Association of HLA-DRB1 locus with treatment response to abatacept or TNF inhibitors in patients with seropositive rheumatoid arthritis.

The strongest genetic risk factor for rheumatoid arthritis (RA) has been known as HLA-DRB1 based on amino acid positions 11, 71, and 74. This study analyzed the association between specific HLA-DRB1 locus and treatment response to abatacept or TNF inhibitors (TNFi) in patients with seropositive RA. A total of 374 Korean RA patients were treated with abatacept (n = 110) or TNFi (n = 264). Associations between HLA-DRB1 and treatment response after 6 months were analyzed using multivariable logistic regression. Seropositive RA patients with HLA-DRB1 shared epitope (SE) had a favorable response to abatacept (OR = 3.67, P = 0.067) and an inversely associated response to TNFi (OR 0.57, P = 0.058) based on EULAR response criteria, but the difference was not statistically significant in comparison to those without SE. In analyses using amino acid positions of HLA-DRB1, a significant association was found between valine at amino acid position 11 of SE and good response to abatacept (OR = 6.46, P = 5.4 × 10-3). The VRA haplotype also showed a good response to abatacept (OR = 4.56, P = 0.013), but not to TNFi. Our results suggest that treatment response to abatacept or TNFi may differ depending on HLA-DRB1 locus in seropositive RA, providing valuable insights for selecting optimal therapy.

Comparative effectiveness of tofacitinib and tumour necrosis factor inhibitors in patients with rheumatoid arthritis in real-world practice: a prospective observational study.

OBJECTIVE: To assess the effectiveness of tofacitinib vs tumour necrosis factor inhibitors (TNFi) in Korean patients with rheumatoid arthritis (RA). METHODS: The study used data from a single academic referral hospital's registries of biologic disease-modifying anti-rheumatic drugs (bDMARDs) and tofacitinib and examined remission rates based on the disease activity score (DAS)28-erythrocyte sedimentation rate (ESR) after 12 months. Multivariable logistic regression analysis was used to estimate the odds ratio (OR) for achieving remission with tofacitinib compared with TNFi, adjusting for potential confounders. RESULTS: This analysis included 665 patients (200 on tofacitinib and 455 on TNFi) who were followed up for at least 12 months. Of these, 96 patients in the tofacitinib group (48.0%) and 409 patients in the TNFi group (89.9%) were treatment-naïve to bDMARDs. Intention-to-treat analysis revealed no significant difference in the remission rates between the two groups (18.0% vs 19.6%, p = 0.640). Multivariable analysis demonstrated comparable remission rates with tofacitinib and TNFi (OR 1.204, 95% confidence interval [CI] 0.720-2.013). In the subpopulation naïve to JAKi and bDMARD, tofacitinib showed better remission rates than TNFi (OR 1.867, 95% CI 1.033-3.377). Tofacitinib had more adverse events (AEs) but similar rates of serious AEs (SAEs) to TNFi. CONCLUSION: In real-world settings, there was no significant difference in remission rates at 12 months between the tofacitinib and TNFi groups. In terms of safety, tofacitinib exhibited a higher incidence of AEs compared with TNFi, while the occurrence of SAEs was comparable between the groups. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02602704.

Comparative effectiveness of JAK inhibitors and biologic disease-modifying antirheumatic drugs in patients with rheumatoid arthritis.

BACKGROUND/AIMS: We aimed to compare the effectiveness and safety of Janus kinase inhibitors (JAKi) vs. biologic disease- modifying antirheumatic drugs (bDMARD) in Korean patients with rheumatoid arthritis (RA) who had an inadequate response to conventional synthetic DMARDs. METHODS: A quasi-experimental, multi-center, prospective, non-randomized study was conducted to compare response rates between JAKi and bDMARDs in patients with RA naïve to targeted therapy. An interim analysis was performed to estimate the proportion of patients achieving low disease activity (LDA) based on disease activity score (DAS)-28- erythroid sedimentation rate (ESR) (DAS28-ESR) at 24 weeks after treatment initiation and to evaluate the development of adverse events (AEs). RESULTS: Among 506 patients enrolled from 17 institutions between April 2020 and August 2022, 346 (196 JAKi group and 150 bDMARD group) were included in the analysis. After 24 weeks of treatment, 49.0% of JAKi users and 48.7% of bDMARD users achieved LDA (p = 0.954). DAS28-ESR remission rates were also comparable between JAKi and bDMARD users (30.1% and 31.3%, respectively; p = 0.806). The frequency of AEs reported in the JAKi group was numerically higher than that in the bDMARDs group, but the frequencies of serious and severe AEs were comparable between the groups. CONCLUSION: Our interim findings reveal JAKi have comparable effectiveness and safety to bDMARDs at 24 weeks after treatment initiation.

