Arno W. R. van Kuijk

The relationship between synovial lymphocyte aggregates and the clinical response to infliximab in rheumatoid arthritis: A prospective study

OBJECTIVE Some patients with rheumatoid arthritis (RA) exhibit lymphocyte aggregates in the synovium. This study was undertaken to address whether the presence of lymphocyte aggregates before treatment could serve as a biomarker for the clinical response to tumor necrosis factor (TNF) blockade, and to confirm whether the aggregation of synovial lymphocytes is reversible after anti-TNF treatment. METHODS Synovial tissue biopsy samples were obtained from 97 patients with active RA before the initiation of infliximab treatment. Lymphocyte aggregates in the synovial tissue were counted and also graded for size. Logistic regression analysis was performed to identify whether the presence of lymphocyte aggregates could be a predictor of the clinical response at week 16. Furthermore, the effects of TNF blockade on lymphocyte aggregates were compared between patients with RA and patients with psoriatic arthritis (PsA). RESULTS Fifty-seven percent of RA synovial tissue samples contained lymphocyte aggregates, and 32% of the patients had large aggregates. Aggregates were found in 67% of clinical responders compared with 38% of nonresponders. The presence of aggregates at baseline was a highly significant predictor of the clinical response to anti-TNF treatment (R(2) = 0.10, P = 0.008). Positivity for lymphocyte aggregates increased the power to predict the clinical response (R(2) = 0.29), when analyzed in a prediction model that included baseline disease activity evaluated by the Disease Activity Score in 28 joints, anti-cyclic citrullinated peptide antibody positivity, and synovial TNFalpha expression. There was a reduction in lymphocyte aggregates after anti-TNF antibody therapy in both RA and PsA. CONCLUSION RA patients with synovial lymphocyte aggregates have, on average, a better response to infliximab treatment than those with only diffuse leukocyte infiltration. Moreover, the aggregation of synovial lymphocytes is reversible after anti-TNF antibody treatment.

Patient Global Assessment in Psoriatic Arthritis: A Multicenter GRAPPA and OMERACT Study

Objective. During OMERACT 8, delegates selected patient global assessment (PGA) of disease as a domain to be evaluated in randomized controlled trials in psoriatic arthritis (PsA). This study assessed the reliability of the PGA, measured by means of 0–100 mm visual analog scale (VAS), and the additional utility of separate VAS scales for joints (PJA) and skin (PSA). Methods. In total, 319 consecutive patients with PsA (186 men, 133 women, mean age 51 ± 13 yrs) were enrolled. PGA, PJA, and PSA were administered at enrolment (W0) and after 1 week (W1). Detailed clinical data, including ACR joint count, Psoriasis Area and Severity Index (PASI), and Hospital Anxiety and Depression Scale, were recorded. Results. Comparison of W0 and W1 scores showed no significant variations (intraclass correlation coefficients for PGA 0.87, PJA 0.86, PSA 0.78), demonstrating the reliability of the instrument. PGA scores were not influenced by patient anxiety or depression, but were dependent on PJA and PSA (p = 0.00001). PJA was dependent on the number of swollen and tender joints (p < 0.00001). PSA scores were influenced by the extent of skin psoriasis and by hand skin involvement (p = 0.00001). Joint and skin disease were found not to correlate in terms of disease activity as evidenced by the swollen joint count compared to PASI (r = 0.11) and by the PJA compared to PSA (r = 0.38). Conclusion. PGA assessed by means of VAS is a reliable tool related to joint and skin disease activity. Because joint and skin disease often diverge it is suggested that in some circumstances both PJA and PSA are also assessed.

