Performance of the 2019 ACR/EULAR Classification Criteria for IgG4-Related Disease in a Large Chinese Cohort.

OBJECTIVE: The purpose of this research was to ascertain the effectiveness of the newly established criteria for classifying IgG4-related disease (IgG4-RD), as applied to a large Chinese cohort in real-world clinical settings. METHODS: Patient data were procured from the digital health records of 4 prominent academic hospitals. The criterion standard for identifying IgG4-RD patients was from a seasoned rheumatologist. The control group consisted of individuals with other ailments such as cancer, other forms of pancreatitis, infectious diseases, and illnesses that mimic IgG4-RD. RESULTS: A total of 605 IgG4-RD patients and 760 mimickers were available for analysis. The 2019 EULAR/ACR criteria have a sensitivity of 69.1% and a specificity of 90.9% in this large Chinese cohort. IgG4-RD had a greater proportion of males (55.89% vs 36.25%, p < 0.001), an older average age at diagnosis (54.91 ± 13.44 vs 48.91 ± 15.71, p < 0.001), more pancreatic (29.59% vs 6.12%, p < 0.001) and salivary gland (63.30% vs 27.50%, p < 0.001) involvement, and a larger number of organ involvement (3.431 ± 2.054 vs 2.062 ± 1.748, p < 0.001) compared with mimickers. CONCLUSIONS: The 2019 EULAR/ACR criteria are effective in classifying IgG4-RD in Chinese patients, demonstrating high specificity and moderate sensitivity.

Analysis of environmental biological effects and OBT accumulation potential of microalgae in freshwater systems exposed to tritium pollution.

The ecological risk of tritiated wastewater into the environment has attracted much attention. Assessing the ecological risk of tritium-containing pollution is crucial by studying low-activity tritium exposure's environmental and biological effects on freshwater micro-environment and the enrichment potential of organically bound tritium (OBT) in microalgae and aquatic plants. The impact of tritium-contaminated wastewater on the microenvironment of freshwater systems was analyzed using microcosm experiments to simulate tritium pollution in freshwater systems. Low activity tritium pollution (105 Bq/L) induced differences in microbial abundance, with Proteobacteria, Bacteroidota, and Desulfobacterota occupying important ecological niches in the water system. Low activity tritium (105-107 Bq/L) did not affect the growth of microalgae and aquatic plants, but OBT was significantly enriched in microalgae and two aquatic plants (Pistia stratiotes, Spirodela polyrrhiza), with the enrichment coefficients of 2.08-3.39 and 1.71-2.13, respectively. At the transcriptional level, low-activity tritium (105 Bq/L) has the risk of interfering with gene expression in aquatic plants. Four dominant cyanobacterial strains (Leptolyngbya sp., Synechococcus elongatus, Nostoc sp., and Anabaena sp.) were isolated and demonstrated good environmental adaptability to tritium pollution. Environmental factors can modify the tritium accumulation potential in cyanobacteria and microalgae, theoretically enhancing food chain transfer.

[Significance of anti-Jo-1 antibody's clinical stratification in idiopathic inflammatory myopathy and disease spectrum].

