[Gout, beyond the joint: How should we treat it?] / La gota, más allá de la articulación: ¿cómo debemos tratarla?

Gout is a disease caused by the chronic deposition of monosodium urate crystals. Its clinical presentation as an acute, self-limiting arthritis and the belief that it is a banal, self-inflicted disease have led to its poor management. Despite advances in the knowledge of the disease and the simplicity of its management, no more than 30% of patients are well treated. In Spain, the prevalence of gout is 2.5% and its incidence is increasing. In the following article we will review the pathogenesis of gout and hyperuricaemia, highlighting the greater weight of genetics and renal function over diet. We will look at the consequences of crystal deposition. Gout, in addition to its joint presentation and renal involvement, has been shown to be an independent cardiovascular risk factor. Hypouricemic therapy is the most important treatment, as it is the one that dissolves the crystals and cures the disease. This requires the sustained achievement of uricemia levels below 6mg/dl. We will also review preventive and flares treatment, as well as the role of patient education in terms of both lifestyle and dietary habits and adherence to pharmacological treatment.

Clinical factors associated with discontinuation of ts/bDMARDs in rheumatic patients from the BIOBADASER III registry.

Biologic and targeted synthetic disease-modifying antirheumatic drugs (ts/bDMARDs) play a pivotal role in the treatment of rheumatoid arthritis (RA), psoriatic arthritis (PsA), and ankylosing spondylitis (AS). Persistence of therapy provides an index of a drug's overall effectiveness. The objective of the study was to identify factors associated with discontinuation of ts/bDMARDs in a real-world dataset. The study population comprised patients diagnosed with RA, PsA, and AS included in the BIOBADASER registry for whom follow-up data were available until November 2019. Patient features and treatment data were included in the analysis. The Kaplan-Meier method was used to study survival of the different drugs according to the reason for discontinuation. Factors associated with discontinuation were studied using Cox regression models and bivariate and multivariate analyses. P values of less than 0.05 were regarded as statistically significant. The study population comprised 4,752 patients who received a total of 8,377 drugs, of which 4,411 (52.65%) were discontinued. The Kaplan-Meier curves showed that survival for first-line treatment was greater in all 3 groups (p < 0.001). Patients with RA had a greater risk of discontinuation if they were younger (HR, 0.99; 95% CI 0.99-1.00), if they were receiving anti-TNFα agents (HR, 0.61; 95% CI 0.54-0.70), and if they had more comorbid conditions (HR, 1.09; 95% CI 1.00-1.17). Patients with PsA had a higher risk if they were women (HR, 1.36; 95% CI 1.15-1.62) and if they were receiving other ts/bDMARDs (HR, 1.29; 95% CI 1.05-1.59). In patients with AS, risk increased with age (HR, 1.01; 95% CI 1.00-1.02), as did the number of comorbid conditions (HR, 1.27; 95% CI 1.12-1.45). The factors that most affected discontinuation of ts/bDMARDs were line of treatment, age, type of drug, sex, comorbidity and the year of initiation of treatment. The association with these factors differed with each disease, except for first-line treatment, which was associated with a lower risk of discontinuation in all 3 diseases.

Cost-effectiveness analysis of febuxostat in patients with gout in Spain.

UNLABELLED: Objectives Cost-effectiveness of febuxostat compared with allopurinol in the treatment of hyperuricemia in patients with gout. Methods Costs, clinical outcomes, and QALYs were estimated using a Markov model. Febuxostat 80 mg and 120 mg sequentially, used as first line and second line therapy, was compared with allopurinol 300 mg. Patients switched to the next treatment in the sequence according to a dichotomous response vs no response (target serum urate level < 6 mg/dl outcome) after 3 months of active treatment. A 3% discount rate and 5-year time horizon were applied. PERSPECTIVE: National Health System. Results The addition of febuxostat to any therapeutic strategy was an efficient option, with incremental cost-effectiveness ratios (ICER) compared with allopurinol 300 mg ranging from €5268-€9737. Conclusions Febuxostat is a cost-effective treatment in Spain for the management of hyperuricemia in gout patients, with ICERs far below accepted Spanish efficiency thresholds (30 000€/QALY).

