Neutrophilic Activity Biomarkers (Plasma Neutrophil Extracellular Traps and Calprotectin) in Established Patients with Rheumatoid Arthritis Receiving Biological or JAK Inhibitors: A Clinical and Ultrasonographic Study.

INTRODUCTION: This study assesses the accuracy of neutrophil activation markers, including neutrophil extracellular traps (NETs) and calprotectin, as biomarkers of disease activity in patients with established rheumatoid arthritis (RA). We also analyse the relationship between NETs and various types of therapies as well as their association with autoimmunity. METHODS: Observational cross-sectional study of patients with RA receiving treatment with biological disease-modifying antirheumatic drugs or Janus kinase inhibitors (JAK-inhibitors) for at least 3 months. Plasma calprotectin levels were measured using an enzyme-linked immunosorbent assay test kit and NETs by measuring their remnants in plasma (neutrophil elastase-DNA and histone-DNA complexes). We also assessed clinical disease activity, joint ultrasound findings and autoantibody status [reumatoid factor (RF), anti-citrullinated peptide/protein antibodies (ACPAs) and anti-carbamylated protein (anti-CarP)]. Associations between neutrophilic biomarkers and clinical or ultrasound scores were sought using correlation analysis. The discriminatory capacity of both neutrophilic biomarkers to detect ultrasound synovitis was analysed through receiver-operating characteristic (ROC) curves. RESULTS: One hundred fourteen patients were included. Two control groups were included to compare NET levels. The active control group consisted of 15 patients. The second control group consisted of 30 healthy subjects. Plasma NET levels did not correlate with clinical disease status, regardless of the clinic index analysed or the biological therapy administered. No significant correlation was observed between NET remnants and ultrasound synovitis. There was no correlation between plasma NET and autoantibodies. In contrast, plasma calprotectin positively correlated with clinical parameters (swollen joint count [SJC] rho = 0.49; P < 0.001, Clinical Disease Activity Index [CDAI] rho = 0.30; P < 0.001) and ultrasound parameters (rho > 0.50; P < 0.001). Notably, this correlation was stronger than that observed with acute phase reactants. CONCLUSION: While NET formation induced by neutrophils may play a role in RA pathogenesis, our study raises questions about the utility of NET remnants in peripheral circulation as a biomarker for inflammatory activity. In contrast, this study strongly supports the usefulness of calprotectin as a biomarker of inflammatory activity in patients with RA.

Synovial tissue features associated with poor prognosis in inflammatory arthritis.

BACKGROUND: Inflammatory arthritis encompasses a group of immune-mediated diseases characterized by chronic joint inflammation. Despite having pathogenic mechanisms in common, the prognosis of rheumatoid arthritis (RA), psoriatic arthritis (PsA), and undifferentiated arthritis (UA) could be different regarding progression to chronic, to erosive, or to self-limited disease. Our aim was to evaluate the potential association of synovial tissue (ST) inflammatory cell infiltrate, the presence of ectopic lymphoid neogenesis (LN +) structures, and poor prognosis factors (PPF) in patients with RA, PsA, and UA. METHODS: We conducted a retrospective study including patients with active arthritis (RA, PsA, UA) who had ST obtained by rheumatological arthroscopy or ultrasound-guided biopsy. Clinical, demographic, and immunohistochemical data of the synovium was evaluated. Patients with biological therapy at the time of synovial biopsy were excluded. PPF in patients with RA and UA were defined by the presence of anti-cyclic citrullinated peptide antibodies and/or rheumatoid factor, development of bone erosions, or requirement of biological therapy during the follow-up. PPF in patients with PsA were defined as the presence of high levels of acute-phase reactants (ESR/CRP), dactylitis or nail involvement at the time of biopsy, development of bone erosion, or requirement of biological therapy during the follow-up. RESULTS: A total of 88 patients were included: 26 RA, 33 PsA, and 29 UA. All patients were followed up for 5 years after the biopsy. Fourteen (53.84%) RA patients had PPF, and 17 (65.38%) had LN + . LN + was associated with PPF (p 0.038) and biologic therapy initiation (p 0.018). A total of 14 (43.75%) PsA patients had PPF. CD15 infiltrate (410.68 [SD 477.63] cells/mm2) was associated with PPF (p 0.008) in PsA patients. Sixteen (55.17%) patients with UA had PPF, and 13 (44.82%) had LN + . In this group, synovial CD68 + macrophages cells density was negatively correlated with DAS28-CRP (r = - 0.346, p 0.042). CONCLUSIONS: The presence of LN + and higher CD15 + polymorphonuclear cells infiltrate was associated with PPF in RA and PsA, respectively. No associations were found for UA. These findings suggest a great heterogeneity of the ST features and its pathogenic implications in the subtypes of inflammatory arthritis.