Increased risk of herpes zoster with tofacitinib treatment in Korean patients with rheumatoid arthritis: a single-center prospective study.

We aimed to determine the risk of herpes zoster (HZ) in Korean rheumatoid arthritis (RA) patients on tofacitinib compared with tumor necrosis factor inhibitor (TNFi) treatment. From the prospective cohorts of RA patients who started tofacitinib or TNFi in an academic referral hospital in Korea, patients who started tofacitinib between March 2017 and May 2021 and those who started TNFi between July 2011 and May 2021 were included. Baseline characteristics of tofacitinib and TNFi users were balanced through inverse probability of treatment weighting (IPTW) using the propensity score including age, disease activity of RA and medication use. The incidence rate of HZ in each group and incidence rate ratio (IRR) were calculated. A total of 912 patients were included: 200 tofacitinib and 712 TNFi users. There were 20 cases of HZ among tofacitinib users and 36 among TNFi users during observation period of 331.4 person-years (PYs) and 1950.7 PYs, respectively. In IPTW analysis with a balanced sample, IRR of HZ was 8.33 (95% confidence interval 3.05-22.76). Tofacitinib use increased the risk of HZ compared with TNFi in Korean patients with RA, but the rate of serious HZ or permanent discontinuation of tofacitinib due to HZ event was low.

Risk of venous thromboembolism in Korean patients with rheumatoid arthritis treated with Janus kinase inhibitors: A nationwide population-based study.

OBJECTIVE: There was a safety concern about an increased risk of thromboembolic events in patients with rheumatoid arthritis (RA) treated with Janus kinase inhibitors (JAKis). This study aimed to determine the risk of venous thromboembolism (VTE) in Korean patients with RA treated with JAKis compared with tumour necrosis factor (TNF) inhibitors. METHODS: Using the National Health Insurance Service database between 2015 and 2019, patients with prevalent RA who started JAKi or TNF inhibitor were selected as the study population. All participants were naïve to targeted therapy. Patients that had experienced any VTE event or used anticoagulant agents within 30 days were excluded. Demographic and clinical characteristics were all balanced by stabilised inverse probability of treatment weighting (sIPTW) using propensity score. The Cox proportional hazard model considering death as a competing risk was used to evaluate the risk of VTE in JAKi users compared with TNF inhibitor users. RESULTS: A total of 4,178 patients were included: 871 JAKi users and 3,307 TNF inhibitor users were followed up for 1,029.2 person-years (PYs) and 5,940.3 PYs, respectively. With a balanced sample after sIPTW, the incidence rates (IR) of VTE were 0.06 per 100 PYs (95% confidence interval [CI] 0.00-1.23) in JAKi users and 0.38 per 100 PYs (95% CI 0.25-0.58) in TNF inhibitor users. The hazard ratio was 0.18 (95% CI 0.01-3.47) after adjusting for unbalanced variables after performing sIPTW. CONCLUSION: There is no increased risk of VTE in RA patients treated with JAKis compared with TNF inhibitors in Korea.

Quantitative comparison of EGFR expression levels of optically trapped individual cells using a capacitance biosensor.

