CXCL10 predicts autoimmune features and a favorable clinical course in patients with IIP: post hoc analysis of a prospective and multicenter cohort study.

BACKGROUND: Interstitial pneumonia with autoimmune features (IPAF), which does not meet any of the criteria for connective tissue diseases (CTD), has been attracting an attention in patients with idiopathic interstitial pneumonia (IIP). However, the biomarkers that reflect the clinical course of these patients have not been fully elucidated. OBJECTIVE: To identify useful serum biomarkers reflecting CTD-related features and favorable prognoses in patients with IIP. METHODS: This was a post hoc analysis of a prospective and multicenter cohort study between 2015 and 2020. Newly diagnosed patients with IIP were consecutively enrolled, and 74 autoimmune features and autoantibodies were comprehensively checked during IIP diagnosis. Serum levels of CXCL10, CXCL1, CCL2, BAFF, angiopoietin-2, and leptin were evaluated at the time of IIP diagnosis. RESULTS: Two hundred twenty-two patients (159 men and 63 women) with IIP were enrolled. The median observation duration was 36 months. The median age was 71 years old, and median %forced vital capacity (FVC) was 84.1% at the time of IIP diagnosis. The proportion of patients who met the classification criteria for IPAF was 11.7%. In patients with high serum CXCL10, changes in both %FVC and %diffusion lung capacity for carbon monoxide at one year were significantly higher than those in patients with low CXCL10 (p = 0.014 and p = 0.009, respectively), whereas these changes were not significant for other chemokines and cytokines. High CXCL10 levels were associated with acute/subacute onset (p < 0.001) and the diagnosis of nonspecific interstitial pneumonia with organizing pneumonia overlap (p = 0.003). High CXCL10 levels were related to a higher classification of IPAF (relative risk for IPAF was 3.320, 95%CI: 1.571-7.019, p = 0.003) and lower classification of progressive pulmonary fibrosis (PPF; relative risk for PPF was 0.309, 95%CI: 0.100-0.953, p = 0.027) compared to those with low CXCL10. Finally, survival was higher in patients with IPF and high CXCL10 (p = 0.044), and high CXCL10 was a significant prognostic factor in multivariate Cox proportional hazards models (hazard ratio 0.368, p = 0.005). CONCLUSIONS: High serum levels of CXCL10 are associated with CTD-related features, the favorable clinical course, and survival in patients with IIP, especially IPF. CLINICAL TRIAL NUMBER: Not applicable.

Clinical Characteristics and Treatment Outcomes of Patients With Newly Diagnosed Takayasu Arteritis in Japan During the First 2 Years of Treatment　- A Nationwide Retrospective Cohort Study.

BACKGROUND: This study aimed to clarify recent clinical features and treatment outcomes in Japanese patients with newly diagnosed Takayasu arteritis (TAK) during the first 2 years of treatment. METHODS AND RESULTS: A nationwide multicenter retrospective cohort study for TAK was implemented to collect data between 2007 and 2014. The primary outcome of the study was clinical remission at Week 24. Of the 184 participants registered, 129 patients with newly diagnosed TAK were analyzed: 84% were female and the mean age at onset was 35 years. Clinical symptoms at diagnosis were mostly associated with large-vessel lesions. Frequent sites of vascular involvement included the carotid artery, subclavian artery, aortic arch, and descending aorta. The mean initial dose of prednisolone administered was 0.68 mg/kg/day, and 59% and 17% of patients received immunosuppressive drugs and biologics, respectively, by Week 104. Clinical remission at Week 24 and sustained clinical remission with daily prednisolone at ≤10 mg at Week 52 were achieved in 107 (82.9%) and 51 (39.5%) patients, respectively. The presence of signs and symptoms linked to large-vessel lesions was associated with failure to achieve sustained clinical remission at Week 52. CONCLUSIONS: We elucidated the clinical characteristics, treatment outcomes, and factors associated with failure to achieve sustained clinical remission in patients with newly diagnosed TAK in Japan during the first 2 years of treatment.

Detailed tracking of antigen and antibody levels during coronavirus disease 2019 treatment in an immunosuppressed patient with anti-neutrophil cytoplasmic autoantibody-associated vasculitis.

