Targeting pathogenic fibroblast-like synoviocyte subsets in rheumatoid arthritis.

Fibroblast-like synoviocytes (FLSs) play a central role in RA pathogenesis and are the main cellular component in the inflamed synovium of patients with rheumatoid arthritis (RA). FLSs are emerging as promising new therapeutic targets in RA. However, fibroblasts perform many essential functions that are required for sustaining tissue homeostasis. Direct targeting of general fibroblast markers on FLSs is challenging because fibroblasts in other tissues might be altered and side effects such as reduced wound healing or fibrosis can occur. To date, no FLS-specific targeted therapies have been applied in the clinical management of RA. With the help of high-throughput technologies such as scRNA-seq in recent years, several specific pathogenic FLS subsets in RA have been identified. Understanding the characteristics of these pathogenic FLS clusters and the mechanisms that drive their differentiation can provide new insights into the development of novel FLS-targeting strategies for RA. Here, we discuss the pathogenic FLS subsets in RA that have been elucidated in recent years and potential strategies for targeting pathogenic FLSs.

Seronegative primary Sjögren's syndrome, a distinct subtype of primary Sjögren's syndrome in Chinese patients.

BACKGROUND: To investigate the clinical and immune characteristics of patients with primary Sjögren's syndrome (pSS) who were negative for anti-Sjögren's-syndrome-related antigen A antibodies (anti-SSA) and anti-Sjögren's-syndrome-related antigen B antibodies (anti-SSB) in Chinese population. METHODS: A retrospective study were performed and 232 patients with pSS were analyzed. Patients positive for anti-SSA or/and anti-SSB were termed as seropositive pSS, and these negative for both anti-SSA and anti-SSB (non-antinuclear antibodies) as seronegative pSS. Clinical manifestations and laboratory findings were compared between the two groups. RESULTS: Among the 232 patients with pSS, 192 (82.8%) were seropositive pSS and 40 (17.2%) were seronegative pSS. Compared to seropositive pSS, seronegative pSS were older and with higher percentage of low disease activity (ESSDAI < 5), xerostomia and xerophthalmia, with higher platelet count and level of creatine kinase. This subgroup was with lower levels of gamma globulin, immunoglobulin G, immunoglobulin A and autoantibodies including rheumatoid factor and antinuclear antibody in serum, and less immunoglobulin G deposition in labial gland. CONCLUSION: Seronegative pSS was a distinct subtype of pSS different from seropositive pSS. Clinical manifestations in seronegative pSS subgroup were restricted to exocrine gland and less B lymphocyte activation, while seropositive pSS were prone to present with systemic involvement and high disease activity. Specific underlying pathogenesis mechanisms and therapeutic strategies in this subgroup needed to be further studied.

Regulatory Fibroblast-Like Synoviocytes Cell Membrane Coated Nanoparticles: A Novel Targeted Therapy for Rheumatoid Arthritis.

Fibroblast-like synoviocytes (FLS) are the main cell component in the inflamed joints of patients with rheumatoid arthritis (RA). FLS intimately interact with infiltrating T cells. Fibroblasts have potent inhibitory effects on T cells, leading to the resolution of inflammation and immune tolerance. However, this "regulatory" phenotype is defect in RA, and FLS in RA instead act as "proinflammatory" phenotype mediating inflammation perpetuation. Signals that orchestrate fibroblast heterogeneity remain unclear. Here, it is demonstrated that different cytokines can induce distinct phenotypes of FLS. Interferon-gamma (IFN-γ) is pivotal in inducing the regulatory phenotype of FLS (which is termed FLSreg ) characterized by high expressions of several inhibitory molecules. Rapamycin enhances the effect of IFN-γ on FLS. Based on the characteristics of FLSreg , a novel biomimetic therapeutic strategy for RA is designed by coating cell membrane derived from FLSreg induced by IFN-γ and rapamycin on nanoparticles, which is called FIRN. FIRN show good efficacy, stability, and inflammatory joint targeting ability in an RA mouse model. The findings clarify how fibroblast phenotypes are modulated in the inflammatory microenvironment and provide insights into novel therapeutic designs for autoimmune diseases based on regulatory fibroblasts.

Association between antinuclear antibody and female infertility: A meta-analysis.

Autoimmunity is reported involving in reproductive failures, and antinuclear antibody (ANA) positivity has been regarded as a typical feature of autoimmunity. Published studies on the association of ANA with reproductive failures including infertility are controversial. The aim of this meta-analysis was to analyse whether the presence of ANA positivity increases the risk of infertility in women. We searched the PubMed and Embase databases for relevant literature without any restrictions prior to April 28, 2021. All analyses were performed using the RevMan 5.3 software. Twelve studies with 2734 participants, including 1482 patients with infertility, met the inclusion and exclusion criteria. The total positivity rate of ANA was 23.8% (353/1482) in all infertile patients and 8.5% (107/1252) in the control group. Infertile females had a significantly higher ANA positivity rate than the control group (odds ratio [OR] = 2.90, 95% confidence interval [CI]: 1.72-4.87, I2 = 65%, P < .0001). Several subgroup analyses were performed to reduce the heterogeneity. ANA positivity was associated with female infertility in studies either performed by indirect immunofluorescence (OR = 2.26, 95% CI:1.67-3.06, P < .00001) or by ELISA (OR = 10.76, 95% CI:1.82-63.64, P < .00001). ANA was significantly associated with increased risk of women infertility either after the definite exclusion of individuals with autoimmune diseases (AID) or without exclusion [(OR = 1.99, 95% CI:1.29-3.06, P = .002), (OR = 2.76, 95% CI:1.56-4.88, P = .0005), respectively]. This meta-analysis provides a comprehensive overview of the prevalence of antinuclear antibodies (ANA) in infertile women and suggests that ANA positivity increases the risk of infertility.