Calprotectin in Patients with Rheumatic Immunomediated Adverse Effects Induced by Checkpoints Inhibitors.

BACKGROUND: this is an exploratory study to evaluate calprotectin serum levels in patients with rheumatic immune-related adverse events (irAEs) induced by immune checkpoint inhibitor (ICI) treatment. METHODS: this is a retrospective observational study including patients with irAEs rheumatic syndromes. We compared the calprotectin levels to those in a control group of patients with RA and with a control group of healthy individuals. Additionally, we included a control group of patients treated with ICI but without irAEs to check calprotectin levels. We also analysed the performance of calprotectin for the identification of active rheumatic disease using receiver operating characteristic curves (ROC). RESULTS: 18 patients with rheumatic irAEs were compared to a control group of 128 RA patients and another group of 29 healthy donors. The mean calprotectin level in the irAE group was 5.15 µg/mL, which was higher than the levels in both the RA group (3.19 µg/mL) and the healthy group (3.81 µg/mL) (cut-off 2 µg/mL). Additionally, 8 oncology patients without irAEs were included. In this group, calprotectin levels were similar to those of the healthy controls. In patients with active inflammation, the calprotectin levels in the irAE group were significantly higher (8.43 µg/mL) compared to the RA group (3.94 µg/mL). ROC curve analysis showed that calprotectin had a very good discriminatory capacity to identify inflammatory activity in patients with rheumatic irAEs (AUC of 0.864). CONCLUSIONS: the results suggest that calprotectin may serve as a marker of inflammatory activity in patients with rheumatic irAEs induced by treatment with ICIs.

Psoriatic Arthritis: Pathogenesis and Targeted Therapies.

Psoriatic arthritis (PsA), a heterogeneous chronic inflammatory immune-mediated disease characterized by musculoskeletal inflammation (arthritis, enthesitis, spondylitis, and dactylitis), generally occurs in patients with psoriasis. PsA is also associated with uveitis and inflammatory bowel disease (Crohn's disease and ulcerative colitis). To capture these manifestations as well as the associated comorbidities, and to recognize their underlining common pathogenesis, the name of psoriatic disease was coined. The pathogenesis of PsA is complex and multifaceted, with an interplay of genetic predisposition, triggering environmental factors, and activation of the innate and adaptive immune system, although autoinflammation has also been implicated. Research has identified several immune-inflammatory pathways defined by cytokines (IL-23/IL-17, TNF), leading to the development of efficacious therapeutic targets. However, heterogeneous responses to these drugs occur in different patients and in the different tissues involved, resulting in a challenge to the global management of the disease. Therefore, more translational research is necessary in order to identify new targets and improve current disease outcomes. Hopefully, this may become a reality through the integration of different omics technologies that allow better understanding of the relevant cellular and molecular players of the different tissues and manifestations of the disease. In this narrative review, we aim to provide an updated overview of the pathophysiology, including the latest findings from multiomics studies, and to describe current targeted therapies.

Complete disappearance of pulmonary rheumatoid nodules after long term rituximab treatment: case report.

The natural history of pulmonary rheumatoid nodules in rheumatoid arthritis remains uncertain. We present a case of a patient with rheumatoid arthritis with pulmonary rheumatoid nodules diagnosed while receiving etanercept in whom pulmonary nodules resolved completely after 5 years of rituximab treatment. Rituximab has been evaluated in case series of patients with pulmonary rheumatoid nodules, resulting in most cases in no progression or a reduction in the size of the nodules, although the complete resolution is uncommon probably due to the short follow-up period. Complete disappearance of pulmonary rheumatoid nodules may be expected after long-term treatment with rituximab.