CCR5 blockade in rheumatoid arthritis: a randomised, double-blind, placebo-controlled clinical trial

Objective C-C chemokine receptor type 5 (CCR5), a chemokine receptor expressed on T cells and macrophages, and its ligands are found in inflamed synovial tissue (ST) of patients with rheumatoid arthritis (RA). The rationale for testing CCR5 blockade in patients with RA was supported by the effects of a CCR5 antagonist in collagen-induced arthritis in rhesus monkeys. The effects of CCR5 blockade in patients with active RA were explored. Methods In this phase Ib randomised, placebo-controlled trial, treatment with an oral CCR5 inhibitor (SCH351125) in patients with active RA was evaluated. Clinical efficacy was assessed using European League Against Rheumatism and American College of Rheumatology response criteria. ST biopsies were taken before and after 28 days of treatment, and analysed for CCR5+ cells. In a subset of patients, MRIs of an inflamed joint were obtained before and after treatment. Results In all, 32 patients were included; 20 received SCH351125 and 12 placebo. Three patients who received SCH351125 did not complete the study due to adverse events; none of these were serious. No improvement was observed in the active treatment group compared to placebo. Results were consistent for clinical evaluation, ST analysis and MRI. Conclusion This proof of concept study does not support the use of CCR5 blockade as a therapeutic strategy in patients with active RA.

Anti-adalimumab antibodies and adalimumab concentrations in psoriatic arthritis; an association with disease activity at 28 and 52 weeks of follow-up

Objectives To investigate the relationship between antidrug antibodies (ADA), adalimumab concentrations and clinical response in patients with psoriatic arthritis (PsA) during 52 weeks of follow-up. Methods This prospective cohort study included 103 consecutive patients with PsA. Disease Activity Score of 28 joints (DAS28), Erythrocyte Sedimentation Rate, C reactive protein and Psoriasis Area and Severity Index were assessed. Adalimumab concentrations and ADA were measured in serum trough samples, using an ELISA and a radio immunoassay, respectively. Results Adalimumab concentrations were significantly lower at 28 and 52 weeks in patients with detectable ADA compared with patients without detectable ADA (at week 28: 1.3 mg/L (IQR 0.0–3.2) versus 8.7 mg/L (IQR 5.7–11.5), p<0.001; at week 52: 0.9 mg/L (IQR 0.0–2.9) vs 9.4 mg/L (IQR 5.7–12.1), p=0.0001). DAS28 at 28 weeks (2.16 vs 2.95, p=0.023) and 52 weeks (2.19 vs 2.95, p=0.024) showed a significant difference; patients with detectable ADA had a poorer clinical outcome than patients without. Conclusions Patients with detectable ADA had lower adalimumab concentrations and a significantly poorer clinical outcome compared with patients in whom ADA were not detected.

Brief report: a phase IIa, randomized, double-blind, placebo-controlled trial of apilimod mesylate, an interleukin-12/interleukin-23 inhibitor, in patients with rheumatoid arthritis.

OBJECTIVE To investigate the safety, tolerability, pharmacokinetics, and efficacy of apilimod mesylate, an oral interleukin-12 (IL-12)/IL-23 inhibitor, in patients with rheumatoid arthritis (RA). METHODS We performed a phase IIa, randomized, double-blind, placebo-controlled proof-of-concept study of apilimod, in combination with methotrexate, in 29 patients with active RA (3:1 ratio of apilimod-treated to placebo-treated patients) in 3 stages. Patients received apilimod 100 mg/day or placebo for 4 weeks (stage 1) or 8 weeks (stage 2). In stage 3, patients received apilimod 100 mg twice a day or placebo for 8 weeks, with an optional extension of 4 weeks. Clinical response (Disease Activity Score in 28 joints [DAS28] and American College of Rheumatology [ACR] criteria) was assessed throughout; synovial tissue samples collected at baseline and on day 29 (stages 1 and 2) or day 57 (stage 3) were stained for cellular markers and cytokines for immunohistochemistry analysis. RESULTS While only mild adverse events were observed in stages 1 and 2, in stage 3, all patients experienced headache and/or nausea. Among apilimod-treated patients (100 mg/day), there was a small, but significant, reduction in the DAS28 on day 29 and day 57 compared with baseline. ACR20 response was reached in only 6% of patients on day 29 and 25% of patients on day 57, similar to the percentage of responders in the placebo group. Increasing the dosage (100 mg twice a day) did not improve clinical efficacy. Consistent with clinical results, apilimod did not have an effect on expression of synovial biomarkers. Of importance, we also did not observe an effect of apilimod on synovial IL-12 and IL-23 expression. CONCLUSION Our results do not support the notion that IL-12/IL-23 inhibition by apilimod is able to induce robust clinical improvement in RA.

