[Hypogonadism in men with inflammatory joint diseases: Frequency and clinical characteristics].

AIM: To study the frequency of hypogonadism (HG) in men with rheumatoid arthritis (RA), ankylosing spondylitis (AS) and psoriatic arthritis (PsA) and to evaluate the impact of HG on the course of RA and and concomitant diseases. MATERIALS AND METHODS: A single-stage continuous study included 170 men with RA, 57 men with AS and 85 men with PsA, who were hospitalized at the Nasonova Research Institute of Rheumatology. Patients were assessed for total testosterone (ТS) levels and subsequently divided into subgroups with normal (>12 nmol/l) and reduced levels. An intergroup comparison was carried out on the main indicators used in clinical rheumatological practice to assess the stage, activity and other medical and demographic characteristics of rheumatic disease, as well as on concomitant conditions. The second stage of the study involved a pairwise intergroup comparison among patients with HG with RA, AS and PsA. RESULTS: The incidence of ТS deficiency among patients with RA was 24.1%, among patients with AS - 17.5%, and with PsA - 31.8%. In patients with RA, HG was associated with a significantly higher mean body mass index, higher fasting blood glucose and uric acid, higher erythrocyte sedimentation rate and anemia. Patients with AS with HG had significantly lower hemoglobin levels and more frequent anemia, as well as higher levels of C-reactive protein and erythrocyte sedimentation rate. In PsA, older age was observed in the androgen deficiency group, as well as higher body mass index and fasting glucose levels; obesity was more common. An intergroup comparison of quantitative and qualitative indicators between patients with androgen deficiency in all three rheumatic diseases (RDs) did not reveal significant differences in the average concentrations of ТS, luteinizing hormone, sex hormone binding globulin, experience of RD, laboratory markers of inflammatory activity, as well as glucose and uric acid. A similar incidence of diabetes mellitus, obesity and anemia was noted for all three nosologies. CONCLUSION: ТS levels and the presence of HG were not associated with the stage and activity of RD, but ТS deficiency was accompanied by higher laboratory indicators of inflammatory activity, lower hemoglobin values, and metabolic disorders. Patients with HG, regardless of nosology, had similar levels of sex hormones and indicators reflecting RD and concomitant conditions.

[Bone mineral density in women with rheumatoid arthritis: A link between immune and biochemical markers].

AIM: To study the association of bone mineral density (BMD) with serum biochemical and immunological markers in postmenopausal women with rheumatoid arthritis (RA). MATERIALS AND METHODS: The study included 173 women with RA (age 61.0 [56.0; 66.0] years). A survey, dual-energy X-ray absorptiometry to measure the BMD of the lumbar spine (LI-LIV), femoral neck (FN) and total hip (TH), routine blood chemistry, measurement of C-reactive protein (CRP), rheumatoid factor, cyclic citrullinated peptide antibodies (CCPA), parathyroid hormone (PTH), vitamin D3, myostatin, follistatin, interleukin-6 (IL-6), IL-6 receptors, insulin-like growth factor 1, adiponectin, leptin, fibroblast growth factor 23, and tumor necrosis factor SF12 were performed. RESULTS: PTH (ß=-0.22, -0.35 and -0.30 for LI-LIV, FN and TH, respectively), CRP (ß=-0.18, 0.23 and -0.22 for LI-LIV, FN and TH, respectively) and leptin (ß=0.35, 0.32 and 0.42 for LI-LIV, FN and TH, respectively) were shown a significant association with BMD in all sites of measurement. It was independent of age, body mass index and postmenopause duration. Associations were also found between adiponectin and BMD of LI-LIV and TH (ß=-0.36 and -0.28, respectively), CCPA and BMD of FN and TH (ß=-0.21, -0.24, respectively) and IL-6 and BMD of FN (ß=0.37). CONCLUSION: The study of biochemical and immunological markers in women with RA demonstrated that CRP, CCPA, PTH, IL-6, adiponectin, and leptin influenced BMD.

Differences in referral path, clinical and radiographic outcomes between seronegative and seropositive rheumatoid arthritis Mexican Mestizo patients: A cohort study.