Plasma calprotectin as a biomarker of ultrasound synovitis in rheumatoid arthritis patients receiving IL-6 antagonists or JAK inhibitors.

Objectives: To analyse the accuracy of plasma calprotectin in patients with rheumatoid arthritis (RA) receiving monoclonal antibodies against IL-6 receptors (anti-rIL-6) or JAK inhibitors (JAKis) in detecting ultrasound (US) synovitis and compare it with acute phase reactants [high-sensitivity C-reactive protein (hs-CRP) and ESR]. Methods: An observational cross-sectional study of RA patients receiving anti-rIL-6 (tocilizumab or sarilumab) or JAKi, (baricitinib or tofacitinib) was made. Plasma calprotectin for the diagnosis of US synovitis [synovial hypertrophy grade (SH) ⩾ 2 plus power Doppler signal (PD) ⩾ 1] was analysed using receiver operating characteristic curves (ROCs). The performance of ESR and hs-CRP was also studied. The three ROC curves were compared to determine which had the highest discriminatory power. Associations between plasma calprotectin and US scores were made using correlation analysis. Results: Sixty-three RA patients were included. Mean plasma calprotectin levels were significantly higher in patients with US synovitis than in those without (0.89 ± 0.85 vs 0.30 ± 0.12 µg/ml; p = 0.0003). A moderate correlation between calprotectin and all US scores (HS score Rho = 0.479; PD score Rho = 0.492; and global score Rho = 0.495) was found. The discriminatory capacity of plasma calprotectin showed an AUC of 0.795 (95% CI: 0.687-0.904). The AUC of hs-CRP and ESR was 0.721 and 0.564, respectively. hs-CRP serum levels showed a low positive correlation with the three US scores (Rho < 0.40). After analysis according to the drugs administered, the correlation disappeared in patients receiving anti-rIL-6. Conclusion: Plasma calprotectin may be a sensitive biomarker of synovial inflammation in RA patients treated with anti-rIL-6 or JAKi.

Imaging Findings in Patients with Immune Checkpoint Inhibitor-Induced Arthritis.

Immune checkpoint inhibitor (ICI)-induced arthritis is an increasingly recognized adverse event in patients with oncologic disease during immunotherapy. Four patterns are well described, including rheumatoid arthritis (RA)-like, polymyalgia rheumatica (PMR)-like, psoriatic arthritis (PsA)-like, and oligo-monoarthritis, among others. Despite better clinical recognition of these syndromes, information about the main imaging findings is limited. METHODS: We conducted a retrospective observational study including all adult patients referred to the Rheumatology Department of a single-center due to ICI-induced arthritis who underwent imaging studies [ultrasound (US), magnetic resonance imaging (MRI), and 18F-FDG PET/CT)] between January 2017 and January 2022. RESULTS: Nineteen patients with ICI-induced arthritis with at least one diagnostic imaging assessment were identified (15 US, 4 MRI, 2 18F-FDG PET/CT). Most patients were male (84.2%), with a median age at inclusion of 73 years. The main underlying diagnoses for ICI treatment were melanoma in five cases. The distribution of ICI-induced arthritis was as follows: PMR-like (5, 26.2%), RA-like (4, 21.1%), PsA-like (4, 21.1%), and others (6, 31.6%). All RA-like patients had US findings indistinguishable from conventional RA patients. In addition, 3/5 (60%) of PMR-like patients had significant involvement of the hands and wrists. Abnormal findings on MRI or PET-CT were reported by clinical symptoms. No erosions or myofascitis were seen. CONCLUSIONS: ICI-induced arthritis patients present inflammatory patterns on imaging studies similar to conventional inflammatory arthropathies, and therefore these syndromes should be followed carefully and treated according to these findings.

The synovial and blood monocyte DNA methylomes mirror prognosis, evolution, and treatment in early arthritis.

