[Clinical characteristics and genetic analysis of a Chinese pedigree affected by glycogen storage disease type Ia with gout as the first manifestation].

OBJECTIVE: To explore the clinical and genetic characteristics of a Chinese pedigree affected by glycogen storage disease (GSD) type Ia with gout as the first manifestation. METHODS: Clinical and biochemical data of the pedigree were collected. Available members of the pedigree were subjected to gene sequencing, and the result was analyzed by bioinformatics software. The pedigree was followed up for five years. RESULTS: The proband was a young female manifesting recurrent gout flare, hypoglycemia, and hypertriglyceridemia. One of her younger brothers also presented with dysplasia and hepatic adenoma. Gene sequencing revealed that the proband and her younger brother both harbored c.1022T>A (p.I1e341Asn) and c.230+5G>A compound heterozygous variants of the G6PC gene , which were inherited from their father and mother, respectively. Among these, the c.230+5G>A is an intron region variant which was unreported previously, and bioinformatics analysis showed that it may impact mRNA splicing of the gene. The proband was treated with raw corn starch, allopurinol, and fenofibrate. Gout was well controlled, and she had given birth to a baby girl without GSD. CONCLUSION: GSD Ia should be considered among young gout patients with hypoglycemia and hepatomegaly, for which gene sequencing is warranted. GSD Ia has a good prognosis after comprehensive treatment with diet and medicine.

Elevated serum cholesterol levels are associated with proteinuria over 0.5 g/day in premenopausal women with systemic lupus erythematosus.

Background: Systemic lupus erythematosus (SLE) commonly occurs in premenopausal women and is associated with elevated estrogen levels. Patients with SLE may have abnormal serum triglyceride (TG) levels, and lipid reportedly promotes kidney damage in patients with nephrosis. Since estrogen regulates lipid levels, we investigated the serum lipid levels of premenopausal women with SLE and their relationship with proteinuria. Methods: This cross-sectional study included 123 premenopausal women with SLE (SLE group), who were classified into 24-h urine protein exceeding 0.5 g (24 h-UPRO > 0.5 g, n = 22) and 24 h-UPRO ≤ 0.5 g (n = 101) subgroups, and 100 similarly aged healthy women (control group). Clinical characteristics and biomarker levels were compared between these groups. The associated factors of proteinuria over 0.5 g/day were evaluated using multivariate logistic regression. A receiver operating characteristic (ROC) curve was plotted to assess the cholesterol (CH) cut-off associated with increased development of proteinuria over 0.5 g/day. Results: The SLE group had significantly higher serum TG levels than that of control group. 24 h-UPRO were significantly correlated with serum creatinine, CH, TG, and uric acid levels. Serum CH level was the greatest associated factor for proteinuria over 0.5 g/day. The area under the ROC curve was 0.843, with a CH cut-off of 4.58 mmol/L. Patients with serum CH above 4.58 mmol/L had a higher proportion of type IV LN, but with no statistical difference. Conclusions: In premenopausal SLE patients, serum TG levels were higher than in healthy women, and serum CH levels were the primary associated factor for proteinuria over 0.5 g/day. Proteinura over 0.5 g/day may occur in women with SLE with serum CH levels >4.58 mmol/L. CH levels may be useful for predicting proteinuria.

A Matrix Prediction Model for the 6-Month Mortality Risk in Patients With Anti-Melanoma Differentiation-Associated Protein-5-Positive Dermatomyositis.