Cellular endocytosis is an essential phenomenon which induces cellular reactions, such as waste removal, nutrient absorption, and drug delivery, in the process of cell growth, division, and proliferation. To observe capacitance responses upon endocytosis on a single-cell scale, this study combined an optical tweezer that can optically place a single cell on a desired location with a capacitance sensor and a cell incubation chamber. Single HeLa cancer cell was captured and moved to a desired location through optical trapping, and the single-cell capacitance change generated during the epidermal growth factor (EGF) molecule endocytosis was measured in real time. It was found that single HeLa cells showed a larger increase in capacitance values compared to that of the single NIH3T3 cells when exposed to varying EGF concentrations. In addition, the capacitance change was in proportion to the cell's EGF receptor (EGFR) level when cells of different levels of EGFR expression were tested. An equation derived from these results was able to estimate the EGFR expression level of a blind-tested cell. The biosensor developed in this research can not only quickly move a single cell to a desired location in a non-invasive manner but also distinguish specific responses between cancer and normal cells by continuous measurement of real-time interactions of a single cell in culture to the external ligands.

Clinical characteristics of rheumatoid arthritis patients with interstitial lung disease: baseline data of a single-center prospective cohort.

BACKGROUND: To introduce a prospective cohort for rheumatoid arthritis (RA) patients with interstitial lung disease (ILD) and to identify their clinical features in comparison with RA patients without ILD. METHODS: Using a multidisciplinary collaborative approach, a single-center cohort for RA patients with ILD (RA-ILD) was established in May 2017, and enrolment data from May 2017 to March 2021 were used to compare the clinical features of RA patients without ILD (RA-non ILD). Multivariable logistic regression analysis was used to identify factors associated with ILD in RA patients. RESULTS: Among 148 RA-ILD and 410 RA-non ILD patients, participants in the RA-ILD group were older (65.8 ± 9.9 vs. 58.0 ± 10.4 years, P < 0.001) and included more males (35.8% vs. 14.6%, P < 0.001) than in the RA-non ILD group. The RA-ILD group had a higher proportion of late-onset RA patients (age ≥ 60 years) than in the comparator group (43.9% vs. 14.2%, P < 0.001). Multivariable logistic regression analysis showed that higher age at RA onset (OR 1.056, 95% CI 1.021-1.091), higher body mass index (BMI; OR 1.65, 95% CI 1.036-2.629), smoking history (OR 2.484, 95% CI 1.071-5.764), and oral glucocorticoid use (OR 3.562, 95% CI 2.160-5.874) were associated with ILD in RA patients, whereas methotrexate use was less likely to be associated with ILD (OR 0.253, 95% CI 0.155-0.412). CONCLUSIONS: Higher age at RA onset, smoking history, and higher BMI were associated with the presence of ILD among RA patients. Oral glucocorticoids were more frequently used whereas methotrexate was less likely to be used in RA-ILD patients.

Factors associated with selection of targeted therapy in patients with rheumatoid arthritis.

OBJECTIVE: Deciding which drug to choose for targeted therapy is an important step in sequential treatment for rheumatoid arthritis (RA). This study aimed to identify factors for selecting Janus kinase inhibitors (JAKis) rather than biologic disease-modifying antirheumatic drugs (bDMARDs) in patients with RA in real-world practice. METHODS: We selected RA patients starting JAKis or bDMARDs from single-center prospective cohorts in Korea. Patients were divided into JAKi, tumor necrosis factor (TNF) inhibitor, and non-TNF inhibitor groups. We performed multinomial logistic regression analyses to identify factors associated with selecting JAKis. RESULTS: 145, 205, and 89 patients were included in the JAKi, TNF inhibitor, and non-TNF inhibitor groups. In multinomial regression analysis, the JAKi group was older than the TNF inhibitor group (OR 1.03, 95% confidence interval [CI] 1.01-1.05) but younger than the non-TNF inhibitor group (OR 0.97, CI 0.95-1.00). The JAKi group was less likely to have chronic pulmonary diseases compared with the TNF inhibitor group (OR 0.07, CI 0.01-0.56) or the non-TNF inhibitor group (OR 0.06, CI 0.01-0.50). Higher disease activity assessed by physician (OR 1.80, CI 1.51-2.38) and previous tacrolimus use (OR 2.05, CI 1.20-3.51) were factors suggesting selection of JAKis than TNF inhibitors. CONCLUSION: Age, pulmonary comorbidities, previous tacrolimus use, and high disease activity assessed by physician were factors influencing the selection of JAKis for RA patients in Korea.

Association between malignancy risk and Janus kinase inhibitors versus tumour necrosis factor inhibitors in Korean patients with rheumatoid arthritis: a nationwide population-based study.

