Specific increase in enzymatic activity of adenosine deaminase 1 in rheumatoid synovial fibroblasts

OBJECTIVE

Adenosine deaminase (ADA; EC 3.5.4.4) activity is elevated in the synovial fluid (SF) of patients with rheumatoid arthritis (RA). Since the antiinflammatory effect of methotrexate is reportedly associated with increased levels of extracellular adenosine, the present study was undertaken to clarify the role of 2 ADA isozymes, ADA1 and ADA2, in the pathogenesis of RA.

METHODS

The activities of ADA1 and ADA2 were measured in SF from RA and osteoarthritis (OA) patients, in sera from RA patients, and in lysates prepared from mononuclear and polymorphonuclear cells from SF from RA patients, peripheral blood from RA patients, and fibroblast-like synoviocytes (FLS) from RA and OA patients. Also measured were the effects of proinflammatory cytokines on ADA1 activity and ADA messenger RNA (mRNA) expression in RA FLS, as determined using real-time polymerase chain reaction. The adenosine concentration in RA SF was measured by radioimmunoassay.

RESULTS

The adenosine concentration in RA SF ranged from 0.027 microM to 0.508 microM (mean +/- SD 0.156 +/- 0.132 microM). At those concentrations, ADA1 would be expected to be functionally dominant due to its higher affinity for adenosine. ADA1 activity in RA SF (mean +/- SD 14.4 +/- 8.5 IU/liter) was significantly higher than that in OA SF (3.0 +/- 1.1 IU/liter) or RA sera (3.0 +/- 0.6 IU/liter); moreover, ADA1 activity in RA FLS lysate was the highest among the cell lysates tested. Proinflammatory cytokines did not affect ADA1 activity or ADA mRNA expression in RA FLS.

CONCLUSION

Elevated ADA1 activity is an intrinsic characteristic of RA FLS, which likely contributes to the pathogenesis of RA by neutralizing the antirheumatic properties of endogenous adenosine.

Thioredoxin protects against joint destruction in a murine arthritis model

Thioredoxin (TRX) is an oxidative stress-inducible biological antioxidant that is highly expressed in the synoviocytes of rheumatoid arthritis (RA) patients. There is much evidence that oxidative stress plays a key role in the inflammation and destruction of RA joints; the functional relationship between TRX and RA remains unknown, however. We therefore investigated the role played by TRX in the inflammatory and joint-damaging processes of RA using a murine model in which arthritis was induced by administering a mixture of anti-type II collagen monoclonal antibodies (mAb) and lipopolysaccharide (LPS). In Wt mice mAb/LPS injection induced neutrophil infiltration, cartilage destruction, and chondrocyte apoptosis within the joints, all of which were dramatically suppressed in TRX transgenic (TRX-Tg) mice. Moreover, the 8-hydoxy-2'-deoxyguanosine (8-OHdG) expression seen in Wt mice after mAb/LPS injection was almost completely inhibited in TRX-Tg mice. The administration of recombinant TRX also suppressed mAb/LPS-induced joint swelling in Wt mice. Taken together, these results suggest that TRX protects against arthritis and is a plausible candidate with which to develop novel therapies for the treatment of RA.

Acute Chlamydia pneumoniae infection in the pathogenesis of autoimmune diseases

Autoimmune diseases have several etiologies. Acute Chlamydia pneumoniae (C. pneumoniae) infection may be involved in the pathogenesis of several autoimmune diseases. In this study, 82 patients with several autoimmune diseases and 70 controls were enrolled, and acute C. pneumoniae infection has been evaluated by monitoring the levels of IgM antibody. Chlamydia pneumoniae IgM positive results were observed in 29% (P < 0.05) of the patients with several autoimmune diseases and in 10% of the controls. Chlamydia pneumoniae IgM positive cases were more frequent among the patients with rheumatoid arthritis (RA; 30%, P < 0.05), systemic lupus erythematosus (SLE; 28.0%, P < 0.05), dermatomyositis/polymyositis (23%, NS), myeloperoxidase-antineutrophil cytoplasmic autoantibody (MPO-ANCA)-associated vasculitis (33%, NS), adult onset of Still's disease (29%, NS) and giant cell arteritis/Takayasu arteritis (50%, NS) than among the controls. This positive frequency was statistically significant in RA and SLE. These results suggest that acute C. pneumoniae infection is probably involved in the pathogenesis of autoimmune diseases.