IL-6 blockade reverses the abnormal STAT activation of peripheral blood leukocytes from rheumatoid arthritis patients.

Considering the interplay of multiple STATs in response to cytokines, we investigated how IL-6 and its blocking affect STAT signaling in rheumatoid arthritis (RA). Leukocytes obtained from RA patients before and after tocilizumab treatment and healthy donors (HDs) were cytokine-stimulated and STAT phosphorylation was analyzed by cytometry. RA patients had significantly fewer pSTAT1+, pSTAT3+, and pSTAT6+ monocytes and pSTAT5+ lymphocytes than HDs. After 24weeks of treatment, percentages of IFNγ-induced pSTAT1+ and IL-10-induced pSTAT3+ monocytes in RA patients increased, reaching levels comparable to HDs. pSTAT1+ and pSTAT3+ cells correlated inversely with RA disease activity index and levels of pSTAT+ cells at baseline were higher in patients with good EULAR response to tocilizumab. IFNγ-induced pSTAT1+ cells correlated inversely with memory T cells and anti-CCP levels. IL-10-induced pSTAT3+ cells correlated with Treg/Teff ratio. Our findings suggest that IL-6 blocking reduces the inflammatory mechanisms through the correction of STAT1 and STAT3 activation status.

Identification of broadly discriminatory tissue biomarkers of synovitis with binary and multicategory receiver operating characteristic analysis.

Immunohistochemical synovial tissue biomarkers are used increasingly to classify arthropathies, study their pathogenesis, and to measure disease activity in clinical trials. We have used receiver operating characteristic (ROC) analysis to quantify the discriminatory abilities of markers for common inflammatory cells (subintimal CD15, CD68, CD3, CD20, CD38, and lining CD68), proliferating cells (Ki-67) and blood vessels (von Willebrand factor, vWF) among inflammatory (chronic septic arthritis, early arthritis and rheumatoid arthritis (RA)) and degenerative arthropathies (osteoarthritis (OA) and orthopedic arthropathies) and normal synovium. Six of the eight markers distinguished accurately between RA and the degenerative arthropathies (area under the curve (AUC) 0.91-0.97), whereas subintimal CD68 (AUC 0.92) and Ki-67 (AUC 0.87) distinguished best between OA and normal synovium. Fold differences in mean expression correlated only modestly with AUCs (r(2) = 0.44). Multicategory ROC analysis ranked Ki-67, subintimal CD68, and CD15 as discriminating best among all six sample groups, and thus identified them as the most broadly applicable markers.

Epidemiology of gout: an update.

Gout is the most common inflammatory joint disease in men, characterised by formation of monosodium urate (MSU) crystals in the synovial fluid of joints and in other tissues. The epidemiology of gout provides us with the understanding of the disease distribution and its determinants. In an attempt to update the knowledge on the topic, more recent research reports on the descriptive epidemiology of gout are reviewed in this article. The review describes clinical characteristics and case definitions of gout, including the Rome and New York diagnosis criteria of gout, '1977 American Rheumatism Association (ARA) criteria' and the 10 key propositions of the European League Against Rheumatism (EULAR) recommendations. Gout incidence, prevalence, morbidity and mortality, geographical variation of the disease, relevant risk factors for both the occurrence and outcome of gout and trends of the disease over time are then described. Difficulties in obtaining the information and data reported are also discussed.

Local cytokine profiles in knee osteoarthritis: elevated synovial fluid interleukin-15 differentiates early from end-stage disease.

