-selectin is an adhesion molecule expressed by activated endothelial cells and platelets favouring the leukocyte adherence to microvascular endothelium. A soluble form of this molecule has been described, whose serum levels were found to be elevated and correlate with disease activity in rheumatoid arthritis (RA) patients. Aim of this study was to determine soluble P-selectin levels in synovial fluid (SF) and serum from patients with psoriatic arthritis (PsA), where it has never been investigated, to define its involvement in PsA synovial damage. METHODS: we analysed, by ELISA, soluble P-selectin serum and SF levels in 100 patients presenting a knee joint effusion: 38 of them presented PsA, 40 RA and 22 osteoarthritis (OA). We examined the main clinical and laboratory parameters of these patients. Soluble P-selectin serum levels were also detected in 15 healthy subjects. RESULTS: soluble P-selectin SF levels were significantly higher in PsA and RA patients respect to OA subjects. Soluble P-selectin SF levels were lower than those found in serum and the SF/serum ratio was higher in PsA and RA patients respect to OA. Soluble P-selectin serum levels were not significantly different among patients and controls. No correlation was found between SF and serum levels of soluble P-selectin and the main clinical parameters. CONCLUSIONS: our study of soluble P-selectin in PsA reveals a prominent local role of this molecule, with no differences respect to RA. Histological findings may be of help in understanding the role of this adhesion molecule in PsA.

Nailfold capillaroscopy changes in systemic lupus erythematosus: correlations with disease activity and autoantibody profile.

In systemic lupus erythematosus (SLE) nailfold capillaroscopy (NC) studies have described many different nonspecific patterns. We decided to evaluate NC changes in 44 SLE patients, comparing them with the main clinical, demographic and laboratory parameters, thus to define the real role for NC and its abnormalities in the management of this disease. Fifteen patients (34%) complained of Raynaud's phenomenon; nine of them (20%) showed relevant capillaroscopic changes (capillaroscopic score >1). In details: three patients (6.8%) had loss of capillaries, while 18 (41%) had a capillary length variability, 16 (36.5%) showing shorter and two (4.5%) longer capillaries; tortuous, meandering, bizarre, ramified and/or bushy capillaries were found in 26 (59%), seven (16%), two (4.5%), three (7%) cases, respectively. An irregular distribution of the capillary array was present in six cases (14%) while microhaemorrhages were found in four cases (9%). 4 patients (9%) showed enlarged capillaries and changes of blood flow. A capillaroscopic score >1 was more frequently associated with higher ECLAM (P < 0.005) and SLEDAI (P < 0.01) activity scores, with the presence of anti-cardiolipin (P < 0.04) and anti-Sm (P < 0.04) antibodies, and also with the presence (P < 0.04) and higher titer (P < 0.001) of anti-dsDNA antibodies. No statistically significant correlation was found among the different capillaroscopy findings, age, disease duration, or treatment, nor with any clinical manifestation of the disease, such as cutaneous, renal or neurological. Our findings confirm the importance of the microvascular involvement in SLE. The NC abnormalities seem to be related to the disease activity and to the presence of many different antibodies, highly involved in the expression of SLE. NC proved to be an easy-to-perform noninvasive technique, able to achieve useful data to better evaluate such a pleomorphic disease as SLE.

Natural killer cells and gamma/delta T cells in synovial fluid and in peripheral blood of patients with psoriatic arthritis.

OBJECTIVE: NK surface markers and gamma/delta TCR antigen are involved in non-MHC-restricted cytotoxicity, which represents a major effector mechanism of the cell-mediated immune response. We evaluated in PsA patients SF and PB lymphocytes expressing these cellular subsets in order to obtain information on the possible role played by them in the disease. METHODS: We studied 29 PsA and 27 RA patients, as well as 27 healthy controls. In 17 PsA and 16 RA patients with knee joint effusion, analysis of SF was performed. SF and PB lymphocyte analysis was performed by direct dual immunofluorescence flow cytomettry using anti-CD3, anti-CD4, anti-CD8, anti-CD19, anti-TCR-gamma/delta-1 and anti-CD16 and anti-CD56 monoclonal antibodies. RESULTS: PsA and RA patients had, with respect to controls, lower values (both as percentages and in absolute numbers) of PB T cells expressing gamma/delta TCR. SF Iymphocytes of PsA and RA patients were characterised, as compared to PB lymphocytes, by lower numbers (both in absolute numbers and in relative terms) of NK and NK-T cells. Considering the absolute numbers of the various lymphocyte subsets, a strong correlation was found in PsA SF between gamma/delta T cells and NK (p < 0.0007) or NK-T cells (p < 0.0003), as well as between NK and NK-T cells (p < 0.0019). There was instead no statistically significant correlation among the different SF or PB lymphocytes and the most relevant clinical or serological parameters. CONCLUSION: This study, analyzing the impairment of different subsets involved in non-MHC-restricted cytotoxicity, suggests that this component of the cell-mediated immune response seems to play a pivotal role in the development of PsA.

