Etoricoxib in the treatment of Korean patients with osteoarthritis in a double-blind, randomized controlled trial

OBJECTIVE

We evaluated the COX-2 inhibitors, etoricoxib and celecoxib, in Korean patients with osteoarthritis (OA).

METHODS

This study included patients (≥ 40 years of age) with a clinical and radiographic diagnosis of knee OA. Patients were randomized to etoricoxib 30 mg (qd) or celecoxib 200 mg (qd) in a 12 week randomized, controlled, double-blind study. Prior NSAID users were to demonstrate a worsening of symptoms upon withdrawal of medication. Efficacy endpoints included the time-weighted average change from baseline in the WOMAC VA 3.0 Pain Subscale (100 mm Visual Analog Scale [VAS]; primary endpoint), the WOMAC VA 3.0 Physical Function Subscale (100 mm VAS), and Patient Global Assessment of Disease Status (PGAD) (100 mm VAS). The primary hypothesis was that etoricoxib 30 mg is non-inferior to celecoxib 200 mg as assessed by the primary endpoint (the non-inferiority margin was set at 10 mm VAS). Adverse events (AEs), laboratory parameters, and vital signs were monitored.

RESULTS

There were 239 patients (89.5% female; mean age: 63.3 years) randomized to etoricoxib 30 mg (n = 120) and celecoxib 200 mg (n = 119). The differences (etoricoxib vs celecoxib) in least square (LS) mean change (95% CI) for WOMAC Pain, WOMAC Physical Function, and PGAD were -1.63 mm (-5.37, 2.10), -1.32 mm (-4.88, 2.23), and -1.09 mm (-5.48, 3.30), respectively. Drug-related clinical AEs occurred in 6.7% (etoricoxib) and 2.5% (celecoxib) of patients. This study was limited because it was not designed or powered to adequately capture and evaluate rare AEs associated with NSAID treatment.

CONCLUSIONS

Etoricoxib 30 mg administered once daily in Korean patients with knee OA demonstrated non-inferior clinical efficacy to celecoxib 200 mg over 12 weeks of treatment as assessed by all primary and secondary outcomes. Etoricoxib 30 mg qd and celecoxib 200 mg qd were generally safe and well tolerated.

CLINICAL TRIAL REGISTRATION

NCT01554163.

Comparison of the efficacy and safety profiles of a pelubiprofen versus celecoxib in patients with rheumatoid arthritis: a 6-week, multicenter, randomized, double-blind, phase III, non-inferiority clinical trial

BACKGROUND

Pelubiprofen is a prodrug of 2-arylpropionic acid with relatively selective effects on cyclooxygenase-2 activity. The aim of this study was to compare the efficacy and safety profiles of pelubiprofen with those of celecoxib in patients with rheumatoid arthritis.

METHODS

This was a 6-week, multicenter, randomized, double-blind, double-dummy, parallel-group, phase III, non-inferiority clinical trial. The primary end point was non-inferiority of pain decrease from baseline to week-6 as determined using a 100 mm pain visual analog scale (VAS). Pelubiprofen was considered non-inferior to celecoxib if the lower limit of the 97.5% confidence interval for treatment difference [(pain reduction in pelubiprofen group) - (pain reduction in celecoxib group)] was more than -10 mm. The secondary end points were as follows: non-inferiority of (1) reduction of Korean health assessment questionnaire (KHAQ) score; (2) decreased duration of morning stiffness; and (3) decrease in the frequency and total dose of rescue drugs after 6 weeks of treatment.