BACKGROUND: The study compared the referral path, the first two-year clinical outcomes, and the first five-year radiographic outcomes between seronegative patients (SNPs) from a recent-onset rheumatoid arthritis dynamic cohort initiated in 2004 and seropositive patients (SPPs). Predictors of incidental erosive disease were investigated. PATIENTS AND METHODS: Up to March 2023, one independent observer reviewed the charts from 188 patients with at least two years of clinical assessments and up to five years of annual radiographic assessments. SNPs were defined when baseline RF and ACPA serum titers were within local normal ranges. The erosive disease was defined on hand and/or foot radiographs when at least one unequivocal cortical bone defect was detected. The incidental erosive disease was defined in baseline erosive disease-free patients who developed erosions at follow-ups. Multivariate Cox regression analyses identified hazard ratios (95% confidence interval) for factors to predict incidental erosive disease. RESULTS: There were 17 (9%) SNPs, and they had a shorter time from symptoms onset to first physician evaluation, visited a lower number of physicians, and received less intensive treatment at referral and during the first years of follow-up than SPPs. Also, they had fewer 0-66 swollen joints and were less frequently persistent on therapy. The erosive disease was detected only in SPPs, and its frequency increased from 10.1% at baseline to 36.1% at the five-year radiographic assessment. There were 53 (31.4%) patients with incidental erosive disease, and differences between SPPs and SNPs were statistically significant at the feet location. Incidental erosive disease was predicted by baseline ACPA, ESR, substantial morning stiffness, and cumulative CRP. CONCLUSIONS: SNPs showed mild differences in their referral path and clinical outcomes compared to SPPs. However, erosive disease was detected only in SPPs and was predicted by baseline and cumulative clinical and serologic variables.

Differences in IDO1+ dendritic cells and soluble CTLA-4 are associated with differential clinical responses to methotrexate treatment in rheumatoid arthritis.

Objective: Antigen-presenting dendritic cells (DCs) and monocytes play an essential role in rheumatoid arthritis (RA) pathogenesis, however, their tolerogenic potential remains unclear. Herein, the tolerogenic profiles of DCs are characterized in treatment-naïve RA patients to determine their role to inflammatory arthritis management. Methods: Thirty-six treatment-naïve RA patients were enrolled, of which 62% were non-responders to methotrexate (MTX) monotherapy based on disease activity score (DAS) after 6-months of therapy. DC and monocyte subset frequencies, activation (CD40, CD86, CD209 expression), and tolerogenic profile (intracellular indoleamine-2,3-dioxygenase [IDO1] and cytotoxic T lymphocyte antigen 4 [CTLA-4] expression) were examined in the baseline peripheral blood by multicolor flow-cytometry. Soluble CTLA-4 (sCTLA-4) levels in plasma were measured. Results: DC subsets were decreased in RA compared to healthy controls (HC), and the frequency of conventional DCs (cDC) inversely correlated with inflammatory markers and improvement in disease activity. CD141+ cDC1s were the major IDO1-expressing cells. IDO1+cDC1s were reduced in RA patients compared to HC. The baseline frequency of IDO1+cDC1s inversely correlated with improvement in disease activity. CTLA-4 expression in CD1c+ cDC2s and monocytes was lower in RA patients compared to HC. Moreover, MTX-responders had a significantly lower frequency of IDO1+cDC1 cells and higher level of sCTLA-4 in the plasma compared to MTX non-responders. There was a strong predictive association of low IDO1+cDC1 cells, low sCTLA-4 and non-response to MTX. Conclusions: Our findings reveal altered DC and monocytes immunophenotypes that are associated with RA pathology and treatment response. The frequencies of tolerogenic IDO1+cDC1s and the low level of sCTLA-4 are strongly associated with MTX non-responsiveness and therapeutic outcome. These results suggest that investigation of the association IDO1+cDC1 and sCTLA-4 with response to treatment may be more generalizable to other autoimmune diseases.

[Regulatory effect of lactate on peripheral blood CD4+ T cell subsets in patients with rheumatoid arthritis].