Objectives: The purpose of this study was to investigate the baseline independent risk factors for predicting 6-month mortality of patients with anti-melanoma differentiation-associated gene 5 (anti-MDA5)-positive dermatomyositis (DM) and develop a matrix prediction model formed by these risk factors. Methods: The hospitalized patients with DM who completed at least 6-month follow-up were recruited as a derivation cohort. The primary exposure was defined as positive anti-MDA5 at the baseline. The primary outcome was all-cause 6-month mortality after enrollment. A matrix prediction model was developed in the derivation cohort, and another published cohort was used for external validation. Results: In derivation cohort, 82 patients with DM were enrolled (mean age of onset 50 ± 11 years and 63% women), with 40 (49%) showing positive anti-MDA5. Gottron sign/papules (OR: 5.135, 95%CI: 1.489-17.708), arthritis (OR: 5.184, 95%CI: 1.455-18.467), interstitial lung disease (OR: 7.034, 95%CI: 1.157-42.785), and higher level of C4 (OR: 1.010, 95%CI: 1.002-1.017) were the independent associators with positive anti-MDA5 in patients with DM. Patients with anti-MDA5-positive DM had significant higher 6-month all-cause mortality than those with anti-MDA5-negative (30 vs. 0%). Among the patients with anti-MDA5-positive DM, compared to the survivors, non-survivors had significantly advanced age of onset (59 ± 6 years vs. 46 ± 9 years), higher rates of fever (75 vs. 18%), positive carcinoma embryonic antigen (CEA, 75 vs. 14%), higher level of ferritin (median 2,858 ug/L vs. 619 ug/L, all p < 0.05). A stepwise multivariate Cox regression showed that ferritin ≥1,250 µg/L (HR: 10.4, 95%CI: 1.8-59.9), fever (HR: 11.2, 95%CI: 2.5-49.9), and positive CEA (HR: 5.2, 95%CI: 1.0-25.7) were the independent risk factors of 6-month mortality. A matrix prediction model was built to stratify patients with anti-MDA5-positive DM into different subgroups with various probabilities of 6-month mortality risk. In an external validation cohort, the observed 6-month all-cause mortality was 78% in high-risk group, 43% in moderate-risk group, and 25% in low-risk group, which shows good accuracy of the model. Conclusion: Baseline characteristics such as fever, ferritin ≥1,250 µg/L, and positive CEA are the independent risk factors for 6-month all-cause mortality in patients with anti-MDA5-positive DM. A novel matrix prediction model composed of these three clinical indicators is first proposed to provide a chance for the exploration of individual treatment strategies in anti-MDA5-positive DM subgroups with various probabilities of mortality risk.

Joint damage is amplified in rheumatoid arthritis patients with positive thyroid autoantibodies.

BACKGROUND: Autoimmune thyroid disease (AITD), which is characterized by an increased presence of thyroid autoantibodies (TAbs), such as antibodies against thyroid peroxidase (TPOAbs) and antibodies against thyroglobulin (TgAbs), has been reported to be associated with rheumatoid arthritis (RA) because AITD and RA both involve autoimmunity. However, few data are available on the incidence of TAbs in Chinese RA patients, and studies on the association between TAbs and joint damage as well as synovitis in RA patients remain sparse. Here, we aimed to evaluate the incidence of TAbs in a consecutive Chinese RA cohort and to investigate whether the elevated presence of TAbs is associated with joint damage and synovitis in RA patients. METHODS: A total of 125 hospitalized RA patients were consecutively recruited. Clinical data and available synovial tissues were collected at baseline, and TAbs and thyroid function were detected by chemiluminescent immunoassay. Patients who tested positive for TPOAbs or TgAbs were classified as the TAbs-positive group, and patients who tested positive for neither TPOAbs nor TgAbs were recruited as the TAbs-negative group. Disease activity was assessed using DAS28-ESR (the disease activity score in 28 joints and including the erythrocyte sedimentation rate). X-ray assessment of the hand/wrist was performed according to the Sharp/van der Heijde-modified Sharp score (mTSS), and patients with an mTSS score >10 were defined as having radiographic joint damage (RJD). Serial tissue sections were stained immunohistochemically for CD3, CD15, CD20, CD34, CD38, and CD68, and synovitis were assessed according to Krenn's synovitis score. RESULTS: A total of 44 (35%) patients were positive for either TPOAbs or TgAbs. Importantly, there was a significantly greater percentage of patients with RJD in the TAbs-positive group versus the TAbs-negative group (68% vs. 42%, p = 0.005). Compared with the TAbs-negative group, significantly more CD38-positive plasma cells infiltrated the TAbs-positive synovium, and a higher percentage of patients with high-grade synovitis were observed in the TAbs-positive group (5/8, 63% vs. 5/14, 36%). Moreover, RF positivity and disease activity indicators, including TJC28, DAS28-ESR, and CDAI, were significantly higher in the TAbs-positive group (all p < 0.05). Adjusted logistic regression analysis revealed that positive TAbs (OR 2.999, 95% CI [1.301-6.913]; p = 0.010) and disease duration (OR 1.013, 95% CI [1.006-1.019]; p < 0.001) were independently associated with RJD, and an odds ratio of 2.845 (95% CI [1.062-7.622]) was found for RJD in women with positive TAbs (n = 37) compared with those without TAbs (n = 59) (p = 0.038). CONCLUSION: Our data showed that joint destruction was amplified in RA patients with an elevated presence of TAbs, which supports the importance and necessity of TAbs and thyroid function screening and monitoring in RA patient management in clinical practice.