OBJECTIVE: To investigate the significance of anti-histidyl tRNA synthetase (Jo-1) antibody in idiopathic inflammatory myopathies (IIM) and its diseases spectrum. METHODS: We enrolled all the patients who were tested positive for anti-Jo-1 antibody by immunoblotting in Peking University People's Hospital between 2016 and 2022. And the patients diagnosed with anti-synthetase antibody syndrome (ASS) with negative serum anti-Jo-1 antibody were enrolled as controls. We analyzed the basic information, clinical characteristics, and various inflammatory and immunological indicators of the patients at the onset of illness. RESULTS: A total of 165 patients with positive anti-Jo-1 antibody were enrolled in this study. Among them, 80.5% were diagnosed with connective tissue disease. And 57.6% (95/165) were diagnosed with IIM, including ASS (84/165, 50.9%), immune-mediated necrotizing myopathy (7/165, 4.2%) and dermatomyositis (4/165, 2.4%). There were 23.0% (38/165) diagnosed with other connective tissue disease, mainly including rheumatoid arthritis (11/165, 6.7%), undifferentiated connective tissue disease (5/165, 3.0%), interstitial pneumonia with autoimmune features (5/165, 3.0%), undifferentiated arthritis (4/165, 2.4%), Sjögren's syndrome (3/165, 1.8%), systemic lupus erythematosus (3/165, 1.8%), systemic vasculitis (3/165, 1.8%), and so on. Other cases included 3 (1.8%) malignant tumor patients, 4 (2.4%) infectious cases and so on. The diagnoses were not clear in 9.1% (15 /165) of the cohort. In the analysis of ASS subgroups, the group with positive serum anti-Jo-1 antibody had a younger age of onset than those with negative serum anti-Jo-1 antibody (49.9 years vs. 55.0 years, P=0.026). Clinical manifestations of arthritis (60.7% vs. 33.3%, P=0.002) and myalgia (47.1% vs. 22.2%, P=0.004) were more common in the ASS patients with positive anti-Jo-1 antibody. With the increase of anti-Jo-1 antibody titer, the incidence of the manifestations of arthritis, mechanic hands, Gottron sign and Raynaud phenomenon increased, and the proportion of abnormal creatine kinase and α-hydroxybutyric dehydrogenase index increased in the ASS patients. The incidence of myalgia and myasthenia were significantly more common in this cohort when anti-Jo-1 antibody-positive ASS patients were positive for one and more myositis specific antibodies/myositis associated autoantibodies (P < 0.05). CONCLUSION: The disease spectrum in patients with positive serum anti-Jo-1 antibody includes a variety of diseases, mainly ASS. And anti-Jo-1 antibody can also be found in many connective tissue diseases, malignant tumor, infection and so on.

Study of 43 SLE patients with autoimmune liver cirrhosis: emphasis on clinical features and differences from lupus without cirrhosis.

OBJECTIVE: To investigate the clinical characteristics of systemic lupus erythematosus accompanied by autoimmune liver cirrhosis (SLE-ALC) patients and differences from the non-cirrhosis group. METHODS: Forty-three patients with SLE-ALC were enrolled in this study from 2653 patients with SLE in Peking University People's Hospital. A descriptive case-control study was performed between SLE-ALC patients and the entry time-matched non-cirrhosis group. RESULTS: Among the 43 SLE-ALC patients, 41 (95.3%) were female. Eight patients (18.6%) were first found to have cirrhosis and then diagnosed with SLE. Eighteen patients (41.9%) had jaundice and 27 (62.8%) had esophageal and gastric varices. The age of SLE-ALC patients was 51.1 ± 17.2 years, which was significantly older than the non-cirrhosis group (P < 0.001). Lung involvement was more common as initial manifestations in SLE-ALC patients during the SLE course (P=0.027). Compared with the non-cirrhosis group, SLE-ALC patients had worse liver function. A significantly higher rate of hematological system involvement (anemia, leucopenia, and thrombocytopenia) and a higher level of immunoglobulins were observed in SLE-ALC patients (P<0.05). Moreover, SLE-ALC patients displayed a lower positive rate of anti-double-stranded DNA and anti-ribosomal P protein (P<0.05). The most common radiologic manifestations are ascitic fluid (72.1%) and splenomegaly (71.4%) in SLE-ALC patients. Six SLE-ALC patients underwent liver biopsy, and interface hepatitis was present in all patients. CONCLUSIONS: Cirrhosis is rare in SLE patients but is manifested as a unique pattern of clinical features characterized by late-onset age, lung involvement, high immunoglobulins, and impaired liver function.

Tritium and Carbon-14 Contamination Reshaping the Microbial Community Structure, Metabolic Network, and Element Cycle in the Seawater Environment.

The potential ecological risks caused by entering radioactive wastewater containing tritium and carbon-14 into the sea require careful evaluation. This study simulated seawater's tritium and carbon-14 pollution and analyzed the effects on the seawater and sediment microenvironments. Tritium and carbon-14 pollution primarily altered nitrogen and phosphorus metabolism in the seawater environment. Analysis by 16S rRNA sequencing showed changes in the relative abundance of microorganisms involved in carbon, nitrogen, and phosphorus metabolism and organic matter degradation in response to tritium and carbon-14 exposure. Metabonomics and metagenomic analysis showed that tritium and carbon-14 exposure interfered with gene expression involving nucleotide and amino acid metabolites, in agreement with the results seen for microbial community structure. Tritium and carbon-14 exposure also modulated the abundance of functional genes involved in carbohydrate, phosphorus, sulfur, and nitrogen metabolic pathways in sediments. Tritium and carbon-14 pollution in seawater adversely affected microbial diversity, metabolic processes, and the abundance of nutrient-cycling genes. These results provide valuable information for further evaluating the risks of tritium and carbon-14 in marine environments.