OBJECTIVE: To investigate the serum lactate level in patients with rheumatoid arthritis (RA) and its relationship with disease activity, and to analyze the effect of sodium lactate on the activation of CD4+ T cells, the ability of secreting cytokines and CD4+T cell subsets in peripheral blood of the RA patients. METHODS: The peripheral blood of healthy controls (HC) and RA patients was collected, and the content of lactate in the supernatant was detected by lactate detection kit, the correlation between the content of lactate and the disease score of the RA patients was analyzed; the activation level of CD4+ T cells, the proportion of CD4+ T cell subsets and the cytokines secreted by CD4+ T cells in peripheral blood of all the RA patients were detected by flow cytometry after being stimulated with sodium lactate. RESULTS: The serum lactate level in the RA patients (n=66) was significantly higher than that in the HC (n=60, P < 0.001), and there was a certain correlation with disease activity score in 28 joints (DAS28)-C-reactive protein (CRP) (r=0.273, P=0.029), The levels of rheumatoid factor [RF, 197.50 (26.03, 783.00) IU/mL vs. 29.30 (0.00, 102.60) IU/mL, P < 0.01], CRP [37.40 (11.30, 72.60) mg/L vs. 5.83 (2.36, 12.45) mg/L, P < 0.001], were increased in patients with the lactate concentration greater than 5 mmol/L were significantly higher than those in patients with the lactate concentration less than or equal 5 mmol/L, however, there was no significant difference in the expression of erythrocyte sedimentation rate [ESR, 42.00 (19.00, 77.00) mm/h vs. 25.00 (12.50, 45.50) mm/h, P>0.05] and anti-cyclic citrullinated peptied (CCP) antibody [82.35 (17.70, 137.00) RU/mL vs. 68.60 (25.95, 119.70) RU/mL, P>0.05]. Compared with the control group, the expression of PD-1 (46.15%±8.54% vs. 41.67%±9.98%, P < 0.001), inducible costimulatory molecule (ICOS, 5.77%±8.60% vs. 18.65%±7.94%, P < 0.01) and CD25 (25.89%±5.80% vs. 22.25%±4.59%, P < 0.01) on the surface of CD4+ T cells in the RA patients treated with sodium lactate was significantly increased. Compared with the control group, the proportion of Th17 (4.62%±1.74% vs. 2.93%±1.92%, P < 0.05) and Tph (28.02%±6.28% vs. 20.32%±5.82%, P < 0.01) cells in CD4+T cells of the RA patients in the sodium lactate treatment group increased. Compared with the control group, the expression of IL-21 (5.73%±1.59% vs. 4.75%±1.71%, P < 0.05) in CD4+T cells was up-regulated in the RA patients treated with sodium lactate. CONCLUSION: The level of serum lactate in RA patients is increased, which promotes the activation of CD4+T cells and the secretion of IL-21, and up-regulates the proportion of Th17 and Tph cells in the RA patients.

Platelet-to-lymphocyte ratios as a haematological marker of synovitis in rheumatoid arthritis with normal acute phase reactant level.

BACKGROUND: Although normal acute phase reactants (APRs) play an important role in assessing disease activity of rheumatoid arthritis (RA), some studies pointed out the discordance between disease activity and APR level. Neutrophil-to-lymphocyte ratios (NLRs), platelet-to-lymphocyte ratios (PLRs) and lymphocyte-to-monocyte ratios (LMRs) have been reported to be sensitive measures of inflammatory reaction. This study aims to explore the value of these haematological makers in assessment of APR-negative RA patients. METHODS: Out of a cohort of 418 consecutive patients with RA, we enrolled 135 patients with normal APR for this study. We performed ultrasound assessments to evaluate synovitis and bone erosion in the affected joints. Synovitis was evaluated by ultrasound grey scale (GS) and power Doppler (PD) with semi-quantitative scoring (0-3). Demographic, clinical and laboratory data were collected from the patients. Disease Activity Score-28 joints (DAS28), NLR, MLR and PLR were calculated. RESULTS: In RA patients with normal APR, PLR exhibited a positive correlation with ultrasound-detected synovitis and bone erosion, whereas NLR, MLR showed no significant correlation with ultrasonography parameters. The area under the ROC curve (AUC) for identifying synovitis with a GS grade ≥2 based on a PLR cutoff value of ≥159.6 was 0.7868 (sensitivity: 80.95%, specificity: 74.24%). For synovitis with a PD grade ≥2, the AUC was 0.7690, using a PLR cutoff value of ≥166.1 (sensitivity: 68.0%, specificity: 83.87%). CONCLUSIONS: Our findings suggested that PLR might be a reliable and cost-effective marker for identifying moderate-to-severe synovitis in RA patients with normal APR.

Relationship of immature granulocytes with disease activity in rheumatoid arthritis.

AIM: To determine whether the IG count (#) and IG percentage (%) are associated with disease activity in rheumatoid arthritis (RA). METHODS: This retrospective study included 65 RA patients and 65 healthy controls. Clinical and demographic characteristics of controls and RA patients (at active period and when the patients achieved remission) were obtained from medical records. Disease activity was defined by disease activity score 28 (DAS28). Furthermore, the clinical disease activity index (CDAI), and simple disease activity index (SDAI) were calculated. For the differential diagnosis of RA patients from healthy controls, the cut-off value was estimated by making receiver-operator curves (ROC). RESULTS: In active RA patients, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), IG#, and IG% levels were significantly higher compared to the healthy controls (p < .001, for all). When the patients achieved remission, DAS28, CDAI, SDAI, ESR, CRP, IG#, and IG% values were significantly decreased (p < .001, for all). IG# and IG% were significantly positively correlated with DAS28, CDAI, SDAI, ESR, and CRP (p = .024, p = .008, p = .003, p < .001, p < .001, respectively). According to ROC curve analysis, IG% and IG# were the biomarkers to have a significant diagnostic value for RA with the area under the curve of 0.853 and 0.865 (p < .001, for all). CONCLUSION: The present study demonstrated that two novel inflammatory markers, IG# and IG%, can be useful for monitoring RA patients' disease activity. Furthermore, IG# and IG% can also be used as fast, inexpensive, and easily available complementary diagnostic markers to diagnose RA patients.