Continuously elevated serum matrix metalloproteinase-3 for 3 ~ 6 months predict one-year radiographic progression in rheumatoid arthritis: a prospective cohort study.

INTRODUCTION: Core disease activity indicators of rheumatoid arthritis (RA) have been found to be limited in predicting joint destruction progression. Matrix metalloproteinase (MMP) 3 plays an essential role in joint destruction and was found elevated in some remission patients. We aimed to monitor dynamic core disease activity indicators and serum MMP-3 for one year and evaluate their value for predicting radiographic progression. METHODS: Patients with active RA (Simplified disease activity index > 3.3) were treated according to the treat-to-target strategy. Serum MMP-3 was detected by enzyme-linked immunosorbent assay and clinical data were collected simultaneously at 0, 1st, 3rd, 6th and 12th month. X-ray assessment of hand/wrist was repeated at baseline and the 12th month and a change of total Sharp score > 0.5 units was defined as radiographic progression. RESULTS: Fifty-six patients completed one year follow-up and 29 % showed radiographic progression. Although not significantly different at baseline, serum MMP-3 and all core disease activity indicators, except for erythrocyte sedimentation rate, at the 12th month were significantly higher in the progressive group than in the non-progressive group. Among sixteen progressive patients, 69 % achieved the therapeutic target and 56 % had continuous elevated serum MMP-3, 38 % had continuous elevated serum MMP-3 and normal C-reactive protein (CRP) at the 6th month. Log-rank tests and repeated measures analysis revealed a significant difference in dynamic serum MMP-3 between progressive and non-progressive patients. Receiver operating characteristic curve and univariate logistic regression analysis showed that elevated serum MMP-3 at 0, 1st, 3rd and 6th months, compared with CRP at the 1st month, were significant predictors for one-year radiographic progression (MMP-3 odds ratio (OR):10.500 ~ 27.000, all P < 0.05; CRP: OR = 7.400, P = 0.011). CONCLUSIONS: Our data showed that continuously elevated serum MMP-3 for 3 ~ 6 months predicted one-year radiographic progression which implied that monitoring of dynamic serum MMP-3 combined with core disease activity indicators may be more helpful for predicting radiographic progression and treatment decision in RA.

[Value of serum matrix metalloproteinase-3 in the assessment of active disease in patients with rheumatoid arthritis].

OBJECTIVE: To investigate the value of serum matrix metalloproteinase-3 (sMMP-3) in the assessment of active disease in patients with rheumatoid arthritis (RA). METHODS: One hundred and ninety-one RA patients were recruited from the Department of Rheumatology of Sun Yat-sen Memorial Hospital from June 2010 to June 2014. sMMP-3 level of these RA patients and 58 healthy people was tested by enzyme-linked immunosorbent assay, while clinical data was collected simultaneously. Receiver operating characteristic (ROC) curve was used for the analysis of optimal cut-off point for the evaluation of disease activity. RESULTS: There were 128 female patients and 63 male patients recruited. sMMP-3 was significantly higher in RA patients than healthy control and it was higher in patients with active disease than that in patients in remission (all P < 0.01). ROC curve analysis showed that the optimal cut-off point for diagnosing active RA was 84 µg/L with area under the curve (AUC) 0.822 in female and 168 µg/L with AUC 0.824 in male (both P < 0.01). According to the optimal cut-off points, the sensitivity of sMMP-3 + CRP combined detection was 97.2% for diagnosing active RA, which was significantly higher than that of sMMP-3 (84.7%) or C-reactive protein (CRP) (88.2%, both P < 0.05). The specificity of combined detection was 95.7%, which was significantly higher than that of sMMP-3 (68.1% , P < 0.01). And Youden's index of combined detection (0.951) was significantly higher than that of sMMP-3 (0.528) or CRP (0.754, both P < 0.05). CONCLUSION: sMMP-3 is a helpful indicator for disease activity measurement in RA patients. Combined detection of sMMP-3 and CRP can improve the accuracy of disease activity assessment.