Identifying predictive biomarkers at early stages of inflammatory arthritis is crucial for starting appropriate therapies to avoid poor outcomes. Monocytes (MOs) and macrophages, largely associated with arthritis, are contributors and sensors of inflammation through epigenetic modifications. In this study, we investigated associations between clinical features and DNA methylation in blood and synovial fluid (SF) MOs in a prospective cohort of patients with early inflammatory arthritis. DNA methylation profiles of undifferentiated arthritis (UA) blood MOs exhibited marked alterations in comparison with those from healthy donors. We identified additional differences both in blood and SF MOs after comparing patients with UA grouped by their future outcomes, i.e., good versus poor. Patient profiles in subsequent visits revealed a reversion toward a healthy level in both groups, those requiring disease-modifying antirheumatic drugs and those who remitted spontaneously. Changes in disease activity between visits also affected DNA methylation, which was partially concomitant in the SF of UA and in blood MOs of patients with rheumatoid arthritis. Epigenetic similarities between arthritis types allow a common prediction of disease activity. Our results constitute a resource of DNA methylation-based biomarkers of poor prognosis, disease activity, and treatment efficacy for the personalized clinical management of early inflammatory arthritis.

High Sensitivity C Reactive Protein in Patients with Rheumatoid Arthritis Treated with Antibodies against IL-6 or Jak Inhibitors: A Clinical and Ultrasonographic Study.

BACKGROUND: We examined whether high-sensitivity CRP (hsCRP) reflected the inflammatory disease status evaluated by clinical and ultrasound (US) parameters in RA patients receiving IL-6 receptor antibodies (anti-IL-6R) or JAK inhibitors (JAKi). METHODS: We conducted a cross-sectional study of patients with established RA receiving anti-IL-6R (tocilizumab, sarilumab) or JAKi (tofacitinib, baricitinib). Serum hsCRP and US synovitis in both hands were measured. Associations between hsCRP and clinical inflammatory activity were evaluated using composite activity indices. The association between hsCRP and US synovitis was analyzed. RESULTS: 63 (92% female) patients (42 anti- IL-6R and 21 JAKi) were included, and the median disease duration was 14.4 (0.2-37.5) years. Most patients were in remission or had low levels of disease. Overall hsCRP values were very low, and significantly lower in anti-IL-6R patients (median 0.04 mg/dL vs. 0.16 mg/dL). Anti-IL-6R (82.4%) patients and 48% of JAKi patients had very low hsCRP levels (≤0.1 mg/dL) (p = 0.002). In the anti-IL-6R group, hsCRP did not correlate with the composite activity index or US synovitis. In the JAKi group, hsCRP moderately correlated with US parameters (r = 0.5) but not clinical disease activity, and hsCRP levels were higher in patients with US synovitis (0.02 vs. 0.42 mg/dL) (p = 0.001). CONCLUSION: In anti-IL-6R RA-treated patients, hsCRP does not reflect the inflammatory disease state, but in those treated with JAKi, hsCRP was associated with US synovitis.

Synovial Immunohistological Biomarkers of the Classification of Undifferentiated Arthritis Evolving to Rheumatoid or Psoriatic Arthritis.

Background: Undifferentiated arthritis (UA) is defined as an inflammatory arthritis that does not fulfill criteria for a definite diagnosis. Delay in reaching a specific diagnostic and therapy may lead to impaired functional outcomes. Our aim was to identify synovial biomarkers associated with definitive diagnostic classification in patients with UA. Methods: DMARD-naïve UA patients with available initial synovial tissue (ST) and a final diagnosis of rheumatoid arthritis (RA) or psoriatic arthritis (PsA) during follow-up were included and compared with patients with well-defined disease (RA or PsA). Clinical, arthroscopic, and pathological data were compared between groups. Pathology included quantitative immunohistochemical (IHC) analysis of cell types and human interferon-regulated MxA. Principal component analysis (PCA) was performed to extract disease patterns. Results: One hundred and five patients were included: 31 patients with DMARD-naïve UA (19 evolving to RA and 12 to PsA during a median follow up of 7 years), 39 with established RA, and 35 with established PsA. ST from the UA group showed higher macrophage density compared with the established RA and PsA groups. Patients with UA evolving to RA (UA-RA) showed higher MxA expression and CD3+ T-cell density compared with established RA. UA patients evolving to PsA (UA-PsA) showed increased vascularity and lining synovial fibroblast density compared with established PsA. Synovitis of UA-PsA patients showed more mast cells and lining fibroblasts compared with UA-RA. No between-group differences in local or systemic inflammation markers were found. Conclusions: Our results show differences in the cellular composition of UA synovium compared with RA and PsA, with higher density of the cellular infiltrate in the UA groups. Initial expression of the interferon inducible gene MxA could be a biomarker of progression to RA, while higher mast cell and fibroblastic density may be associated with PsA progression.