OBJECTIVE: To determine the risk of malignancy in Korean patients with rheumatoid arthritis (RA) receiving Janus kinase inhibitors (JAKis) compared with tumour necrosis factor inhibitors (TNFis). METHODS: A retrospective cohort of patients with RA initiating their first JAKi or TNFi was established using the Korean National Health Insurance database between 2015 and 2019. They were followed up from treatment initiation to the occurrence of malignancy, drug discontinuation, death or until December 2019. Baseline features of the patients were balanced through inverse probability of treatment weighting (IPTW) using a propensity score. A Cox proportional hazard model was established to estimate the HR for malignancy risk in JAKi users compared with TNFi users. RESULTS: A total of 4929 patients (1064 JAKi-treated and 3865 TNFi-treated patients) were included, and the observation periods were 1288.6 person-years (PYs) for JAKi users and 6823.8 PYs for TNFi users. The incidence rates of overall malignancy were 0.54 per 100 PYs (95% CI 0.26 to 1.14) in JAKi users and 0.85 per 100 PYs (95% CI 0.66 to 1.10) in TNFi users. In IPTW analysis with a balanced sample (4101 JAKi-treated and 5131 TNFi-treated patients), HR was 0.83 (95% CI 0.55 to 1.27) for overall malignancy: 0.77 (95% CI 0.50 to 1.19) for solid malignancy and 2.86 (95% CI 0.41 to 20.00) for haematological malignancy. CONCLUSION: Malignancy risk in Korean patients with RA was not increased with JAKi use compared with TNFi use.

MUC5B promoter variant rs35705950, rare but significant susceptibility locus in rheumatoid arthritis-interstitial lung disease with usual interstitial pneumonia in Asian populations.

BACKGROUND: MUC5B variant rs35705950 is the common and most significant risk variant for rheumatoid arthritis-interstitial lung disease (RA-ILD) in Western populations. However, little is known about its significant association with RA-ILD in Asian populations. We here investigate the association of rs35705950 with Korean patients with RA-ILD. METHODS: In this cross-sectional study, we genotyped rs35705950 in 2444 patients with RA. Among them, 683 patients with RA who have chest CT were divided into RA-ILD and RA-noILD. RA-ILD was classified as usual interstitial pneumonia (UIP) and other than UIP. The associations of rs35705950 with RA-ILD and its subtype were analysed using multivariable regression adjusted for age at RA diagnosis. Meta-analysis of a previously reported Japanese dataset and Korean dataset obtained for this study was conducted. RESULTS: The minor allele (T) frequency of rs35705950 was 0.37%, 1.43% and 2.38% in 2444 patients with RA, 105 patients with RA-ILD and 63 patients with UIP, respectively. Genotypic association of rs35705950 with RA-ILD was insignificant (OR 2.49, 95% CI 0.64 to 9.69, p=0.187), but showed significant association with UIP (OR 4.90, 95% CI 1.23 to 19.59, p=0.024) compared with RA-noILD. In meta-analysis (123 UIP and 878 RA-noILD) combining our data with previously reported Japanese data, this variant was found to be significantly associated with UIP (OR 3.51, 95% CI 1.19 to 10.37, p=0.023). CONCLUSION: MUC5B variant rs35705950 is a rare but significant risk factor for Asian patients with RA-ILD with UIP, suggesting a sharing of the genetic background between Asian and Western populations.

Increased risk of malignancy in patients with systemic lupus erythematosus: population-based cohort study in Korea.

