Characteristics of patients with psoriatic arthritis in Korea: focusing on axial involvement.

BACKGROUND/AIMS: We aimed to clarify the clinical characteristics of psoriatic arthritis (PsA) in Korean patients focusing on PsA with axial involvement. METHODS: A retrospective medical chart review was performed to identify PsA patients at a single tertiary center. Cases of AS patients with psoriasis were recruited from a prospective AS registry of the same center. Demographics, laboratory findings, and radiologic characteristics were assessed. RESULTS: A total of 69 PsA patients were identified. In PsA patients, spondylitis (46.4%) was the most common form. Compared to AS patients with psoriasis, PsA patients with radiographic axial involvement were older (50.9 vs. 32.4 years; p < 0.001) and showed greater peripheral disease activity (peripheral arthritis 78.1 vs. 12.5%, p < 0.001; enthesitis 50.0 vs. 6.3%, p = 0.003). AS patients with psoriasis presented a higher rate of HLA-B*27 positivity (81.3 vs. 17.2%; p < 0.001) and a more frequent history of inflammatory back pain (100.0 vs. 75.0%; p = 0.039) than PsA patients with radiographic axial involvement. Significant proportions of PsA patients with radiographic axial involvement had cervical spine involvement (10/18, 55.6%) and spondylitis without sacroiliitis (10/23, 43.5%). CONCLUSION: We demonstrate that axial involvement is common in Korean PsA patients, and its characteristics can be distinct from those of AS.

Predictors for future development of systemic lupus erythematosus in Korean Sjögren's syndrome patients.

OBJECTIVE: This study determined the impact of demographic factors, clinical manifestations, disease activity, and serological tests at baseline on future SLE development in Sjögren's syndrome (SS) patients. METHODS: This retrospective study assessed 1,082 SS patients without other autoimmune diseases at baseline who visited our hospital between January 2012 and March 2021. We analyzed demographic features, extra-glandular manifestations (EGMs), clinical indices, and laboratory values at baseline between the two groups divided per future SLE development (SS/SLE group vs SS group). The probability and predictors of SLE development in SS patients were estimated using the Kaplan-Meier method and Cox proportional hazards models. RESULTS: The median follow-up duration was 1083.5 days. Forty-nine patients (4.5%) developed SLE that met the 2012 Systemic Lupus International Collaborating Clinics or 2019 EULAR/ACR classification criteria. The baseline EULAR SS disease activity index (ESSDAI) score was significantly higher in the SS/SLE group (p < .001). The SS/SLE group had more lymphadenopathy and renal involvement (p = .015 and p = .017, respectively). Shorter SS disease duration (<3 years) (hazard ratio [HR] = 2.12, p = .0328), high ESSDAI (HR = 8.24, p < .0001), leukopenia (HR = 4.17, p = .0005), thrombocytopenia (HR = 3.38, p = .0059), hypocomplementemia (HR = 29.06, p<.0001), and positive for anti-dsDNA (HR = 13.70, p < .0001), anti-ribonucleoprotein (RNP) (HR = 3.82, p = .0027), and anti-ribosomal P (HR = 6.70, p = .0002) at baseline were SLE development predictors in SS patients. CONCLUSION: Shorter disease duration and higher disease activity of SS at baseline may be risk factors for future SLE development. Serologic predictors of SLE development are hypocomplementemia, leukopenia, thrombocytopenia, and positivity for anti-dsDNA, anti-RNP, and anti-ribosomal P antibodies. If the above factors are observed, close monitoring will be necessary during the follow-up period, considering the possibility of future SLE development.

Reliability and Validity of the Korean Version of the Gout Impact Scale.

