[Efficacy and safety of low-dose rasburicase for refractory chronic gouty arthritis]

Objective: To explore the efficacy and safety of low-dose rasburicase for refractory chronic gouty arthritis. Methods: A cohort study. The clinical data of patients with refractory chronic gouty arthritis who were treated with rasburicase at Sun Yat-sen Memorial Hospital, Sun Yat-sen University between January 2021 and July 2022 were retrospectively analyzed. Refractory chronic gouty arthritis was defined as serum uric acid (sUA)>360 μmol/L and urate volume>10 cm³ under dual-energy computed tomography after tolerable maximal oral urate-lowering therapy for at least 3 months. The administration of low-dose rasburicase was applied intravenously with total dosage ranging from 4.5 to 7.5 mg each dose, at 4-week intervals for a maximum of three doses. Efficacy was evaluated by the changes of sUA level, tophus and urate volume. Results: A total of 22 patients were included for analysis, with 95.4% (21/22) male, the mean age was (44±15) years, and the median duration of gout was 11 (6-15) years. The mean sUA at baseline was (667±112) μmol/L. The levels of sUA significantly decreased after each dose of rasburicase (P<0.001), and the median reduction of sUA after each dose of rasburicase was 568 (471-635), 187 (66-335) and 123 (49-207) μmol/L, respectively. At week 12, nine patients (40.9%) exhibited sUA<360 μmol/L and tophus disappeared in one patient. The urate volume significantly decreased at week 12 when compared with that before the first dose of rasburicase in all the patients [40 (16-172) cm³ vs 17 (7-134) cm³, P<0.001], with a median reduction rate of 41.6% (22.9%-58.5%). The everall safety of rasburicase was good, and no serious adverse reactions occurred. Conclusions: Low-dose rasburicase is well-tolerated and effective for decreasing the urate burden in patients with refractory chronic gouty arthritis. Further prospective randomized controlled trials are needed to validate these findings.

AB1057 EFFICACY AND SAFETY OF LOW-DOSE RASBURICASE IN COMBINATION WITH CONVENTIONAL URATE-LOWERING THERAPY FOR REFRACTORY CHRONIC GOUTY ARTHRITIS: A PILOT STUDY IN

Background

Recombinant uricase such as pegloticase are indicated for chronic gouty arthritis who have failed to achieve serum urate level <300μmol/L even though receiving conventional urate-lowering drugs. Rasburicase which is currently approved at a dosage of 0.2 mg/(kg.d) for 5 days for the prevention of tumor lysis syndrome in pediatric patients with hematological tumors, is the only available uricase in China at present.

Objectives

To evaluate the efficacy and safety of low-dose rasburicase in refractory chronic gouty arthritis.

Methods

We retrospectively collected data of 17 patients with refractory chronic gouty arthritis who were treated with rasburicase from January 2021 to September 2021 at Sun Yat-sen Memorial Hospital, Sun Yat-sen University. The refractory chronic gouty arthritis was defined as serum urate level was still more than 300μmol/L and dual-energy CT showed the volume of urate more than 10 cm3, even though the allopurinol, febuxostat, and/or benzbromarone of the maximum tolerable amount were received for more than 3 months. Rasburicase was added every four weeks (week 0, week 4, and week 8) with a dosage of 1.5 mg/d for three consecutive days, on the basis of daily oral urate-lowering drugs of the maximum tolerable amount. The serum urate level was monitored. The primary outcome was the change in urate volume at week 12 compared to week 0 by dual-energy CT.

Results

① Seventeen patients were recruited with 16 males (94%) and mean age 47±15 years old. The median gout course was 11 (6.5, 15) years with gout flares number 20 (11, 36) times in the previous year. At week 0 before the rasburicase add-on treatment, the mean serum urate was 652±94μmol/L and the median urate volume was 44 (21, 215) cm3 (Table 1). ② Urate level after the rasburicase add-on treatment was significantly decreased than that before the treatment either at week 0, week 4, or week 8 (Figure 1A, all p< 0.001). The median reduction of serum urate were 565 (446, 621) at week 4, 214 (57, 373) at week 8, and 118 (21, 185) at week 12 (all p<0.017). Five cases (29%) showed serum urate lower than 300μmol/L at week 12. ③ The urate volume decreased at week 12 compared to week 0 in all patients (Figure 1B~D). The median volume of urate reduction was 24 (12, 60) cm3 (p<0.001) and the median percentage of urate reduction 42% (25%, 66%). Urate reduction volume was positively correlated with baseline urate volume (r=0.890, p<0.001), while the percentage of urate reduction volume negatively correlated with baseline urate volume (r=-0.689, p=0.002). ④ Rasburicase was generally well tolerated. No gout attack occurred on the basis of intravenous methylprednisone 20mg before each rasburicase add-on treatment and oral colchicine 0.5mg/d to 1mg/d. No hypersensitive reaction occurred during the treatment. Phlebitis occurred in a patient (6%), while dizziness and nausea occurred in two patients (13%). One patient (6%) who was suffering chronic kidney disease of stage 3 developed acute kidney injury after rasburicase injection at week 0 and week 8, but the serum creatinine spontaneously returned to the baseline level during follow-up.

Figure 1.

The serum urate and urate volume before and after rasburicase add-on treatment. A: Paired comparison of serum urate level before and after each time of rasburicase administration; B. Reduction value and percentage of urate volume at week 12 for each patient. C&D: Dual-energy CT (DECT) showed a dramatical reduction in urate volume from week 0 (C, urate volume: 72.15 cm3) to week 12 (D, urate volume: 7.66 cm3). ***: p< 0.001; #: Received rasburicase at week 0 only; ##&###: Received rasburicase 7.5mg at week 0.

Conclusion

This pilot study shows rasburicase is well tolerated in patients with refractory chronic gouty arthritis and may be a reasonable option to effectively lower the urate burden of these patients, although this is an off-label use. Further prospective randomized controlled studies to verify the efficacy and safety are needed.

Funding

This study was funded by Yat-sen Clinical Research Project.

Disclosure of Interests

None declared

POS0889 CASE SERIES OF PATIENTS WITH EOSINOPHILIC FASCIITIS SECONDARY TO IMMUNE CHECKPOINT INHIBITORS THERAPY

Background

Eosinophilic fasciitis (EF), a fibrotic disease that causes inflammatory infiltration in the subcutaneous fascia is clinically characterized by edema and subsequent induration and tightening of the skin and subcutaneous tissue. EF is a rare immune-related adverse event of immune checkpoint inhibitors (ICI).