Serum and urine lipidomic profiles identify biomarkers diagnostic for seropositive and seronegative rheumatoid arthritis.

Objective: Seronegative rheumatoid arthritis (RA) is defined as RA without circulating autoantibodies such as rheumatoid factor and anti-citrullinated protein antibodies; thus, early diagnosis of seronegative RA can be challenging. Here, we aimed to identify diagnostic biomarkers for seronegative RA by performing lipidomic analyses of sera and urine samples from patients with RA. Methods: We performed untargeted lipidomic analysis of sera and urine samples from 111 RA patients, 45 osteoarthritis (OA) patients, and 25 healthy controls (HC). These samples were divided into a discovery cohort (n = 97) and a validation cohort (n = 84). Serum samples from 20 patients with systemic lupus erythematosus (SLE) were also used for validation. Results: The serum lipidome profile of RA was distinguishable from that of OA and HC. We identified a panel of ten serum lipids and three urine lipids in the discovery cohort that showed the most significant differences. These were deemed potential lipid biomarker candidates for RA. The serum lipid panel was tested using a validation cohort; the results revealed an accuracy of 79%, a sensitivity of 71%, and a specificity of 86%. Both seropositive and seronegative RA patients were differentiated from patients with OA, SLE, and HC. Three urinary lipids showing differential expression between RA from HC were identified with an accuracy of 84%, but they failed to differentiate RA from OA. There were five lipid pathways that differed between seronegative and seropositive RA. Conclusion: Here, we identified a panel of ten serum lipids as potential biomarkers that can differentiate RA from OA and SLE, regardless of seropositivity. In addition, three urinary lipids had diagnostic utility for differentiating RA from HC.

The role of platelets in central hubs of inflammation: A literature review.

Platelets are increasingly recognized for their multifaceted roles in inflammation beyond their traditional involvement in haemostasis. This review consolidates knowledge on platelets as critical players in inflammatory responses. This study did an extensive search of electronic databases and identified studies on platelets in inflammation, focusing on molecular mechanisms, cell interactions, and clinical implications, emphasizing recent publications. Platelets contribute to inflammation via surface receptors, release of mediators, and participation in neutrophil extracellular trap formation. They are implicated in diseases like atherosclerosis, rheumatoid arthritis, and sepsis, highlighting their interaction with immune cells as pivotal in the onset and resolution of inflammation. Platelets are central to regulating inflammation, offering new therapeutic targets for inflammatory diseases. Future research should explore specific molecular pathways of platelets in inflammation for therapeutic intervention.

Increased interleukin-26 in the peripheral joints of patients with axial spondyloarthritis and psoriatic arthritis, co-localizing with CD68-positive synoviocytes.

Objectives: IL26 levels are elevated in the blood and synovial fluid of patients with inflammatory arthritis. IL26 can be produced by Th17 cells and locally within joints by tissue-resident cells. IL26 induces osteoblast mineralization in vitro. As osteoproliferation and Th17 cells are important factors in the pathogenesis of axial spondyloarthritis (axSpA), we aimed to clarify the cellular sources of IL26 in spondyloarthritis. Methods: Serum, peripheral blood mononuclear cells (n = 15-35) and synovial tissue (n = 3-9) of adult patients with axSpA, psoriatic arthritis (PsA) and rheumatoid arthritis (RA) and healthy controls (HCs, n = 5) were evaluated by ELISA, flow cytometry including PrimeFlow assay, immunohistochemistry and immunofluorescence and quantitative PCR. Results: Synovial tissue of axSpA patients shows significantly more IL26-positive cells than that of HCs (p < 0.01), but numbers are also elevated in PsA and RA patients. Immunofluorescence shows co-localization of IL26 with CD68, but not with CD3, SMA, CD163, cadherin-11, or CD90. IL26 is elevated in the serum of RA and PsA (but not axSpA) patients compared with HCs (p < 0.001 and p < 0.01). However, peripheral blood CD4+ T cells from axSpA and PsA patients show higher positivity for IL26 in the PrimeFlow assay compared with HCs. CD4+ memory T cells from axSpA patients produce more IL26 under Th17-favoring conditions (IL-1ß and IL-23) than cells from PsA and RA patients or HCs. Conclusion: IL26 production is increased in the synovial tissue of SpA and can be localized to CD68+ macrophage-like synoviocytes, whereas circulating IL26+ Th17 cells are only modestly enriched. Considering the osteoproliferative properties of IL26, this offers new therapeutic options independent of Th17 pathways.