Presepsin and procalcitonin as biomarkers of systemic bacterial infection in patients with rheumatoid arthritis

AIM

To assess the diagnostic values of presepsin and procalcitonin in patients with rheumatoid arthritis (RA) by identifying those with bacterial infection METHOD: During June 2014-September 2015, 126 patients with RA and 25 healthy controls were enrolled. RA patients were divided into an infection group and a non-infection group. Infection was diagnosed by clinical symptoms, microbiological or radiographic methods, and good response to antibiotics. Concentrations of plasma presepsin, serum procalcitonin, C-reactive protein (CRP), and white blood cell counts (WBC) were measured and compared in each group. The correlations with the Sequential Organ Failure Assessment (SOFA) Score and these markers were calculated.

RESULTS

RA patients included 26 patients in the infection group, 45 patients in the CRP-positive non-infection group (CRP > 0.3 mg/dL), and 55 patients in the CRP-negative non-infection group (CRP < 0.3 mg/dL). Levels of presepsin and procalcitonin in the infection group were highest and significantly higher than those in the CRP-positive non-infection group (presepsin 682.8 ± 158.1 pg/mL vs. 192.0 ± 12.0 pg/mL [P < 0.0001]; procalcitonin 4.052 ± 1.637 ng/mL vs. 0.120 ± 0.032 ng/mL [(P < 0.0001]). According to receiver operating characteristic curve (ROC) analysis, presepsin and procalcitonin levels appeared to have a higher diagnostic accuracy for infection than CRP or WBC. For the infection group, the SOFA Score positively correlated with the concentration of presepsin but not with that of procalcitonin.

CONCLUSION

Presepsin and procalcitonin may be useful to identify infection in RA patients. Presepsin may better reflect infection severity than procalcitonin.

Reversible posterior leukoencephalopathy syndrome in a patient with Takayasu arteritis

Reversible posterior leukoencephalopathy syndrome (RPLS) has been identified in several connective tissue diseases. However, there are no reports of RPLS associated with Takayasu arteritis (TA). We report the first case of TA associated with RPLS. A 23-year-old woman presented with sudden headache and vomiting, followed by generalized tonic-clonic seizures and mental changes two weeks after administration of oral prednisolone. MRI showed hyperintense signals on T2 and FLAIR images in the bilateral temporal-parietal-occipital lobes, left frontal lobe, and left cerebellar hemisphere. Three weeks after starting control of convulsions and blood pressure with plasmapheresis, high-dose methylprednisolone, and cyclophosphamide, the clinical manifestations and abnormal signals on MRI completely resolved. These reversible clinical and radiological changes are consistent with vasogenic edema in the central nervous system, indicating RPLS. Although high-dose methylprednisolone and cyclophosphamide are thought to cause RPLS, we think that it is justified to use these agents, at least in difficult cases, for making a clear-cut differentiation from CNS vasculitis, as long as blood pressure and fluid volume are well controlled. Moreover, we suggest that RPLS should be included in differential diagnosis of acute neurological changes in connective tissue diseases, including TA.

Peripheral neuropathies during biologic therapies

Peripheral neuropathies should be recognized as the adverse effects of biological agents, especially anti-TNF agents. However, no solid clinical databases for biological agent-associated peripheral neuropathies (BAPN) have been established in Japan. Here we report two cases of peripheral neuropathy associated with anti-TNF agents. One was peroneal motor neuropathy. The other case was chronic inflammatory demyelinating polyradiculoneuropathy. In addition, we summarize the previous reports on BAPN and discuss their prevalence rate, pathogenesis and management.

A pediatric patient with neuro-Behçet's disease

Behçet's disease is rare in childhood. We describe a 10-year-old boy with neuro-Behçet's disease (NB) who presented with fever, headache, vertigo, and hearing loss. An examination of the cerebrospinal fluid (CSF) revealed pleocytosis as well as elevated protein and interleukin (IL)-6 levels. Brain magnetic resonance imaging (MRI) showed hyperintensity of the right thalamus and midbrain on T2-WI, and gadolinium (Gd) enhancement of left acoustic nerve origin. HLA-B51 was positive. Prednisolone combined with methotrexate resulted in a complete remission. Brain MRI and the CSF IL-6 level were useful for the diagnosis and monitoring of this pediatric patient with NB.