A 67-year-old woman with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis was not vaccinated against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and was on multiple immunosuppressive drugs. She was hospitalized because of interstitial shadowing in the lungs and diagnosed with persistent coronavirus disease 2019 (COVID-19). Despite treatment with a recombinant monoclonal antibody and antivirals, her symptoms persisted and she lacked a specific antibody response. She tested negative for SARS-CoV-2 antigen after the second antiviral treatment, and a subsequent chest radiograph showed improvement. However, the antibody levels did not change. This case highlights the importance of careful monitoring of the SARS-CoV-2 antigen and antibody levels during COVID-19 treatment in patients with immunosuppression.

Associations of disease duration and anti-citrullinated peptide antibody status with the effectiveness of abatacept in biologic-naïve patients with rheumatoid arthritis: Post hoc analysis of a multicentre, real-world observational study in Japan (ORIGAMI).

OBJECTIVES: The aim of the article is to investigate the associations of disease duration and anti-cyclic citrullinated peptide antibody (ACPA) status with the effectiveness of abatacept in biologic-naïve patients with rheumatoid arthritis (RA). METHODS: We performed post hoc analyses of the Orencia® Registry in Geographically Assembled Multicenter Investigation (ORIGAMI) study of biologic-naïve RA patients aged ≥20 years with moderate disease activity who were prescribed abatacept. Changes in the Simplified Disease Activity Index (SDAI) and Japanese Health Assessment Questionnaire (J-HAQ) at 4, 24, and 52 weeks of treatment were analysed in patients divided according to ACPA serostatus (positive/negative), disease duration (<1/≥1 year), or both. RESULTS: SDAI scores decreased from baseline in all groups. SDAI scores tended to decrease more in the ACPA-positive group and disease duration <1-year group than in the ACPA-negative group and disease duration ≥1-year group, respectively. In the disease duration <1-year group, SDAI tended to decrease more in the ACPA-positive group than in the ACPA-negative group. Disease duration was independently associated with the change in SDAI and SDAI remission at Week 52 in multivariable regression models. CONCLUSIONS: These results suggest that starting abatacept within 1 year of diagnosis was associated with greater effectiveness of abatacept in biologic-naïve patients with RA and moderate disease activity.

Pregnancy and childbirth in Takayasu arteritis in Japan: A nationwide retrospective study.

OBJECTIVES: This study aimed to understand the status quo of medical treatments of the primary disease and pregnancy outcomes in patients with Takayasu arteritis (TAK) and children's birth outcomes. METHODS: This study retrospectively enrolled patients with TAK who conceived after the disease onset and were managed at medical facilities participating in the Japan Research Committee of the Ministry of Health, Labor, and Welfare for Intractable Vasculitis. RESULTS: This study enrolled 51 cases and 68 pregnancies 2019-2021. Of these, 48 cases and 65 pregnancies (95.6%) resulted in delivery and live-born babies. The median age of diagnosis and delivery was 22 and 31, respectively. Preconception therapy included prednisolone (PSL) in 51 (78.5%, median 7.5 mg/day), immunosuppressants in 18 (27.7%), and biologics in 12 (18.5%) pregnancies. Six cases underwent surgical treatment before pregnancy. Medications during pregnancy included PSL in 48 (73.8%, median: 9 mg/day), immunosuppressants in 13 (20.0%), and biologics in 9 (13.8%) pregnancies. Enlargement of an aneurysm was reported in one pregnancy, which might be associated with increased circulating plasma volume. TAK relapsed in 4 (6.2%) and 8 (12.3%) pregnancies during pregnancy and after delivery, respectively. Additionally, 13/62 (20.9%) preterm infants and 17/59 (28.8%) low birth weight infants were observed, and none had serious postnatal abnormalities. Of the 51 confirmed infants, 42 (82.4%) were exclusively breastfed or mixed with formula. CONCLUSION: Most pregnancies in TAK were manageable with PSL at ≤10 mg/day. Relapse during pregnancy and postpartum occurred in <20% of pregnancies.

Association between the patterns of large-vessel lesions and treatment outcomes in patients with large-vessel giant cell arteritis.