OBJECTIVE: Much of what is known about the inflammatory response in the synovial membrane (SM) of patients with osteoarthritis (OA) comes from studies of synovial tissues from end-stage disease. In this study, we sought to better characterize the inflammatory infiltrate in symptomatic patients with early signs of knee OA, and to determine how inflammatory cell populations relate to the pattern of cytokine and degradative enzyme production. METHODS: Study populations comprised patients with degenerative meniscal tears and early cartilage thinning undergoing arthroscopic procedures (early OA) and patients undergoing total knee replacement for end-stage OA. Quantitative real-time polymerase chain reaction (PCR) was used to measure expression of SM cytokines and enzymes implicated in the pathogenesis of inflammatory arthritis and OA, as well as cell lineage-specific markers. We quantified synovial fluid (SF) cytokines and enzymes by enzyme-linked immunosorbent assay (ELISA) and SM cell populations by immunohistochemistry. RESULTS: We found increased levels of SF interleukin-15 (IL-15) protein in the early knee OA patients when compared to end-stage OA. Both SF IL-15 protein and numbers of CD8 cells within SM correlated with matrix metalloproteinase-1 (MMP-1) and three levels. TNF-alpha, IL-6 and IL-21 were also detectable in the SF of the majority of patients, and IL-15 levels were associated with IL-6 levels. CONCLUSION: IL-15 is elevated in early knee OA, suggesting activation of an innate immune response in the SM. The association of IL-15 expression with CD8 transcripts and MMPs implicates this cytokine in OA pathogenesis and as a candidate therapeutic target.

Increased angiogenesis and cellular proliferation as hallmarks of the synovium in chronic septic arthritis.

OBJECTIVE: To characterize histologic alterations and inflammatory infiltrates in the synovium of patients with chronic septic arthritis (SeA). METHODS: Synovial membranes from patients with SeA (9 specimens; disease duration >4 weeks) were compared with specimens from patients with septic joint prosthesis loosening (septic total arthroplasty [SeTA]; 9 specimens), rheumatoid arthritis (RA; 25 specimens), osteoarthritis (25 specimens), and normal histology (10 specimens). Sections were stained with hematoxylin and eosin, tissue gram stain, and immunostains for von Willebrand factor (vWF; blood vessels), Ki-67 (dividing cells), CD15 (neutrophils), CD3 (T cells), CD20 (B cells), CD38 (plasma cells), and CD68 (macrophages). RESULTS: Gram stains were positive in all SeA and SeTA specimens. Mixed polymorphonuclear and mononuclear infiltrates predominated in SeA and SeTA. SeA could be differentiated from RA by higher densities of CD15+ cells (SeA:RA ratio 6.5:1; P < 0.001) or Ki-67+ cells (ratio 2.1:1; P = 0.012). The inflammatory infiltrate of SeTA was similar to SeA but contained fewer CD3+ cells (SeTA versus SeA 0.26:1; P = 0.009) and a tendency toward fewer CD20+ cells. Mean vascular density was strikingly increased in SeA (SeA:normal ratio 3.0:1; P < 0.001) and, to a lesser extent, in the vascularized areas of the SeTA specimens (SeTA:normal ratio 1.9:1). Ki-67/CD31 double immunostains demonstrated proliferating endothelial cells in small subintimal blood vessels, suggesting angiogenesis. Receiver operating characteristic curve analysis identified higher densities of CD15+ and Ki-67+ cells and vWF-positive vessels as histologic markers that differentiated SeA from RA. CONCLUSION: This first analysis of the synovium in patients with chronic pyogenic arthritis identified dramatic neovascularization and cell proliferation, accompanied by persistent bacterial colonization and heterogeneous inflammatory infiltrates rich in CD15+ neutrophils, as histopathologic hallmarks.

A histomorphometric analysis of synovial biopsies from individuals with Gulf War Veterans' Illness and joint pain compared to normal and osteoarthritis synovium.