RESULTS

Seventy-seven patients in the pelubiprofen group and 68 patients in the celecoxib group started the study medication. Pelubiprofen was non-inferior to celecoxib with regard to reduction in VAS pain severity (difference, mean ± SD 5.0 ± 20.1; 97.5% CI, -2.3 to ∞). Pelubiprofen was also non-inferior to celecoxib in terms of the secondary end points, such as, decrease in KHAQ score (0.0 ± 0.5, 97.5% CI -0.2 to ∞), decrease in duration of morning stiffness (median 0.0 minute in both groups), and decrease in the frequency (0.7 ± 3.5, 97.5% CI -0.6 to ∞) and total amount (0.7 ± 3.6, 97.5% CI -0.6 to ∞) of rescue medication uses during the 6 week study period. Safety analysis revealed 31.2% patients in the pelubiprofen group and 20.6% patients in the celecoxib group experienced an adverse drug reaction (ADR). The frequency of gastrointestinal ADRs was 20.8 % and 8.8%, respectively.

CONCLUSIONS

Pelubiprofen was found to be as effective as celecoxib at pain reduction and for relieving stiffness in RA patients. However, more patients in the pelubiprofen group experienced ADR and the frequency of gastrointestinal ADRs was higher in the pelubiprofen group. ClinialTrials.gov identifier: NCT01781702.

Cytokine signaling-1 suppressor is inducible by IL-1beta and inhibits the catabolic effects of IL-1beta in chondrocytes: its implication in the paradoxical joint-protective role of IL-1beta

INTRODUCTION

Although IL-1β is believed to be crucial in the pathogenesis of osteoarthritis (OA), the IL-1β blockade brings no therapeutic benefit in human OA and results in OA aggravation in several animal models. We explored the role of a cytokine signaling 1 (SOCS1) suppressor as a regulatory modulator of IL-1β signaling in chondrocytes.

METHODS

Cartilage samples were obtained from patients with knee OA and those without OA who underwent surgery for femur-neck fracture. SOCS1 expression in cartilage was assessed with immunohistochemistry. IL-1β-induced SOCS1 expression in chondrocytes was analyzed with quantitative polymerase chain reaction and immunoblot. The effect of SOCS1 on IL-1β signaling pathways and the synthesis of matrix metalloproteinases (MMPs) and aggrecanase-1 was investigated in SOCS1-overexpressing or -knockdown chondrocytes.

RESULTS

SOCS1 expression was significantly increased in OA cartilage, especially in areas of severe damage (P < 0.01). IL-1β stimulated SOCS1 mRNA expression in a dose-dependent pattern (P < 0.01). The IL-1β-induced production of MMP-1, MMP-3, MMP-13, and ADAMTS-4 (aggrecanase-1, a disintegrin and metalloproteinase with thrombospondin motifs 4) was affected by SOCS1 overexpression or knockdown in both SW1353 cells and primary human articular chondrocytes (all P values < 0.05). The inhibitory effects of SOCS1 were mediated by blocking p38, c-Jun N-terminal kinase (JNK), and nuclear factor κB (NF-κB) activation, and by downregulating transforming growth factor-β-activated kinase 1 (TAK1) expression.

CONCLUSIONS

Our results show that SOCS1 is induced by IL1-β in OA chondrocytes and suppresses the IL-1β-induced synthesis of matrix-degrading enzymes by inhibiting IL-1β signaling at multiple levels. It suggests that the IL-1β-inducible SOCS1 acts as a negative regulator of the IL-1β response in OA cartilage.

Baseline MRA predicts the treatment response to vasodilator udenafil in patients with secondary Raynaud's phenomenon

OBJECTIVES

High-resolution MR angiography (HR-MRA) demonstrates blood flow in the digital arteries, which correlates with the severity of Raynaud's phenomenon (RP). This study investigates whether baseline HR-MRA of the hand can predict the treatment response to udenafil, a new PDE5-inhibitor, in patients with secondary RP.

METHODS

Baseline MRA and Doppler ultrasound were obtained in 12 patients with secondary RP. The patients were treated with udenafil 100 mg/day for 4 weeks and changes in blood flow were measured. Blood flow on MRA was scored on a 4-point scale: 0, no visible flow; 1, visible flow to the proximal phalanx; 2, to the middle phalanx; and 3, to the distal phalanx. Peak systolic velocity (PSV) was measured to determine blood flow. Paired t-test and ANOVA were used to determine the treatment response of the different MRA scores.