Objectives

This article aims to investigate the clinical features of ICI-related EF and to improve the understanding of the disease among rheumatologists.

Methods

Searching relevant articles in the electronic databases Medline, PubMed, Science Citation Index, China Biomedical Literature Database (CBM), China Journal Full Text Database (CNKI), and WANFANG Data with the key words of “eosinophilic fasciitis” or “Shulman syndrome” and “checkpoint inhibitor”, “CTLA-4”, “PD-1” or “PD-L1”. Only articles or case reports with detailed medical records of ICI-related EF patients were included. ICI-related EF patients in our department were also included.

Results

A 58-year-old male patient with angioimmunoblastic T cell lymphoma presented with skin edema, subsequent induration, tightening of the skin, and subcutaneous tissue (Figure 1 A&B). The eosinophils elevated in peripheral blood after 6-month treatment of PD-1 inhibitor (Camrelizumab). The patient was diagnosed as ICI-related EF and then was referred to our rheumatology department. Other seventeen EF patients from the above databases were also included for analysis. Among these 18 patients, 50% (9/18) were male and the mean age was 57±14 years. The most commonly used ICI was PD-1 inhibitor such as nivolumab and pembrolizumab, accounting for 72% (13/18), next was PD-L1 inhibitor (17%, 3/18), and 3 patients used PD-L1 inhibitor combined with CTLA-4 inhibitor. Of all cases, 50% (9/18) was metastatic melanoma and 17% (3/18) was lung cancer. After ICI treatment, the median onset time of EF was 12 months. The most common involved organ was skin and 94% (17/18) of patients presenting with symmetrical skin edema and sclerosis. For other skin manifestations, 44% (8/18) of patients had typical “groove sign”, and one case showed unilateral skin involvement of skin tension and erythema from pubis to left anterior iliac crest. When the affected limb raised, there is a visible sulcus due to the decrease of venous dilation pressure, namely “sulcus sign”. The second common involved organ was the joints which were presented with limited function in 56% (10/18) of patients. Additionally, 39% (7/18) showed muscle involvement such as myalgia and myasthenia. Increased eosinophils in peripheral blood was observed in 72% (13/18) of patients. Twelve patients (63%) received MRI examinations which showed the signal in the subcutaneous and deep fascia increased in both fat-suppressed T2 images(Figure 1 C&E) and post-enhancement T1 images(Figure 1 D&F). Fifteen patients underwent full-thickness skin biopsy at the lesion site, the pathological changes in all patients supported the diagnosis of EF. The ICI was discontinued in 94% of patients. Meanwhile, 83% received glucocorticoids and 56% of patients were treated with methotrexate. After these treatment, the clinical symptoms of EF improved in 89% of patients (n=16), while eosinophils returned to normal after a median treatment time of 2.5 months. EF progressed even through the combined treatment of prednisone, MTX, and abatacept in one patient. Another one case died after 6 months due to metastasis of bladder cancer (stageIV).

Conclusion

Although EF is a rare adverse effect of ICI treatment, individuals receiving these drugs should be monitored closely for symptoms of EF. Discontinuation of ICI and administration of immunosuppressants may prevent the progression of EF.

Disclosure of Interests

None declared

OP0163 A MATRIX PREDICTION MODEL FOR THE SIX-MONTH MORTALITY RISK IN PATIENTS WITH ANTI-MELANOMA DIFFERENTIATION-ASSOCIATED PROTEIN-5 POSITIVE DERMATOMYOSITIS

Background

Recently, the autoantibody recognizing melanoma differentiation-associated gene 5 (anti-MDA5) is of the greatest concern as a specific autoantibody of dermatomyositis (DM), since it delineates a unique clinical phenotype of DM with a high risk of life-threatening lung complications. Considering routine clinical characteristics at baseline are still desired candidates for screening potential mortality predictors, in order to as early as possible stratify the mortality risk in anti-MDA5 positive DM patients before making therapeutic strategies.

Objectives

To investigate the baseline independent risk factors for predicting 6-month mortality of anti-MDA5-positive DM patients and develop a matrix prediction model formed by these risk factors.

Methods

This was a real-world prospective observational study. The hospitalized patients with DM were included if they fulfilled the criteria including: aged over 18 years old; diagnosed as having DM according to the criteria proposed by Bohan and Peter or the modified Sontheimer definitions; and positive anti-MDA5 which was determined by both line immunoassay testing and enzyme-linked immunosorbent testing. The primary outcome was all-cause 6-month mortality after enrolment. A matrix prediction model was built with the mortality risk probability.

Results

There were 82 DM patients enrolled (mean age of onset 50±11 years and 63% female), 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 (ILD, OR: 7.034, 95%CI: 1.157~42.785), and higher level of C4 (OR: 1.010, 95%CI: 1.002~1.017) were independent associators with positive anti-MDA5 in DM patients. Anti-MDA5-positive DM patients had significant higher 6-month all-cause mortality than those with anti-MDA5-negative (30% vs. 0%). Among anti-MDA5-positive DM patients, 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 2858 ug/L vs. 619 ug/L, all p<0.05). Multivariate COX regression showed ferritin≥1250 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 independent risk factors of 6-month mortality.

According to the matrix prediction model, anti-MDA5-positive DM patients could be stratified into three subgroups based on various probabilities of predicted mortality: (i) High-risk: eight patients with two of the above three features (including fever, serum ferritin≥1250 μg/L, and positive CEA) had high predicted mortality probability with 64%~85% (three red grids in Figure 1A), and the actual mortality was 75% (n=6) with 60%, 100%, and 100% respectively in three red grids (Figure 1B). Five patients with all of three features had extremely high predicted mortality probability with 97% (95%CI: 70%~100%, the dark red grid of Figure 1A), and the actual mortality was 100% in Figure 1B; (ii) Moderate-risk: nine patients with one of the above three features had moderate predicted mortality probability with 11%~29% (three yellow grids in Figure 1A), and the actual mortality was 11% (n=1) with 0%, 0%, and 17% respectively in three yellow grids (Figure 1B); (iii) Low-risk: eighteen patients with none of the above three features had low predicted mortality probability with 2% (95%CI: 0.2%~20%, the green grid in Figure 1A), and the actual mortality was 0% in the green grid (Figure 1B).