BACKGROUND: This study aimed to evaluate the crude incidence rates and relative risk of malignancy in Korean patients with SLE. METHODS: We conducted a retrospective nationwide cohort study using databases from the National Health Insurance Service in Korea. All prevalent SLE patients aged over 19 were identified from January 2012 to December 2014 and observed until the diagnosis of malignancy, death, or end of the study, December 2015. The crude incidence rates (IRs) and standardised incidence ratios (SIRs) of overall and site-specific malignancies in SLE patients were estimated. RESULTS: We identified 17,854 SLE patients and during the observation period (60,511 person-years [PYs]), 768 solid malignancies (126.9/10,000 PYs) and 68 haematologic malignancies (11.2/10,000 PYs) occurred in SLE patients. In SLE patients, breast and reproductive system and thyroid cancers occurred predominantly, followed by liver and colon cancers. The SIRs of overall, solid, and haematologic malignancies of SLE patients compared to the general population were 1.8 (95% confidence interval [CI] 1.6-1.9), 1.7 (95% CI 1.5-1.8), and 5.9 (95% CI 4.8-7.3), respectively. In solid malignancies, head and neck (2.7, 95% CI 1.1-4.2), bladder (2.4, 95% CI 1.1-3.8), liver (1.9, 95% CI 1.4-2.3), pancreas (1.9, 95% CI 1.3-2.6), lung (1.8, 95% CI 1.2-2.4), colon (1.7, 95% CI 1.3-2.2), thyroid (1.6, 95% CI 1.3-1.8) and breast and reproductive system (1.5, 95% CI 1.2-1.7) cancers are at increased risk in SLE patients. CONCLUSION: An increased risk of haematologic and solid malignancies was observed in Korean patients with SLE compared to the general population.

Uptake of Biosimilars and Its Economic Implication for the Treatment of Patients with Rheumatoid Arthritis in Korea.

BACKGROUND: We aimed to examine the uptake of infliximab and etanercept biosimilars in patients with rheumatoid arthritis (RA) and its economic implication for healthcare expenditure. METHODS: Using Korean Health Insurance Review and Assessment Service National Patient Samples, we extracted RA patients who used biologic disease modifying anti-rheumatic drugs (bDMARDs) between 2009 and 2018. Descriptive statistics were used to explain the basic features of the data. We calculated the proportion of users of each bDMARD among total patients with bDMARDs half-yearly. We assessed changes in the utilization proportions of bDMARDs including 4 tumor necrosis factor inhibitors (TNFis) and 2 non-TNFis, which have been approved for RA in Korea: etanercept, infliximab, adalimumab, golimumab, tocilizumab, and abatacept, and analyzed the changes in market share of biosimilars among the bDMARDs after their introduction. Overall trends of medical costs for each bDMARD were presented over the 10-year period. RESULTS: Since the introduction of the biosimilar TNFis in 2012, the proportion of their use among bDMARDs steadily increased to 15.8% in 2018. While there has been a gradual increase in the use of biosimilar TNFis, the use of the corresponding originators has been decreasing. The introduction of biosimilar TNFis has resulted in a decrease in the medical costs of patients using either originator or biosimilar TNFis. CONCLUSION: In Korea, the proportional use of biosimilar TNFis has gradually increased since their introduction. The availability of less expensive biosimilar TNFis seems to have brought about a decrease in the medical costs of users of the originators.

Transurethral Foley catheter misplacement into the upper urinary tract in a patient with a history of lung cancer and chemotherapy: a case report and considerations to keep in mind.

Indwelling urethral catheter placement is a common and comparatively safe procedure. Misplacement of a urethral catheter into the upper urinary tract is unusual, and only a few cases have been reported. We describe the case of a 43-year-old man who presented with oliguria and had a history of chemotherapy for known metastatic lung cancer. As he had no history of urological disease, urethral catheterization was expected to be uneventful. The catheter was unable to be pulled back to the bladder neck once the balloon was inflated, and the patient expressed discomfort. Subsequent computed tomography revealed that the tip of the catheter was placed in the middle of the right ureter. Unbeknownst to the physicians before urethral catheterization, the patient had severe lower urinary tract symptoms and urinary bladder dysfunction with hydronephrosis, likely due to chemotherapy. Based on the patient's symptoms and imaging results, we judged the possibility of severe ureteral injury to be low. The malpositioned catheter was removed uneventfully after complete balloon deflation and then reinserted properly. He was admitted to the medical department but died as a result of an exacerbation of the underlying disease unrelated to the incident. If urethral catheter placement seems abnormal, physicians should aspirate and irrigate to confirm correct positioning before balloon inflation; then, they should carefully pull the inflated balloon near the neck of the bladder while monitoring the patient's symptoms. Although urethral catheter placement is comparatively safe, physicians must keep in mind that patients who have undergone chemotherapy might be at a risk for this rare complication.

