Ji-Hyoun Kang

Cost-Effectiveness Analysis of HLA–B5801 Genotyping in the Treatment of Gout Patients With Chronic Renal Insufficiency in Korea

Allopurinol‐induced severe cutaneous adverse reactions (SCARs) are relatively rare but cause high rates of morbidity and mortality. Studies have shown that the HLA–B5801 allele and renal impairment are strongly associated with SCARs. Recent American College of Rheumatology guidelines recommend that, prior to treatment with allopurinol, the HLA–B5801 genotype of gout patients at high risk for SCARs, including Korean patients with chronic renal insufficiency, should be determined. However, whether such genotyping is cost‐effective is unknown. This study evaluated the cost‐effectiveness of HLA–B5801 genotyping for the treatment of gout in patients with chronic renal insufficiency in Korea.

Drug survival rates of tumor necrosis factor inhibitors in patients with rheumatoid arthritis and ankylosing spondylitis.

We investigated the compliance of Korean patients using tumor necrosis factor (TNF) inhibitors to treat rheumatoid arthritis (RA) and ankylosing spondylitis (AS), and identified potential predictors associated with treatment discontinuation. The study population comprised 114 RA and 310 AS patients treated with TNF inhibitors at a single tertiary center for at least 1 yr from December 2002 to November 2011. Of the 114 RA patients, 64 (56.1%) discontinued their first TNF inhibitors with a mean duration of 18.1 months. By contrast, 65 of 310 patients (21.0%) with AS discontinued their first TNF inhibitors, with a mean duration of 84 months. Although the survival rate did not differ among the three TNF inhibitors in the AS patients, the etanercept group had a lower discontinuation rate than the infliximab group in the RA patients. In addition, RA patients who received corticosteroids in combination with TNF inhibitors were more likely to discontinue their TNF inhibitors. The independent predictors of drug discontinuation in AS patients were male gender and complete ankylosis on radiographs of the sacroiliac joint. Our results provide further evidence that real-life treatment outcomes of RA and AS patients may be different from those observed in randomized clinical trials. Graphical Abstract

Exploring Genetic Susceptibility to Fibromyalgia

Fibromyalgia (FM) affects 1% to 5% of the population, and approximately 90% of the affected individuals are women. FM patients experience impaired quality of life and the disorder places a considerable economic burden on the medical care system. With the recognition of FM as a major health problem, many recent studies have evaluated the pathophysiology of FM. Although the etiology of FM remains unknown, it is thought to involve some combination of genetic susceptibility and environmental exposure that triggers further alterations in gene expression. Because FM shows marked familial aggregation, most previous research has focused on genetic predisposition to FM and has revealed associations between genetic factors and the development of FM, including specific gene polymorphisms involved in the serotonergic, dopaminergic, and catecholaminergic pathways. The aim of this review was to discuss the current evidence regarding genetic factors that may play a role in the development and symptom severity of FM.

Associations between body composition measurements of obesity and radiographic osteoarthritis in older adults: Data from the Dong-gu Study

BackgroundWe examined the effects of fat deposition on radiographic osteoarthritis (OA) to determine the role of obesity in the pathogenesis of radiographic OA.MethodsData were taken from the Dong-gu cohort, a cross-sectional study of 2,367 subjects. Baseline characteristics, waist circumference (WC), waist-to-hip ratio (WHR), fat mass, and fat percentage were collected, along with X-rays of the knees and hands. Total knee and hand radiographic OA scores were summed using a semi-quantitative grading system, and then stratified by gender using a multiple linear regression model.ResultsAfter adjusting for confounders, weight was the only factor significantly associated with knee radiographic OA, regardless of gender (all p < 0.01). Regarding the hand, fat percentage had the largest effect on radiographic OA in males (p = 0.008), while WHR was the most significant factor in females (p = 0.001). For the knee, fat mass was the most important factor for radiographic OA in males (p = 0.001), while in females, body mass index was the most important factor (p < 0.001). Among the variables, only fat percentage was significantly related to both hand and knee radiographic OA in both genders (all p < 0.01).ConclusionsRegardless of gender, weight was significantly associated with knee radiographic OA. Otherwise, fat deposition correlated with hand and knee radiographic OA in both genders, while the distribution of fat tissue was significantly associated with hand and knee radiographic OA only in females.

Anti-centromere antibody-positive Sjögren's syndrome: A distinct clinical subgroup?

To investigate whether patients with Sjögrens syndrome (SS) can be distinguished based on the positivity of anti‐centromere antibody (ACA), and if so, whether the subgroups differ in their clinical and laboratory features.