Synovitis in Psoriatic Arthritis: Immunohistochemistry, Comparisons With Rheumatoid Arthritis, and Effects of Therapy

Psoriatic arthritis (PsA) is a chronic inflammatory arthropathy associated with psoriasis that affects the peripheral joints, spine, and entheses. Most patients with PsA present with peripheral synovitis of the oligoarticular or polyarticular subtype. As one of the targets of this disease, studies on the synovium may provide insight into the mechanisms involved in this condition. Key findings from the available studies comparing synovial tissue of PsA and rheumatoid arthritis patients are discussed in this review. Also, changes in the synovial infiltrate, expression of proinflammatory cytokines and adhesion molecules, and vascularity in synovial tissue after treatment with various medications are addressed. Finally, a model for proof-of-principle study design using serial synovial biopsies is described, which could be used to predict clinical (in)efficacy in early clinical trial design in PsA.

TWEAK and its receptor Fn14 in the synovium of patients with rheumatoid arthritis compared to psoriatic arthritis and its response to TNF blockade

Objective: To investigate the expression of tumour necrosis factor (TNF)-like weak inducer of apoptosis (TWEAK) and its receptor fibroblast growth factor inducible 14 (Fn14) in the inflamed synovium of patients with arthritis, as TWEAK blockade has been observed to have a beneficial effect in an animal model of rheumatoid arthritis (RA). Methods: Synovial tissue (ST) biopsies were obtained from 6 early, methotrexate-naive patients with RA as well as 13 patients with RA and 16 patients with psoriatic arthritis (PsA) who were matched for treatment and disease duration. Serial ST samples were obtained from a separate cohort of 13 patients with RA before and after infliximab treatment. TWEAK and Fn14 expression was evaluated by immunohistochemistry and digital image analysis. Results: TWEAK and Fn14 were clearly expressed in ST of patients with RA and PsA. TWEAK expression was significantly higher in RA (sub)lining samples compared to PsA (p = 0.005 and p = 0.014, respectively), but Fn14 expression was comparable. Double immunofluorescence showed TWEAK and Fn14 expression on fibroblast-like synoviocytes and macrophages, but not T cells. Of interest, persistent TWEAK and Fn14 expression was found after anti-TNF therapy. Conclusions: TWEAK and Fn14 are abundantly expressed in the inflamed synovium of patients with RA and PsA. This raises the possibility that blocking TWEAK/Fn14 signalling could be of therapeutic benefit in inflammatory arthritis.

Serum 14-3-3η is a Novel Marker that Complements Current Serological Measurements to Enhance Detection of Patients with Rheumatoid Arthritis

Objective. Serum 14-3-3η is a novel joint-derived proinflammatory mediator implicated in the pathogenesis of rheumatoid arthritis (RA). In our study, we assessed the diagnostic utility of 14-3-3η and its association with standard clinical and serological measures. Methods. A quantitative ELISA was used to assess 14-3-3η levels. Early (n = 99) and established patients with RA (n = 135) were compared to all controls (n = 385), including healthy subjects (n = 189). The sensitivity, specificity, positive and negative predictive values of 14-3-3η, and the likelihood ratios (LR) for RA were determined through receiver-operator curve analysis. The incremental value of adding 14-3-3η to anticitrullinated protein antibody (ACPA) and rheumatoid factor (RF) in diagnosing early and established RA was assessed. Results. Serum 14-3-3η differentiated established patients with RA from healthy individuals and all controls (p < 0.0001). A serum 14-3-3η cutoff of ≥ 0.19 ng/ml delivered a sensitivity and specificity of 77% and 93%, respectively, with corresponding LR positivity of 10.4. At this cutoff in early RA, 64% of patients with early RA were positive for 14-3-3η, with a corresponding specificity of 93% (LR+ of 8.6), while 59% and 57% were positive for ACPA or RF, respectively. When ACPA, RF, and 14-3-3η positivity were used in combination, 77 of the 99 patients (78%) with early RA were positive for any 1 of the 3 markers. Serum 14-3-3η did not correlate with C-reactive protein, erythrocyte sedimentation rate, or Disease Activity Score, but patients who were 14-3-3η-positive had significantly worse disease. Conclusion. Serum 14-3-3η is a novel RA mechanistic marker that is highly specific, associated with worse disease, and complements current markers, enabling a more accurate diagnosis of RA.