Differences in the expression of long noncoding RNAs in peripheral blood mononuclear cells indicate potential biomarkers for rheumatoid arthritis.

OBJECTIVE: Long noncoding RNAs (lncRNAs) play an increasingly important role in various autoimmune diseases. We aimed to characterize the expression profiles of lncRNAs in peripheral blood mononuclear cells (PBMCs) from RA patients and to assess the potential of these lncRNAs as RA biomarkers. METHODS: Whole-transcriptome sequencing was used to establish a lncRNA expression profile. A total of 155 RA patients, 145 healthy controls, 59 systemic lupus erythematosus (SLE) patients and 59 primary Sjögren's syndrome (pSS) patients were recruited for this study. Four candidate lncRNAs (linc00152, lnc-ADM-1, ITSN1-2, and lnc-FTH1-7) were validated via qRT-PCR in independent samples, and their expression, association with RA clinical features and value as RA biomarkers were evaluated. RESULTS: Linc00152 and lnc-ADM-1 exhibited upregulated expression (p = 0.001, p = 0.014, respectively), while ITSN1-2 and lnc-FTH1-7 exhibited downregulated expression (both p < 0.001, respectively) in RA patients compared to controls. Lnc-ADM-1 and lnc-FTH1-7 expression correlated positively with the C4 level (p = 0.016 and p = 0.012, respectively). ITSN1-2 levels were negatively associated with CRP levels (p = 0.024). Linc00152, lnc-ADM-1, ITSN1-2, and lnc-FTH1-7 showed potential as RA biomarkers, with the four-lncRNA panel distinguishing RA patients from controls, SLE patients, or pSS patients (AUC = 0.886, 0.746, and 0.749, respectively). CONCLUSION: The altered expression of linc00152, lnc-ADM-1, ITSN1-2 and lnc-FTH1-7 in RA patients suggested that these genes may serve as potential biomarkers for RA and could be involved in its pathogenesis.

Correlation of serum matrix metalloproteinase 3 with osteoporosis in patients of postmenopausal rheumatoid arthritis.

Osteoporosis (OP) is a common complication of postmenopausal women with rheumatoid arthritis (RA). Herein, the objective of our study was to explore the correlation between serum matrix metalloproteinase 3 (MMP3) and OP among postmenopausal women with RA to foster better diagnosis and treatment. A total of 208 elderly postmenopausal women with RA were included in this study, with 83 patients diagnosed with OP after RA diagnosis and 125 patients without OP. Serum MMP3 levels and bone mineral density (BMD) were measured and compared. The predictive value of serum MMP3 for OP in this population was also analyzed using receiver operating curve (ROC) analysis. Postmenopausal women with RA and OP diagnosis had markedly higher serum MMP3 levels, compared to those without OP. ROC analysis showed that serum MMP3 had predictive value for OP. Additionally, a negative correlation was observed between serum MMP3 levels and BMD. High serum MMP3 levels were also found to be associated with high abnormal bone metabolism. We found that serum MMP3 levels are strongly correlated with OP in postmenopausal women with RA and that elevated levels of serum MMP3 are linked to low BMD and high abnormal bone metabolism. Serum MMP3 may be a useful biomarker for predicting OP in this population, and could potentially aid in the development of targeted prevention and treatment strategies.

Identification of autoantibodies against PsoP27 in synovial fluid derived from psoriatic arthritis and rheumatoid arthritis patients.

PsoP27 is an antigen expressed in psoriatic lesions. It plays an inflammatory role in psoriasis. This study objective was to characterize antibodies (Abs) against PsoP27 in patients with psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Levels of Abs against native and citrullinated PsoP27 in PsA and RA patients' synovial fluid (SF) and sera were determined by ELISA. SF of osteoarthritis (OA) patients and sera of healthy donors were used as controls. Levels of Abs against PsoP27 were correlated with disease activity scores. Abs against native and citrullinated PsoP27 levels in SF of PsA (n = 48; 0.38 ± 0.03 and 0.44 ± 0.04, respectively) and RA (n = 22; 0.57 ± 0.1 and 0.62 ± 0.09, respectively) were significantly higher than in OA patients (n = 23; 0.14 ± 0.01 and 0.15 ± 0.01, respectively) (p < .0001). For both Abs, there were no significant differences between their level in PsA and RA patients. There was no difference in the level of Abs against citrullinated PsoP27 in SF of seronegative versus seropositive RA patients. Levels of Abs against both native and citrullinated PsoP27 in the SF and level of systemic C-reactive protein in PsA correlated positively, while in RA there were no significant correlations with disease activity scores. No differences in level of Abs against PsoP27 were found in the sera of all three study groups. Abs against native and citrullinated PsoP27 are present in PsA and RA SF but not in those of OA patients, suggesting a potential role of those Abs in inflammatory joint diseases.

