Evaluation of 12 GWAS-drawn SNPs as biomarkers of rheumatoid arthritis response to TNF inhibitors. A potential SNP association with response to etanercept.

Research in rheumatoid arthritis (RA) is increasingly focused on the discovery of biomarkers that could enable personalized treatments. The genetic biomarkers associated with the response to TNF inhibitors (TNFi) are among the most studied. They include 12 SNPs exhibiting promising results in the three largest genome-wide association studies (GWAS). However, they still require further validation. With this aim, we assessed their association with response to TNFi in a replication study, and a meta-analysis summarizing all non-redundant data. The replication involved 755 patients with RA that were treated for the first time with a biologic drug, which was either infliximab (n = 397), etanercept (n = 155) or adalimumab (n = 203). Their DNA samples were successfully genotyped with a single-base extension multiplex method. Lamentably, none of the 12 SNPs was associated with response to the TNFi in the replication study (p > 0.05). However, a drug-stratified exploratory analysis revealed a significant association of the NUBPL rs2378945 SNP with a poor response to etanercept (B = -0.50, 95% CI = -0.82, -0.17, p = 0.003). In addition, the meta-analysis reinforced the previous association of three SNPs: rs2378945, rs12142623, and rs4651370. In contrast, five of the remaining SNPs were less associated than before, and the other four SNPs were no longer associated with the response to treatment. In summary, our results highlight the complexity of the pharmacogenetics of TNFi in RA showing that it could involve a drug-specific component and clarifying the status of the 12 GWAS-drawn SNPs.

To what extend is nail ultrasound discriminative between psoriasis, psoriatic arthritis and healthy subjects?

To assess the discriminative utility of nail features detected by B-mode (BM) and color Doppler (CD) ultrasound (US) between patients with psoriasis (PsO) and psoriatic arthritis (PsA) and healthy controls. Sixty patients with PsA, 21 patients with PsO, and 20 healthy controls were prospectively included. All patients underwent a dermatologic assessment and PsA patients also a rheumatologic assessment. All patients and controls underwent a US assessment of the finger nails that included a BM score for nail plate integrity and four different CD scores based on the amount and location of CD signals in the nail bed/matrix. In addition, we measured the thickness of the nail bed (TNB) and nail plate (TNP). The BM score and the CD score based on the amount of signals in the nail bed in contact with the ventral plate discriminated between the control group (median, range 0.0, 0-4 and 2.0, 0-9, respectively) and the PsO/PsA group (median, range: 7.0, 0-31 and 5.14, 0-13, respectively) (p < 0.05) with or without clinical nail involvement. The CD scores based on the percentage of the nail bed/matrix occupied by Doppler signals did not discriminate between controls and PsO/PsA patients. TNB and TNP were significantly higher in psoriatic nails with or without clinical involvement than in control nails. In PsO/PsA patients, the BM score, TNB and TNP were significantly higher in clinically involved nail than in clinically non-involved nails. Our results showed discriminative utility of BM US and some CD US features for PsO/PsA nails.

Agreement between semiquantitative and quantitative Doppler scoring systems for the assessment of synovial pathological vascularisation in rheumatoid arthritis.

OBJECTIVES: To compare colour Doppler (CD) versus power Doppler (PD) semiquantitative and quantitative scoring of synovial vascularisation and to evaluate the relationship between semiquantitative and quantitative scores in patients with rheumatoid arthritis (RA). METHODS: One hundred RA patients underwent B-mode, PD, and CD assessments of 12 joints at two European centres. Each joint with synovial hypertrophy (SH) detected on B-mode was semiquantitatively scored (0-3) for PD (SPD score) and CD (SCD score) synovial signal. PD and CD synovial signal were also quantitatively scored (0-100%) (QPD and QCD scores, respectively) using a software integrated in the US equipment for counting the colour fraction. RESULTS: We found SH in 184 joints. SPD and SCD agreed in 92.3% (95%CI: 88.4; 96.2%) of paired scores, with Kendall rank correlation coefficient tau-b=0.95. QPD and QCD scores were highly correlated (Pearson's coefficient=0.70) but Blamd-Altman plot showed insufficient agreement, being the QCD scores systematically slightly higher than the QPD scores. The comparison of mean values of QPD and QCD between scores of SPD and SCD, respectively, showed significant differences between grade 0 and grade 1 (p<0.001), and grade 2 and grade 3 (p=0.042 and p=0.007, respectively) but not between grade 1 and 2 (p=0.154 and p=0.150, respectively). CONCLUSIONS: The SPD and SCD scores were concordant and the QPD and QCD scores highly correlated but were not concordant. There was an overlap between SPD and SCD mild and moderate scores regarding QPD and QCD scores.