Predictors of Switching Anti-Tumor Necrosis Factor Therapy in Patients with Ankylosing Spondylitis

The aim of this study was to investigate the potential predictors of switching tumor necrosis factor (TNF)-α inhibitors in Korean patients with ankylosing spondylitis (AS). The patients who had been treated with TNF-α inhibitors were divided into two groups depending on whether they had switched TNF-α inhibitors. Demographic, clinical, laboratory, and treatment data at the time of initiation of TNF-α inhibitor treatment were compared between switchers and non-switchers, and within switchers according to the reasons for switching. Of the 269 patients, 70 (23%) had switched TNF-α inhibitors once; of these, 11 switched again. The median follow-up time was 52.7 months. Three- and five-year drug survival rates were 52%/48% for infliximab, 62%/42% for etanercept, and 71%/51% for adalimumab, respectively. Switchers were more likely to be prescribed disease-modifying anti-rheumatic drugs than non-switchers. A history of joint surgery and complete ankylosis of the sacroiliac joint was more frequent in switchers. Multivariate Cox’s proportional hazard analysis showed that the use of adalimumab as the first TNF-α inhibitor was less likely to lead to switching and complete ankylosis of the sacroiliac joints was more likely to lead to switching. The principal reasons for switching were drug inefficacy and adverse events, but the differences in the clinical data of these two groups of switchers were not significant. In AS patients who are candidates for TNF-α inhibitor therapy, switching may improve the therapeutic outcome based on clinical information.

Risk factors for treatment failure in osteoporotic patients with rheumatoid arthritis

Objective. No available anti-osteoporotic medication has been shown to completely prevent declines in bone mineral density (BMD) and the resulting increased risk of fracture. The objective of this study was to investigate the risk factors for treatment failure in osteoporotic patients with rheumatoid arthritis (RA). Methods. A retrospective cohort study of 103 patients with RA and osteoporosis was conducted. Patients were divided into two groups for comparison: those whose osteoporosis treatment was effective and those whose treatment failed. Risk factors for treatment failure were identified by univariate and multivariate logistic regression using variables that differed significantly between the groups. Results. Osteoporosis treatment failed in 66 of 103 patients (64.1%). During 14.01 months of follow-up, non-adherence to bisphosphonate use was the most powerful risk factor for treatment failure. Daily glucocorticoid dosage ≥ 7.5 mg/day before the first BMD measurement, immobilization > 3 months, and Disease Activity Score in 28 joints (DAS28) ≥ 3.2 were also significantly related to treatment failure. Conclusion. Our findings indicate that osteoporosis treatment fails frequently in RA patients and adherence to bisphosphonate use, daily glucocorticoid dosage, immobilization, and DAS28 score should be taken into consideration when treating osteoporotic patients with RA.

The Significance of Ectopic Germinal Centers in the Minor Salivary Gland of Patients with Sjögren's Syndrome

We investigated the clinical and biological significance of germinal centers (GC) present in the minor salivary glands of patients with Sjögren’s syndrome (SS). Minor salivary gland tissue biopsies from 93 patients with SS were used to identify GC-like structures, which were confirmed by CD21-positive follicular dendritic cell networks. Patients were compared based upon sociodemographics, glandular and extraglandular manifestations, and laboratory findings including autoantibody profiles, complement, and immunoglobulin levels; EULAR SS disease activity index (ESSDAI) and SS disease damage index (SSDDI) were also measured. GC-like structures were observed in 28 of 93 SS patients (30.1%). Mean focus scores and CRP levels were significantly higher in GC-positive patients than in GC-negative patients; GC-positive patients also exhibit a higher prevalence of rheumatoid factor and anti-SS-A/Ro antibodies compared to GC-negative patients. No differences in glandular or extra-glandular manifestations were evident between groups. In conclusion, SS patients with GC-like structures in the minor salivary glands exhibited laboratory profiles significantly different from those of their GC-negative counterparts. Long-term follow-up of these patients will be necessary to determine whether these laboratory abnormalities are predictive of clinical outcomes.

Comparison of heart rate variability and classic autonomic testing for detection of cardiac autonomic dysfunction in patients with fibromyalgia.

Cardiac autonomic dysfunction (CAD) is frequently found in patients with fibromyalgia (FM). Thus, we evaluated whether heart rate variability (HRV) is superior to the Ewing tests in detecting CAD in FM patients.

The relationships between bone mineral density and radiographic features of hand or knee osteoarthritis in older adults: data from the Dong-gu Study

OBJECTIVE The relationship between OA and osteoporosis has exhibited contradictory features over the past four decades. The aim of this study was to determine using separate analysis of the radiographic features of OA whether various radiographic features of OA were associated differently with BMD in the Korean elderly. METHODS Data were derived from the Dong-gu cohort; 2354 subjects were enrolled in the present cross-sectional study. Baseline characteristics, the BMDs of the lumbar spine and femoral neck measured by DXA, and X-rays of knees and hands were collected. A semi-quantitative grading system was used to estimate the severities of individual radiographic features. We adjusted for confounders using multiple linear regression modelling to analyse the relationships. RESULTS After adjustment for confounders, hand and knee OA total scores were negatively associated with the BMDs of the lumbar spine and femoral neck, except for the total knee OA score and lumbar spine BMD. In detail, hand osteophytes and sclerosis exhibited positive relationships with the BMDs of the lumbar spine and femoral neck, except for hand osteophytes and femoral neck BMD. On the contrary, however, knee joint space narrowing (JSN), hand JSN, and hand subchondral cysts were negatively associated with the BMD of the lumbar spine and femoral neck. Knee JSN and hand subchondral cysts exerted the greatest effects on BMD. CONCLUSION Separate analysis of the radiographic features of OA better reveals associations of OA with the BMD of the lumbar spine and femoral neck.