Assessing the ecological risk of tritium and Carbon-14 discharge on cyanobacteria through metabolic profiling.

The ecological risk posed by tritium (T) and carbon-14 (C-14) discharge from nuclear accidents has gained attention. This study evaluated the toxic impact of T and C-14 (at a concentration of 37 kBq/L for 15 days) on the cyanobacteria (Synechococcus elongatus). The results showed that the assimilation efficiency of cyanobacteria was significantly higher for C-14 than T, and the intracellular C-14 activity reached 30.62-40.58 kBq/kg. T and C-14 exposure had no significant effect on cell proliferation but impacted photosynthesis and respiration. T exposure increased the content of Ca, Mg, Na, P, K, and Mn, while C-14 exposure primarily affected trace element absorption in cyanobacteria. 31, 27, and 58 different metabolites (DEMs) were identified under T, C-14, and combined exposure conditions. These DEMs were enriched in the amino acid biosynthesis pathway, and nitrogen assimilation was one of the crucial pathways affected by T and C-14 exposure. The absorption of mineral elements by cyanobacteria was influenced by the variation in metabolites in the ABC transporter pathway caused by T and C-14 exposure. Our findings provide insights into the metabolic response of cyanobacteria to T and C-14 exposure and will help to guide the ecological risk evaluation of nuclear accidents.

Degradation of Uranium-Contaminated Decontamination Film by UV Irradiation and Microbial Biodegradation.

This research provides a complete degradation scheme for acrylic copolymer/cellulose acetate butyrate peelable decontamination films. This study analyzed the removal efficiency of uranium by peelable decontamination film. More importantly, the degradability of the films was evaluated by a combined treatment with UV radiation and microbial biodegradation. The results showed that UV radiation would rupture the surface of the decontamination films, which leaded the weight-average molecular weight decreased by 55.3% and number-average molecular weight decreased by 75.83%. Additionally, the microbial flora induced light-degradable decontamination film weight-average molecular weight and number-average molecular weight decreased by 9.3% and 30.73%, respectively. 16S rRNA microbial diversity analysis indicated that Pantoea, Xylella, Cronobacter, and Olivibacter were the major degrading bacteria genera. Among them, 4 key strains that can be stripped of decontamination films have been isolated and identified from the dominant degrading bacteria group. The results show that UV radiation combined with microbial flora can achieve rapid degradation of the decontamination films.

The performance of the diagnostic scoring system or criteria for macrophage activation syndrome in systemic juvenile idiopathic arthritis for adult-onset Still's disease. A multicentre case-control study in China.

OBJECTIVES: To evaluate the performance of the diagnostic scoring system/criteria for macrophage activation syndrome (MAS) used in systemic juvenile idiopathic arthritis (sJIA) for adult-onset Still's disease (AOSD). METHODS: This retrospective case-control study included AOSD patients with and without MAS from six hospitals in China. The cut-off values that best discriminated MAS from active AOSD were determined by receiver operating characteristic (ROC) curve analysis. The performance of the present diagnostic scoring system/criteria for sJIA-MAS was evaluated in AOSD-associated MAS. The optimal critical value of the ROC curve replaces the relevant indicators of the existing scoring system and different models were tested for sensitivity/specificity. RESULTS: A total of 56 AOSD-associated MAS patients (AOSD-MAS) and 112 AOSD patients without MAS matched with age and sex treated at six centres between 2007 and 2017 were enrolled. The 2016 MAS in sJIA classification criteria had an overall sensitivity of 100.0% and specificity of 80.4% for classifying AOSD-MAS. Excluding hypertriglyceridemia and substituting some other criteria with newly obtained cut-off values could increase specificity. An MS score ≥-2.1 yielded a sensitivity of 95.2% and a specificity of 76.6% in classifying AOSD-MAS. ROC curve analysis revealed that a score of -1.74 could best discriminate AOSD-MAS from AOSD without MAS. An MS score ≥-1.74 yielded a sensitivity of 93.5% and a specificity of 92.6% in diagnosing AOSD-MAS (AUC=0.96, 95%CI: 0.93-0.99, p<0.0001). CONCLUSIONS: The diagnostic tool for MAS in sJIA with modification appears to apply to AOSD-MAS.

Characteristics and mortality in primary Sjögren syndrome-related interstitial lung disease.