RESULTS

On baseline MRA, 53.3% of digital arteries had an MRA score of 0, 25.8% MRA score of 1, 9.2% MRA score of 2, and 11.6% MRA score of 3. Overall, 4-week udenafil treatment improved digital flow (p<0.05) in all MRA scores. Digital arteries with MRA score 2 showed the best response with improvement in PSV by 14.5 mm/sec (p<0.01), whereas improvement in arteries of MRA scores 1 and 3 were not better than an MRA score of 0 (all, p>0.05).

CONCLUSIONS

Digital arteries with moderate blood flow observed on MRA respond best to treatment with udenalfil. Therefore, baseline MRA may help predict treatment response in patients with secondary RP.

Characteristics of pleural effusions in systemic lupus erythematosus: differential diagnosis of lupus pleuritis

We investigated the clinical characteristics of pleural effusion in systemic lupus erythematosus (SLE). A prospective analysis of 17 SLE patients with pleural effusion (seven lupus pleuritis, eight transudative effusions and two parapneumonic effusions) was performed. Thirty non-SLE patients with pleural effusion were recruited as controls. A pleural fluid ANA titer ≥1:160 was found in 8/17 (47.1%) SLE patients and none of the 30 non-SLE patients (p = 0.0001). Pleural fluid to serum C3 ratios were significantly lower in SLE than in non-SLE (median (minimum-maximum) 0.29 (0.03-0.43) versus 0.52 (0.26-0.73), p = 0.0002). Among SLE patients, pleural fluid ANA titers ≥1:160 were more frequently found in patients with lupus pleuritis than in those with pleural effusion from causes other than lupus itself (85.7% versus 20.0%, p = 0.0152). Serum CRP levels were significantly increased in patients with lupus pleuritis compared with SLE patients with transudative pleural effusion (2.30 (0.30-5.66) versus 0.7 (0.12-1.47) mg/dl, p = 0.0062). In conclusion, pleural fluid ANA titer and serum CRP levels are significantly increased in lupus pleuritis.

The association of radiographic progression with serum R-spondin 1 (RSPO1) levels or Dickkopf-1 (DKK1)/RSPO1 ratios in rheumatoid arthritis patients: clinical evidence for reciprocal inhibition between DKK1 and RSPO1

OBJECTIVES

To investigate the clinical implications of serum levels of R-spondin 1 (RSPO1), a natural antagonist for Dickkopf-1 (DKK1), and of DKK1/RSPO1 ratios in rheumatoid arthritis (RA) patients.

METHOD

Serum DKK1 and RSPO1 levels were measured in 102 RA patients and 39 age- and gender-matched healthy controls. In addition, DKK1 and RSPO1 levels were determined prior to and 3 months after anti-tumour necrosis factor alpha (anti-TNF-α) therapy in 15 RA patients. Clinical and laboratory data and baseline radiographs of the hands and feet were obtained. Serial radiographs were evaluated in 83 RA patients. Radiographic joint damage was assessed by the modified Sharp/van der Heijde score (SHS).

RESULTS

Serum RSPO1 levels were significantly reduced whereas serum DKK1 levels and DKK1/RSPO1 ratios were significantly increased in RA patients compared with controls (all p < 0.0001). Anti-TNF-α treatment significantly suppressed DKK1/RSPO1 ratios (p < 0.01). In contrast to DKK1 or RSPO1 levels, the ratios were significantly associated with erosive disease, elevated acute phase reactants, Disease Activity Score in 28 joints (DAS28) > 3.2, and radiographic progression rate (all p < 0.05). Although the RA patients with radiographic progression exhibited significantly increased DKK1 and reduced RSPO1 levels (p < 0.05), only the DKK1/RSPO1 ratio (log-transformed) was found to be a significant predictor of subsequent radiographic progression [odds ratio (OR) 2.07, p < 0.01].