Down-regulating peroxisome proliferator-activated receptor-gamma coactivator-1 beta alleviates the proinflammatory effect of rheumatoid arthritis fibroblast-like synoviocytes through inhibiting extracellular signal-regulated kinase, p38 and nuclear factor-kappaB activation.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction and disability. Peroxisome proliferator-activated receptor-gamma coactivator-1 beta (PGC-1ß) is a transcriptional coactivator that plays important roles in regulating multiple aspects of energy metabolism and cytokine signaling pathways. PGC-1ß overexpression leads to the attenuation of macrophage-mediated inflammation. In this study, we aimed to determine the expression of PGC-1ß in RA synovium and fibroblast-like synoviocytes (FLS), and explore the mechanisms of PGC-1ß on both the proinflammatory effects and apoptosis in RA-FLS. METHODS: Synovium was obtained from 31 patients with active RA, as well as 13 osteoarthritis (OA) and 10 orthopedic arthropathies (Orth.A) as "less inflamed" disease controls. FLS were then isolated and cultured. Synovial PGC-1ß expression was determined by immunohistochemistry staining, while FLS PGC-1ß expression was detected by immunofluorescence staining, quantitative real-time PCR (qPCR) assay and western blot. PGC-1ß was depleted by lentivirus sh-RNA, and up-regulated by pcDNA3.1- PGC-1ß. The expression of proinflammatory cytokines, matrix metalloproteinases and receptor activator of nuclear factor-kappaB ligand was analyzed by qPCR, cytometric bead array and western blot. The expression of mitogen-activated protein kinases and nuclear factor-kappaB (NF-κB) was determined by qPCR and western blot. Besides, cell apoptosis was examined using flow cytometry. The interaction between PGC-1ß and NF-κB was performed by dual-luciferase reporter gene assays. RESULTS: (A) Synovial PGC-1ß was over-expressed in RA patients compared with OA or Orth.A patients. (B) PGC-1ß expression significantly increased in RA-FLS compared with OA-FLS. (C) PGC-1ß mediated the expression of proinflammatory cytokines and apoptosis through extracellular signal-regulated kinase (ERK), p38 and NF-κB in RA-FLS. (D) PGC-1ß mediated NF-κB transcription in RA-FLS, but did not affect ERK and p38. CONCLUSION: The results indicate that PGC-1ß may play important roles in the proinflammatory effects and apoptosis of RA-FLS.

Serum matrix metalloproteinase-3 as a noninvasive biomarker of histological synovitis for diagnosis of rheumatoid arthritis.

OBJECTIVE: To explore the correlation between matrix metalloproteinase- (MMP-) 3 and histological synovitis in rheumatoid arthritis (RA). METHODS: Serum MMP-3 of 62 patients with active RA was detected by ELISA. Serial synovial tissue sections from all RA patients, 13 osteoarthritis, and 10 orthopedic arthropathies patients were stained with hematoxylin and eosin and immunohistochemically for MMP-3, CD3, CD20, CD38, CD68, and CD15. RESULTS: The percentage of lining MMP3+ cells was significantly higher in RA patients especially with high grade synovitis and it was significantly correlated with Krenn's synovitis score (r = 0.574, P < 0.001) and sublining inflammatory cells. Multivariate stepwise linear regression analysis revealed that the association of the percentage of lining MMP3+ cells with activation of synovial stroma, sublining CD68+ macrophages, and CD15+ neutrophils was stronger than other histological indicators. The percentage of lining MMP3+ cells was significantly correlated with serum MMP-3 in RA (r = 0.656, P < 0.001). Serum MMP-3 was higher in RA patients with high grade synovitis than that of low grade synovitis and significantly correlated with synovitis score and activation of synovial stroma subscore (all P < 0.05). CONCLUSION: Serum MMP-3 may be an alternative noninvasive biomarker of histological synovitis and RA diagnosis.

[Correlation between synovial TRAF6 expression and serum bone metabolism markers in rheumatoid arthritis].