We compared histologic, immunohistochemical, and vascular findings in synovial biopsies from individuals with Gulf War Veterans Illness and joint pain (GWVI) to findings in normal and osteoarthritis (OA) synovium. The following parameters were assessed in synovial biopsies from ten individuals with GWVI: lining thickness, histologic synovitis score, and vascular density in hematoxylin & eosin-stained sections; and CD68+ lining surface cells and CD15+, CD3+, CD8+, CD20+, CD38+, CD68+, and Ki-67+ subintimal cells and von Willebrand Factor+ vessels immunohistochemically. Comparisons were made to synovial specimens from healthy volunteers (n = 10) and patients with OA or RA (n = 25 each). Histologic appearance and quantitative assessments were nearly identical in the GWVI and normal specimens. Vascular density was between 25% (H & E stains; p = 0.003) and 31% (vWF immunostains; p = 0.02) lower in GWVI and normal specimens than in OA. CD68+ macrophages were the most common inflammatory cells in GWVI (45.3 +/- 10.1 SEM cells/mm(2)) and normal synovium (45.6 +/- 7.4) followed by CD3+ T cells (GWVI, 15.1 +/- 6.3; normal, 27.1 +/- 9.2), whereas there were practically no CD20+, CD38+, and CD15+ cells. All parameters except lining thickness and CD15 and CD20 expression were significantly higher in OA. Five (20%) OA specimens contained significant fractions of humoral immune cells in mononuclear infiltrates, although the overall differences in the relative composition of the OA mononuclear infiltrates did not reach statistical significance compared to GWVI and normal synovium. In summary, the GWVI and normal synovia were indistinguishable from each other and contained similar low-grade inflammatory cell populations consisting almost entirely of macrophages and T cells.

The synovitis of "non-inflammatory" orthopaedic arthropathies: a quantitative histological and immunohistochemical analysis.

OBJECTIVE: To quantify inflammatory changes in synovial membranes from orthopaedic "non-inflammatory" arthropathies (Orth. A). METHODS: Synovial membranes from patients with femur fracture, avascular necrosis of the femur, plica syndrome, and meniscus and/or ligament injury (n = 23); rheumatoid arthritis (n = 28); osteoarthritis (OA; n = 25); and from normal controls (n = 10) were assessed by light microscopy, a histological synovitis score, immunostaining for CD3, CD20, CD38, CD68, Ki-67 and von Willebrand factor, and with an immunohistochemical inflammation score. RESULTS: Orth. A histology varied between normal and markedly inflamed. Predominant abnormalities were mild lining hyperplasia, scattered inflammatory cells and small perivascular infiltrates. The synovitis score classified Orth. A as "mild synovitis". Inflammatory cells occurred frequently: CD68+ cells in 100% of Orth. A specimens; CD3+, 91%; CD38+, 70%; and CD20+, 39%. Orth. A had 36% greater lining thickness (p = 0.04), 40% higher vascular density (p = 0.009) and 51.3-fold higher CD38+ cell density (p = 0.02) than normal controls; and 60% fewer subintimal Ki-67+ cells (p = 0.003), 42% fewer CD68+ lining cells (p<0.01) and 40% fewer subintimal CD68+ cells (p<0.01) than OA. The immunohistochemical inflammation score was 2.2-fold higher in Orth. A than in controls (p = 0.048) and similar to OA, with three Orth. A specimens showing marked inflammation. CONCLUSIONS: Synovial membranes from "non-inflammatory" arthropathies featured neovascularisation and inflammation intermediate between normal and OA synovium. These results expand previous findings that mechanical joint injury may lead to a mild-to-moderate synovitis.

A modified Delphi exercise to determine the extent of consensus with OMERACT outcome domains for studies of acute and chronic gout.

OBJECTIVES: To reach consensus with recommendations made by an OMERACT Special Interest Group (SIG). METHODS: Rheumatologists and industry representatives interested in gout rated and clarified, in three iterations, the importance of domains proposed by the OMERACT SIG for use in acute and chronic gout intervention studies. Consensus was defined as a value of less than 1 of the UCLA/RAND disagreement index. RESULTS: There were 33 respondents (61% response rate); all agreed the initial items were necessary, except "total body urate pool". Additional domains were suggested and clarification sought for defining "joint inflammation" and "musculoskeletal function". Items that demonstrated no clear decision were re-rated in the final iteration. There were six highly rated items (rating 1-2) with four slightly lower rating items (rating 3) for acute gout; and 11 highly rated items with eight slightly lower ratings for chronic gout. CONCLUSIONS: Consensus is that the following domains be considered mandatory for acute gout studies: pain, joint swelling, joint tenderness, patient global, physician global, functional disability; and for chronic gout studies: serum urate, gout flares, tophus regression, health-related quality of life, functional disability, pain, patient global, physician global, work disability and joint inflammation. Several additional domains were considered discretionary.