Risk of Tuberculosis Development in Patients with Rheumatoid Arthritis Receiving Targeted Therapy: a Prospective Single Center Cohort Study.

BACKGROUND: Patients with rheumatoid arthritis (RA) undergoing targeted therapy have a higher risk of developing tuberculosis (TB). This requires diagnosis and treatment of latent tuberculosis infection (LTBI). We aimed to evaluate whether diagnosis and treatment of LTBI in RA are effective in Korea, and to estimate the risk of TB development by calculating the incidence rate of active TB among RA patients receiving targeted therapy. METHODS: We analyzed data from two prospective cohort studies of RA patients who received biologic disease-modifying antirheumatic drugs (bDMARDs) or Janus kinase (JAK) inhibitor. We selected new starters of targeted therapy and classified them into three groups receiving tumor necrosis factor (TNF) inhibitor, non-TNF inhibitor, and JAK inhibitor, respectively. We then compared LTBI prevalence, treatments, and active TB incidence during first-line therapy in each group. RESULTS: A total of 765 RA patients (574 TNF inhibitor users, 132 non-TNF inhibitor users, and 59 JAK inhibitor users) were included in this study. Observation periods were 1,255.2 person-years (PYs), 264.7 PYs, and 53.3 PYs, respectively. All 765 patients underwent LTBI screening, and the positivity rate was 26.5% (n = 203). Of the 203 LTBI-positive patients, 189 (93.1%) received treatment. Only one patient, who was in the TNF inhibitor group, and was negative for the interferon gamma release assay (IGRA), did not receive LTBI treatment and developed active TB during follow-up. CONCLUSION: Although the prevalence of LTBI in RA patients who started targeted therapy was slightly elevated, the Korean guidelines specifying LTBI screening and treatment were effective in preventing latent TB from becoming active.

Gender differences in factors associated with low quality of life and depression in Korean patients with ankylosing spondylitis.

PURPOSE: To identify predictors of low health-related quality of life (HRQoL) and depression in ankylosing spondylitis (AS) patients with a focus on gender differences. METHODS: We conducted a cross-sectional cohort study. Both AS-related clinical data and contextual factors were obtained. HRQoL and depressive mood were assessed by EuroQol-5 dimension (EQ-5D) and the Center for Epidemiological Studies Depression Scale (CES-D), respectively. Gender-stratified multivariable logistic regression analyses were performed. RESULTS: Among 211 patients, 161 were males. Males had similar disease activity and higher radiographic damage compared with females. There was no significant difference in EQ-5D index score between genders. CES-D score was higher in females. Higher ASDAS-C-reactive protein (CRP) was associated with low HRQoL in both males (Odds ratio [OR] 4.25, 95% confidence interval [CI] 2.42-7.46) and females (OR 2.94, 95% CI 1.02-8.48). Being employed was associated with decreased possibility of having low HRQoL in males (OR 0.39, 95% CI 0.16-0.95). Regarding depression, higher ASDAS-CRP (OR 1.87, 95% CI 1.03-3.40), current smoking (OR 2.98, 95% CI 1.09-8.15), and being employed (OR 0.17, 95% CI 0.06-0.46) were associated with depression in males. For females, living with a partner was related to depression (OR 0.08, 95% CI 0.01-0.93). CONCLUSION: AS patients with high disease activity are likely to be suffering from low HRQoL. Both disease-related factors and contextual factors were associated with depression, and predictors showed some differences between genders. Awareness of gender differences in comprehensive assessment can lead us to better personalized management in AS patients.

Prevalence, incidence and cause-specific mortality of rheumatoid arthritis-associated interstitial lung disease among older rheumatoid arthritis patients.

