The aim of this study was to investigate differences between the gut microbiota composition in patients with rheumatoid arthritis (RA) and those with osteoarthritis (OA). Stool samples from nine RA patients and nine OA patients were collected, and DNA was extracted. The gut microbiome was assessed using 16S rRNA gene amplicon sequencing. The structures and differences in the gut microbiome between RA and OA were analyzed. The analysis of diversity revealed no differences in the complexity of samples. The RA group had a lower Bacteroidetes: Firmicutes ratio than did the OA group. Lactobacilli and Prevotella, particularly Prevotella copri, were more abundant in the RA than in the OA group, although these differences were not statistically significant. The relative abundance of Bacteroides and Bifidobacterium was lower in the RA group. At the species level, the abundance of certain bacterial species was significantly lower in the RA group, such as Fusicatenibacter saccharivorans, Dialister invisus, Clostridium leptum, Ruthenibacterium lactatiformans, Anaerotruncus colihominis, Bacteroides faecichinchillae, Harryflintia acetispora, Bacteroides acidifaciens, and Christensenella minuta. The microbial properties of the gut differed between RA and OA patients, and the RA dysbiosis revealed results similar to those of other autoimmune diseases, suggesting that a specific gut microbiota pattern is related to autoimmunity.

Background and Objectives: We investigated whether nutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphoycte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) are associated with the presence of osteoporosis (OP) and vertebral fractures in patients with rheumatoid arthritis (RA). Materials and Methods: This retrospective cohort study included 413 postmenopausal patients with RA and 200 healthy controls who underwent dual-energy X-ray absorptiometry (DEXA) between January 2005 and December 2017. DEXA examination data were defined as the index date, and all laboratory values were measured within one month from the index date. OP was defined as a T-score < −2.5, and incident vertebral fractures were defined as the first occurrence of non-traumatic fractures after the index date. NLR, PLR, and MLR measures were dichotomized by a median split (low vs. high). Results: The median NLR, PLR, and MLR in RA patients were significantly higher than those in controls. The frequencies of OP of the lumbar spine, hip, and either site in postmenopausal patients with RA were 24.7%, 15.5%, and 32%, respectively, and were significantly higher than those in controls. After adjusting for confounding factors, a high baseline NLR was significantly associated with OP at either site (OR = 1.61, p = 0.041). In addition, high baseline NLR (OR = 2.11, p = 0.025) and PLR (OR = 2.3, p = 0.011) were related with the presence OP at hip. During the follow-up period, 53 (12.8%) patients with RA developed vertebral fractures incidentally. In multivariable Cox regression models, a high baseline NLR (HR = 4.72, p < 0.001), PLR (HR = 1.96, p = 0.024), and MLR (HR = 2.64, p = 0.002) were independently associated with a higher risk of incidental vertebral fractures. Conclusions: Our data suggest that NLR, PLR, and MLR can be used as potential markers of systemic bone loss among individuals with RA.

Background: To investigate the diagnostic performance of the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and monocyte-to-lymphocyte ratio (MLR) in the diagnosis of rheumatoid arthritis (RA) in subjects with undifferentiated inflammatory arthritis (UIA). Methods: This retrospective cohort study investigated 201 female patients with UIA (≥1 swollen joint) and 280 age-matched, healthy female controls. “Clinical RA” was defined based on the clinical judgment of a rheumatologist and “disease-modifying anti-rheumatic drugs (DMARDs) RA” was defined as a case of initiating DMARDs treatment within 6 months after the first visit. “Classified RA” was defined as fulfilling the 2010 classification criteria for RA. Receiver operating characteristics were used to determine the optimal cut-off value. Results: UIA patients had a significantly higher NLR, PLR, and MLR than the controls. Among the 201 UIA patients, 65 (32.3%), 63 (31.3%), and 61 (30.3%) subjects were classified as clinical RA, DMARDs RA, and classified RA, respectively. At a cut-off of 0.24, MLR showed moderate accuracy for the diagnosis of DMARDs RA (sensitivity, 65.1%; specificity, 62.3%; area under the curve [AUC], 0.701; p < 0.001). However, the diagnostic accuracies of NLR and PLR were low. Conclusions: MLR may be used as a complementary diagnostic indicator for RA diagnosis in patients with UIA.

Poor adherence with oral bisphosphonates (BPs) can mitigate their therapeutic benefit for osteoporosis and is a significant clinical burden. Most previous studies regarding adherence with oral BPs have focused on postmenopausal osteoporosis, but little attention has been given to patients with rheumatoid arthritis (RA). Thus, we investigated compliance and persistence with oral BPs in the treatment of osteoporosis and analyzed risk factors for poor adherence in female patients with (RA) in real setting. This is a retrospective longitudinal study including 396 female patients with RA in whom oral BPs were newly initiated from Aug 2004 to Aug 2014 at a university rheumatology center in South Korea. Compliance was quantified using the 1-year medication possession ratio (MPR), while persistence was defined as duration from the initiation to the end of BPs therapy without interruption exceeding 56 days. Seropositve RA was defined as having a positive test result for the presence of either rheumatoid factor or anti-cyclic citrullinated peptide antibody. Of 396 RA patients, 221 (55.8%) were prescribed risedronate 35 mg weekly; 17 (4.3%) received alendronate 70 mg weekly; and 158 (39.9%) received ibandronate 150 mg monthly. The 1-year MPR was 70.1% and the proportion of RA patients with the 1-year MPR ≥ 0.8 was 60.1%. A total of 274 (69.2%) patients discontinued oral BPs during the study period and persistence with BPs was 63.3% at 1 year, 50.7% at 2 years and 33.3% at 3 years. The most common cause of non-persistence was adverse events (47.5%), followed by poor health literacy (40.5%) and cost (12%). Both compliance and persistence with monthly oral BPs were significantly lower than those with weekly regimens (OR: 2.48, 95% CI: 1.59–3.89, P < 0.001 and HR: 2.19, 95% CI: 1.69–2.83, P < 0.001, respectively). Additionally, patients with seropositive RA showed better compliance and persistence with BPs compared with their seronegative counterparts. Compliance and persistence with oral BPs in RA patients were suboptimal in real practice, thereby limiting the efficacy of osteoporosis treatment. Extending the dosing interval of BPs may improve medication adherence in RA patients.