Identifying markers of sustained remission in rheumatoid arthritis patients on long-term tapered biological disease-modifying antirheumatic drugs.

To identify features associated with long-term persistent remission in rheumatoid arthritis (RA) patients on tapered biological disease-modifying antirheumatic drugs (bDMARD) (tap-bDMARD) therapy. We carried out a 40-month (m) extension follow-up study of 77 RA patients from a previous 12 m tap-bDMARD study. Disease activity was assessed at baseline and every 3 months. Doppler US investigation of 42 joints for the presence and grade (0-3) of B-mode synovial hypertrophy (SH) and synovial power Doppler signal (i.e., Doppler synovitis) was performed before starting the tap-bDMARD strategy by a rheumatologist blinded to clinical and laboratory data. At the 40 m mark, 44 (57.1%) patients failed the tap-bDMARD strategy, while 33 (42.9%) succeeded. Patients who presented a failed tap-bDMARD had significantly longer disease duration, a longer time from symptom onset to synthetic (s) DMARD start, longer duration of sDMARD treatment, a greater number of sDMARDs, and a higher baseline DAS28 and SDAI than patients with successful tap-bDMARD at 40 months. In logistic regression analysis, the presence of baseline Doppler synovitis, a DAS28 ≥ 2.2, and the presence of rheumatoid factor were identified as predictors of tap-bDMARD failure at 40 m. In those patients who succeed tap-bDMARD at 12 m, a smoking habit was significantly more frequently found in tap-bDMARD failures at 40 m. Our results showed that DAS28 and the presence of Doppler synovitis, RF and a smoking habit predicted long-term tap-bDMARD failure.

Validation study of genetic biomarkers of response to TNF inhibitors in rheumatoid arthritis.

Genetic biomarkers are sought to personalize treatment of patients with rheumatoid arthritis (RA), given their variable response to TNF inhibitors (TNFi). However, no genetic biomaker is yet sufficiently validated. Here, we report a validation study of 18 previously reported genetic biomarkers, including 11 from GWAS of response to TNFi. The validation was attempted in 581 patients with RA that had not been treated with biologic antirheumatic drugs previously. Their response to TNFi was evaluated at 3, 6 and 12 months in two ways: change in the DAS28 measure of disease activity, and according to the EULAR criteria for response to antirheumatic drugs. Association of these parameters with the genotypes, obtained by PCR amplification followed by single-base extension, was tested with regression analysis. These analyses were adjusted for baseline DAS28, sex, and the specific TNFi. However, none of the proposed biomarkers was validated, as none showed association with response to TNFi in our study, even at the time of assessment and with the outcome that showed the most significant result in previous studies. These negative results are notable because this was the first independent validation study for 12 of the biomarkers, and because they indicate that prudence is needed in the interpretation of the proposed biomarkers of response to TNFi even when they are supported by very low p values. The results also emphasize the requirement of independent replication for validation, and the need to search protocols that could increase reproducibility of the biomarkers of response to TNFi.

Facts and controversies in mixed connective tissue disease. / Hechos y controversias en la enfermedad mixta del tejido conectivo.