OBJECTIVE: We aimed to investigate the prevalence, incidence and cause-specific mortality of RA-associated interstitial lung disease (RA-ILD) among older US patients with RA. METHODS: We performed a nationwide cohort study using Medicare claims data (parts A, B and D for 2008-2017). RA was identified with a validated algorithm using RA diagnosis codes and DMARD prescription. RA-ILD was identified with a validated algorithm using ILD diagnosis codes by a rheumatologist/pulmonologist. RA-ILD was categorized as prevalent or incident relative to the initial RA observation (baseline/index date). We compared the total mortality of RA-ILD to RA without ILD using multivariable Cox regression, adjusting for baseline covariates. For cause-specific mortality, Fine and Gray subdistribution hazard ratios (sdHRs) were estimated to handle competing risks of alternative mortality causes. RESULTS: Among 509 787 RA patients (mean age 72.6 years, 76.2% female), 10 306 (2.0%) had prevalent RA-ILD at baseline. After baseline, 13 372 (2.6%) developed RA-ILD during 1 873 127 person-years of follow-up (median 3.0 years/person). During follow-up, 38.7% of RA-ILD patients died compared with 20.7% of RA patients without ILD. After multivariable adjustment, RA-ILD had an HR of 1.66 (95% CI 1.60, 1.72) for total mortality. Accounting for competing risk of other causes of death, RA-ILD had an sdHR of 4.39 (95% CI 4.13, 4.67) for respiratory mortality and an sdHR of 1.56 (95% CI 1.43, 1.71) for cancer mortality compared with RA without ILD. CONCLUSIONS: RA-ILD was present or developed in nearly 5% of patients in this nationwide study of older patients with RA. Compared with RA without ILD, RA-ILD was associated with excess total, respiratory and cancer mortality that was not explained by measured factors.

Risk of malignancy in Korean patients with primary Sjögren's syndrome.

OBJECTIVES: To evaluate the risks of overall and site-specific malignancies in Korean patients with primary Sjögren's syndrome (pSS). METHODS: Using the Korean nationwide healthcare claims database, we constructed a retrospective cohort for prevalent pSS aged over 50 years. After enrollment between January 2012 and December 2014, patients were followed until the development of any malignancy, or until December 2015. Crude incidence rates of malignancies of pSS patients were calculated, and their standardized incidence ratios (SIRs) for malignancies were calculated compared to those in knee osteoarthritis (OA) patients. RESULTS: A total of 6,359 pSS and 5,476,302 knee OA patients were included in this study. During follow-up (19,474 person-years [PYs]), 310 cases of solid malignancy (158.8/10,000 PYs) and 47 cases of hematologic malignancies (23.5/10,000 PYs) were observed in pSS patients. The risks of overall (SIR 1.30, 95% CI 1.16-1.43), solid (SIR 1.16, 95% CI 1.03-1.29), and hematologic malignancies (SIR 4.80, 95% CI 3.43-6.17) were increased in pSS patients. There was an elevated risk of site-specific malignancy in non-Hodgkin's lymphoma (NHL, SIR 6.45, 95% CI 4.05-8.83), multiple myeloma (SIR 4.88, 95% CI 2.00-7.76), and oropharynx (SIR 4.16, 95% CI 1.90-6.42). The risk of lung cancer was increased only in male pSS patients (2.50, 95% CI 1.02-3.99), while the risk of thyroid cancer was increased in female patients (1.44, 95% CI 1.04, 1.84). CONCLUSION: In patients with pSS over age 50, the risk of solid cancers such as oropharynx, thyroid, and lung cancers is also increased in addition to NHL.

Validation of claims-based algorithms to identify interstitial lung disease in patients with rheumatoid arthritis.

OBJECTIVE: To develop and validate claims-based algorithms to identify interstitial lung disease (ILD) in patients with rheumatoid arthritis (RA) METHODS: Using Medicare claims data linked with the electronic medical records (2012-2014), we first selected RA patients based on ≥2 diagnostic codes for RA and ≥1 disease-modifying antirheumatic drugs.Then, to identify ILD in RA, we developed eight claims-based algorithms using a combination of ICD-9 diagnosis codes and procedure codes related to the diagnosis or management of ILD. We assessed the positive predictive value (PPV) for each of the eight algorithms relative to confirmed ILD cases using chest computerized tomography or lung biopsy as the gold standard. RESULTS: A total of 5,214 RA patients were included in the study, and the ILD cases identified by each algorithm ranged from 181 to 993. The PPV of the diagnosis code-based algorithms ranged from 43.4% (≥1 diagnosis code by any physician) to 52.0% (≥2 diagnosis codes by any physician). When the algorithms further required ≥1 procedure code (e.g., imaging, bronchoscopy), the PPV did not improve. However, the algorithms that required ILD diagnosis codes by specialists (i.e., pulmonologist or rheumatologist) had PPVs of 61.5% with ≥1 code; 72.4% with ≥2 codes. CONCLUSIONS: In a cohort of RA patients, our algorithm that required ≥2 ILD diagnosis codes by specialists demonstrated a PPV of 72.4% in ascertaining ILD. Our results support the utility of the claims-based algorithm to identify a population-based cohort of RA patients with ILD using large administrative claims data.

