Synovial Fluid Of Psoriatic Arthritis Patients Research Articles

Characterization of the inflammatory proteome of synovial fluid from patients with psoriatic arthritis: Potential treatment targets.

1) To characterize the inflammatory proteome of synovial fluid (SF) from patients with Psoriatic Arthritis (PsA) using a high-quality throughput proteomic platform, and 2) to evaluate its potential to stratify patients according to clinical features. Inflammatory proteome profile of SF from thirteen PsA patients with active knee arthritis were analyzed using proximity extension assay (PEA) technology (Olink Target 96 Inflammation panel). Four patients with OA were included as control group. Seventy-nine inflammation-related proteins were detected in SF from PsA patients (SF-PsA). Unsupervised analyzes of the molecular proteome profile in SF-PsA identified two specific phenotypes characterized by higher or lower levels of inflammation-related proteins. Clinically, SF-PsA with higher levels of inflammatory proteins also showed increased systemic inflammation and altered glucose and lipid metabolisms. Besides, SF from PsA patients showed 39 out of 79 proteins significantly altered compared to SF-OA specifically related to cell migration and inflammatory response. Among these, molecules such as TNFα, IL-17A, IL-6, IL-10, IL-8, ENRAGE, CCL20, TNFSF-14, OSM, IFNγ, MCP-3, CXCL-11, MCP4, CASP-8, CXCL-6, CD-6, ADA, CXCL-10, TNFβ and IL-7 showed the most significantly change. This is the first study that characterizes the inflammatory landscape of synovial fluid of PsA patients by analyzing a panel of 92 inflammatory proteins using PEA technology. Novel SF proteins have been described as potential pathogenic molecules involved in the pathogenesis of PsA. Despite the flare, inflammatory proteome could distinguish two different phenotypes related to systemic inflammation and lipid and glucose alterations.

Assessment of Crystals in the Synovial Fluid of Psoriatic Arthritis Patients in Relation to Disease Activity.

Background: This study examines the relationship between the presence of crystals in the synovial fluid of patients with psoriatic arthritis (PsA) and disease activity. Methods: The synovial fluid of 156 PsA patients was analyzed and compared to 50 patients with gonarthrosis (GoA). The Leica DM4500P polarization microscope was used for crystal detection. Results: The presence of crystals was observed in 23.71% of PsA patients and none of the GoA patients, p < 0.001. Monosodium urate crystals (67.58%) and calcium pyrophosphate crystals (21.62%) were prevalent. The presence of crystals in the synovial fluid of PsA patients was associated with high disease activity according to the Composite Psoriatic Disease Activity Index (OR = 18.75, 95%; CI: 7.13 to 49.25) and the Disease Activity for Psoriatic Arthritis (OR = 15.96, 95%; CI: 5.76 to 44.23), with severe disability according to the Health Assessment Questionnaire Disability Index (OR = 13.60, 95%; CI: 5.09 to 36.31), and with severe pain on the Visual Analog Scale (OR = 157.25, 95%; CI: 39.50 to 625.94). Conclusion: Our results suggest that synovial fluid examination should be included in the treatment pathway for PsA patients with active disease, to aid in determining whether urate-lowering therapy is required.

Serum IFI16 and anti-IFI16 antibodies in psoriatic arthritis.

Nuclear interferon-inducible protein 16 (IFI16) and anti-IFI16 antibodies have been detected in subjects with several rheumatic diseases, often correlating with disease severity, and in this study we investigated their prevalence and clinical associations in psoriatic arthritis (PsA) compared to psoriasis (Pso). We tested sera and synovial fluids of patients with PsA for IFI16 protein levels by capture enzyme-linked immunosorbent assay (ELISA) and for anti-IFI16 immunoglobulin (Ig)G and IgA by ELISA, protein radio-immunoprecipitation and immunoprecipitation-Western blot of IgG. Sera from patients with Pso and healthy subjects were used as controls, and in a subgroup of patients with PsA we also studied sera after treatment with etanercept. IFI16 was detectable in the sera of 66% of patients with Pso, 46% with PsA and 19% of controls. Among PsA cases, 51% of IFI16-positive cases had elevated levels of C-reactive protein (CRP) compared to 31% of patients with undetectable IFI16. Anti-IFI16 of both IgG and IgA isoforms were detected with significantly higher frequency in PsA and Pso compared to healthy controls, with higher IgG titres in patients with elevated C-reactive protein (CRP) (P=0·015). Immunoprecipitation confirmed the presence of anti-IFI16 IgG antibodies and these preferentially recognized epitopes outside the N-terminus of the protein. Lastly, IFI16 was detected in one of seven and anti-IFI16 in three of seven synovial fluids from patients with PsA. Therefore, IFI16 and anti-IFI16 are detectable in serum and synovial fluid of PsA patients, especially in cases of elevated CRP.

Exploring the Psoriatic Arthritis Proteome in Search of Novel Biomarkers.