Interleukin-13 in systemic sclerosis: relationship to nailfold capillaroscopy abnormalities.

The aim of this study was to investigate whether interleukin-13 (IL-13) serum levels correlate to different nailfold capillaroscopy (NC) findings in patients with systemic sclerosis (SSc). IL-13 serum levels were measured using an ELISA method. The following NC abnormalities were considered: the presence of giant loops, haemorrhages, loss of capillaries, disorganisation of the vascular array, ramified/bushy capillaries and sludging of blood. A semiquantitative rating scale was adopted to score these changes, as well as a rating system for avascular areas and three morphological NC patterns ('early', 'active' and 'late'). Mean capillary density was determined by counting the total number of capillaries in a 1 mm length, and the arterial and venous diameters of the capillary as well as the total loop diameter were measured. In SSc patients IL-13 serum levels were significantly higher than in controls ( P < 00.1), whereas in patients with ( n=8) and without ( n=24) abnormal IL-13 serum levels (>17 pg/ml) the comparison of the NC features showed significantly relevant differences concerning a more frequent 'active' NC pattern ( P < 0.02), the presence of haemorrhages ( P < 0.0037) and sludging of blood ( P < 0.038), as well as larger total loop ( P < 0.036) and arterial ( P < 0.03) diameters, in those patients with elevated IL-13 serum levels. The study confirmed that IL-13 serum levels are higher in the sera of patients with SSc, and shows for the first time the significant correlations between this serological finding and some of the main relevant SSc capillaroscopic features, leading us to believe that this cytokine not only seems to sustain the immunological and fibrotic process of SSc, but might have a role in determining the more severe microvascular lesions in this disease.

Relationship of interleukin-12 and interleukin-13 imbalance with class-specific rheumatoid factors and anticardiolipin antibodies in systemic lupus erythematosus.

The aim of the study was to evaluate whether the imbalance between IL-12 and IL-13 serum levels, reflecting Th1/Th2 activity, is related to class-specific circulating rheumatoid factors (RF) and anticardiolipin (aCL) antibodies in SLE. Using ELISA we measured serum IL-12, IL-13, RF and aCL antibodies in 73 SLE patients and 20 healthy controls. The determination of IL-12/IL-13 ratio showed that IL-12 levels were above (group A), equal to (group B) or below (group C) IL-13 levels in 71.2%, 15.1% and 13.7% of SLE patients, respectively. IgM-RF levels were significantly higher in group C than in groups A ( P < 0.002) and B ( P < 0.019). Group C had also higher IgM-aCL levels than group A ( P < 0.04). No relationship between IL-12/IL-13 ratio and clinical or other laboratory parameters was found. It was concluded that the increased levels of both IgM-RF and IgM-aCL in patients with prevalent Th2 activity suggest that the predominance of Th2 over Th1 could drive autoantibody production in SLE patients.

Anti-tumour necrosis factor (TNF) alpha treatment of rheumatoid arthritis (infliximab) selectively down regulates the production of interleukin (IL) 18 but not of IL12 and IL13.

OBJECTIVE: To measure interleukin (IL)18 serum concentrations in patients with rheumatoid arthritis (RA) undergoing infliximab treatment (tumour necrosis factor (TNF) alpha blockade) and to evaluate the concomitant modification of IL12 and IL13 serum concentrations, two cytokines belonging to the Th1 and Th2 profile respectively and biologically related to IL18. METHODS: Ten patients with RA not responding to disease modifying antirheumatic drugs (DMARDs) received intravenous infliximab at a dose of 3 mg/kg at baseline and after two and six weeks. Serum samples were collected from all patients before each infusion and assayed for IL18, IL12, and IL13 by enzyme linked immunosorbent assay (ELISA); IL18 was also measured eight weeks after the last infusion. RESULTS: Serum concentrations of IL18 in all patients were already markedly reduced from baseline after two weeks (p<0.005). Serum IL18 was also decreased in a stable manner after six (p<0.01) and 14 weeks (p<0.01) compared with baseline concentrations. No significant modifications were found in serum concentrations of IL12 and IL13 at any time point. CONCLUSION: There was a rapid and persistent decrease in serum concentrations of IL18 in all the patients studied. This result provides evidence of an in vivo regulation of IL18 by TNFalpha and suggests that anti-TNFalpha therapy is likely to interrupt the synergistic effect between these two cytokines.