Temporal relationship between idiopathic inflammatory myopathies and malignancies and its mortality: a nationwide population-based study.

OBJECTIVES: To examine the temporal relationship between malignancies and idiopathic inflammatory myopathies (IIMs) and its impact on mortality. METHODS: A retrospective cohort for IIM patients was conducted using the Korean National Health Insurance Service databases. We observed more than 5 years before and after the diagnosis of IIM (2002~2016) to identify IIM patients who developed any malignancy and classified these patients into two groups: the cancer-associated myositis (CAM) group, who developed malignancy within 3 years before or after the diagnosis of IIM and the cancer-not-associated myositis (CNAM) group, who developed malignancy beyond 3 years of IIM onset. The survival rates of the two groups were compared. RESULTS: We identified 1072 incident cases of IIM between 2007 and 2011. A total 225 patients of these patients were diagnosed with malignancy. The development of malignancy was frequent within 1 year before and after the time of IIM diagnosis. The common sites of malignancies in the CAM group differed from those in the CNAM group: the lung, hematologic malignancy, and the liver were common in both groups, but thyroid and oropharynx followed them in CAM while prostate, stomach, breast, and thyroid followed them in CNAM. CAM patient mortality was worse compared with CNAM patients (log-rank test, p < 0.01). CONCLUSIONS: Among IIM patients with malignancy, common sites of malignancy were different between the CAM and CNAM groups, and patients with CAM had poor prognosis compared with CNAM patients. Key Points • The malignancies commonly occurred in incident idiopathic inflammatory myopathy (IIM) patients, especially within 1 year before and after the initial IIM diagnosis. • Patients with malignancy had poor survival compared with patients without malignancy. • Among the IIM patients with malignancy, patients who developed malignancy within 3 years of IIM diagnosis (cancer-associated myositis, or CAM, group) showed higher mortality than cancer-not-associated myositis, CNAM group. • We also found that the common types of malignancy were different between the CAM and CNAM groups.

Factors for starting biosimilar TNF inhibitors in patients with rheumatic diseases in the real world.

BACKGROUND: To identify factors for starting biosimilar TNF inhibitors (TNFI) in patients with rheumatic diseases. METHODS AND FINDING: Using a national claims database, we identified patients with rheumatoid arthritis (RA) or ankylosing spondylitis (AS) who had used TNFIs since they were approved in Korea in 2004. We assessed changes in the proportion of each form of TNFI used between 2004 and 2017. We then selected patients starting on TNFIs between 2013 and 2017 to identify factors for starting biosimilars. In RA (n = 4,216), biosimilars were more likely to be initiated in clinics [odds ratio (OR) 2.54] and in the metropolitan area (OR, 2.02), but were less likely to be initiated in general hospitals (OR 0.40) or orthopedics (OR 0.44). In AS (n = 2,338), biosimilars were common at the hospital level (OR 2.20) and tended to increase over the years (OR 1.16), but were initiated less in orthopedics (OR 0.07). In addition, RA patients were more likely to initiate biosimilars in combination with methotrexate (OR 1.37), but biosimilars were not initiated frequently by patients with higher comorbidity scores (OR 0.97) or receiving glucocorticoids (OR 0.67). The patient factors favoring biosimilar in AS use were not clear. CONCLUSIONS: In Korea, the proportion of biosimilar TNFIs has increased. Type of institution and physician specialty are more important than patient factors in affecting biosimilar use. In RA, biosimilar TNFIs tend to be initiated in combination with MTX, and are less likely to be initiated in patients taking glucocorticoids or in those with high comorbidities.