Conclusion

Baseline characteristics of fever, positive CEA, and ferritin≥1250 μg/L are risk factors for 6-month all-cause mortality in anti-MDA5-positive DM patients. A novel matrix prediction model composed of these three clinical indicators is firstly proposed to provide a chance for exploration of individual treatment strategies in anti-MDA5-positive DM subgroups with various probabilities of mortality risk.

Disclosure of Interests

None declared

AB0125 CLINICAL CHARACTERISTICS OF RHEUMATOID ARTHRITIS PATIENTS WITH IGG4-RELATED SYNOVITIS

Background:

Elevated serum IgG4 (sIgG4) and IgG4+ plasma cell tissue infiltration are outstanding features of IgG4-related disease (IgG4-RD). However, elevated IgG4 is not specific for IgG4-RD. Our previous study reported elevated sIgG4 in 46% of rheumatoid arthritis (RA) patients (Mediators Inflamm 2014). Whether synovium from RA patients show similar characteristics of IgG4-RD and how about the clinical characteristics of RA patients with IgG4-related synovitis have not been reported yet.

Objectives:

To explore the serum and synovial IgG4 level and their correlation with disease indicators in RA.

Methods:

Active RA patients who underwent needle synovial biopsy with qualified synovium tissue were recruited. Demographic and clinical data were collected simultaneously. Synovium tissue were stained with H&E for Krenn synovitis score and immunohistochemistry for positive cell densities of CD20, CD38, IgG and IgG4. Serum IgG4 level was detected by immunonephelometry.

Results:

Among 96 RA patients recruited, 74 (77.1%) were female, the median age was 55.0 (46.0~61.0) years, disease duration was 42.0 (12.0~120.0) months and SDAI was 31.2 (22.1~42.8).

The median sIgG4 was 1.38 (0.86~2.42) g/L and 49(51.0%) patients had elevated sIgG4. Compared with those with normal sIgG4, RA patients with elevated sIgG4 had significantly higher levels of PrGA [7 (5~8) vs. 6 (4~7)], ESR [90 (64~116) mm/h vs. 61 (38~75) mm/h], CRP [46.20 (17.20~74.20) mg/L vs. 18.90 (9.46~49.20) mg/L], DAS28-ESR [6.3 (5.6~7.4) vs. 5.7 (4.7~6.4)], SDAI [34.2 (25.3~48.8) vs. 27.8 (18.9~35.9)] and HAQ-DI [1.70 (0.61~2.28) vs. 0.88 (0.40~1.75), all P<0.05]. Meanwhile, they also showed significantly higher synovial counts of CD38+ plasma cells [1240(559~2290) /mm2 vs. 1020(354~1777) /mm2], IgG4+ plasma cells [106 (39~249) /mm2 vs. 68 (3~123) /mm2], and higher ratio of IgG4+/IgG+ plasma cells [26.3 (15.5~38.0) % vs. 15.2 (0.9~24.7) %, all P<0.05].

The median IgG4+ plasma cells count was 83 (10~192) /mm2 and median ratio of IgG4+/IgG+ plasma cells was 19.1 (8.4~31.5)%. Both of them correlated positively with ESR, CRP and sIgG4 (r=0.216~0.394, all P<0.05). There were 46 (47.9%) patients with IgG4+ plasma cells >10/HPF, who had significant higher ESR [86 (50~109) mm/h vs. 65 (40~84) mm/h] and CRP [43.35 (16.93~77.85) mg/L vs. 26.15 (9.54~52.53) mg/L, both P<0.05] than those with IgG4+ plasma cells ≤10/HPF. There were 13 (13.5%) patients with the ratio of IgG4+/IgG+ plasma cells >40%, and 11 (11.5%) patients with both IgG4+ plasma cells >10/HPF and IgG4+/IgG+ plasma cells ratio >40% (IgG4-related synovitis). RA patients with IgG4-related synovitis had significant higher ESR than the others [106 (53~125) mm/h vs. 69 (41~91) mm/h, P<0.05].

There were 10 (10.4%) patients showing elevated sIgG4 and IgG4-related synovitis. Four patients completed 1-year follow-up and all of them achieved remission at 6th month (SDAI≤3.3, Figure 1). Only one patient had radiographic progression at 12th month.

Figure 1.

Dynamic disease activity of 4 RA patients with elevated sIgG4 and IgG4-related synovitis during 1-year follow-up.

Conclusion:

IgG4-related synovitis can be found in RA patients. Their clinical significance in disease characteristics and outcomes are worth further study.

Acknowledgements:

This work was supported by National Natural Science Foundation of China (no. 81971527, 81801606 and 81801605), Guangdong Natural Science Foundation (no. 2018A030313541 and 2018A030313690), Guangdong Medical Scientific Research Foundation (no. A2018062), Guangdong Basic and Applied Basic Research Foundation (no. 2019A1515011928 and 2020A1515110061), and Science and Technology Program of Guangzhou (no. 201904010088).

Disclosure of Interests:

None declared

AB0398 CASE SERIES OF PATIENTS WITH CHOLESTEROL CRYSTAL EMBOLISM SYNDROME THAT MIMICS SYSTEMIC VASCULITIS

Background:

Cholesterol crystal embolism (CCE) syndrome is a multisystemic disorder caused by small arteries cholesterol crystal emboli subsequent to small pieces of atheromatous plaques from the aorta or other major arteries break off. CCE is often overlooked because it mimics symptoms of systemic vasculitis due to its clinical characteristics such as ulceration and gangrene of toes, livedo reticularis, renal insufficiency. Acute inflammatory reactants such as ESR, CRP may elevate in CCE patients since the cholesterol crystals trigger a foreign-body inflammatory reaction around the arterioles.

Objectives:

This study aimed to explore the clinical characteristics of CCE patients, to make rheumatologists learn more about this disease.

Methods:

Peer-reviewed articles in the electronic databases Medline, PubMed, Science Citation Index, China Biomedical Literature Database (CBM), China Journal Full Text Database (CNKI), and WANFANG Data were searched using the terms “cholesterol crystal embolism syndrome”, “cholesterol embolism”, “atherosclerotic embolism”, “atherosclerotic nephropathy”, or “CCE”. Only articles or case reports containing detailed medical records of CCE patients were included. We also included CCE patients in our department.