ABSTRACT: Aim of the study was to determine the characteristics and prognosis, and to identify the risk factors for mortality in patients with primary Sjögren syndrome (pSS) with interstitial lung disease (pSS-ILD).A total of 1422 patients with SS were screened and 178 patients with pSS-ILD were recruited. The medical records and outcomes were retrospectively reviewed. Overall survival and case control study were performed to explore the predictors of death.Among 178 pSS-ILD patients, 87.1% were women. Mean age was 61.59 ±â€Š11.69-year-old. Median disease duration was 72.0 (24.0, 156.0) months. Nonspecific interstitial pneumonia was the predominant high-resolution computed tomography pattern (44.9%). Impairment in diffusion capacity was the most common abnormality of pulmonary function test (75.8%) and the most severe consequence. Type 1 respiratory failure and hypoxia were observed in 15.0% and 30.0% patients, respectively. Mean survival time after confirmation of pSS-ILD diagnosis was 9.0 (6.8, 13.0) years. The 10-year survival rate for all patients with pSS-ILD was 81.7%. Forty-four (24.7%) of 178 patients died during the follow-up period. The most predominant cause of death was respiratory failure (n = 27). Twenty-seven patients died of ILD and formed study group. The 78 patients who survived formed control group. Age and smoking were risk factors for mortality in patients with pSS-ILD. In addition, severity of ILD, as reflected by high-resolution computed tomography, pulmonary function test, and arterial blood gas, was an independent risk factor. However, inflammation status (erythrocyte sedimentation rate, C-reactive protein) and anti-Sjögren syndrome-related antigen A and anti-Sjögren syndrome-related antigen B were not.ILD is a severe complication of pSS. Age, smoking, and severity of lung involvement are more critical for prognosis rather than inflammation status and autoantibodies.

Disparities between IgG4-related kidney disease and extrarenal IgG4-related disease in a case-control study based on 450 patients.

We aimed to compare the demographic, clinical and laboratory characteristics between IgG4-related kidney disease (IgG4-RKD+) and extrarenal IgG4-related disease (IgG4-RKD-) in a large Chinese cohort, as well as describing the radiological and pathological features of IgG4-RKD+. We retrospectively analyzed the medical records of 470 IgG4-related disease (IgG4-RD) patients at Peking University People's Hospital from January 2004 to January 2020. The demographic, clinical, laboratory, radiological and pathological characteristics between IgG4-RKD+ and IgG4-RKD- were compared. Twenty IgG4-RD patients who had definite etiology of renal impairment including diabetes, hypertension and etc. were excluded. Among the remained 450 IgG4-RD patients, 53 were diagnosed with IgG4-RKD+ . IgG4-RKD+ patients had older age at onset and at diagnosis. Male to female ratio of IgG4-RKD+ patients is significantly higher. In the IgG4-RKD+ group, the most commonly involved organs were salivary gland, lymph nodes and pancreas. It was found that renal function was impaired in approximately 40% of IgG4-RKD+ patients. The most common imaging finding is multiple, often bilateral, hypodense lesions. Male sex, more than three organs involved, and low serum C3 level were risk factors for IgG4-RKD+ in IgG4-RD patients. These findings indicate potential differences in pathogenesis of these two phenotypes.

Biodegradation and physiological response mechanism of a bacterial strain to 2,4,6-trinitrotoluene contamination.

The aim of this study was to reveal the biodegradation characteristics and physiological response mechanism of a newly isolated bacterium to 2,4,6-trinitrotoluene (TNT) contamination. A Klebsiella variicola strain with high efficiency of TNT degradation was used as the test strain to analyze the changes in cell growth, morphology, and functional groups under different TNT concentrations (0, 100 mg⋅L-1) and the effects of TNT stress on the metabolic profile as revealed by non-targeted metabonomics. A TNT concentration of 100 mg L-1 caused a significant increase in the 5-day biochemical oxygen demand (BOD5) to 950 mg L-1, while the degradation rate of TNT reached 100% within 30 h after inoculation with Klebsiella variicola. Fourier transform infrared spectroscopy (FTIR) analysis showed changes in the characteristic peak of triamide by TNT treatment. Non-targeted metabonomics identified a total of 544 differentially produced metabolites under TNT treatment (252 upregulated and 292 downregulated), mainly lipids and lipid-like molecules. The metabolic pathways associated with amino acid biosynthesis and metabolism were the most significantly enriched pathways, and simultaneous detection showed that TNT was degraded to 4-amino-2,6-dinitrotoluene (DNT), 2-hydroxylamino-4,6-DNT, 2-amino-4,6-DNT, 2-amino-4-nitrotoluene, and 2,4-DNT. These results confirmed that Klebsiella variicola has a high tolerance to TNT and efficiently degrades it. The degradation mechanism involves TNT-induced accelerated amino acid biosynthesis, production of a protease to catalyze the TNT transformation, and the participation of the transformed TNT products in cell metabolism.