Impact of Comorbidities on Disease Activity, Patient Global Assessment, and Function in Psoriatic Arthritis: A Cross-Sectional Study.

INTRODUCTION: The aim of this study was to evaluate the impact of comorbidities on disease activity, patient's impact of the disease, patient global assessment, and function in psoriatic arthritis (PsA). METHODS: Consecutive PsA patients were enrolled in this cross-sectional study. During the visit, the patients underwent a complete physical examination and clinical/laboratory data were collected, including type and number of comorbidities, recorded as simple comorbidity count (SCC). Disease activity was assessed using the Disease Activity Score for Psoriatic Arthritis (DAPSA) and the Minimal Disease Activity (MDA) was also evaluated. The Psoriatic Arthritis Impact of Disease (PsAID), the Health Assessment Questionnaire-Disability Index (HAQ-DI), and the Patient Global Assessment of disease activity (PtGA) were also collected. RESULTS: A total of 144 patients were enrolled. At least one comorbidity was registered in 104 (72.2%) patients. The SCC was associated with DAPSA (ß = 1.48, p = 0.013), PsAID (ß = 0.41, p < 0.01), HAQ-DI (ß = 0.11, p < 0.01) and PtGA (ß = 0.50, p < 0.01). The comorbidities that showed an impact on outcome measures were anxiety and fibromyalgia (FM). Anxiety showed an impact on DAPSA (ß = 14.46, p < 0.001), PsAID (ß = 1.98, p = 0.039) and HAQ-DI (ß = 0.54, p = 0.036). FM showed an impact on DAPSA (ß = 6.46, p = 0.025), PsAID (ß = 2.88, p < 0.001), HAQ-DI (ß = 0.70, p < 0.001), PtGA (ß = 2.00, p = 0.014), and MDA (ß = - 2.79, p = 0.01). The median PtGA value was different among patients with different numbers of comorbidities. CONCLUSIONS: This study showed that comorbidities, either as a simple comorbidity count number or as single comorbidity, might have an impact on the main domains affecting PsA patients in real clinical practice.

Assessment of the Patient Acceptable Symptom State (PASS) in psoriatic arthritis: association with disease activity and quality of life indices.

OBJECTIVE: The aim of this study was to evaluate the discriminant capability of the Patient Acceptable Symptom State (PASS) according to disease activity, remission/low disease activity indices and quality of life indices in patients with psoriatic arthritis (PsA). METHODS: Consecutive patients with PsA were enrolled in this cross-sectional study. At each visit, the patients underwent a complete physical examination and their clinical/laboratory data were collected. Disease activity was assessed using the Disease Activity Score for Psoriatic Arthritis (DAPSA) and remission/low disease activity using the DAPSA minimal disease activity (MDA) and very low disease activity (VLDA) criteria. The Psoriatic Arthritis Impact of Disease (PsAID) and the Health Assessment Questionnaire-Disability Index scores were also collected. Finally, PASS was assessed by asking all patients to answer yes or no to a single question. RESULTS: Patients who answered yes to PASS showed a significantly better overall mean DAPSA score than those who were not in PASS. Furthermore, patients in PASS showed a significantly lower level of systemic inflammation, lower Leeds Enthesitis Index score, a significantly lower impact of disease (PsAID), lower pain and better function than patients who answered no to PASS. A moderate to good agreement was found between PASS, MDA, DAPSA low disease activity and PsAID score ≤4. Good sensitivity and specificity were found with PASS with respect to DAPSA low disease activity, and although PASS is sensitive in the identification of patients with MDA, DAPSA remission and VLDA it lacks of specificity. DISCUSSION: This study showed that PASS might be used as an alternative to determine disease activity in patients with PsA in real clinical practice, mainly in patients with low disease activity according to DAPSA criteria.