OBJECTIVES: We aimed to identify associations between patterns of large-vessel lesions of large-vessel giant cell arteritis (LV-GCA) and treatment outcomes. METHODS: We extracted data on 68 newly diagnosed patients with LV-GCA from a retrospective, multi-centric, nationwide registry of GCA patients treated with glucocorticoids between 2007 and 2014. Patients with aortic lesions were identified based on the findings from contrast-enhanced computed tomography, magnetic resonance imaging, or positron emission tomography-computed tomography (Group 2, n = 49). Patients without aortic lesions were subdivided into LV-GCA with or without subclavian lesions defined as Group 1 (n = 9) or Group 3 (n = 10), respectively. The primary outcome evaluation was failure to achieve clinical remission by Week 24 and/or relapse within 104 weeks. RESULTS: The mean age and proportion of patients with cranial lesions and polymyalgia rheumatica in Group 2 were numerically lower than in the other two groups. Large-vessel lesions in Group 3 included carotid, pulmonary, renal, hepatic, or mesenteric lesions. The cumulative rate of poor treatment outcomes >2 years was 11.1%, 55.3%, and 88.0% in Groups 1, 2, and 3, respectively (by Kaplan-Meier analysis). The mean time to poor outcome was significantly different between the groups. CONCLUSIONS: Classification by subclavian and aortic lesions may be useful to determine treatment strategy.

Prospective nationwide multicentre cohort study of the clinical significance of autoimmune features in idiopathic interstitial pneumonias.

BACKGROUND: Some patients with idiopathic interstitial pneumonia (IIP) show autoimmune features. Interstitial pneumonia with autoimmune features (IPAF) was recently proposed as a research concept in these patients. However, retrospective studies reported conflicting results of its prognosis. Therefore, this study was conducted to prospectively evaluate the clinical significance of autoimmune features in patients with IIP. METHODS: This nationwide multicentre study prospectively enrolled consecutive patients with IIP. At the diagnosis, we systematically evaluated 63 features suggestive of connective tissue diseases using a checklist including symptoms/signs and autoantibodies, which contained most items of the IPAF criteria and followed up with the patients. Clinical phenotypes were included in a cluster analysis. RESULTS: In 376 patients with IIP enrolled, 70 patients (18.6%) met the IPAF criteria. The proportion of patients with IPAF was significantly lower in idiopathic pulmonary fibrosis (IPF) than in non-IPF (6.0% vs 24.3%, respectively). During a median observation period of 35 months, patients with IPAF more frequently developed systemic autoimmune diseases and had less frequent acute exacerbation of IIPs than patients with non-IPAF. IPAF diagnosis was significantly associated with better survival and was an independent positive prognostic factor in total and patients with non-IPF. Cluster analysis by similarity of clinical phenotypes identified a cluster in which there was a higher number of women, and patients had more autoimmune features and a better prognosis than other clusters. INTERPRETATION: These observations suggest that some patients with IIP show autoimmune features with distinct characteristics and favourable prognosis. However, we were not able to determine the appropriate therapies for these patients.

Early changes of pulmonary arterial hemodynamics in patients with systemic sclerosis: flow pattern, WSS, and OSI analysis with 4D flow MRI.

OBJECTIVES: To study the pulmonary artery (PA) hemodynamics in patients with systemic sclerosis (SSc) using 4D flow MRI (4D-flow). METHODS: Twenty-three patients with SSc (M/F: 2/21, 57 ± 15 years, 3 manifest PA hypertension (PAH) by right heart catheterization) and 10 control subjects (M/F: 1/9, 55 ± 17 years) underwent 4D-flow for the in vivo measurement of 3D blood flow velocities in the PA. Data analysis included area-averaged flow quantification at the main PA, 3D wall shear stress (WSS), oscillatory shear index (OSI) calculation along the PA surface, and Reynolds number. The composite outcome of all-cause death and major adverse cardiac events was also investigated. RESULTS: The maximum PA flow at the systole did not differ, but the minimum flow at the diastole was significantly greater in patients with SSc compared with that in control subjects (7.7 ± 16.0 ml/s vs. ­ 13.0 ± 17.3 ml/s, p < 0.01). The maximum WSS at the peak systole was significantly lower and OSI was significantly greater in patients with SSc compared with those in control subjects (maximum WSS: 1.04 ± 0.20 Pa vs. 1.33 ± 0.34 Pa, p < 0.01, OSI: 0.139 ± 0.031 vs. 0.101 ± 0.037, p < 0.01). The cumulative event-free rate for the composite event was significantly lower in patients with minimum flow in main PA ≤ 9.22 ml/s (p = 0.012) and in patients with Reynolds number ≤ 2560 (p < 0.001). CONCLUSIONS: 4D-flow has the potential to detect changes of PA hemodynamics noninvasively and predict the outcome in patients with SSc at the stage before manifest PAH. KEY POINTS: • The WSS at the peak systolic phase was significantly lower (p < 0.05), whereas OSI was greater (p < 0.01) in patients with SSc without manifest PAH than in controls. • The hemodynamic change detected by 4D-flow may help patient management even at the stage before manifest PAH in SSc. • The minimum PA flow and Reynolds number by 4D-flow will serve as a predictive marker for SSc.

