Defective apoptotic death of activated macrophages has been implicated in the pathogenesis of rheumatoid arthritis (RA). However, the molecular signatures defining apoptotic resistance of RA macrophages are not fully understood. Here, global transcriptome profiling of RA macrophages revealed that the osmoprotective transcription factor nuclear factor of activated T cells 5 (NFAT5) critically regulates diverse pathologic processes in synovial macrophages including the cell cycle, apoptosis, and proliferation. Transcriptomic analysis of NFAT5-deficient macrophages revealed the molecular networks defining cell survival and proliferation. Proinflammatory M1-polarizing stimuli and hypoxic conditions were responsible for enhanced NFAT5 expression in RA macrophages. An in vitro functional study demonstrated that NFAT5-deficient macrophages were more susceptible to apoptotic death. Specifically, CCL2 secretion in an NFAT5-dependent fashion bestowed apoptotic resistance to RA macrophages in vitro. Injection of recombinant CCL2 into one of the affected joints of Nfat5^+/– mice increased joint destruction and macrophage infiltration, demonstrating the essential role of the NFAT5/CCL2 axis in arthritis progression in vivo. Moreover, after intra-articular injection, NFAT5-deficient macrophages were more susceptible to apoptosis and less efficient at promoting joint destruction than were NFAT5-sufficient macrophages. Thus, NFAT5 regulates macrophage survival by inducing CCL2 secretion. Our results provide evidence that NFAT5 expression in macrophages enhances chronic arthritis by conferring apoptotic resistance to activated macrophages.

Nailfold capillaroscopy (NFC) has been used to examine morphological and functional microcirculation changes in connective tissue diseases. It has been demonstrated that NFC patterns reflect abnormal microvascular dynamics, which may play a role in fibromyalgia (FM) syndrome. The aim of this study was to determine NFC patterns in FM, and their association with clinical features of FM. A total of 67 patients with FM, and 30 age- and sex-matched healthy controls, were included. Nailfold capillary patterns were quantitatively analyzed using computerized NFC. The parameters of interest were as follows: number of capillaries within the central 3 mm, deletion score, apical limb width, capillary width, and capillary dimension. Capillary dimension was determined by calculating the number of capillaries using the Adobe Photoshop version 7.0. FM patients had a lower number of capillaries and higher deletion scores on NFC compared to healthy controls (17.3 ± 1.7 vs. 21.8 ± 2.9, p < 0.05; 2.2 ± 0.9 vs. 0.7 ± 0.6, p < 0.05, respectively). Both apical limb width (µm) and capillary width (µm) were significantly decreased in FM patients (1.1 ± 0.2 vs. 3.7 ± 0.6; 5.4 ± 0.5 vs. 7.5 ± 1.4, respectively), indicating that FM patients have abnormally decreased digital capillary diameter and density. Interestingly, there was no difference in capillary dimension between the two groups, suggesting that the length or tortuosity of capillaries in FM patients is increased to compensate for diminished microcirculation. FM patients had altered capillary density and diameter in the digits. Diminished microcirculation on NFC may alter capillary density and increase tortuosity.

Kim HS. Korean J Intern Med. 2014 Jul;29(4):544-545. http://dx.doi.org/10.3904/kjim.2014.29.4.544

Microbiome research has been on the rise recently for a more in-depth understanding of gout. Meanwhile, there is a need to understand the gut microbiome related to uric acid-lowering drug resistance. In this study, 16S rRNA gene-based microbiota analysis was performed for a total of 65 stool samples from 17 healthy controls and 48 febuxostat-treated gout patients (including 28 controlled subjects with decreased uric acid levels and 20 uncontrolled subjects with non-reduced uric acid levels). Alpha diversity of bacterial community decreased in the healthy control, controlled, and uncontrolled groups. In the case of beta diversity, the bacterial community was significantly different among groups (healthy control, controlled, and uncontrolled groups). Taxonomic biomarker analysis revealed the increased population of g-Bifidobacterium in healthy controls and g-Prevotella in uncontrolled patients. PCR further confirmed this result at the species level. Additionally, functional metagenomics predictions led to the exploration of various functional biomarkers, including purine metabolism. The results of this study can serve as a basis for developing potential new strategies for diagnosing and treating gout from microbiome prospects.

This single-center, retrospective study aimed to investigate the course and prognostic factors of patients with primary Sjögren syndrome-associated interstitial lung disease (pSS-ILD). We included 120 pSS patients who underwent at least two high-resolution computed tomography (HRCT) scans between 2013 and 2021. Clinical symptoms, laboratory data, HRCT findings, and pulmonary function test results were collected. Two thoracic radiologists reviewed the HRCT findings. In patients with pSS without ILD at baseline (n = 81), no development of ILD was found on follow-up (median, 2.8 years). In patients with pSS-ILD (n = 39), total disease extent, extent of coarse reticulation, and traction bronchiectasis increased on HRCT, whereas the extent of ground glass opacity (GGO) decreased at follow-up (median, 3.2 years) (each p < 0.001). In progressive group of pSS-ILD (48.7%), the extent of coarse reticulation and coarseness score of fibrosis were increased at follow-up (p < 0.05). Usual interstitial pneumonia pattern on CT (OR, 15.237) and follow-up duration (OR, 1.403) were independent risk factors for disease progression in patients with pSS-ILD. In both progressive and non-progressive pSS-ILD, GGO decreased, whereas the extent of fibrosis increased even after treatment with glucocorticoid and/or immunosuppressants. In conclusion, progression occurred in approximately half of the pSS-ILD patients with slow gradual deterioration. Our study identified a definite group of progressive pSS-ILD who did not respond to current anti-inflammatory treatment.