OBJECTIVE: To evaluate the correlation between synovial tumor necrosis factor receptor-associated factor (TRAF) 6 expression and serum bone metabolism markers in rheumatoid arthritis (RA). METHODS: Serum biochemical markers of bone formation (N-terminal propeptide of type I collagen, PINP and N-terminal midfragment of osteocalcin, N-MID.OC) and bone resorption (C-terminal telopeptide of type I collagen, CTX-I) were detected by chemiluminescence in 51 RA patients and 102 age and gender-matched healthy controls from Sun Yat-sen Memorial Hospital during the period of April 2010 to December 2012. Clinical and other serological parameters of reflecting RA activity and severity were collected and correlated with bone metabolism markers. TRAF6 was stained immunohistochemically in synovium from 30 active RA patients and the intensity of TRAF6+ cells was analyzed semiquantitatively. Correlation between synovial TRAF6 expression and serum bone metabolism markers was analyzed. RESULTS: Serum CTX-I level was significantly higher in RA patients than healthy controls ((0.53 ± 0.33) × 10⁻³ vs (0.33 ± 0.16) × 10⁻³ g/L, P < 0.01). Serum PINP and N-MID. OC levels of RA patients were correlated negatively with morning stiffness (P < 0.05), Health Assessment Questionnaire (HAQ) score (P < 0.05) and pain visual analogue scales (VAS) score (P < 0.05). Serum PINP level of RA patients correlated positively with gripping power (r = 0.296, P < 0.05). TRAF6 expression was observed in lining and sublining area of RA synovium and a higher expression of TRAF6 was seen in patients with severe synovitis than those with mild synovitis. Significant correlation was found between synovial TRAF6 expression and serum PINP level (r = 0.381, P < 0.05), as well as serum N-MID.OC level (r = 0.345, P < 0.05). CONCLUSION: Increased bone resorption and altered skeletal bone metabolism are present in RA. An elevated expression of synovial TRAF6 may be correlated with increased compensatory bone formation. And TRAF6 is probably involved in the pathogenesis of bone metabolism imbalance through modulating synovial inflammation in RA.

Upregulation of tumor necrosis factor receptor-associated factor 6 correlated with synovitis severity in rheumatoid arthritis.

INTRODUCTION: Rheumatoid arthritis (RA) is a chronic inflammatory disease leading to joint destruction and disability. Focal bone erosion is due to excess bone resorption of osteoclasts. Tumor necrosis factor receptor-associated factor 6 (TRAF6) is one of the critical mediators both in inflammatory signal pathway and differentiation and resorption activity of osteoclasts. Here we aimed to investigate TRAF6 expression in RA synovium and its correlation with histological synovitis severity and radiological joint destruction in RA. METHODS: Synovitis score was determined in needle biopsied synovium from 44 patients with active RA. Synovium from nine patients with osteoarthritis (OA) and seven with orthopedic arthropathies (Orth.A) were enrolled as "less inflamed" disease controls. Serial sections were stained immunohistochemically for TRAF6 as well as CD68 (macrophage), CD3 (T cell), CD20 (B cell), CD38 (plasmocyte), CD79a (B lineage cells from pre-B cell to plasmocyte stage), and CD34 (endothelial cell). Double immunofluorescence staining of TRAF6 and CD68 were tested. Densities of positive staining cells were determined and correlated with histological disease activity (synovitis score) and radiographic joint destruction (Sharp score). RESULTS: TRAF6 expression was found in the intimal and subintimal area of RA synovium, with intense staining found in the endochylema and nucleus of intimal synoviocytes and subintimal inflammatory cells. Double immunofluorescence staining showed TRAF6 was expressed in most of the intimal cells and obviously expressed in CD68+ cells and some other CD68- cells in subintimal area. Synovial TRAF6 was significantly over-expressed in the RA group compared with the OA and Orth.A group (2.53 ± 0.94 vs. 0.72 ± 0.44 and 0.71 ± 0.49, P < 0.0001). Synovial TRAF6 expression in RA correlated significantly with synovitis score (r = 0.412, P = 0.006), as well as the inflammatory cell infiltration (r = 0.367, P = 0.014). Significant correlation was detected between synovial TRAF6 expression and intimal CD68+ cells, as well as the cell density of subintimal CD68+ cells, CD3+ cells, CD20+ cells, CD38+ cells, and CD79a+ cells (all P < 0.05). CONCLUSIONS: Elevated synovial TRAF6 expression correlated with synovitis severity and CD68+ cell density in RA. It is, therefore, hypothesized that synovial TRAF6 is involved in the pathogenesis of synovial inflammation and osteoclast differentiation in RA.

Synovial infiltration with CD79a-positive B cells, but not other B cell lineage markers, correlates with joint destruction in rheumatoid arthritis.