CONCLUSIONS

In this study, the presence of RSPO1 in the circulation was shown for the first time. Our results suggest that the serum DKK1/RSPO1 ratio represents a better predictor of structural progression than either DKK1 or RSPO1 levels alone in RA patients.

Comparison of cancer incidence among patients with rheumatic disease: a retrospective cohort study

Introduction

Rheumatic diseases (RDs) are associated with different cancers; however, it is unclear whether particular cancers are more prevalent in certain RDs. In the present study, we examined the relative incidence of several cancers in a single homogeneous cohort of patients with different RDs.

Methods

Patients (N = 3,586) diagnosed with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), systemic sclerosis (SSc), dermatomyositis (DM) or polymyositis were included. Cancer diagnosis was based on histopathology. The 2008 Korean National Cancer Registry served as the reference for calculating standardized incidence ratios (SIRs).

Results

During the follow-up period of 31,064 person-years, 187 patients developed cancer. RA and SLE patients showed an increased risk of non-Hodgkin’s lymphoma (SIR for RA patients = 3.387, 95% confidence interval (CI) = 1.462 to 6.673; SIR for SLE patients = 7.408, 95% CI = 2.405 to 17.287). SLE patients also had a higher risk of cervical cancer (SIR = 4.282, 95% CI = 1.722 to 8.824). SSc patients showed a higher risk of lung cancer (SIR = 4.917, 95% CI = 1.977 to 10.131). Endometrial cancer was increased only in patients with DM (SIR = 30.529, 95% CI = 3.697 to 110.283). RA patients had a lower risk for gastric cancer (SIR = 0.663, 95% CI = 0.327 to 0.998). The mean time between the RD and cancer diagnoses ranged from 0.1 to 16.6 years, with the shortest time observed in patients with DM (2.0 ± 2.1 years).

Conclusions

Different RDs are associated with particular cancers. Thus, cancer surveillance tailored to specific RDs might be beneficial.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-014-0428-x) contains supplementary material, which is available to authorized users.

Single nucleotide polymorphisms in IL-10-mediated signalling pathways in Korean patients with Behçet's disease

OBJECTIVES

Previous genome-wide association studies have demonstrated an association between the IL-10 region and Behçet's disease (BD) in Turkish and Japanese populations. Our aim was to fully examine the relationship between IL-10 and BD, the associations between BD and single nucleotide polymorphisms (SNPs) in IL-10-mediated signalling pathways (JAK1, TYK2, and STAT3) were examined in Korean patients with BD.

METHODS

DNA samples were obtained from 223 patients who met the international study group criteria for BD and from 222 age- and sex-matched healthy controls. Twenty-four tag SNPs in JAK1, STAT3, and TYK2 were selected for genotyping based on the Japanese panel of international HapMap data with a minor allele frequency >5% and r2 >0.8.

RESULTS

The allele-based analysis showed that the T allele of rs310245 in JAK1 was associated with BD (odds ratio [95% confidence interval] = 1.34 [1.03-1.76], p=0.031), which lost statistical significance after permutation-based correction for multiple testing. In the genotype-based analysis, the JAK1 rs310245 TT homozygote (1.79 [1.14-2.82], p=0.012) and the STAT3 rs2293152 GG homozygote (2.01 [1.16-3.47], p=0.011) showed associations with BD. However, these associations did not achieve significance after correction for multiple testing. We did not observe any genetic interaction between the JAK1 rs310245 TT homozygote and the STAT3 rs2293152 GG homozygote. In the haplotype analysis, GT haplotype at rs17127024 and rs310245 (1.34 [1.03-1.74], p=0.032), and the AA haplotype at rs2256298 and rs3818753 (1.41 [1.03-1.92], p=0.034) in JAK1 were associated with BD, but lost statistical significance after correction for multiple testing.

