The aim of this study was to determine the serum interleukin-18 (IL-18) levels in patients with systemic lupus erythematosus (SLE) and to assess their relationship with disease activity. Thirty-five patients with SLE and 35 age- and sex-matched controls were enrolled in this study. Paired serum samples were collected from all the patients with SLE, both at active stage before treatment and at the stable stage after treatment. The serum IL-18 levels were determined using ELISA and their correlations with the disease activity, measured using the SLE Disease Activity Index (SLEDAI) and laboratory parameters such as anti-dsDNA antibody, CH50, C3, C4, and circulating immune complex levels, were analyzed. The serum IL-18 levels in patients with SLE were significantly higher than those in the controls, particularly when the disease status was active (mean+/-SD: active stage, 721.23+/-360.15 pg/ml; inactive stage, 343.68+/-317.78 pg/ml; controls, 113.98+/-13.22 pg/ml, p<0.05). The IL-18 levels measured at the active stage before treatment correlated well with SLEDAI (r=0.41, p<0.05) and anti-dsDNA antibody titer (r=0.35, p<0.05). When we compared the changes of the IL-18 level and those of parameters reflecting the disease activity between the active stage and the stable stage of the disease, it was found that the changes in IL-18 level correlated well with the changes of SLEDAI score during the patient's disease course (r=0.39, p<0.05). In conclusion, the serum IL-18 levels were elevated in patients with SLE, and these increased levels correlated well with SLE disease activity.

We aimed to investigate differences in clinical manifestations and outcomes between adult and child patients with Henoch-Schönlein purpura (HSP), and to analyze the factors associated with poor prognosis for HSP nephritis. This retrospective 10-yr study enrolled 160 patients with HSP who visited Severance Hospital. Purpura was mostly detected in lower extremities, but purpura in upper extremities was more frequently observed in adults than children (41.7% vs 19.3%). Children had a greater frequency of arthralgia (55.4% vs 27.1%), while adults had a greater frequency of diarrhea (20% vs 1.6%). Anemia, elevated C-reactive protein, and level of IgA were more frequently observed in adults (25% vs 7.1%, 65.6% vs 38.4%, 26.3% vs 3.5%). Renal involvement in adults was more severe than in children (79.2% vs 30.4%). Chronic renal failure showed a significant difference in outcomes of HSP between adults (10.4%) and children (1.8%) after a follow up period of an average of 27 months. Furthermore, renal insufficiency at diagnosis was significantly related to the progression to chronic renal failure. Our results showed several differences in the clinical features of HSP between adults and children. Adults with HSP had a higher frequency of renal insufficiency and worse renal outcomes than children. Renal insufficiency at diagnosis might be of predictive value for the progression to chronic renal failure in HSP patients.Graphical Abstract

Objective. Recent studies have suggested increased cardiovascular disease among patients with rheumatoid arthritis (RA). We undertook this study to obtain morphologic evidence of subclinical atherosclerosis in RA patients.Methods. We used high-resolution B-mode ultrasound to compare carotid artery intima-media wall thickness (IMT) between 53 postmenopausal women with RA and 53 controls matched by age, sex, and menopause status. No subject in either group had a history of atherosclerosis or its complications. We investigated the association between IMT and relevant clinical and therapeutic variables, including the impact of low-dose corticosteroid therapy (<10 mg/day prednisolone).Results. The mean ؎ SD IMT of the left and right common carotid arteries in RA patients was significantly greater than that in controls (0.77 ؎ 0.09 mm versus 0.68 ؎ 0.14 mm; P < 0.001). Early RA (duration <1 year) was associated with lesser IMT than was RA of longer duration (0.72 ؎ 0.03 mm versus 0.78 ؎ 0.01 mm; P < 0.04). Prednisolone use was not associated with increased IMT (0.78 ؎ 0.02 mm in nonusers versus 0.76 ؎ 0.01 mm in users; P ‫؍‬ 0.38).Conclusion. Our data indicate that RA patients have an ultrasonic marker of early atherosclerosis consistent with an increased risk for atherosclerosis.

Objective. Sarcopenic obesity is a body composition category in which obesity is accompanied by low skeletal muscle mass, offsetting the increase in body weight caused by increased adipose tissue. The purpose of this study was to analyze the association between knee osteoarthritis (OA) and 4 different categories of body composition: normal, sarcopenic nonobesity, nonsarcopenic obesity, and sarcopenic obesity.Methods. This was a cross-sectional study using the data from 2,893 participants in the Fifth Korean National Health and Nutrition Examination Survey. Radiographic knee OA was defined as a Kellgren/ Lawrence grade of >2. Appendicular skeletal muscle mass (ASM) and whole-body fat mass were measured using dual x-ray absorptiometry. Sarcopenia was defined as a skeletal muscle mass index (ASM/body weight [%]) below -2SD of the value in sex-matched young reference groups. Nonsarcopenic obesity was defined as a body mass index (BMI) >27.5 kg/m 2 .Results. The prevalence of each body composition category was as follows: 83.5% normal, 4.3% sarcopenic nonobesity, 9.2% nonsarcopenic obesity, and 3.0% sarcopenic obesity. Compared with nonsarcopenic obesity participants, participants with sarcopenic obesity were significantly older, had lower ASM, higher whole-body fat mass, and higher waist circumference. Conclusion. Sarcopenic obesity was more closely associated with knee OA than was nonsarcopenic obesity, although both groups had equivalent body weight. This finding supports the importance of the systemic metabolic effect of obesity in knee OA.Osteoarthritis (OA) is the most common articular disorder in the elderly, with ϳ40% of those over the age of 65 years affected at the knee joint (1). Although the exact pathophysiology of OA is unclear, the association between OA and obesity is well known (2-4). The biomechanical effect of increased body weight is one explanation for this association, especially in weightbearing joints such as the knee (5).The association between OA and obesity may be explained by factors other than biomechanical stress. Obesity is associated with OA not only in the weightbearing joints, but also in the joints of the hand (6), where mechanical load or factors such as grip strength (7) are unlikely to play an important role. Adipose tissue is an endocrine organ that secretes various adipokines (8). Data obtained in vitro have suggested a role of adipokines, including leptin, adiponectin, resistin, and visfatin, in the pathophysiology of OA (9). Recently, leptin, acting synergistically with other inflammatory cytokines, was shown to have a catabolic effect on articular cartilage metabolism via the up-regulation of proteolytic enzymes (10). In addition, extreme obesity induced in leptin (receptor)-deficient mice did not cause knee OA in the absence of leptin signaling (11).

We have developed RGD-attached gold (Au) half-shell nanoparticles containing methotrexate (MTX) for the treatment of rheumatoid arthritis (RA), where MTX is the most widely used disease-modifying anti-rheumatic drug (DMARD) for the treatment of RA, and RGD peptide is a targeting moiety for inflammation. Upon near-infrared (NIR) irradiation, heat is locally generated due to Au half-shells, and the drug release rate is enhanced, delivering heat and drug to the inflamed joints simultaneously. RA is a chronic inflammatory disease characterized by synovial inflammation in multiple joints within the penetration depth of NIR light. When combined with NIR irradiation, these nanoparticles containing a much smaller dosage of MTX (1/930 of MTX solution) showed greater therapeutic effects than that of a conventional treatment with MTX solution in collagen-induced arthritic mice. This novel drug delivery system is a good way to maximize therapeutic efficacy and minimize dosage-related MTX side effects in the treatment of RA. Furthermore, these multifunctional nanoparticles could be applied to other DMARDs for RA or other inflammatory diseases.