Successful classification of macrophage-mannose receptor CD206 in severity of anti-MDA5 antibody positive dermatomyositis associated ILD.

OBJECTIVES: Macrophage-mannose receptor, CD206, is a marker of alternatively activated macrophages. Activated macrophages play key roles in DM. Interstitial lung disease (ILD) is a leading cause of mortality in patients with DM/clinically amyopathic DM (CADM). In particular, patients with the anti-melanoma differential gene 5 antibody (MDA5) frequently develop fatal rapid progressive ILD. This study aimed to evaluate the clinical implications of alternatively activated macrophages in patients with CADM/DM-ILD with anti-MDA5 antibody (MDA5-CADM/DM-ILD). METHODS: We measured serum concentrations of soluble CD206 (sCD206) in 33 patients with MDA5-CADM/DM-ILD and 36 age- and sex-matched control subjects. Expression levels of CD206 in the lungs from MDA5-CADM/DM-ILD were also examined. RESULTS: Patients with MDA5-CADM/DM-ILD had higher levels of sCD206 than those in controls (P < 0.0001). Of the 33 patients, 10 MDA5-CADM/DM-ILD patients developed fatal respiratory failure. Concentrations of sCD206 in patients with fatal ILD cases were significantly higher than those in the survivors, and increased sCD206 levels were associated with a higher mortality rate (Log-rank test, P = 0.0009). Age- and gender-adjusted logistic regression analyses showed that sCD206 was an independent prognostic factor for MDA5-CADM/DM-ILD. Importantly, assessment by sCD206 together with PaO2 successfully divided into three groups by their prognosis (P < 0.005, respectively). Pathological analyses showed accumulations of CD206-positive macrophages in lungs from the fatal case rather than those in the non-fatal cases. CONCLUSIONS: Levels of serum sCD206 are increased in MDA5-CADM/DM-ILD and associated with poor prognosis. sCD206 is a potential biomarker to predict the severity of MDA5-CADM/DM-ILD.

A novel method predicting clinical response using only background clinical data in RA patients before treatment with infliximab.

OBJECTIVES: The aim of the present study was to generate a novel method for predicting the clinical response to infliximab (IFX), using a machine-learning algorithm with only clinical data obtained before the treatment in rheumatoid arthritis (RA) patients. METHODS: We obtained 32 variables out of the clinical data on the patients from two independent hospitals. Next, we selected both clinical parameters and machine-learning algorithms and decided the candidates of prediction method. These candidates were verified by clinical variables on different patients from two other hospitals. Finally, we decided the prediction method to achieve the highest score. RESULTS: The combination of multilayer perceptron algorithm (neural network) and nine clinical parameters shows the best accuracy performance. This method could predict the good or moderate response to IFX with 92% accuracy. The sensitivity of this method was 96.7%, while the specificity was 75%. CONCLUSIONS: We have developed a novel method for predicting the clinical response using only background clinical data in RA patients before treatment with IFX. Our method for predicting the response to IFX in RA patients may have advantages over the other previous methods in several points including easy usability, cost-effectiveness and accuracy.

Characteristics and clinical relevance of late gadolinium enhancement in cardiac magnetic resonance in patients with systemic sclerosis.

Cardiac involvement in systemic sclerosis (SSc) is considerably frequent in autopsy, but the early identification is clinically difficult. Recent advantages in cardiac magnetic resonance (CMR) enabled to detect myocardial fibrotic scar as late gadolinium enhancement (LGE). We aimed to examine the prevalence and distribution of LGE in patients with SSc, and associate them with clinical features, electrocardiographic abnormalities and cardiac function. Forty patients with SSc (58 ± 14 years-old, 35 females, limited/diffuse 25/15, disease duration 106 ± 113 months) underwent serological tests, 12-lead electrocardiogram (ECG) and CMR. Seven patients (17.5 %) showed LGE in 26 segments of left ventricle (LV). LGE distributed mainly in the basal to mid inter-ventricular septum and the right ventricular (RV) insertion points, but involved all the myocardial regions. More patients with LGE showed NYHA functional class II and more (71 vs. 21 %, p < 0.05), bundle branch blocks (57 vs. 6 %, p < 0.05), LV ejection fraction (LVEF) < 50 % (72 vs. 6 %, p < 0.01), LV asynergy (43 vs. 0 %, p < 0.01) and RVEF < 40 % (100 vs. 39 %, p < 0.01). There was no difference in disease duration, disease types, or prevalence of positive autoimmune antibodies or high serum NT-proBNP level (>125 pg/ml). When cardiac involvement of SSc was defined as low LVEF, ECG abnormalities or high NT-proBNP, the sensitivity, specificity positive and negative predictive values of LGE were 36, 92, 71 and 72 %, respectively. We could clarify the prevalence and distribution of LGE in Japanese patients with SSc. The presence of LGE was associated with cardiac symptom, conduction disturbance and impaired LV/RV contraction.