Subintimal Ki-67 as a synovial tissue biomarker for inflammatory arthropathies.

OBJECTIVES: Ki-67 is expressed in the nuclei of dividing cells and can be used to assess proliferation of synovial inflammatory and stromal cells. We evaluated subintimal Ki-67+ cell density as a tissue biomarker for inflammatory arthropathies and compared it to subintimal CD68, a synovial biomarker of RA. METHODS: Subintimal Ki-67+ and CD68+ cell densities were measured immunohistochemically in synovial specimens obtained from patients with rheumatoid arthritis (RA; n = 19), osteoarthritis (OA; n = 18), "non-inflammatory" orthopaedic arthropathies (avascular necrosis, meniscus injury, femur fracture; n = 16), chronic septic arthritis (n = 9), and histologically normal synovium (n = 10). RESULTS: were correlated with a histological synovitis score. Utilising the areas under receiver operating characteristic curves (AUCs), we compared the abilities of Ki-67 and CD68 to differentiate among these arthropathies. Results: Ki-67 was expressed widely in the subintimal of inflamed specimens and in RA pannus invading hard tissues. Compared to normal controls, it was highly overexpressed in RA (26.6-fold) and chronic septic arthritis (55-fold), and mildly elevated in OA (3.9-fold) and orthopaedic arthropathies (2.1-fold). Ki-67 and CD68 differentiated similarly well between RA and OA (AUC: Ki-67 = 0.91, CD68 = 0.94), Ki-67 better between chronic septic arthritis and RA, and CD68 better between OA and normal controls. Ki-67 (r = 0.80) and CD68 (r = 0.79) correlated positively with the synovitis score. CONCLUSIONS: Subintimal Ki-67 was overexpressed in inflammatory arthropathies, distinguished among differentially inflamed arthropathies, and correlated positively with the histological severity of synovitis. It may prove useful in synovial tissue classification and as a synovial marker of disease activity in clinical trials when biopsies are available.

Absence of histologic evidence of synovitis in patients with Gulf War veterans' illness with joint pain.

OBJECTIVE: An unexplained multisymptom illness, Gulf War veterans' illness (GWVI), has been described among allied force veterans of the first Gulf War (1990-1991). It has been proposed that some of its symptoms reflect an immune dysfunction, and rheumatologic symptoms including joint pain and stiffness are reported frequently. However, it is unknown whether synovial inflammation causes the articular symptoms. We examined synovial tissue from individuals with GWVI and joint pain for evidence of inflammation. METHODS: We compared synovial biopsy samples from 6 individuals with GWVI and joint pain with samples from 9 clinically asymptomatic controls (hematoxylin and eosin [H&E] stains only) and biopsy samples or surgically obtained specimens from 10 patients with rheumatoid arthritis (RA) and 12 with osteoarthritis (OA). Inflammatory changes were quantified in H&E stained sections with a modified synovitis score by immunostaining for CD3, CD20, CD38, CD68, Ki-67, and von Willebrand factor, and with a composite inflammation score based on these markers. RESULTS: Normal histology was seen in the GWVI specimens, except for mild focal lining hyperplasia and rare low-grade perivascular infiltrates in 1 specimen each. Mean +/- SEM synovitis scores were lowest and nearly identical in control (1.38 +/- 0.30) and GWVI specimens (1.41 +/- 0.29), intermediate in OA specimens (2.64 +/- 0.39), and highest in RA specimens (6.0 +/- 0.19). Likewise, inflammatory cells, cell division, vascular density, and composite inflammation score were lowest in the GWVI specimens. CONCLUSION: Despite significant joint pain, the GWVI synovia did not differ from normal controls. These results agree with other studies that have failed to document inflammatory or immunologic etiologies in GWVI.