Results:

A 66-year-old male CCE patient presented with multiple ulceration and gangrene of toes and heels (Figure 1), subacute renal insufficiency, and elevated CRP and ESR. This patient had been considered as “suspected systemic vasculitis” and was referred to our rheumatology department. Another 39 Chinese CCE patients from the above databases were qualified for analysis. Among these 40 patients, 87.5% (35/40) were male and the mean age was 68±6 years. The most common involved was kidney and 90% (36/40) of patients presenting with renal insufficiency including the progressive increase of serum creatinine, hematuria, proteinuria, or sudden (or sharp) aggravation of hypertension. Next common involved was skin that occurred in 87.5% (35/40) of patients, especially in the toes and heels. For skin manifestations, blue toe syndrome occurred in 82.5% (33/40) of patients, ulceration or gangrene in 25% (10/40), and livedo reticularis in 15% (6/40). Additionally, 12.5% (5/40) showed ocular involvement such as visual impairment and visual field defect. In 2 patients, embolized cholesterol crystal in retinal arteries that is called Hollenhorst plaques was detected by fundoscopy. There were 62.5% (25/40) of patients having elevated CRP or ESR. The positive rate for skin or subcutaneous biopsies was 58% (11/19) and for kidney biopsies was 100% (6/6). The precipitating factors preceding the occurrence of classical symptoms such as blue toe syndrome, livedo reticularis and/or subacute renal insufficiency is important for CCE diagnosis especially for patients who had contraindications or were intolerant to biopsy. The precipitating factors include endovascular intervention (80%), vascular surgery (5%), and anticoagulant or thrombolytic therapy (2.5%). Only 12.5% (5/40) of patients were spontaneous and didn’t have any predisposing factors. General interventions of CCE included statins (82.5%), antiplatelets (32.5%), and dialysis (32.5%). Twelve patients (30%) received glucocorticoids and 75% (9/12) of them renal function improved and ulceration healed (Figure 1). Among 36 patients who presented with renal insufficiency, the renal function returned to normal after treatment in 2 patients (5.6%), but 27 patients (75%) still showed abnormal renal function even though somewhat improved, and 7 patients (19.4%) needed renal replacement therapy or dialysis for maintenance.

Conclusion:

This study reported CCE patients had high prevalence of renal insufficiency, blue toe syndrome, and ulceration or gangrene of toes, as well as elevated CRP or ESR, thus rheumatologists should be alert to this disease as one of the differential diagnosis of systemic vasculitis, especially for elderly patients with evidence of atherosclerosis who undergo a recent cardiovascular procedure.

Disclosure of Interests:

None declared

AB0296 PASSIVE TRANSFER OF ANTI-SSA, ANTI-Ro52, AND ANTI-MITOCHONDRIAL M2 FROM INTRAVENOUS IMMUNOGLOBULIN PRODUCTS TO PATIENTS WITH RHEUMATIC DISEASES

Background:

Passive transfer of ANA and anti-SSA has been reported in patients with common variable immunodeficiency disorder who received intravenous immunoglobulin (IVIG). IVIG is also recommended to treat some special or life-threatening rheumatic diseases.

Objectives:

This study was aimed to explore whether any extractable nuclear antibodies (ENAs) were transferred to these rheumatic patients who received IVIG therapy.

Methods:

IVIG products of three batches were tested for ANA by using indirect immunofluorescent assay, and for ENAs by using line immunoassay (LIA) and chemiluminescence immunoassay (CLIA). These IVIG products were administrated to rheumatic patients at a dose of 20g/d×3 days (day1 to day3). Serum samples of these patients before IVIG (day0) and after IVIG (day4, day8, day10, day12, and more than one month) were tested by using LIA and CLIA. Anti-SSA was also detected using ELISA.

Results:

In these IVIG products, ANA was positive at a titer of 1:640 (cytoplasmic speckled) and 1:80 (speckled). Among 14 types of ENAs that could be tested using LIA, anti-SSA, anti-Ro52, anti-mitochondrial M2, and anti-centromere B antibodies were clearly detectable in IVIG products (Table 1). Likewise, another assay CLIA also detected the same positive autoantibodies in these products. LIA showed the highest concentration in anti-mitochondrial M2, while CLIA showed the highest concentration in anti-mitochondrial M2 and anti-Ro52. One 31-year-old male patient who was diagnosed as SLE (Figure 1) and one 72-year-old male patients who was diagnosed as necrotizing myositis received these IVIG products. Anti-SSA, anti-Ro52, anti-mitochondrial M2, but not anti-centromere B, were positive in the day4 serum samples, although all of these antibodies were negative at baseline (day0). The concentration of these antibodies decreased gradually as days passed and became undetectable around one month after IVIG.

Table 1.

The concentration of autoantibodies in intravenous immunoglobulin products

anti-SSAanti-Ro-52anti-mitochondrial M2anti-centromere BCut-offLIA(grey value)20±328±369±1019±4≥11CLIA (U/ml)333±107444±86434±66390±89>20ELISA (U/ml)90±13NANANA>20

LIA, line immunoassay; CLIA, chemiluminescence immunoassay; ELISA, enzyme linked immunosorbent assay

Conclusion:

This study preliminarily reported transient positivity of anti-SSA, anti-Ro52, and anti-mitochondrial M2 in rheumatic patients maybe because the passive transfer of these antibodies from IVIG products to the patients, although the potential influence of this transfer on the rheumatic diseases remained unknown.

Figure 1.

The concentration of autoantibodies in a 31-year-old male SLE patient receiving intravenous immunoglobulin at a dose of 20g/d×3 days (day1 to day3). Serum samples of these patients before IVIG (day0) and after IVIG (day4, day8, day10, day12, and day51) were tested by using line immunoassay (LIA) and chemiluminescence immunoassay (CLIA). Anti-SSA was also detected using ELISA. The horizontal red lines were the corresponding cut-off values of each assay.

Disclosure of Interests:

None declared

AB0394 CLINICAL CHARACTERISTICS OF EOSINOPHILIC GRANULOMATOSIS WITH POLYANGIITIS: A SINGLE-CENTER RETROSPECTIVE ANALYSIS ON 52 CASES OF CHINESE PATIENTS

Background:

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare and heterogeneous systemic vasculitis. Different patients or the same patient in different stages show different manifestations, which may lead to misdiagnosis and delay treatment.