Plasma mtDNA as a possible contributor to and biomarker of inflammation in rheumatoid arthritis.

OBJECTIVES: Neutrophil extracellular trap formation and cell-free DNA (cfDNA) contribute to the inflammation in rheumatoid arthritis (RA), but it is unknown if mitochondrial DNA (mtDNA) or nuclear DNA (nDNA) is more abundant in the circulation. It is unclear if DNA concentration measurements may assist in clinical decision-making. METHODS: This single-center prospective observational study collected plasma from consecutive RA patients and healthy blood donors. Platelets were removed, and mtDNA and nDNA copy numbers were quantified by polymerase chain reaction (PCR). RESULTS: One hundred six RA patients and 85 healthy controls (HC) were recruited. Circulating median mtDNA copy numbers were increased 19.4-fold in the plasma of patients with RA (median 1.1 x108 copies/mL) compared to HC (median 5.4 x106 copies/mL, p<0.0001). Receiver operating characteristics (ROC) curve analysis of mtDNA copy numbers identified RA patients with high sensitivity (92.5%) and specificity (89.4%) with an area under the curve (AUC) of 0.97, p <0.0001 and a positive likelihood ratio of 8.7. Demographic, serological (rheumatoid factor (RF) positivity, anti-citrullinated protein antibodies (ACPA) positivity) and treatment factors were not associated with DNA concentrations. mtDNA plasma concentrations, however, correlated significantly with disease activity score-28- erythrocyte sedimentation rate (DAS28-ESR) and increased numerically with increasing DAS28-ESR and clinical disease activity index (CDAI) activity. MtDNA copy numbers also discriminated RA in remission (DAS28 <2.6) from HC (p<0.0001). Also, a correlation was observed between mtDNA and the ESR (p = 0.006, R= 0.29). Similar analyses showed no significance for nDNA. CONCLUSION: In contrast to nDNA, mtDNA is significantly elevated in the plasma of RA patients compared with HC. Regardless of RA activity, the abundance of circulating mtDNA is a sensitive discriminator between RA patients and HC. Further validation of the diagnostic value of mtDNA testing is required.

Expression and diagnostic value of interleukin-22 in rheumatoid arthritis-associated interstitial lung disease.

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is characterized by a high incidence and mortality rate, highlighting the need for biomarkers to detect ILD early in RA patients. Previous studies have shown the protective effects of Interleukin-22 (IL-22) in pulmonary fibrosis using mouse models. This study aims to assess IL-22 expression in RA-ILD to validate foundational experiments and explore its diagnostic value. The study included 66 newly diagnosed RA patients (33 with ILD, 33 without ILD) and 14 healthy controls (HC). ELISA was utilized to measure IL-22 levels and perform intergroup comparisons. The correlation between IL-22 levels and the severity of RA-ILD was examined. Logistic regression analysis was employed to screen potential predictive factors for RA-ILD risk and establish a predictive nomogram. The diagnostic value of IL-22 in RA-ILD was assessed using ROC. Subsequently, the data were subjected to 30-fold cross-validation. IL-22 levels in the RA-ILD group were lower than in the RA-No-ILD group and were inversely correlated with the severity of RA-ILD. Logistic regression analysis identified IL-22, age, smoking history, anti-mutated citrullinated vimentin antibody (MCV-Ab), and mean corpuscular hemoglobin concentration (MCHC) as independent factors for distinguishing between the groups. The diagnostic value of IL-22 in RA-ILD was moderate (AUC = 0.75) and improved when combined with age, smoking history, MCV-Ab and MCHC (AUC = 0.97). After 30-fold cross-validation, the average AUC was 0.886. IL-22 expression is dysregulated in the pathogenesis of RA-ILD. This study highlights the potential of IL-22, along with other factors, as a valuable biomarker for assessing RA-ILD occurrence and progression.

Association between secondhand smoke exposure and rheumatoid arthritis in US never-smoking adults: a cross-sectional study from NHANES.