Presence of anti-nuclear antibodies is a risk factor for the appearance of anti-drug antibodies during infliximab or adalimumab therapy in patients with rheumatoid arthritis

This study aimed to directly analyze the potential relationship of anti-nuclear antibodies (ANA) before and after the administration of TNF-α inhibitors (TNFi) with the appearance of anti-drug antibodies (ADrA) in patients with rheumatoid arthritis (RA). A total of 121 cases, viz., 38, 53, and 30 cases treated with infliximab (IFX), adalimumab (ADA), and etanercept (ETN), respectively, were enrolled. The ANA titers were measured using indirect immunefluorescence assay (IF-ANA) and multiplex flow immunoassay (ANA Screen) before and serially during the therapy. The anti-IFX antibodies (HACA) and anti-ADA antibodies (AAA) were measured with a radioimmunoassay. ADrA turned positive in 14 (36.8%) among 38 patients treated with IFX, and 16 (30.2%) among 53 treated with ADA. All of them were positive for IF-ANA before TNFi administration, while ADrA never appeared in any of the 15 patients negative for IF-ANA (< 40). IF-ANA of high titers (≥ 320 and ≥ 640) before IFX treatment showed a significant association with the appearance of HACA 52 weeks after IFX (P = 0.040 and 0.017, respectively), whereas AAA appearance was not related to IF-ANA titers before treatment. Moreover, IF-ANA of high titers before IFX treatment was significantly associated with inefficacy and discontinuation of the treatment. The positivity of anti-SS-A antibodies before therapy might be a risk factor for ADrA appearance in patients treated with IFX or ADA. The percentage of patients whose IF-ANA titers increased was significantly higher with IFX than with ADA or ETN treatments (P = 0.026 and 0.022, respectively). High ANA titers and positive ANA Screen after IFX therapy showed a significant association with HACA appearance and possibly led to treatment failure. Among the three TNFi, only IFX showed a close relationship with IF-ANA and ADrA appearance, suggesting the interaction of immunogenicity with autoimmunity as well as the advantage of ANA measurement before TNFi therapy.

Thioredoxin may exert a protective effect against tissue damage caused by oxidative stress in salivary glands of patients with Sjögren's syndrome

OBJECTIVE

To demonstrate the existence of oxidative stress and the role of the antioxidant thioredoxin (TRX) in Sjögren's syndrome (SS).

METHODS

Labial biopsy specimens from patients with SS were analyzed immunohistochemically to detect 8-hydroxy-2'-deoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal (4-HNE), nitrotyrosine, and TRX. Levels of TRX in saliva and plasma were quantified by ELISA. To analyze the effect of TRX on human salivary gland (HSG) cells, recombinant TRX (rTRX)-treated HSG cells were stimulated by interferon-gamma (IFN-gamma) for detecting interleukin 6 (IL-6) with ELISA and RT-PCR, or stimulated with IFN-gamma and anti-Fas antibody for analyzing Fas-induced apoptosis with PI/annexin V staining.

RESULTS

Large amounts of 8-OHdG, 4-HNE, nitrotyrosine, and TRX were produced in salivary duct cells of SS patients, whether there was periductal lymphocytic infiltration or not. Strong TRX expression was detected in acinar cells from 13 of 19 SS specimens. Levels of salivary TRX were significantly higher in SS patients than in controls (p < 0.05), and were inversely related to the salivary flow rates in SS patients. Patients who showed acinar TRX expression had higher salivary TRX levels than those who did not (p < 0.05). Interferon-gamma-induced expression of IL-6 and Fas-mediated apoptosis in HSG cells were significantly suppressed by pretreating cells with rTRX.

CONCLUSION

Parallel production of oxidative stress markers together with massive secretion of TRX suggests that oxidative stress induces TRX in the salivary gland. Moreover, suppression of IL-6 production and apoptosis by rTRX in HSG cells suggests TRX acts to protect the salivary glands of SS patients from tissue damage.