Objectives:

To analyze the clinical characteristics in Chinese patients with EGPA.

Methods:

EGPA patients who fulfilled the 1990 ACR classification criteria were included between December 2003 and April 2020. The demographic and clinical characteristics were collected and analyzed retrospectively.

Results:

There were 52 EGPA patients recruited, 34 (65.4%) patients were males and the median age at onset was 47(38~55) years. The median duration from disease onset to diagnosis was 30(4~96) months. For initial symptoms, respiratory manifestations (61.5%) were the most common, including 42.3% patients beginning with asthma, followed by 21.2% with nose/paranasal sinuses manifestations. Respiratory medicine (53.8%) were the most common department at first visit, followed by rheumatology medicine (11.5%, Figure 1A). There were 44.2% EGPA patients definitely diagnosed at the department of rheumatology or after consultation by rheumatologists.

During the whole disease process, the most common clinical manifestations were asthma (88.5%), then nose/ paranasal sinuses (84.6%), pulmonary (76.9%) and nervous system (61.5%) manifestations, followed by constitutional symptom (44.2%), heart (36.5%) and skin (23.1%) involvement. Only 9.6% patients had gastrointestinal tract involvement and 3.8% had renal involvement (Figure 1B).

There were 46 (88.5%) patients showing the ratio of peripheral blood eosinophils >10% at diagnosis. Among the rest 6 patients, 3 had higher eosinophil ratio before diagnosis, while the other 3 patients had been treated with glucocorticoid before diagnosis, of whom 2 patients showed pathological eosinophil infiltration in lung or paranasal sinuses mucosa, respectively. There were 8(15.4%) patients with positive ANCA. Compared with EGPA patients with negative ANCA, they had lower incidence of asthma (62.5% vs. 93.2%), but higher incidence of constitutional symptoms (87.5% vs. 36.4%), arthralgia (50.0% vs. 6.8%) and renal involvement (25.0% vs. 0.0%), higher peripheral eosinophil count [2.06(0.80~4.51) ×109/L vs. 1.81(0.93~3.32) ×109/L], ESR [20(7~77) mm/h vs. 18(9~42) mm/h] and CRP [18.5(3.2~65.9) mg/L vs. 3.3(3.2~13.0) mg/L], higher Birmingham vasculitis activity score [17(10~22) vs. 13(9~15)] and vasculitis damage index [3(1~3) vs. 2(1~2), all P<0.05]. There were 21.2% EGPA patients showing poor prognostic factors according to five-factor score (FFS) and 34.6% patients according to the revised FFS.

Conclusion:

EGPA patients may have no asthma especially those with positive ANCA. Multi-disciplinary collaboration especially based on rheumatologists and pulmonologists should be emphasized for early identification and prompt treatment.

Figure 1.

Department at first visit (A) and clinical manifestations during the whole disease process of 52 Chinese EGPA patients(B).

Disclosure of Interests:

None declared

POS0452 SYNOVIAL MYELOID-STROMAL PATHOTYPE PREDICTS ONE-YEAR RADIOGRAPHIC PROGRESSION IN ACTIVE RHEUMATOID ARTHRITIS

Background:

Rheumatoid arthritis (RA) is a heterogeneous disease with variable prognosis. The cellular composition in synovium is the driving force of joint destruction in RA, and the predictive values of histopathological assessments on the clinical outcomes of RA have been identified. However, current synovial histopathological assessments mainly focus on the infiltrated immunocytes to distinguish RA synovium into different synovial pathotypes. Whether addition of stromal cells improve the accuracy of histopathological assessments remains unknow.

Objectives:

To distinguish synovial pathotypes of RA based on intercellular connection and explore their predictive value on one-year radiographic progression.

Methods:

Active RA patients who underwent needle synovial biopsy at baseline were recruited from a real-world prospective cohort. Clinical data were evaluated at baseline and 1, 3, 6, 12 months. Histopathologic assessments included Krenn synovitis score and semiquantitative score of immunohistochemical staining for CD20, CD38, CD4, CD8, CD68, CD31 and CD90. Cluster analysis was used to distinguish synovial pathotypes. The primary outcome was one-year radiographic progression defined as a change in total Sharp/van der Heijde modified score≥0.5 units.

Results:

1. Among 134 RA patients who received synovial biopsy at baseline and finished one-year follow-up, 105 had qualified synovial tissue. The mean age was 50.2±13.3 years with 77.1% female. The median disease duration was 24 (9-120) months. All patients were active RA, and 64.8%, 26.7% and 8.6% patients in high, moderate and low disease activity, respectively. There were 41 (39%) patients who have never been treated with corticosteroids or disease-modifying anti-rheumatic drugs.

2. During one-year follow-up, there were 48.6%, 63.8%, 71.4%, and 69.5% patients achieved CDAI LDA target, and 12.4%, 30.5%, 34.3%, and 32.4% patients achieved CDAI remission after 1, 3, 6, and 12 months, respectively. A total of 33 (31.4%) patients had radiographic progression.

3. All patients were divided into three clusters using cluster analysis based on the seven synovial cellular scores. Patients in cluster 1 (n=50, 47.6%) had higher scores of sublining CD68+ macrophages, CD31+ endothelial cells and CD90+ fibroblasts, thus named as myeloid-stromal pathotype. Patients in cluster 2 (n=26, 24.8%) had higher scores of CD20+ B cells, CD38+ plasma cells, CD4+ T cells and CD8+ T cells, thus named as lymphoid pathotype. Patients in cluster 3 (n=29, 27.6%) had lower scores of all seven cell types, thus named as pauci-cellular pathotype (Figure 1).

4. RA patients with baseline synovial myeloid-stromal pathotype showed higher rate of one-year radiographic progression versus lymphoid and pauci-cellular pathotypes (48% vs. 16.4%, P<0.001), whereas there was no difference between lymphoid and pauci-cellular pathotypes (11.5% vs. 20.7, P=0.475). Adjusted for confounding factors including age, sex, smoking, disease duration, RF status, ACPA status, CDAI, HAQ-DI and mTSS at baseline, multivariate logistic regression analysis showed that baseline synovial myeloid-stromal pathotype independently predicted one-year radiographic progression (AOR=3.602, 95%CI:1.257-10.324, P=0.017, Table 1).