Mixed connective tissue disease (MCTD) is a systemic autoimmune rheumatic disease (SARD) characterised by the combination of clinical manifestations of systemic lupus erythematosus (SLE), cutaneous systemic sclerosis (SSc) and polymyositis-dermatomyositis, in the presence of elevated titers of anti-U1-RNP antibodies. Main symptoms of the disease are polyarthritis, hand oedema, Raynaud's phenomenon, sclerodactyly, myositis and oesophageal hypomobility. Although widely discussed, most authors today accept MCTD as an independent entity. Others, however, suggest that these patients may belong to subgroups or early stages of certain definite connective diseases, such as SLE or SSc, or are, in fact, SARD overlap syndromes.

An exploratory study to determine whether infliximab modifies levels of rheumatoid factor and antibodies to cyclic citrullinated peptides in rheumatoid arthritis patients.

OBJECTIVES: The aim of this study was to investigate the relationship between serum infliximab (IFX) levels and changes of RF and ACPA levels in patients with rheumatoid arthritis (RA). METHODS: Enzyme-linked immunosorbent assays (ELISA) [Promonitor® IFX R1 (version 2) (Progenika Biopharma, Spain)] were used to measure drug levels and antidrug-antibodies (ADAb) in IFX RA-treated patients (n=19). Disease activity was assessed using DAS28. IgM rheumatoid factor (RF) and IgM, IgA and IgG anti-cyclic citrullinated peptide (ACPA) were determined through ELISA. RESULTS: A significant decrease in RF (p=0.01), ACPA IgG (p=0.007), IgM (p=0.01) and IgA (p=0.03) was observed in patients presenting adequate levels of serum IFX. No significant changes to RF or ACPA were observed in patients with undetectable IFX. CONCLUSIONS: Data from this study support the hypothesis that the anti-TNF antagonist IFX downregulates autoantibody levels in RA patients when IFX levels are detectable. Larger-scale studies need to be performed to establish RF and ACPA presence as therapeutic response predictive factors.

Impact of the Polymorphism rs9264942 near the HLA-C Gene on HIV-1 DNA Reservoirs in Asymptomatic Chronically Infected Patients Initiating Antiviral Therapy.

Several genome-wide association studies have identified a polymorphism located 35 kb upstream of the coding region of HLA-C gene (rs9264942; termed -35 C/T) as a host factor significantly associated with the control of HIV-1 viremia in untreated patients. The potential association of this host genetic polymorphism with the viral reservoirs has never been investigated, nor the association with the viral control in response to the treatment. In this study, we assess the influence of the polymorphism -35 C/T on the outcome of virus burden in 183 antiretroviral-naïve HIV-1-infected individuals who initiated antiviral treatment (study STIR-2102), analyzing HIV-1 RNA viremia and HIV-1 DNA reservoirs. The rs9264942 genotyping was investigated retrospectively, and plasma levels of HIV-1 RNA and peripheral blood mononuclear cell- (PBMC-) associated HIV-1 DNA were compared between carriers and noncarriers of the protective allele -35 C before antiretroviral therapy (ART), one month after ART and at the end of the study (36 months). HIV-1 RNA and HIV-1 DNA levels were both variables significantly different between carriers and noncarriers of the allele -35 C before ART. HIV-1 DNA levels remained also significantly different one month posttherapy. However, this protective effect of the -35 C allele was not maintained after long-term ART.

The feet in systemic lupus erythematosus; are we underestimating their involvement and functional impact?

OBJECTIVES: To evaluate biomechanical and ultrasound (US) abnormalities in SLE patients as compared with controls and to assess the relationship between these abnormalities and SLE activity. METHODS: Fifty-four consecutive female patients with SLE with and without foot pain and 60 female controls (30 with foot pain and 30 without foot pain) were recruited. SLE activity was assessed by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). SLE patients and controls blindly underwent a comprehensive podiatric, biomechanical and US evaluation of the feet. US assessment included detection of B-mode synovitis, tenosynovitis, enthesopathy, bone changes and synovial, tenosynovial and entheseal power Doppler (PD) signal. RESULTS: Thirty-one (57.4%) SLE patients had bilateral foot pain and 5 (9.3%) had unilateral foot pain. Metatarsalgia was the most common location for pain but without significant difference between groups (p=0.284). Toe joint deformities were significantly more common in SLE feet as compared with control feet (p<0.0005). SLE feet showed significantly more biomechanical abnormalities than control feet (p<0.05). B-mode synovitis in the tibiotalar joint was strongly associated with having SLE (p<0.0005) and the presence of synovial PD signal in the MTP joints was found only in painful feet of SLE patients. SLEDAI was significantly higher in patients with foot pain than in those with painless feet (p=0.008). However, SLEDAI did not discriminate between patients with and without biomechanical or US abnormalities. CONCLUSIONS: SLE patients showed more biomechanical and US abnormalities in the feet than controls, which were not captured by standardised assessment of the disease activity.