Possible usefulness of fluorodeoxyglucose positron emission tomography in diagnosing polyarteritis nodosa: A case report and literature review.

Polyarteritis nodosa (PAN) is a systemic rheumatic disease that affects medium-sized arteries. PAN is typically not associated with anti-neutrophil cytoplasmic antibodies and has no serological surrogate markers. Therefore, its diagnosis requires pathological findings. However, the positive rate of biopsy in diagnosing PAN is not high, and the biopsy area is often limited. Several investigators have reported the usefulness of imaging findings in diagnosing PAN, independent of pathological findings. 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET)/CT has recently been approved for the diagnosis of large-vessel vasculitis in Japan. Several studies have also demonstrated the usefulness of FDG-PET/CT in diagnosing medium-vessel vasculitis. However, no studies have evaluated the usefulness of FDG-PET/CT for diagnosing PAN compared to other modalities, and it is not clear whether FDG-PET/CT is superior to other modalities for diagnosing PAN. Herein, we report a case of PAN and compare the usefulness of FDG-PET/CT with other modalities in diagnosing PAN.

Possible Case of Elderly-onset Intestinal Behcet's Disease with Trisomy 8 Following COVID-19 Vaccination Exacerbated by COVID-19 Infection.

Coronavirus disease 2019 (COVID-19) vaccines are effective in reducing the prevalence of this disease. However, some patients develop autoimmune diseases after vaccination. We herein report a case of elderly onset intestinal Behçet's disease (BD) with trisomy 8 following COVID-19 vaccination in which the disease was exacerbated by COVID-19 infection. The patient developed refractory stomatitis and genital ulcers two weeks after receiving the second vaccination and presented with bloody stool two years later. Intestinal BD with trisomy 8, exacerbated by COVID-19, was treated with high-dose glucocorticoids and infliximab; however, surgical intervention was required. The findings of this case suggest that the COVID-19 vaccination may induce BD.

Ventricular Thrombus Formation Caused by Subendomyocardial Inflammation in Eosinophilic Granulomatosis With Polyangiitis.

Cardiac involvement of eosinophilic granulomatosis with polyangiitis is a rare but life-threatening complication. We present a case of eosinophilic granulomatosis with polyangiitis with moderately impaired ventricular function forming a ventricular thrombus. Pathological assessment of endomyocardial biopsy specimen revealed aggregated eosinophils in the subendocardium, suggesting ventricular endothelial damage leading to thrombus formation.

Radiological and histopathological features and treatment response by subtypes of interstitial pneumonia with autoimmune features: A prospective, multicentre cohort study.

BACKGROUND: Patients with idiopathic interstitial pneumonia (IIP) have a favourable prognosis when they have interstitial pneumonia with autoimmune features (IPAF). However, precise IPAF-related findings from high-resolution computed tomography (HRCT) and lung histopathological specimens and the treatment response have not been fully determined. Therefore, this study was conducted to evaluate the relationship between findings on HRCT or lung histopathological specimens and the progression of interstitial pneumonia in patients with IPAF. METHODS: This multicentre cohort study prospectively enrolled consecutive patients with IIP. At the diagnosis of IIP, we systematically evaluated 74 features suggestive of connective tissue diseases and followed them up. HRCT, lung specimens, serum antibodies, and the clinical course were also evaluated. RESULTS: Among 222 patients with IIP, 26 (11.7%) fulfilled the IPAF criteria. During a median observation period of 36 months, patients with IPAF showed better survival than those without IPAF (p = 0.034). While histopathological findings were not related to IPAF, nonspecific interstitial pneumonia (NSIP) with organizing pneumonia (OP) overlap was the most prevalent HRCT pattern (p < 0.001) and the consolidation opacity was the most common radiological finding in IPAF (p = 0.017). Furthermore, in patients with IPAF, the diagnosis of COP or NSIP with OP overlap was associated with a higher increase in %FVC in 1 year than in those with idiopathic pulmonary fibrosis, NSIP, or unclassifiable IIP (p = 0.002). CONCLUSIONS: This study shows the presence of consolidation opacity on HRCT and the diagnosis of COP or NSIP with OP overlap are associated with IPAF and its favourable treatment response in patients with IPAF.