Conclusion:

Baseline synovial myeloid-stromal pathotype in RA can predict one-year radiographic progression.

Funding:

This work was supported by National Natural Science Foundation of China (no. 81971527, 81801606 and 81801605), Guangdong Natural Science Foundation (no. 2018A030313541 and 2018A030313690), Guangdong Medical Scientific Research Foundation (no. A2018062), Guangdong Basic and Applied Basic Research Foundation (no. 2019A1515011928 and 2020A1515110061), and Science and Technology Program of Guangzhou (no. 201904010088).

Acknowledgements:

We thank all subjects and medical staff who generously contributed to this study.

Disclosure of Interests:

None declared

[Predictive value of anti-mutated citrullinated vimentin antibody on one-year radiographic progression in patients with rheumatoid arthritis]

Objective: To investigate the value of baseline anti-mutated citrullinated vimentin (MCV) antibody for predicting one-year radiographic progression in patients with rheumatoid arthritis (RA). Methods: Consecutive RA patients were recruited from November 2014 to July 2018 at Department of Rheumatology, Sun Yat-sen Memorial Hospital, Clinical data were collected including disease activity score in 28 joints with four variables including C-reactive protein (CRP).Serum anti-MCV antibody at baseline was detected by enzyme-linked immunosorbent assay. X ray assessment of both hands/wrists was performed and assessed according to the Sharp/van der Heijde modified score (mTSS) at baseline and the 12th month. Univariate and multivariate logistic regression analyses were used to identify the risk factors for one-year radiographic progression. Results: Among 220 RA patients recruited, the positive rate of anti-MCV antibody at baseline was 77.7%. Compared with those with negative anti-MCV antibody, RA patients with positive anti-MCV antibody had higher disease activity score in 28 joints with four variables induding CRP [3.8 (2.4, 5.0) vs. 3.1 (2.1, 4.0), P=0.007], more physical dysfunction (21.6% vs. 8.2%, P=0.033) and higher radiographic indicators including mTSS [11 (2, 27) vs. 4 (1, 10), P=0.003], joint space narrowing [JSN, 4 (0, 14) vs. 2 (0, 6), P=0.024] and joint erosion[JE, 5 (1, 18)vs. 3 (0, 5), P=0.003]. After one-year follow-up, sixty-six RA patients (30.0%) developed radiographic progression, the percentage of whom was significantly higher in positive anti-MCV group than that in negative anti-MCV group (33.9% vs.16.3%, P=0.018). Multivariate logistic regression analysis suggested that positive anti-MCV antibody at baseline was an independent risk factor for one-year radiographic progression (OR=2.341, 95%CI 1.002-5.469). Conclusion: Positive anti-MCV antibody at baseline predicts one-year radiographic progression in RA patients. In the future, anti-MCV antibody can be used not only as a supplementary laboratory marker, but also in disease activity assessment and prognosis prediction for RA.

AB1020 APPLICATION OF THE 2019 ACR/EULAR CLASSIFICATION CRITERIA CONTRIBUTES TO THE DIAGNOSIS OF IgG4-RELATED DISEASE

Background:

IgG4-related disease (IgG4-RD) is a rare and systemic disease characterized by swelling or masses in the involved organs, elevated serum IgG4, marked IgG4+ plasma cells infiltration and fibrosis. However, lacking of pathological data limited the definite diagnosis of IgG4-RD. As results of high-quality clinical and epidemiological investigations collected, new classification criteria for IgG4-RD were approved by ACR and EULAR in 2019. Whether this new criteria improve the diagnosis efficiency needs to be validated in clinical practice.

Objectives:

To applicate the 2019 ACR/EULAR classification criteria for the diagnosis of IgG4-RD in previously suspected patients and explore the clinical characteristics of patients with IgG4-RD according to the new classification criteria.

Methods:

Patients suspected of having IgG4-RD due to elevated serum IgG4 and swelling or masses in single or multiple organs were recruited in Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University from May 2013 and November 2019. Demographic and clinical data were collected. The diagnosis was reevaluated with the 2011 comprehensive diagnostic criteria (CDC) for IgG4-RD and the 2019 ACR/EULAR classification criteria for IgG4-RD, respectively.

Results:

(1) There were 68 patients recruited and 59(86.8%) of them had elevated serum IgG4 (≥135mg/dl) and 53(77.9%) patients showed swelling or masses in single or multiple organs. Most patients first visit general surgery (17.6%), gastroenterology (16.2%), respiratory medicine (16.2%) and rheumatology (14.7%).

(2) According to the 2011 CDC for IgG4-RD, 4(5.9%) patients were definite IgG4-RD, 1(1.5%) was probable and 42(61.8%) were possible. According to the 2019 ACR/EULAR criteria, 20(29.4%) patients were diagnosed as IgG4-RD, including the 4 definite patients using the 2011 CDC.

(3) Among the 20 IgG4-RD patients according to the 2019 ACR/EULAR criteria, 19(95.0%) were male and median age of symptom onset was 62(46~69) years. There were 6(30.0%) patients diagnosed at rheumatology, 5(25.0%) at gastroenterology, 3(15.0%) at general surgery, 2(10.0%) at respiratory medicine and 1(5.0%) at stomatology, endocrinology, orthopedics and urinary surgery, respectively. There were 9(45.0%) patients with bilateral lacrimal or salivary glands involved, 9(45.0%) with pancreas and biliary tree involved, 5(25.0%) with retroperitoneum involved, 2(10.0%) with kidney involved and 1(5.0%) with chest involved.

(4) The median serum IgG4 of the 20 IgG4-RD patients was 15.40(4.14~55.10)g/L, median serum IgG was 27.9(17.2~50.2)g/L. There were 20.0%(4/20) patients had elevated serum eosinophil and 93.3%(14/15) had elevated serum IgE. There were 60.0%(9/15) patients had elevated C-reactive protein, 85.7%(12/14) had elevated erythrocyte sedimentation rate and 26.7%(4/15) had hypocomplementemia. There were 35.7%(5/14) patients had positive rheumatoid factor and 14.3%(2/14) had positive antinuclear antibodies. There were 6(30.0%) patients didn’t received biopsies, 8(40.0%) patients received surgical removal of salivary glands, lacrimal glands or pancreatic masses and 6(30.0%) patients received needle biopsies of the salivary glands or biopsies by bronchoscopy, gastroscopy or enteroscopy.