Rapid Onset of Efficacy of Baricitinib in Chinese Patients with Moderate to Severe Rheumatoid Arthritis: Results from Study RA-BALANCE.

INTRODUCTION: Baricitinib is an oral, selective inhibitor of Janus kinase which demonstrates clinical efficacy in patients with rheumatoid arthritis (RA). This report aims to analyze the onset time of baricitinib in Chinese patients with moderately to severely active RA who had an inadequate response to methotrexate. METHODS: This post hoc analysis evaluated clinical improvements of Chinese patients treated with baricitinib 4 mg once daily compared with placebo, based on data from a phase 3 study RA-BALANCE. Efficacy measures including American College of Rheumatology 20% (ACR20) response, ACR core set values, Disease Activity Score modified to include the 28 diarthrodial joint count (DAS28) using high-sensitivity C-reactive protein (hsCRP), DAS28-erythrocyte sedimentation rate, Simplified Disease Activity Index, Clinical Disease Activity Index, DAS28-hsCRP ≤ 3.2 response (low disease activity), and Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) were evaluated at weeks 1, 2, 4, 8, 12, 14, 16, 20, and 24 (except for FACIT-F evaluated every 4 weeks). A logistic regression model and an analysis of covariance model were used to analyze treatment comparisons of categorical and continuous measures, respectively. RESULTS: Statistically significant (p ≤ 0.05) improvements were observed as early as week 1 or 2 for the baricitinib group compared to placebo in almost all main efficacy measures. For other outcomes including 66 swollen joint count, 68 tender joint count, FACIT-F, and DAS28-hsCRP ≤ 3.2 response rate, differences were evident (p ≤ 0.05) by week 4 in the baricitinib group compared with placebo. Significant improvements in all efficacy measures were sustained through 24 weeks. CONCLUSIONS: Baricitinib demonstrated a rapid onset of efficacy on ACR20 response, ACR core set values, disease activity, and patient-reported outcome improvements in Chinese patients from RA-BALANCE. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT02265705.

Efficacy and Safety of Baricitinib in Chinese Rheumatoid Arthritis Patients and the Subgroup Analyses: Results from Study RA-BALANCE.

INTRODUCTION: Baricitinib is an oral selective inhibitor of Janus kinase (JAK) 1 and JAK 2, which has demonstrated significant efficacy in patients with moderately to severely active rheumatoid arthritis (RA). This analysis aims to describe the efficacy and safety of baricitinib in Chinese RA patients with an inadequate response to methotrexate (MTX-IR), and to analyze the effects of baseline characteristics on the efficacy of baricitinib treatment. METHODS: In this 52-week, randomized, double-blind, placebo-controlled study, 231 Chinese patients with moderately to severely active RA who had MTX-IR were randomly assigned to placebo (n = 115) or baricitinib 4 mg once daily (n = 116). The primary endpoint was American College of Rheumatology 20% (ACR20) response at week 12. Other efficacy measures included ACR50, ACR70, Physician's Global Assessment of Disease Activity, Patient's Global Assessment of Disease Activity, patient's assessment of pain, Disease Activity Score in 28 joints using high-sensitivity C-reactive protein, remission and low disease activity rates according to Simplified Disease Activity Index or Clinical Disease Activity Index, Health Assessment Questionnaire-Disability Index, and mean duration and severity of morning joint stiffness, worst tiredness and worst joint pain were analyzed. Additionally, subgroup analyses were performed across baseline characteristics. RESULTS: Statistically significant improvement in ACR20 response was achieved with baricitinib at week 12 (53.4 vs. 22.6%, p = 0.001) in Chinese patients, compared to placebo. Most of the secondary objectives were met with statistically significant improvements. Efficacy of baricitinib was irrespective of patient demographics and baseline characteristics. Safety events were similar between the baricitinib and placebo groups. CONCLUSIONS: The efficacy of baricitinib 4 mg in Chinese patients with moderately to severely active RA and prior MTX-IR was clinically significant compared to placebo regardless of baseline characteristics. Baricitinib was well tolerated with an acceptable safety profile during the full study period. TRIAL REGISTRATION: NCT02265705.