Psoriatic arthritis (PsA) is an inflammatory arthritis which develops in up to one-third of patients suffering from the cutaneous disorder, psoriasis. The complex and heterogeneous nature of PsA renders it difficult to diagnose, leading to poor outcomes and, therefore, warrants an examination into soluble biomarkers, which may facilitate early detection of the disease. Protein biomarkers are a dynamic resource of pathophysiological information able to provide an immediate reflection of pathological changes caused by disease. Investigations of the serum and synovial fluid of PsA patients has provided new insights into the molecular basis of this disease and led to the identification of sensitive diagnostic and prognostic biomarkers. The collection of novel PsA biomarkers identified through proteomic studies has been reviewed below.

Interleukin (IL)-9/IL-9R axis drives γδ T cells activation in psoriatic arthritis patients.

Cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-12, interferon (IFN)-γ, IL-23 and, more recently, IL-9, have been implicated in the initiation/maintenance of inflammation in psoriasis and psoriatic arthritis (PsA). In the present study we aimed to characterize the role of γδ T cells in peripheral blood and synovial fluid of PsA patients and to investigate their response to in-vitro stimulation with antigen or cytokines (IL-9 and IL-23). γδ T cells isolated from peripheral blood mononuclear cells and synovial fluid were analysed by flow cytometry to evaluate the phenotype and cytokine production. IL-23R and IL-9R gene expression were also evaluated by reverse transcription-polymerase chain reaction (RT-PCR). Peripheral blood mononuclear cells (PBMC), sorted γδ T cells and γδ cell lines were also stimulated in vitro with isopentenyl pyrophosphate (IPP), recombinant IL-9 or recombinant IL-23. Our results show an expansion of γδ T cells with a predominant effector memory phenotype in peripheral blood and synovium of untreated PsA patients, which reverses significantly after treatment with anti-TNF-α or anti-IL-12/IL-23R monoclonal antibodies (mAbs). Moreover, in PsA patients γδ T cells activation is driven prevalently by IL-9/IL-9R interaction, and not only by IL-23/IL-23R. Together these findings indicate γδ T cells and IL-9 as new players in the pathogenesis of PsA.

Transcriptional network profile on synovial fluid T cells in psoriatic arthritis.

The objective of the study was to quantify the transcriptional profile, as the main T cell lineage-transcription factors on synovial fluid (SF) T cells, in relation to SF cytokines and T cell frequencies (%) of psoriatic arthritis (PsA) patients. Reverse phase protein array was employed to identify interleukin (IL)-23Rp19-, FOXP3- and related orphan receptor gamma T (RORγt)- protein and Janus associated tyrosine kinases 1 (JAK1), signal transducer and activator and transcription 1 (STAT1), STAT3 and STAT5 phosphoproteins in total T cell lysates from SF of PsA patients. IL-1β, IL-2, IL-6, IL-21 and interferon (INF)-γ were measured using a multiplex bead immunoassay in SF from PsA patients and peripheral blood (PB) from healthy controls (HC). Frequencies of CD4(+)CD25(-), CD4(+)CD25(high) FOXP3(+) and CD4(+)CD25(high) CD127(low) Treg, and either mean fluorescence intensity (MFI) of FOXP3(+) on CD4(+) Treg or MFI of classic IL-6 receptor (IL-6R) α expression on CD4(+)CD25(-) helper/effector T cells (Th/eff) and Treg cells, were quantified in SF of PsA patients and in PB from HC by flow cytometry (FC). In PsA SF samples, IL-2, IL-21 and IFN-γ were not detectable, whereas IL-6 and IL-1β levels were higher than in SF of non-inflammatory osteoarthritis patients. Higher levels of IL-23R-, FOXP3- and RORγt proteins and JAK1, STAT1, STAT3 and STAT5 were found in total T cells from SF of PsA patients compared with PB from HC. Direct correlations between JAK1 Y1022/Y1023 and STAT5 Y694, and STAT3 Y705 and IL6, were found in SF of PsA patients. Increased proportion of CD4(+)CD25(high) FOXP3(+) and CD4(+)CD25(high) CD127(low) Treg cells and brighter MFI of IL-6Rα were observed both on CD4(+)CD25(high)- and CD4(+)CD25(-) T cells in PsA SF. The study showed a distinctive JAK1/STAT3/STAT5 transcriptional network on T cells in the joint microenvironment, outlining the interplay of IL-6, IL-23, IL-1β and γC cytokines in the polarization and plasticity of Th17 and Treg cells, which might participate in the perpetuation of joint inflammation in PsA patients.