While smoking is widely acknowledged as a risk factor for rheumatoid arthritis (RA), the connection between secondhand smoke (SHS) exposure and RA in never-smoking adults remains limited and inconsistent. This study aims to explore and quantify this association using serum cotinine levels. We conducted a cross-sectional study with 14,940 adults who self-report as never smokers, using National Health and Nutrition Examination Survey data from 1999 to 2018. Based on previous literature, SHS exposure was categorized into four groups according to serum cotinine levels. Compared to individuals in the unexposed group (serum cotinine < 0.05 ng/mL), the adjusted odds ratio (OR) for RA was 1.37 (95% CI 1.14-1.64, p = 0.001) in the low exposure group (serum cotinine at 0.05 to 0.99 ng/mL) after adjusting for covariates. However, no significant association was found in the moderate exposure group (serum cotinine at 1 to 10 ng/mL) or the heavy exposure group (serum cotinine ≥ 10 ng/mL). Furthermore, we detected a non-linear, positively saturated correlation between the cotinine levels after log2 transformation and RA, with a turning point at approximately - 2.756 ng/mL (OR = 1.163, 95% CI 1.073-1.261, p = 0.0002). The stability of the results was confirmed by subgroup analysis.

External validation of a multi-biomarker-based score for predicting risk of cardiovascular disease in patients with rheumatoid arthritis.

BACKGROUND: A multi-biomarker disease activity (MBDA)-based cardiovascular disease (CVD) risk score was developed and internally validated in a Medicare cohort to predict 3-year risk for myocardial infarction (MI), stroke or CVD death in patients with rheumatoid arthritis (RA). It combines the MBDA score, leptin, MMP-3, TNF-R1, age and four clinical variables. We are now externally validating it in a younger RA cohort. METHODS: Claims data from a private aggregator were linked to MBDA test data to create a cohort of RA patients ≥18 years old. A univariable Cox proportional hazards regression model was fit using the MBDA-based CVD risk score as sole predictor of time-to-a-CVD event (hospitalized MI or stroke). Hazard ratio (HR) estimate was determined for all patients and for clinically relevant subgroups. A multivariable Cox model evaluated whether the MBDA-based CVD risk score adds predictive information to clinical data. RESULTS: 49,028 RA patients (340 CVD events) were studied. Mean age was 52.3 years; 18.3% were male. HR for predicting 3-year risk of a CVD event by the MBDA-based CVD risk score in the full cohort was 3.99 (95% CI: 3.51-4.49, p = 5.0×10-95). HR were also significant for subgroups based on age, comorbidities, disease activity, and drug use. In a multivariable model, the MBDA-based CVD risk score added significant information to hypertension, diabetes, tobacco use, history of CVD, age, sex and CRP (HR = 2.27, p = 1.7×10-7). CONCLUSION: The MBDA-based CVD risk score has been externally validated in an RA cohort that is younger than and independent of the Medicare cohort that was used for development and internal validation.

Association between serum antinuclear antibody and rheumatoid arthritis.

Background: The relationship between serum antinuclear antibody (ANA) and rheumatoid arthritis (RA) remains unknown. Therefore, we aimed to evaluate whether serum ANA was associated with an increased risk of RA in a case-control study. Methods: Patients with rheumatoid arthritis hospitalized at Shandong Provincial Hospital from January 2018 to December 2022 were recruited as the case group, and patients with other types of arthritis and healthy people at the same time were taken as the control group. Antinuclear antibody (ANA) was detected by indirect immunofluorescence assays. Propensity score matching was employed to construct a cohort of patients exhibiting comparable baseline characteristics. The relationship between serum ANA and the risk of rheumatoid arthritis was analyzed by logistic regression analysis. Results: A total of 1,175 patients with RA and 1,662 control subjects were included in this study. After adjusting for potential confounding factors in the propensity-score matched cohort, the risk of RA gradually increased with rising of ANA titers. When ANA titers were divided into three groups (1:100, 1:320, and 1:1,000), the OR (95% CI) for ANA titers from low to high was 3.95 (3.01, 5.18), 16.63 (9.44, 29.30), and 17.34 (9.53, 31.54), respectively, compared to those when ANA was negative. The ANA patterns closely related to the occurrence of RA include nuclear homogeneous, nuclear speckled, and cytoplasmic speckled. Among them, the positive rate of nuclear homogeneous was the highest, which accounted for 42.64%. The OR (95% CI) of ANA patterns including nuclear homogeneous, nuclear speckled, and cytoplasmic speckled was 16.81 (11.46, 24.65), 3.40 (2.49, 4.63), and 3.09 (1.77, 5.40), respectively. Conclusion: There was a curve relation between ANA titer and RA, and the higher the ANA titer, the higher the probability of RA. However, there was no statistical difference in probability of RA for 1:320 versus 1:1,000 ANA titers. The most important kind of ANA pattern in the blood of RA patients was nuclear homogeneous. These findings suggest that ANA may be a novel risk marker for RA.