To what extent is foot pain related to biomechanical changes and ultrasound-detected abnormalities in rheumatoid arthritis?

OBJECTIVES: To investigate the presence of biomechanical abnormalities and ultrasound (US)-detected inflammation and damage in low disease or remission status rheumatoid arthritis (RA) patients with foot complaints. METHODS: We recruited 136 subjects with foot complaints. Sixty-two were biologic disease-modifying antirheumatic drug-treated RA patients presenting Disease Activity Score-determined remission or low disease activity while the remaining 74 were gender matched controls without rheumatic or musculoskeletal disorders. Both groups underwent a comprehensive podiatric, biomechanical and B-mode and Doppler US assessment of the feet. RESULTS: Most RA patients and controls were female (77.4% and 83.8%, respectively). There was no statistical difference in the proportion of obese subjects in either group (p=0.792). Inappropriate shoes were used by 50.0% of RA patients and 33.8% of controls (p=0.080). Talalgia, particularly heel pain, was more frequent in the control group, with associated talalgia and metatarsalgia being more prevalent in the RA group (p<0.05). The RA patient group was also more likely to present greater foot deformity, more limited joint movement and biomechanical abnormalities than the controls (p<0.05). US inflammatory and structural changes were significantly more frequent in RA patients than in controls (p<0.05). US structural involvement was significantly associated with limited joint mobility and pathologic biomechanical tests only in RA patients (p<0.05). CONCLUSIONS: RA foot complaints seemed to be linked to US-detected RA involvement and biomechanical abnormalities. Podiatric and US assessments can be useful to help the clinician to optimise the management of RA patients in remission/low disease activity with foot complaints.

Ultrasound-detected joint inflammation and B cell count: related variables for rituximab-treated RA patients?

This cross-sectional observational study aimed to explore the relationship between B cell count and ultrasound (US)-detected synovitis, in patients with rheumatoid arthritis treated with rituximab. Thirty-seven consecutive RA patients treated with RTX were recruited for the study. The patients underwent clinical [i.e., Disease Activity Score 28 joints (DAS28)], laboratory, and US assessment of 12 joints. Each joint was semiquantitatively (0-3) scored on B-mode and power Doppler mode. The scores were summed, and a global index was created for BM (BMS) and PD scores (PDI) synovitis. BM subclinical synovitis was evident in all patients, with PD synovial signal detected in 16 patients (43.2 %). No correlation was found between DAS28 and US scores. B cells were detected in 27 (72.9 %) patients, but there was no association in the mean B cell count and disease activity as measured by DAS28 (DAS28 < 2.6 = 34.53, DAS28 > 2.6 = 49.45, p = 0.52) and PDI score (PDI < 1 = 49.48, PDI > 1 = 35.44, p = 0.54). There was no correlation between the B cell count and DAS28, BMS, and PDI (r = 0.020, p = 0.907; r = -0.151, p = 0.371; r = -0.099, p = 0.558, respectively). In RTX-treated RA patients, no relationship could be established between US-detected synovitis and peripheral blood B cell count.

Structural damage in rheumatoid arthritis: comparison between tendon damage evaluated by ultrasound and radiographic damage.