Role of IL-17 in Psoriasis and Psoriatic Arthritis

The role of T cell subpopulations in human disease is in a transition phase due to continuous discovery of new subsets of T cell, one of which is Th17, characterized by the production of signature cytokine IL-17. In the last couple of years, many articles are coming out on the role of Th17 and its signature cytokine IL-17 in different autoimmune diseases like rheumatoid arthritis, psoriasis, psoriatic arthritis (PsA), SLE and multiple sclerosis. Psoriasis and PsA are immune-mediated diseases, affecting the skin and joints, respectively. Initially, it was thought that psoriasis and PsA were Th1-mediated diseases; however, studies in knockout animal models (IL-17 knockout mice) as well as human experimental data indicate that Th17 and its signature cytokine IL-17 have a critical role in the pathogenesis of psoriatic disease. Th17 cells have been identified from the dermal extracts of psoriatic lesions. Subsequently, our research group has substantiated this observation that Th17 cells are enriched in the papillary dermis of psoriatic plaques and in freshly isolated effector T lymphocytes from the synovial fluid of PsA patients, and we have reported that the majority of these CD4 + IL-17+ T cells are of memory phenotype (CD4RO(+)CD45RA(-)CD11a(+)). Recent reports also suggest that the synovial tissue in psoriatic arthritis is enriched with IL-17R, and its most well recognized receptor IL-17RA is functionally active in psoriatic arthritis. In this review article, we have discussed the role of IL-17 in psoriatic disease and have narrated about the novel IL17/IL-17R antibodies currently in preparation for its therapeutic uses in autoimmune diseases.

Functional role of IL-22 in psoriatic arthritis

IntroductionInterleukin-22 (IL-22) is a cytokine of IL-10 family with significant proliferative effect on different cell lines. Immunopathological role of IL-22 has been studied in rheumatoid arthritis (RA) and psoriasis. Here we are reporting the functional role of IL-22 in the inflammatory and proliferative cascades of psoriatic arthritis (PsA).MethodFrom peripheral blood and synovial fluid (SF) of PsA (n = 15), RA (n = 15) and osteoarthritis (OA, n = 15) patients, mononuclear cells were obtained and magnetically sorted for CD3+ T cells. Fibroblast like synoviocytes (FLS) were isolated from the synovial tissue of PsA (n = 5), RA (n = 5) and OA (n = 5) patients. IL-22 levels in SF and serum were measured by enzyme linked immunosorbent assay (ELISA). Proliferative effect of human recombinant IL-22 (rIL-22) on FLS was assessed by MTT (3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide, a yellow tetrazole) and CFSE dilution (Carboxyfluorescein succinimidyl ester) assays. Expression of IL-22Rα1 in FLS was determined by western blot.ResultsIL-22 levels were significantly elevated in SF of PsA patients (17.75 ± 3.46 pg/ml) compared to SF of OA (5.03 ± 0.39 pg/ml), p < 0.001. In MTT and CFSE dilution assays, rIL-22 (MTT, OD: 1.27 ± 0.06) induced significant proliferation of FLS derived from PsA patients compared to media (OD: 0.53 ± 0.02), p < 0.001. In addition, rIL-22 induced significantly more proliferation of FLS in presence of TNF-α. IL-22Rα1 was expressed in FLS of PsA, RA and OA patients. Anti IL-22R antibody significantly inhibited the proliferative effect of rIL-22. Further we demonstrated that activated synovial T cells of PsA and RA patients produced significantly more IL-22 than those of OA patients.ConclusionSF of PsA patients have higher concentration of IL-22 and rIL-22 induced marked proliferation of PsA derived FLS. Moreover combination of rIL-22 and TNF-α showed significantly more proliferative effect on FLS. IL-22Rα1 was expressed in FLS. Successful inhibition of IL-22 induced FLS proliferation by anti IL-22R antibody suggests that blocking of IL-22/IL-22R interaction may be considered as a novel therapeutic target for PsA.

Distinct serum and synovial fluid interleukin (IL)-33 levels in rheumatoid arthritis, psoriatic arthritis and osteoarthritis

Objectives Recent evidence suggests a role for interleukin (IL)-33 and its receptor ST2 in arthritis. In this study, we quantified IL-33 and soluble (s)ST2 levels in serum and synovial fluid (SF), and assessed synovial IL-33 expression levels and pattern in patients with rheumatoid arthritis (RA), psoriatic arthritis (PsA), or osteoarthritis (OA). Methods Serum and SF IL-33 and sST2 levels were assessed by ELISA. IL-33 mRNA was quantified by RT-qPCR. Synovial IL-33 protein expression pattern was examined by immunohistochemistry. Results Serum and SF IL-33 levels tended to be higher in RA than in OA patients. In contrast to RA, IL-33 was not detectable in PsA serum and SF. Serum sST2 levels were higher in RA than in OA. There was a wide variation of synovial tissue IL-33 mRNA expression within each disease group and IL-33 mRNA levels were not significantly different between the groups. A similar IL-33 protein expression pattern was observed in RA, PsA and OA synovium, with strong nuclear expression of IL-33 in endothelial cells and, in a subset of RA, PsA and OA patients, in cells morphologically consistent with synovial fibroblasts. Discussion/Conclusions This study confirms increased circulating IL-33 levels in RA. In addition, we report that IL-33 is undetectable in the serum or SF of PsA patients. Local expression of IL-33 in the synovium was observed at similar variable levels in RA, PsA and OA, suggesting that inflamed joints do not represent the primary source of elevated serum and SF levels of IL-33 in RA.

Interleukin 33 expression in human arthritis

Background and objectivesInterleukin 33 (IL-33) is the most recently discovered member of the IL-1 family of cytokines. Recent evidence in human and mouse suggests a role for IL-33 and its...