OBJECTIVE: The efficacy of B cell depletion in the treatment of patients with rheumatoid arthritis (RA) has revitalized interest in the pathogenic role(s) of B cells in RA. We evaluated the distribution of synovial B lineage cells and their correlation with histologic disease activity and joint destruction in RA. METHODS: Synovial tissue samples were obtained by closed-needle biopsy from 69 Chinese patients with active RA, from 14 patients with osteoarthritis (OA), and from 15 with orthopedic arthropathies (OrthA) as disease controls. Serial tissue sections were stained immunohistochemically for CD79a (pro-B cell to plasma cell), CD20 (B cells), CD38 (plasma cells), CD21 (follicular dendritic cells), CD68 (macrophages), CD3 (T cells), and CD34 (endothelial cells). Densities of positive-staining cells were determined and correlated with histologic disease activity (Krenn 3-component synovitis score) and radiographic joint destruction (Sharp score). RESULTS: Mean sublining CD79a-positive cell density was significantly higher in RA than in OA (p <0.001) or OrthA (p = 0.003). Receiver operating characteristic curve analysis showed that CD79a-positive cell density differentiated RA well from OA [area under the curve (AUC) = 0.79] or OrthA (AUC = 0.75). Spearman's rank order correlation showed significant correlations between sublining CD79a-positive cell density and the synovitis score (r = 0.714, p < 0.001), total Sharp score (r = 0.490, p < 0.001), and the erosion subscore (r = 0.545, p < 0.001), as well as the joint space narrowing subscore (r = 0.468, p = 0.001) in RA. CONCLUSION: Synovial CD79a-positive B cells may be a helpful biomarker for histologic disease activity in RA and may be involved in the pathogenesis of joint destruction in RA.

Effective treatment of Kimura's disease with leflunomide in combination with glucocorticoids.

Kimura's disease (KD) is a rare, benign, chronic inflammatory disease which typically presents as persisting or recurring tumor-like lesions in the head and neck area that can be easily misdiagnosed. We report one patient with KD treated with leflunomide in combination with glucocorticoids and analyzed the literature on treatment of KD. The patient had a recurrent mass in the left upper arm with eosinophilia and elevated serum IgE but no renal involvement. The clinical manifestations improved markedly within 1 month, and blood eosinophil count and serum IgE normalized. Corticosteroids were then tapered gradually without recurrence or severe side effects in the 2-year follow-up period. Literature analysis identified four different non-drug interventions and 18 different drugs for treating KD, most of which were obtained from case reports. Our use of combination therapy of leflunomide and glucocorticoids suggests the need for a controlled trial for the treatment of this rare disorder.

Elevated serum glucose-6-phosphate isomerase correlates with histological disease activity and clinical improvement after initiation of therapy in patients with rheumatoid arthritis.

OBJECTIVE: To determine serum glucose-6-phosphate isomerase (GPI) concentrations in patients with rheumatoid arthritis (RA), and to test whether they correlate with objective measures of disease activity. METHODS: Sera from 116 patients with RA, 69 patients with non-RA rheumatic diseases, and 101 healthy controls were analyzed. Levels of soluble serum GPI were measured by ELISA. Histological disease activity was determined with the synovitis score in synovial needle biopsies from 58 of the 116 patients with RA. Thirty-one of the 58 synovium samples were stained for CD68, CD3, CD20, CD38, CD79a, and CD34 by immunohistochemistry. Demographic data were collected, as well as serological and clinical variables that indicate RA disease activity, for Spearman correlation analysis. RESULTS: Serum GPI level correlated positively with the synovitis score (r = 0.278, p = 0.034). Significantly higher soluble GPI levels were detected in the RA sera compared with sera from healthy controls and the non-RA disease controls (2.25 ± 2.82 vs 0.03 ± 0.05 and 0.19 ± 0.57 µg/ml, respectively; p < 0.0001). The rate of serum GPI positivity was significantly higher in the RA patients than in the non-RA disease controls (64.7% vs 10.1%; p < 0.0001). Spearman analysis showed no significant correlation between serum GPI level and Disease Activity Score in 28 joints at baseline. After initiation of antirheumatic treatments, GPI levels decreased significantly (2.81 ± 3.12 vs 1.44 ± 2.09 µg/ml; p = 0.016), paralleling improvement of the disease activity indices. CONCLUSION: Elevated serum GPI may be involved in the synovitis of RA and may prove useful as a serum marker for disease activity of RA.