BACKGROUND: The Gout Impact Scale (GIS), part of the Gout Assessment Questionnaire 2.0, measures gout-specific health-related quality of life (HRQOL). This study aimed to translate the GIS into Korean and validate the Korean version (K-GIS) using generic HRQOL measures. METHODS: The GIS was translated into Korean and back-translated into English. We asked patients aged 18 years or older who met the 2015 gout classification criteria to fill out the questionnaires (from January 2022 to June 2022); the K-GIS (5 scales [0-100 scores each]), along with the Korean version of Health Assessment Questionnaire (HAQ) and EuroQol-5 dimension (EQ-5D). We investigated the internal consistency, construct validity, and discriminative validity for gout characteristics of K-GIS. The K-GIS form was administrated to patients 4 weeks later to assess the test-retest reliability using the intraclass correlation coefficient (ICC). RESULTS: One hundred patients completed the questionnaire. The mean ± standard deviation age of the patients was 53.0 ± 15.1 years, and 99.0% of the patients were men. All scales had high degree of internal consistency (Cronbach's α = 0.59 to 0.96) and test-retest reliability (n = 18, ICC = 0.83 to 0.94, all P < 0.001), except for unmet gout treatment needs. Weak-to-moderate correlations were observed between the K-GIS scales and HAQ or EQ-5D (r = 0.21 to 0.46). The K-GIS scores were significantly higher in the presence of bone erosion, absence of urate-lowering therapy, serum urate levels > 6 mg/dL, frequent gout flares in the past year, and fewer comorbidities. In contrast, neither the HAQ nor the EQ-5D could discern these subsets of patients. CONCLUSION: The K-GIS is a reliable and valid HRQOL measure for patients with gout. Higher K-GIS scores were associated with clinical characteristics leading to unfavorable outcomes, which were not demonstrated by the HAQ and EQ-5D.

Korean guidelines for the management of gout.

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Korean guidelines for the management of gout.

Gout is the most common form of arthritis, with the prevalence increasing worldwide. The present treatment guidelines provide recommendations for the appropriate treatment of acute gout, management during the inter-critical period, and prevention of chronic complications. The guidelines were developed based on evidence-based medicine and draft recommendations finalized after expert consensus. These guidelines are designed to provide clinicians with clinical evidence to enable efficient treatment of gout.

Identification of gut dysbiosis in axial spondyloarthritis patients and improvement of experimental ankylosing spondyloarthritis by microbiome-derived butyrate with immune-modulating function.

Introduction: Dysbiosis is an environmental factor that affects the induction of axial spondyloarthritis (axSpA) pathogenesis. In the present study, we investigated differences in the gut microbiota of patients with axSpA and revealed an association between specific gut microbiota and their metabolites, and SpA pathogenesis. Method: Using 16S rRNA sequencing data derived from feces samples of 33 axSpA patients and 20 healthy controls (HCs), we examined the compositions of their gut microbiomes. Results: As a result, axSpA patients were found to have decreased α-diversity compared to HCs, indicating that axSpA patients have less diverse microbiomes. In particular, at the species level, Bacteroides and Streptococcus were more abundant in axSpA patients than in HCs, whereas Faecalibacterium (F). prausnitzii, a butyrate-producing bacteria, was more abundant in HCs. Thus, we decided to investigate whether F. prausnitzii was associated with health conditions by inoculating F. prausnitzii (0.1, 1, and 10 µg/mL) or by administrating butyrate (0.5 mM) into CD4+ T cells derived from axSpA patients. The levels of IL-17A and IL-10 in the CD4+ T cell culture media were then measured. We also assessed osteoclast formation by administrating butyrate to the axSpA-derived peripheral blood mononuclear cells. The CD4+ IL-17A+ T cell differentiation, IL-17A levels were decreased, whereas IL-10 was increased by F. prausnitzii inoculation. Butyrate reduced CD4+ IL-17A+ T cell differentiation and osteoclastogenesis. Discussion: We found that CD4+ IL-17A+ T cell polarization was reduced, when F. prausnitzii or butyrate were introduced into curdlan-induced SpA mice or CD4+ T cells of axSpA patient. Consistently, butyrate treatment was associated with the reduction of arthritis scores and inflammation levels in SpA mice. Taken together, we concluded that the reduced abundance of butyrate-producing microbes, particularly F. prausnitzii, may be associated with axSpA pathogenesis.

Kynurenine pathway can be a potential biomarker of fatigue in primary Sjögren's syndrome.