CONCLUSIONS

There was no significant association between BD and SNPs in IL-10-mediated intracellular signalling in Korean patients.

Therapeutic effect of anti-C-X-C motif chemokine 10 (CXCL10) antibody on C protein-induced myositis mouse

INTRODUCTION

C-X-C motif chemokine 10 (CXCL10) is a chemokine that plays a critical role in the infiltration of T cells in autoimmune diseases and is reported to be expressed in muscle tissue of polymyositis. To determine the therapeutic efficacy of CXCL10 blockade, we investigated the role of CXCL10 and the effect of anti-CXCL10 antibody treatment in C protein-induced myositis (CIM), an animal model of polymyositis.

METHODS

CIM was induced with human skeletal muscle C protein fragment in female C57BL/6 mice. Immunohistochemistry of CXCL10 and C-X-C motif chemokine receptor 3 (CXCR3) and measurement of serum CXCL10 were performed. Cell surface markers and interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) in CIM lymph node cells was investigated by flow cytometry. Mice with CIM were treated with anti-CXCL10 antibody or control antibody (anti-RVG1) and the inflammation in muscle tissue was assessed.

RESULTS

Immunohistochemistry showed increased expression of CXCL10 and CXCR3 in the inflammatory lesions of muscle in CIM. Especially, CD8+ T cells invading myofiber expressed CXCR3. Serum level of CXCL10 was increased in CIM compared to the level in normal mice (normal mouse, 14.3 ± 5.3 pg/ml vs. CIM, 368.5 ± 135.6 pg/ml, P < 0.001). CXCR3 positivity in CD8+ T cells was increased compared to that of CD4+ T cells in the lymph node cells of CIM (CXCR3+ among CD8+ T cell, 65.9 ± 2.1% vs. CXCR3+ among CD4+ T cell, 23.5 ± 4.7%, P <0.001). Moreover, IFN-γ+ cells were increased among CXCR3+CD8+ T cells compared to CXCR3-CD8+ T cells (CXCR3+CD8+ T cell, 28.0 ± 4.2% vs. CXCR3-CD8+ T cell, 9.5 ± 1.5%, P = 0.016). Migration of lymph node cells was increased in response to CXCL10 (chemotactic index was 1.91 ± 0.45). CIM mice treated with anti-CXCL10 antibody showed a lower inflammation score in muscles than those with anti-RVG1 (median, anti-CXCL10 treatment group, 0.625 vs. anti-RVG1 treatment group, 1.25, P = 0.007).

CONCLUSIONS

CXCL10/CXCR3 expression was increased in the inflammation of CIM model and its blockade suppressed inflammation in muscle.

Decreased tumour necrosis factor-α production by monocytes of granulomatosis with polyangiitis

OBJECTIVES

We hypothesized that monocytes in patients with granulomatosis with polyangiitis (GPA) are polarized towards alternative activation with decreased tumour necrosis factor (TNF)-α production and that tissue-infiltrating monocytes/macrophages in granulomatous GPA lesions express CD163, a marker of alternative macrophage activation.

METHOD

CD16+ monocytes in peripheral blood mononuclear cells (PBMCs) were quantified by flow cytometry. Monocytes were stimulated with increasing concentrations of lipopolysaccharide (LPS), and TNF-α production was measured at 4 and 24 h. CD163 expression in lung biopsies of patients with GPA was detected by immunohistochemistry.

RESULTS

Circulating CD16+ monocytes were more frequent in GPA patients compared to controls (4.7 ± 2.8% vs. 1.9 ± 1.2%, p < 0.001). Upon activation with LPS, TNF-α production did not differ between CD16+ and CD16- monocytes. Stimulated monocytes from GPA patients produced significantly less TNF-α compared with monocytes from healthy controls (2903 ± 1320 pg/mL vs. 8335 ± 4569 pg/mL, p < 0.001). Macrophages expressing CD163 were enriched in granulomatous lung lesions of GPA patients.