Effect of sustained intensive therapy with disease modifying anti-rheumatic drugs in rheumatoid arthritis: a 5-year real-world consecutive study.

BACKGROUND: Intensive therapy with disease modifying anti-rheumatic drugs (DMARDs) has been reported to improve the outcomes of rheumatoid arthritis (RA). However, real-world study on the effect of intensive therapy on RA sustained remission is still lacking. This study aimed to investigate the outcome of sustained intensive DMARD therapy (SUIT) for RA in a real-world 5-year consecutive cohort. METHODS: Based on a consecutive cohort of 610 out-patients with RA, remission of RA was assessed in 541 patients from 2012 to 2017, by dividing into SUIT, non-SUIT, and intermittent SUIT (Int-SUIT) groups. Changes in the disease activity scores were evaluated by 28-joint disease activity score based on erythrocyte sedimentation rate (DAS28-ESR), 28-joint disease activity score based on C-reactive protein (DAS28-CRP), and clinical deep remission criteria (CliDR). Cumulative remission rates between different groups were compared using Kaplan-Meier curves and predictive factors of sustained remission were identified by univariate and multivariate logistic regression analysis. RESULTS: The remission rates of the SUIT group decreased from 12.0% (65/541) to 5.6% (20/359) based on DAS28-ESR, from 14.0% (76/541) to 7.2% (26/359) based on DAS28-CRP, and from 8.5% (46/541) to 3.1% (11/359) based on CliDR, respectively, with a gradually decreasing trend during the 5 years. The SUIT regimen led to a significantly higher cumulative remission rate than non-SUIT regimen based on DAS28-ESR (39.7% vs. 19.5%, P = 0.001), DAS28-CRP (42.0% vs. 19.6%, P = 0.001), and CliDR (24.5% vs. 8.7%, P = 0.001). The cumulative remission rates of patients treated with SUIT regimen were significantly higher than those treated with Int-SUIT regimen based on DAS28-ESR (39.7% vs. 25.7%, P = 0.043) and CliDR (24.5% vs. 14.2%, P = 0.047), but there was no significant difference between the two groups based on DAS28-CRP (42.0% vs. 27.4%, P = 0.066). Multivariate logistic regression analysis showed that the use of SUIT regimen was an independent favorable predictor according to different remission definitions (for DAS28-ESR: odds ratio [OR], 2.215, 95% confidence interval [CI]: 1.271-3.861, P = 0.005; for DAS28-CRP: OR, 1.520, 95% CI: 1.345-1.783, P = 0.002; for CliDR: OR, 1.525, 95% CI: 1.314-1.875, P = 0.013). CONCLUSION: Sustained intensive treatment of RA is an optimal strategy in daily practice and will lead to an increased remission rate.

Glucose-6-phosphate isomerase is associated with disease activity and declines in response to infliximab treatment in rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA), a systemic autoimmune disease characterized by synovial inflammation, can cause cartilage and bone damage as well as disability. The aim of this study was to explore whether serum glucose-6-phosphate isomerase (GPI) is correlated with disease activity and the value of GPI in the evaluation of infliximab treatment in patients with RA. METHODS: Sixty-two patients with RA who had an inadequate response to methotrexate (MTX) were enrolled in Peking University People's Hospital from July 1, 2016 to July 31, 2018. Infliximab (3 mg/kg, intravenous at weeks 0, 2, and 6 and then every 8 weeks) was administered to patients with stable background MTX therapy. Serum samples were obtained at baseline and week 18. Serum GPI levels were determined using enzyme-linked immunosorbent assay. The associations between serum GPI levels and clinical features were analyzed. RESULTS: Serum GPI was positively correlated with Disease Activity Score in 28 joints (DAS28), swollen joint count, tender joint count and C-reactive protein level (P < 0.001, P < 0.001, P < 0.001, and P = 0.033, respectively). The change of DAS28 in GPI-positive patients was greater than that in GPI-negative patients (P < 0.001). Compared with those for patients receiving MTX monotherapy at baseline, the GPI levels were significantly declined when MTX was combined with infliximab (P < 0.001). CONCLUSION: Serum GPI is related to disease activity and clinical response to infliximab treatment.