OBJECTIVES: Primary Sjögren's syndrome (pSS) is a chronic autoimmune disease with low quality of life caused by various constitutional symptoms and glandular dysfunction. Although fatigue is one of the most frequent symptoms in pSS, its aetiology or biomarkers are poorly elucidated. We investigated potential relationship between severity of fatigue and the kynurenine pathway in pSS. METHODS: Clinical data and blood samples of 81 patients were obtained from a prospective cohort for pSS and compared with age- and sex-matched healthy controls (HC). Severity of fatigue was defined according to the fatigue domain scores in the ESSPRI. Potential biomarkers related to the kynurenine pathway were determined using ELISA. RESULTS: Of the total, 44 patients were defined as the "severe fatigue (ESSPRI fatigue ≥ 5)" group, whereas 37 as the "less fatigue (ESSPRI fatigue < 5)". Serum tryptophan levels in the severe fatigue group were significantly lower while those of kynurenine were higher. Serum interferon gamma, IDO1, and quinolinic acid levels were mostly higher in the less fatigue group. Kynurenine/tryptophan ratios were distinctly higher in the severe fatigue group than both HC and the less fatigue group (p < 0.001). This ratio showed a strong degree of positive correlation (r = 0.624, p < 0.001) with severity of fatigue in pSS while the other markers showed fair degrees of correlation. CONCLUSIONS: Serum markers related to the kynurenine pathway, especially the kynurenine/tryptophan ratio, may be associated with severity of fatigue in pSS. These results can provide guidance for further investigations on fatigue in pSS.

Rheumatoid Arthritis: Pathogenic Roles of Diverse Immune Cells.

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease associated with synovial tissue proliferation, pannus formation, cartilage destruction, and systemic complications. Currently, advanced understandings of the pathologic mechanisms of autoreactive CD4+ T cells, B cells, macrophages, inflammatory cytokines, chemokines, and autoantibodies that cause RA have been achieved, despite the fact that much remains to be elucidated. This review provides an updated pathogenesis of RA which will unveil novel therapeutic targets.

Longitudinal analysis of symptom-based clustering in patients with primary Sjogren's syndrome: a prospective cohort study with a 5-year follow-up period.

BACKGROUND: Sjogren's syndrome (SS) is a heterogenous disease with various phenotypes. We aimed to provide a relevant subclassification based on symptom-based clustering for patients with primary (p) SS. METHODS: Data from patients in a prospective pSS cohort in Korea were analysed. Latent class analysis (LCA) was performed using patient reported outcomes, including pain, fatigue, dryness, and anxiety/depression. Clinical and laboratory differences between the classes were analysed. Latent transition analysis (LTA) was applied to the longitudinal data (annually for up to 5 years) to assess temporal stability of the classifications. RESULTS: LCA identified three classes among 341 patients with pSS (i.e., 'high symptom burden', 'dryness dominant', 'low symptom burden'). Each group had distinct laboratory and clinical phenotypes. LTA revealed that class membership remained stable over time. Baseline class predicted future salivary gland function and damage accrual represented by a Sjogren's syndrome disease damage index. CONCLUSION: Symptom-based clustering of heterogenous patients with primary Sjogren's syndrome provided a relevant classification supported by temporal stability over time and distinct phenotypes between the classes. This clustering strategy may provide more homogenous groups of pSS patients for novel treatment development and predict future phenotypic evolvement.

Transient Systemic Lupus Erythematosus-like Syndrome Associated With Parvovirus B19 Infection: A Case Report.

Human parvovirus B19 (HPV-B19) usually infects children. We report a case of an adult with HPV-B19 infection mimicking systemic lupus erythematosus (SLE). A previously healthy 46-year-old woman presented with an acute illness of cough, fever, chilling, polyarthritis, and skin rash. Laboratory findings showed pancytopenia, increased creatinine level, proteinuria and hypocomplementemia. Anti-double stranded DNA antibody (anti-dsDNA Ab) and antinuclear antibody were positive. Highly suspected of SLE based on clinical and laboratory findings, the patient was initially treated with corticosteroids. Meanwhile, the result of HPV-B19 polymerase chain reaction, which was done initially with other viral tests to exclude infection, turned out to be positive. Steroid was tapered, and pancytopenia, proteinuria, hypocomplementemia gradually improved. On the seventh day, anti-dsDNA Ab was found to be negatively converted. HPV-B19 infections are mostly self-limited and occur rarely in adults, but if a patient presents lupus-like syndrome with transient autoantibody positivity, lupus mimickers including HPV-B19 should be considered.

Combining non-contrast and dual-energy CT improves diagnosis of early gout.