CONCLUSIONS

Decreased TNF-α production by circulating monocytes and CD163 overexpression by tissue monocytes/macrophages in granulomatous pulmonary lesions may suggest that monocytes/macrophages are alternatively activated in GPA.

Phenotype difference between familial and sporadic ankylosing spondylitis in Korean patients

Clustered occurrences of ankylosing spondylitis (AS) in family have been noticed. We evaluated patients with AS confirmed by the modified New York criteria for familial history of AS (one or more first to third degree relatives). The clinical characteristics and the recurrence risks (number of AS patients/number of familial members) of the familial AS compared to sporadic AS were investigated. Out of a total of 204 AS patients, 38 patients (18.6%) reported that they had a familial history of AS. The recurrence risks in the familial AS patients for first, second and third degree family members were 14.5%, 5.2%, and 4.4% respectively. Erythrocyte sedimentation rate (ESR) (22.6 ± 22.2 vs 35.4 ± 34.4, P=0.029) and C-reactive protein (CRP) (1.24 ± 1.7 vs 2.43 ± 3.3, P=0.003) at diagnosis, body mass index (21.9 ± 2.7 vs 23.7 ± 3.3, P=0.002) and frequency of oligoarthritis (13.2% vs 33.7%, P=0.021) were significantly lower in the familial form. The presence of HLA-B27 (97.4% vs 83.1%, P=0.044) was significantly higher in familial AS. In conclusion, Korean familial AS patients show a lower frequency of oligoarthritis, lower BMI, lower ESR and CRP at diagnosis and higher presence of HLA-B27.

Clinical factors and treatment outcomes associated with failure in the detection of urate crystal in patients with acute gouty arthritis

BACKGROUND/AIMS

To investigate the rate of detection of monosodium urate (MSU) crystals in the synovial fluid (SF) of patients with acute gouty arthritis and factors associated with false-negative results.

METHODS

A total of 179 patients with acute gouty arthritis who had undergone SF crystal examination were identified from the data warehouse of two university hospitals. Clinical and laboratory data were obtained from the medical records.

RESULTS

The overall rate of detection of MSU crystals was 78.8%. In univariate analyses, the only significant differences between the variables of crystal-negative and crystal-positive patients were a lower C-reactive protein level (p = 0.040) and fewer patients undergoing emergent surgery in the crystal-positive group (p = 4.5 × 10(-6)). In logistic regression analyses, MSU crystal-negative results were significantly associated with the interval from arthritis onset to crystal examination (p = 0.042), and this was the most significant risk factor for arthroscopic surgery (p = 2.1 × 10(-4)). Seventeen patients who underwent arthroscopic surgery had a significantly longer hospital stay (p = 0.007) and a significant delay in gout treatment (p = 8.74 × 10(-5)). The distribution of crystal-negative patients differed significantly between the SF samples that were evaluated by both the laboratory medicine and the rheumatology departments (p = 1.2 × 10(-14)), and the κ value was 0.108.

CONCLUSIONS

Although several clinical features were associated with detection failure, SF MSU crystal identification was critically dependent on the observer. Considering the impact on the treatment outcomes, implementation of a quality control program is essential.

Bone marrow analysis of immune cells and apoptosis in patients with systemic lupus erythematosus

OBJECTIVES

To examine the immune cell profile in the bone marrow of systemic lupus erythematosus (SLE) patients and to assess its clinical relevance.

METHODS

Sixteen bone marrow samples from 14 SLE patients were compared with seven healthy control samples. The numbers of immune cells and apoptotic cells in the bone marrow were examined by immunohistochemistry. The association between immune cell subsets and clinical features was investigated.