Soluble Biomarkers of Cartilage and Bone Metabolism in Early Proof of Concept Trials in Psoriatic Arthritis: Effects of Adalimumab Versus Placebo

Background There is growing interest in soluble biomarkers that could be used on the group level for screening purposes in small proof of principle studies during early drug development. We investigated early changes in serum levels of several candidate biomarkers involved in cartilage and bone metabolism following the initiation of adalimumab as a prototypic active treatment in psoriatic arthritis (PsA) compared to placebo. Materials and Methods Twenty-four PsA patients were randomized to receive either adalimumab 40 mg s.c. every other week or placebo for 4 weeks, followed by an open label extension phase. Serum samples were obtained at baseline and after 4 and 12 weeks of treatment and analyzed for levels of CPII and PINP (synthesis of type II and type I procollagen), melanoma inhibitory activity (MIA) (chondrocyte anabolism), matrix metalloproteinase (MMP)-3, C2C and cartilage oligomeric matrix protein (COMP) (type II collagen degradation), osteocalcin (OC) (bone formation), NTX-I and ICTP (both type I collagen degradation). Results After 4 weeks, there was a significant decrease in serum MMP-3 levels in adalimumab-treated patients (P<0.005), while no change was observed in the placebo group. A significant increase in serum MIA was noted after adalimumab therapy (P<0.005) but not after placebo treatment. After 12 weeks, there was a marked reduction in serum MMP-3 in both groups (P<0.005), whereas other markers did not show significant changes compared to baseline. Conclusion MMP-3 and MIA could serve as soluble biomarkers associated with inflammation as well as joint remodelling and destruction and may, together with clinical evaluation and in combination with other biomarkers, assist in distinguishing between effective and ineffective therapy in small, proof-of-principle studies of short duration in PsA. Trial Registration Current Controlled Trials ISRCTN23328456

Discovery and confirmation of a protein biomarker panel with potential to predict response to biological therapy in psoriatic arthritis

Objective Biological therapies, which include antitumour necrosis factor-α and T-cell inhibitors, are potentially effective treatments for psoriatic arthritis (PsA) but are costly and may induce a number of side effects. Response to treatment in PsA is variable and difficult to predict. Here, we sought to identify a panel of protein biomarkers that could be used to predict which patients diagnosed with PsA will respond to biologic treatment. Methods An integrated discovery to targeted proteomics approach was used to investigate the protein profiles of good and non-responders to biological treatments in patients with PsA. Reverse-phase liquid chromatography coupled to tandem mass spectrometry was used to generate protein profiles of synovial tissue obtained at baseline from 10 patients with PsA. Targeted proteomics using multiple reaction monitoring (MRM) was used to confirm and prevalidate a potential protein biomarker panel in 18 and 7 PsA patient samples, respectively. Results A panel of 107 proteins was selected, and targeted mass spectrometry MRM assays were successfully developed for 57 of the proteins. The 57 proteins include S100-A8, S100-A10, Ig kappa chain C fibrinogen-α and γ, haptoglobin, annexin A1 and A2, collagen alpha-2, vitronectin, and alpha-1 acid glycoprotein. The proteins were measured simultaneously and confirmed to be predictive of response to treatment with an area under the curve of 0.76. In a blinded study using a separate cohort of patients, the panel was able to predict response to treatment. Conclusions The approach reported here and the initial data provide evidence that a multiplexed protein assay of a panel of biomarkers that predict response to treatment could be developed. Trial registration number ISRCTN23328456.