A Case of Coronary Arteritis and Myocardial Involvement With Associated IgG4-Related Disease.

A 56-year-old male subject with bilateral eyelid swelling was diagnosed with an immunoglobulin G4-related disease. After whole-body surveillance, concomitant coronary arteritis with a mural thrombus and myocardial involvement were observed. In this case, multimodal diagnostic imaging assessment led to the diagnosis of both coronary arteritis and myocardial fibrosis associated with immunoglobulin G4-related disease. (Level of Difficulty: Advanced.).

Long-term effect of tocilizumab on left ventricular hypertrophy and systolic dysfunction in AA amyloidosis with rheumatoid arthritis.

Because cardiac involvement of amyloid A (AA) is not frequent, little is known about the effects of tocilizumab (TCZ; a humanized monoclonal anti-interleukin-6 receptor antibody). We present the case of a 77-year-old man with cardiac AA amyloidosis due to rheumatoid arthritis (RA). He was admitted to our hospital because of gastrointestinal bleeding. Upon admission, chest radiography and electrocardiogram showed progression of cardiomegaly and atrioventricular conduction delay, respectively. Echocardiography showed diffuse left ventricular (LV) hypertrophy with reduced LV contraction. AA amyloid deposits in the myocardium were identified by Congo red staining and immunohistochemical staining with anti-AA antibody, suggesting cardiac AA amyloidosis. After starting treatment with TCZ, his condition improved. Hypertrophic LV mass was significantly reduced, and impaired LV contraction was restored after 10 months of TCZ treatment. The effects of TCZ were sustained for 2 years. Plasma N terminal pro-B-type natriuretic peptide level decreased from 2947 pg/mL (reference level, <125 pg/mL) on admission to 325 pg/mL after 2 years of TCZ treatment. The present case supports that cardiac biopsy is very important to diagnose cardiac AA amyloidosis in patients with RA complicating unexplained cardiac hypertrophy and/or dysfunction and TCZ should be administered if applicable. .

LC-MS/MS method for the quantitation of serum tocilizumab in rheumatoid arthritis patients using rapid tryptic digestion without IgG purification.

The quantitation of serum tocilizumab using liquid chromatography tandem-mass spectrometry (LC-MS/MS) method has not been widely applied in clinical settings because of its time-consuming and costly sample pretreatments. The present study aimed to develop a validated LC-MS/MS method for detecting serum tocilizumab by utilizing immobilized trypsin without an immunoglobulin G purification step and evaluate its applicability in the treatment of rheumatoid arthritis (RA) patients administered intravenously or subcutaneously with tocilizumab. The tocilizumab-derived signature peptide was deciphered using a nano-LC system coupled to a hybrid quadrupole-orbitrap mass spectrometer. The serum tocilizumab was rapidly digested by immobilized trypsin for 30 min. The chromatographic peak of the signature peptide and that of the internal standard were separated from the serum digests for a total run time of 15 min. The calibration curve of serum tocilizumab concentration was linear with a range of 2-200 µg/mL. The intra- and inter-day accuracy and relative standard deviation (RSD) were 90.7%-109.4% and <10%, respectively. The serum tocilizumab concentrations in the RA patients receiving intravenous and subcutaneous injections were 5.8-28.9 and 2.4-63.5 µg/mL, respectively. The serum tocilizumab concentrations using the current method positively correlated with those using the enzyme-linked immunosorbent assay, although a systematic error was observed between these methods. In conclusion, a validated LC-MS/MS method with minimal sample pretreatments for monitoring serum tocilizumab concentrations in RA patients was developed.

Behçet's Disease with Bilateral Renal Infarction Due to Mucormycosis.

We herein report a case of Behçet's disease with renal infarction due to mucormycosis. A 76-year-old man with entero-Behçet's disease had been treated with glucocorticoid and tumor necrosis factor (TNF) inhibitors. His entero-Behçet's disease was refractory to these treatments, and ileocecal resection was performed. After the operation, renal infarction that was unresponsive to anticoagulation therapy developed. He ultimately died of renal failure due to renal infarction. At the autopsy, histopathology of abundant hyphae in the renal vessel wall revealed mucormycosis. Renal mucormycosis is an important cause of renal failure with renal infarction in immunocompromised patients.