RESULTS

CD4+ T cells, macrophages and plasma cells were more common in the bone marrow of SLE patients than in healthy controls (p=0.001, p=0.004 and p<0.001, respectively). Greater numbers of CD4+ T cells and macrophages were associated with high-grade bone marrow damage. The percentage of apoptotic cells in bone marrow of SLE patients was significantly higher than that in controls (p<0.001) and was positively correlated with the number of plasmacytoid dendritic cells (p=0.013). Increased number of plasma cells along with high interleukin-6 expression was correlated with anti-double stranded DNA antibody levels and the SLE disease activity index (p=0.031 and 0.013, respectively).

CONCLUSION

Bone marrow from SLE patients showed a distinct immune cell profile and increased apoptosis. This, coupled with a correlation with disease activity, suggests that the bone marrow may play a critical role in the pathogenesis of SLE.

Patient-reported outcomes and adult patients' disease experience in the idiopathic inflammatory myopathies. report from the OMERACT 11 Myositis Special Interest Group

The newly formed Outcome Measures in Rheumatology (OMERACT) Myositis Special Interest Group (SIG) was established to examine patient-reported outcome measures (PROM) in myositis. At OMERACT 11, a literature review of PROM used in the idiopathic inflammatory myopathies (IIM) and other neuromuscular conditions was presented. The group examined in more detail 2 PROM more extensively evaluated in patients with IIM, the Myositis Activities Profile, and the McMaster-Toronto Arthritis Patient Preference Disability Questionnaire, through the OMERACT filter of truth, discrimination, and feasibility. Preliminary results from a qualitative study of patients with myositis regarding their symptoms were discussed that emphasized the range of symptoms experienced: pain, physical tightness/stiffness, fatigue, disease effect on emotional life and relationships, and treatment-related side effects. Following discussion of these results and following additional discussions since OMERACT 11, a research agenda was developed. The next step in evaluating PROM in IIM will require additional focus groups with a spectrum of patients with different myositis disease phenotypes and manifestations across a range of disease activity, and from multiple international settings. The group will initially focus on dermatomyositis and polymyositis in adults. Qualitative analysis will facilitate the identification of commonalities and divergent patient-relevant aspects of disease, insights that are critical given the heterogeneous manifestations of these diseases. Based on these qualitative studies, existing myositis PROM can be examined to more thoroughly assess content validity, and will be important to identify gaps in domain measurement that will be required to develop a preliminary core set of patient-relevant domains for IIM.

Costs of illness and quality of life in patients with systemic lupus erythematosus in South Korea

OBJECTIVE

To assess the costs of illness, health-related quality of life (HRQOL) and their associated factors in patients with systemic lupus erythematosus (SLE) in South Korea.

METHOD

Two hundred and one patients with SLE were enrolled at the Rheumatology clinic of Seoul National University Hospital. Direct, indirect and total costs and HRQOL were measured using hospital electronic data and face-to-face interview. Socio-demographic and clinical factors associated with cost of illness and HRQOL were analyzed using multiple regression and multivariate logistic regression.

RESULTS

The average total cost of illness was estimated to be KRW 9.82 million (US $ 8993) per year, of which 41.6% was accounted for by direct costs and 58.4% by indirect costs. In multivariate regression, patients with renal involvement and those with depression incurred an average increment in annual total costs of 37.6% (p = 0.050) and 49.1% (p = 0.024), respectively, and an average increment in annual direct costs of 26.4% (p = 0.050) and 43.3% (p = 0.002), respectively, compared with patients without renal involvement and depression, respectively. In addition, disease damage was positively associated with an average increment in annual total and direct costs (55.3%, p = 0.006; 33.3%, p = 0.013, respectively), and the occurrence of indirect costs (OR 2.21, 1.09-4.88). There was no significant difference in HRQOL between patients with and without renal involvement (0.655 vs. 0.693, p = 0.203) CONCLUSION: Renal involvement, depression, and disease damage were major factors associated with higher total and medical costs for patients with SLE in South Korea. Effective treatment of renal disorders and depression may reduce the high economic burden of SLE.