(5) Among the patients didn’t fulfill the 2011 CDC and the 2019 ACR/EULAR criteria, there were 40 patients had elevated serum IgG4, whose serum IgG4 level were significant lower than those of IgG4-RD patients [3.66(2.39~7.68)g/L vs. 15.40(4.14~55.10)g/L,P<0.001], and percentage of serum IgG4 ≥5× upper limit of normal were also lower than those of IgG4-RD patients (27.5% vs. 73.7%,P=0.002).

Conclusion:

The 2019 ACR/EULAR criteria can help diagnosing patients with IgG4-RD even lacking the tissue confirmation. Patients with moderately elevated serum IgG4 need more clinical evidence to diagnose IgG4-RD and exclude mimics.

References:

This work was supported by Guangdong Medical Scientific Research Foundation (grant no. A2017093).

Disclosure of Interests:

None declared

SAT0073 MYOPENIA AGGRAVATES RHEUMATOID ARTHRITIS IN ELDERLY PATIENTS AS A MEDIATOR

Background:

Ageing affects different systems resulting in a special clinical phenotype of rheumatoid arthritis (RA) in elderly patients who are characterized by higher level of systemic inflammatory and poor function. It also leads to loss of muscle mass causing functional limitation and reduced quality of life. However, little is known about muscle loss in growing elderly RA patients.

Objectives:

To explore the characteristics of muscle mass and clinical significance in elderly RA patients.

Methods:

Consecutive RA patients were recruited and clinical data including disease activity (DAS28-CRP), function (HAQ-DI) and radiographic indicators (modified Sharp score) were collected. The mass and distribution of muscle were assessed by bioelectric impedance analysis. Myopenia was defined as appendicular skeletal muscle mass index (ASMI) ≤7.0kg/m2in men and ≤5.7kg/m2in women.

Results:

(1) There were 643 RA patients recruited with 82.3% female, mean age 49.7±12.9 years and median disease duration 48 (IQR 21,108) months. There were 414 (64.4%) RA patients with active disease (DAS28-CRP≥3.2) and 229 (35.6%) with remission. (2) There were 165 (25.7%) elderly RA patients (age≥60 years) with mean age 65.1±4.5 years. Compared with young patients (age<60 years), elderly RA patients had significantly higher disease activity indicators including PtGA, PrGA, ESR, CRP, DAS28-CRP, DAS28-ESR, SDAI and CDAI, higher HAQ-DI (0.38 vs. 0.13) and higher modified total Sharp score (mTSS, 16 vs. 9, allP<0.001). There were 288 (44.8%) RA patients with myopenia and elderly RA patients had higher proportion of myopenia than young patients (54.5% vs. 41.4%,P=0.003). (3) Among 4 subgroups according to age and ASMI, elderly RA patients with myopenia (n=90, 14.0%) had significant higher DAS28-CRP (3.6 vs. 3.0), higher HAQ-DI (0.50 vs. 0.12) and higher mTSS (21 vs. 7) than those in young patients without myopenia (n=280, 43.5%), and had higher mTSS (21 vs. 10) than those in elderly patients without myopenia (n=75, 11.7%, allP<0.0083). (4) Adjusted for confounding factors including gender, disease duration, BMI, smoking habit, RF, ACPA and treatment naïve, multiple linear regression analysis showed that age was positively correlated with DAS28-CRP (β=0.010), HAQ-DI (β=0.003) and mTSS (β=0.005, allP<0.05), while ASMI was negatively correlated with DAS28-CRP (β= -0.445), HAQ-DI (β= -0.124) and mTSS (β= -0.247, allP<0.001). (5) Mediation analysis showed that old age (≥60 years) had total effect on DAS28-CRP (β=0.353), HAQ-DI (β=0.132) or mTSS (β=7.909, allP<0.05), but no direct effect on them (allP>0.05). ASMI fully mediated the associations between old age and DAS28-CRP, HAQ-DI or mTSS.

Conclusion:

Half of elderly RA patients manifest myopenia which aggravates the whole disease of disease activity, joint function and destruction as a mediator. Myopenia, a neglected comorbidity in elderly RA should be emphasized.

Funding:

This work was supported by National Natural Science Foundation of China (81801606 and 81971527,), Natural Science Foundation of Guangdong Province (2018A030313541 and 2019A1515011928), Science and Technology Program of Guangzhou (201904010088).

Disclosure of Interests :

None declared

[Potential mechanism of transcription factor peroxisome proliferator-activated receptor-gamma coactivator-1 beta on promoting osteoclastogenesis]

Objective: To investigate the role of transcription factor peroxisome proliferator-activated receptor-gamma coactivator-1 beta (PGC-1β) on osteoclastogenesis and related regulatory mechanism in the mouse monocyte-macrophage cell line (RAW264.7). Methods: PGC-1β expression and location in RAW264.7 cells was detected by immunofluorescence, flow cytometry and western blot analysis with nuclear protein extraction. RAW264.7 cells were transfected with lentivirus for gene silencing or over-expression of PGC-1β and cultured with macrophage colony-stimulating factor and receptor activator for nuclear factor-κB ligand. Cell viability was detected by cell counting kit-8. Cell apoptosis and cell cycle were detected by flow cytometry. Mature osteoclasts and their bone resorption activity were determined by tartrate-resistant acid phosphatase (TRAP) expression and toluidine blue staining. Western blot analysis was performed for detecting dendritic cell-specific transmembrane protein (DC-STAMP), cathepsin K, TRAP and matrix metalloproteinase (MMP)-9 expression, as well as cytoplasmic NF-κB-inducing kinase (NIK) and nuclear RelB. Results: PGC-1β expression was observed in the nuclei of RAW264.7 cells. Down-regulation or overexpression of PGC-1β in RAW264.7 cells did not affect cell viability, apoptosis or cell cycle. Down-regulation of PGC-1β decreased the count of mature osteoclasts (49±21 cells vs. 147±42 cells, P=0.004) and the pit area of bone resorption lacunae (42.11μm(2)±11.30 μm(2) vs. 204.80μm(2)±31.09 μm(2), P<0.001), as well as the expression of cathepsin K, TRAP and MMP-9, but not DC-STAMP. Overexpression of PGC-1β promoted osteoclast differentiation and bone resorption activity, as well as the expression of cathepsin K, TRAP and MMP-9. Down-regulation of PGC-1β suppressed the protein expression of cytoplasmic NIK and nuclear RelB in RAW264.7 cells. Conclusion: PGC-1β can promote the differentiation of RAW264.7 into osteoclasts and improve the bone resorption ability of the cells via activation of NIK/RelB pathway, which might be a promising therapeutic target for osteoporosis.