OBJECTIVE: To compare structural damage assessed by conventional radiography and tendon damage assessed by musculoskeletal US (MSUS) at wrist and ankle in RA patients. METHODS: We evaluated 72 consecutive patients [56 (77.8%) females] with RA. The MSUS evaluation consisted in a B-mode examination of bilateral extensor carpi ulnaris and tibialis posterior tendons. Tendon damage was defined and scored according to OMERACT. A total score for the tendon damage score (TDS) was calculated by summing the grades for each tendon. For the radiographic evaluations we used the van der Heijde score; a total radiographic score (RTS) was calculated by summing a bone erosion score (ERS) and a joint space narrowing score (JSNS). RESULTS: We evaluated 288 tendons. The mean (s.d.) of TDS was 2.3 (1.8). Fifty-four (75%) patients presented tendon damage of at least one tendon. From all evaluated tendons, 134 (46.5%) had no tendon damage, 146 (50.7%) had grade 1 and 8 (2.8%) had grade 2 tendon damage. The mean (s.d.) for RTS was 91.4 (97), for ERS was 47.3 (61.9) and for JSNS was 44.1 (37.2). We found a significant correlation between disease duration and both TDS and RTS (r = 0.413 and r = 0.560, respectively; P < 0.0001). We found a good significant correlation between TDS and all variables of radiographic structural damage (RTS, r = 0.65; ERS, r = 0.637; JSNS, r = 0.618; P < 0.001). CONCLUSION: The MSUS assessment of only four tendons can be an additional feasible method to assess structural damage in RA patients.

Protein-kinase inhibitors: A new treatment pathway for autoimmune and inflammatory diseases?

Although advances in biological medicine have seen significant progress in the treatment of autoimmune and inflammatory disease, many patients do not experience a satisfactory response. Hence, there are two challenges facing the medical research community. The first is to continue development in the field of existing biological therapies, such as monoclonal antibodies. The second is to open new frontiers of research and explore treatment alternatives for non-responders to other therapies. Attention has increasingly turned to the therapeutic potential of small molecule weight kinase inhibitors (SMKIs), currently used extensively in oncology and haematology. Initial research into the therapeutic value of SMKIs for autoimmune and inflammatory diseases has been encouraging. SMKIs are taken orally, which reduces cost for the health provider, and could increase compliance for the patient. This is why research is now focusing increasingly on SMKIs as a new generation line of treatment in these diseases. Tofacitinib, an inhibitor of Janus-kinase, is currently the only drug approved for the treatment of rheumatoid arthritis by FDA. However, much more needs to be done to understand the intracellular signalling pathways and how these might affect disease progression before solid conclusions can be drawn.

Ultrasound-detected activity in rheumatoid arthritis on methotrexate therapy: Which joints and tendons should be assessed to predict unstable remission?

The aim of the study was to investigate the predictive value of different reduced joint ultrasound (US) assessments of synovitis and tenosynovitis in relation to unstable remission in a cohort of rheumatoid arthritis (RA) patients on methotrexate therapy. Forty-seven RA patients (38 women, 9 men), being treated with methotrexate (MTX), in clinical remission as judged by their consultant rheumatologist were evaluated for disease activity according to the Disease Activity Score (DAS) 28 at baseline and 6 months. Sustained remission and unstable remission were defined according to the baseline and 6-month DAS28 and changes in RA therapy during the follow-up. Each patient underwent at baseline a B-mode and power Doppler (PD) assessment of 44 joints and 20 tendons/tendon compartments by a rheumatologist blinded to the clinical and laboratory data. B-mode synovial hypertrophy (SH), synovial PD signal, B-mode tenosynovitis, and Doppler tenosynovitis were scored 0-3. The presence and index of synovial PD signal in 44 joints [odds ratio (OR) 8.21 (p = 0.016) and OR 2.20 (p = 0.049), respectively] and in 12 joints [OR 5.82 (p = 0.041) and OR 4.19 (p = 0.020), respectively], the presence of SH in wrist and MCP joints [OR 4.79 (p = 0.045)], and the presence of synovial PD signal in wrist-MCP-ankle-MTP joints [OR 4.62 (p = 0.046)] were predictors of unstable remission. The 12-joint or wrist-hand-ankle-MTP US assessments can predict unstable remission in RA patients in apparent clinical remission being treated with MTX.