OBJECTIVES: To determine the incremental value of non-contrast CT (NCCT) on dual-energy CT (DECT) in symptomatic first metatarsophalangeal (MTP) joints in early gout. METHODS: One hundred and fifteen painful joints were consecutively enrolled and gout was diagnosed based on the 2015 EULAR/ACR criteria and/or arthrocentesis. Two readers independently evaluated DECT alone and combined NCCT and DECT (NCCT+DECT) based on four semiquantitative scales. Sensitivities and specificities were compared using McNemar's test. AUC was compared. RESULTS: Of the 115 joints, 72 were defined as an early gout group and 43 as a gout-negative group after exclusion. The sensitivity and specificity for the early gout group on DECT alone were as followed: reader 1 - 52.8% and 100.0% and reader 2 - 51.4% and 100.0%. NCCT+DECT results were as follows: reader 1 - 79.2% and 93.0% and reader 2 - 79.2% and 95.3%. AUC was significantly higher in NCCT+DECT compared to that in DECT alone for the early gout group (0.888 vs. 0.774 for reader 1, p = 0.0004; 0.896 vs. 0.816 for reader 2, p = 0.0142). The false-negative cases on DECT occurred more frequently with the first-onset gout, and tended to be affected by a longer duration of symptoms in the post-hoc analysis. CONCLUSION: The combined analysis of NCCT and DECT improves diagnostic capabilities in symptomatic early gout involving the first MTP joint. KEY POINTS: • MSU crystal depositions in early gout may be seen on non-contrast CT, while still being undetectable by DECT. • Combining non-contrast CT and DECT improves detection of early gout. • False negatives of DECT are more common than previously reported in cases of first-onset gout.

Radiographic Structural Damage Is Worse in the Dominant than the Non-Dominant Hand in Individuals with Early Rheumatoid Arthritis.

OBJECTIVE: The relationship between mechanical stress and radiographic progression in rheumatoid arthritis (RA) is unclear. The assumption is that mechanical stress is greater in the dominant hand. Therefore, the aim of the present study was to compare the presence and progression of erosions and joint space narrowing (JSN) in the dominant and non-dominant hand. METHODS: Data from 194 patients recently diagnosed with seropositive RA, and with hand radiographs taken at the time of diagnosis and at 2-year follow-up, were analyzed retrospectively. Radiographs were scored using the van der Heijde-modified Sharp Score (HSS) method. Each joint group within each hand was rated separately by two independent examiners in a double-blinded manner. RESULTS: One hundred and ninety-four patients were enrolled (80% female, 88% positive rheumatoid factor, 92% positive anti-citrullinated protein antibody, and 95.4% right-handed). The baseline, follow-up erosion and JSN HSS were significantly higher in the dominant hand than in the non-dominant hand. The annual rate of radiographic progression was also higher in the dominant hand. The erosive progression in the wrist joints varied significantly according to handedness, but the erosion in the proximal interphalangeal joints and metacarpophalangeal joints was similar in both hands. The radiographic progression was associated with the dominant hand, an abnormal baseline C-reactive protein level, and joint damage at baseline. There was no significant difference in bone mineral density between the right and left hands. CONCLUSION: Radiological damage was worse and progressed faster in the dominant hand, suggesting that mechanical stress is associated with radiographic joint damage in early and active RA.

The risk of osteoporotic fractures according to the FRAX model in Korean patients with rheumatoid arthritis.

The aim of the current study is to identify patients without osteoporosis who met the criteria of the fracture risk assessment tool (FRAX) of the National Osteoporosis Foundation (NOF) only. The incidence of fractures was investigated in patients who met only the FRAX criteria of the NOF and patients who presented osteoporosis. Five hundred and forty five patients with rheumatoid arthritis who visited a single center were recruited in Korea. In the follow-up period of median 30 months, the new onset of fractures was investigated. Of 223 patients who have no osteoporosis, 39 (17.4%) satisfied the FRAX criteria for pharmacological intervention. During the follow-up period, 2 new onset fractures occurred in patients who met only the FRAX criteria and 22 new onset fractures did in patients with osteoporosis by bone mineral density. The incidence rate for new onset fractures of patients who met only the FRAX criteria was with 295.93 per 10,000 person-years higher than in the general population with 114.99 per 10,000 person-years. Patients who met the FRAX criteria of the NOF only need pharmacological intervention because their numbers of incidence for new onset fractures are similar to those of patients with osteoporosis by BMD.