[Characteristics and clinical significance of body composition in gout patients]

Objective: To investigate the characteristics of body composition (BC) in gout patients and its clinical significance. Methods: Consecutive gout patients were recruited between August 2017 and December 2018. Demographic information, clinical characteristics and comorbidities were collected. BC was assessed by bioelectric impedance analysis including body fat percentage (BF%), trunk and limb BF%, appendicular skeletal muscle index. Overfat was defined by BF% ≥25% for male and ≥35% for female. The association between BC and serum uric acid (sUA) was evaluated by multiple linear regression. Results: A total of 362 gout patients were recruited with median age 38 (30, 52) years, 96.1% (348/362) were male. Mean sUA was (551±133) μmol/L. The mean BF% was (25.8±6.4)% with 53.6%(194/362) patients overfat. Male gout patients with overfat showed more affected joints [4(2, 6) vs. 2(2, 5)], higher sUA [(576±126)μmol/L vs. (523±134) μmol/L], higher prevalence of dyslipidemia [70.1%(131/187) vs. 54.0%(87/161)], metabolic syndrome [60.8%(118/187) vs. 28.0%(47/161)], fatty liver [58.2%(113/187) vs. 35.1%(59/161)] and hypertension [44.4%(83/187) vs. 25.5%(41/161)] than male patients with normal fat (all P<0.05). Their BF%, trunk BF% and limb BF% were positively correlated with the numbers of affected joints, sUA, metabolic syndrome, fatty liver, and hypertension, respectively (r=0.154-0.435, all P<0.05). Multivariable linear regression suggested that BF% (β=4.29, P=0.020) and trunk BF% (β=9.11, P=0.007), but not limb BF%, were positively correlated with sUA. Conclusion: Overfat is very common in gout patients. The proportion of trunk fat in male patients is positively correlated with sUA. When assessing obesity in gout patients clinically, body composition analysis should be performed simultaneously.

[Clinical characteristics and renal uric acid excretion in early-onset gout patients]

Objective: To investigate clinical characteristics and renal uric acid excretion in early-onset gout patients. Methods: Consecutive inpatients with primary gout were recruited between 2013 and 2017. The patients with gout onset younger than 30 were defined as early-onset group while the others were enrolled as control group. Clinical characteristics and uric acid (UA) indicators were compared between two groups. Results: Among 202 recruited patients, the early-onset group included 36 patients (17.8%). Compared with control group, the early-onset group presented more patients with obesity [13 patients (36.1%) vs. 22 patients (13.3%), P<0.05], significantly higher serum UA level [(634±124)μmol/L vs.(527±169)μmol/L] and glomerular load of UA[(7.2±2.8)mg·min(-1)·1.73m(-2) vs. (4.4±2.2)mg·min(-1)·1.73m(-2)] and estimated glomerular filtration rate (GFR) [(83±21)ml·min(-1)·1.73m(-2) vs. (67±21)ml·min(-1)·1.73m(-2)] (all P<0.05), lower fractional excretion of UA [4.4% (3.4%,6.1%) vs. 7.2% (5.2%,9.6%),P<0.05], whereas 24h urinary UA excretion was comparable [(2 788±882)μmol/1.73m(2) vs. (2 645±1 140)μmol/1.73m(2), P=0.274]. Subgroup analysis of patients without chronic kidney disease showed significantly lower fractional excretion of UA in the early-onset group [4.5%(3.3%,6.1%) vs. 6.7% (5.1%,8.7%),P<0.05]. Logistic regression analysis showed that obesity (OR=3.25) and fractional excretion of UA less than 7% (OR=9.01, all P<0.05) were risk factors of gout early onset. Conclusion: The gout patients with early-onset younger than 30 present high serum and glomerular load of uric acid which might be due to obesity and relative under-excretion of renal uric acid.

[Andersson lesion in ankylosing spondylitis: a clinical study of 14 cases]

Objective: To investigate the clinical characteristics of ankylosing spondylitis (AS) combined Andersson lesion (AL). Methods: The clinical data of patients who were diagnosed as AS combined AL at Sun Yat-sen Memorial Hospital between January 2012 and December 2015 were reviewed retrospectively.SPSS 20.0 software was used for statistical analysis.Data of normal distribution was expressed by x±s (standard deviation) and that of abnormal distribution by median and range. Results: Fourteen patients were enrolled. Ten were male, median age (IQR, similarly hereinafter) was 46 (29-53) years, disease duration was 120 (54-150) months, 7 has symptom increased in the beginning, 6 has nerve compression symptom, 7 has kyphosis, and 4 has spinous tenderness or percussion pain in physical examination.Eleven of AL occurred in the thoracolumbar junction.Erythrocyte sedimentation rate was 24 (15-44) mm/1 h, C-reactive protein was 10 (5-18) mg/L, and Serum amyloid A was 19 (5-31) mg/L.All the 14 patients were divided into 2 groups, aggravated group (n=7) and none aggravated group (n=7) according to the symptom.It was no statistic difference between them about all the above indicators. Conclusion: Imageological diagnosis should be performed to identify Andersson lesion, while ankylosing spondylitis patients combined mechanical pain based on inflammatory back pain, or mainly with nerve compression symptom, tenderness or percussion pain, or spinous, even when inflammatory markers were normal.

[grp75 protects cells from injuries caused by glucose deprivation]

To elucidate the functions of grp75, CHL cells over-expressing grp75 are cultured in glucose-free medium in order to simulate energy metabolic stress. Their susceptibilities to injuries caused by glucose deprivation are assessed by trypan blue exclusion, LDH leakage measurement and cytometry analysis. Data shows a stronger resistance to glucose deprivation among cells over-expressing grp75 than among cells constitutively expressing grp75. The outcome suggests that grp75 can protect cells from injuries caused by glucose deprivation.