Changes in metabolic parameters and serum YKL-40 levels in Chinese rheumatoid arthritis patients during tocilizumab therapy.

OBJECTIVE: To investigate the metabolic changes during therapy of tocilizumab (TCZ) and methotrexate (MTX) in non-diabetic rheumatoid arthritis (RA) patients and for the first time explore the associations between metabolic parameters and serum YKL-40 (sYKL-40) levels. METHODS: We enrolled active non-diabetic RA patients who were refractory to MTX. Patients received intravenous TCZ (8 mg/kg) once every 4 weeks combined with MTX for 24 weeks. Metabolic parameters and sYKL-40 levels were measured before TCZ infusion at baseline, week 4, week 12, and week 24. Correlations were assessed by the Spearman's rank correlation analysis. RESULTS: A total of 91 non-diabetic RA patients were enrolled in this study. At week 24, we observed a significant elevation in body mass index (BMI), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) levels. In contrast, there was a significant decrease in TC/HDL­C ratio. No apparent changes in insulin resistance were found. Additionally, we detected a significant reduction in sYKL-40 levels during the study. At week 24, changes in sYKL-40 levels showed a significant negative correlation (r = -0.334, p = 0.002) with changes in TC levels. CONCLUSION: The combined therapy of TCZ and MTX resulted in a significant increase in BMI and lipid levels, while an evident decrease in the TC/HDL­C ratio and sYKL-40 levels in RA patients. Additionally, there was a significant correlation between the decrease in sYKL-40 levels and the increase in TC levels during treatment with TCZ and MTX. Key Points • Lipid levels elevated significantly and sYKL-40 levels decreased obviously after therapy of TCZ combined with MTX in Chinese RA patients. • There was a significant correlation between the increase in TC levels and the decrease in sYKL-40 levels during treatment with TCZ and MTX in RA patients.

Multidimensional biomarker approach integrating tumor markers, inflammatory indicators, and disease activity indicators may improve prediction of rheumatoid arthritis-associated interstitial lung disease.

INTRODUCTION: Rheumatoid arthritis (RA) often leads to interstitial lung disease (ILD), significantly affecting patient outcomes. This study explored the diagnostic accuracy of a multi-biomarker approach to offer a more efficient and accessible diagnostic strategy for RA-associated ILD (RA-ILD). METHODS: Patients diagnosed with RA, with or without ILD, at Beijing Tiantan Hospital from October 2019 to October 2023 were analyzed. A total of 125 RA patients were included, with 76 diagnosed with RA-ILD. The study focused on three categories of indicators: tumor markers, inflammatory indicators, and disease activity measures. The heatmap correlation analysis was employed to analyze the correlation among these indicators. Logistic regression was used to determine odds ratios (OR) for indicators linked to RA-ILD risk. Receiver-operating characteristic (ROC) curve analysis was employed to evaluate the diagnostic potential of these indicators for RA-ILD. RESULTS: The results of logistic regression analysis showed that tumor markers (carbohydrate antigen 19-9 (CA19-9), carbohydrate antigen 125 (CA125), and cytokeratin 19 fragment (CYFRA21-1)), as well as inflammatory indicators (neutrophil, neutrophil-to-lymphocyte ratio (NLR), platelet, C-reactive protein (CRP)) and disease activity measures (disease activity score-28-CRP (DAS28-CRP), rheumatoid factor (RF), and anti-cyclic peptide containing citrulline (anti-CCP)), were significantly associated with RA-ILD. The correlation coefficients among these indicators were relatively low. Notably, the combination indicator 4, which integrated the aforementioned three categories of biomarkers, demonstrated improved diagnostic accuracy with an AUC of 0.857. CONCLUSION: The study demonstrated that combining tumor markers, inflammatory indicators, and disease activity measures significantly enhanced the prediction of RA-ILD. Key Points • Multidimensional strategy: Integrated tumor markers, inflammatory indicators, and disease activity measures to enhance early detection of rheumatoid arthritis-associated interstitial lung disease (RA-ILD). • Diagnostic accuracy: Employed heatmap correlation and logistic regression, identifying significant associations and improving diagnostic accuracy with a multidimensional biomarker combination. • Superior performance: The combined multidimensional biomarker strategy demonstrated higher diagnostic precision compared to individual or dual-category indicators. • Clinical relevance: Offers a promising, accessible approach for early detection of RA-ILD in clinical settings, potentially improving patient outcomes.