FRI0129 DEVELOPMENT OF A PREDICTION MODEL FOR MAXIMUM METHOTREXATE (MTX) DOSE WITHOUT HEPATOTOXICITY USING AN INDEX OF ERYTHROCYTE MTX-POLYGLUTAMATE (MTXPG) LEVELS SPECULATED BY CLINICAL AND GENETIC MARKERS

Background:

MTX is transported into cells and retained long after polyglutamation. MTXPG level can predict response and possibly adverse effects of MTX. We reported erythrocyte MTXPG concentrations efficiently discriminated patients with and without hepatotoxicity1. We also developed genetic and clinical prediction models for efficacy and hepatotoxicity of MTX2. In the present study, we firstly investigated the effects of clinical and secondly genetic variables on the concentration of total MTXPG and determined oral maximum MTX dose without hepatotoxicity using these variables.

Objectives:

To develop a prediction model for maximum MTX dose without hepatotoxicity.

Methods:

Concentrations of erythrocyte MTX-PG (PG1 to PG4) were detected by LC-MS/MS and calculated total MTXPG as sum of them. MTX-PGn levels were measured in 265 RA patients including 40 patients with elevated AST or ALT (≥ 60 U/L; 1.5 times of upper limits) and the 6 SNPs of 6 gens related to MTXPG metabolism were identified by RT-PCR.

Results:

Total concentrations of MTXPG were 141.3 ± 86.5 and 87.6 ± 47.8 nmol/L (mean±SD) in 40 RA patients with hepatotoxicity and 225 patients without, respectively (p<0.0001). By ROC analysis, the two groups were most efficiently discriminated with cutoff concentration of 100.0 nmol/L (AUC 0.731). Next, genetic and clinical model to speculate the MTXPG concentration was established by multivariate analysis using 4 clinical and 3 genetic variables which were selected from 20 clinical and 6 genetic variables by univariate analysis (p<0.1). Finally, a speculation model for MTXPG concentration by 4 clinical variables (MTX dose, BMI, RBC count, and creatinine) and one genetic variable (GGH c.452C>T) was developed (Figure). When MTXPG concentration of 100 nmol/L was applied to the model, maximum MTX dose without hepatotoxicity was calculated for each patient asMTX dose (mg) = {100 (MTXPG) – 96 + 1.7*BMI + 28*RBC - 120*creatinine - 19.3*GGH(C/T)} / 7.7. Real dose of oral MTX exceeded the calculated dose in 23 of 40 patients (57.5%) with hepatotoxicity, whereas it exceeded in 95 of 223 patients (42.6%) without hepatotoxicity (OR 1.82, p=0.081).

Conclusion:

Maximum MTX dose without hepatotoxicity was speculated by several clinical and genetic markers without measurement of erythrocyte MTX-PG concentrations.

References:

[1]Takahashi M, et al: Clinical Pathology (Rinsho Byori), 67:433-442, 2019.

[2]Onishi A, et al: The Pharmacogenomics J, doi.org/10.1038/s41397-019-0134-9, 2019

Disclosure of Interests:

Shunichi Kumagai Grant/research support from: Astellas, Chugai, Mitsubishi Tanabe Co.Ltds, Consultant of: Sysmex Co.Ltd, Speakers bureau: many companies, Soshi Takahashi: None declared, Miho Takahashi: None declared, Toshiharu Saito: None declared, Katsuyuki Yoshida: None declared, Motoko Katayama: None declared, Saki Mukohara: None declared, Norihiko Amano: None declared, Akira Onishi Speakers bureau: AO received a speaker fee from Chugai, Ono Pharmaceutical, Eli Lilly, Mitsubishi-Tanabe, Asahi-Kasei, and Takeda, Masakazu Shinohara: None declared, Saori Hatachi: None declared

Enhanced expression of programmed death-1 (PD-1)/PD-L1 in salivary glands of patients with Sjögren's syndrome

OBJECTIVE

Programmed death-1 (PD-1) mediates a negative signal and introduces tolerance for lymphocytes. Dysfunction of the PD-1 pathway is thought to result in autoimmune diseases such as rheumatoid arthritis (RA). To investigate the role of the PD-1/PD-L system in the pathology of Sjögren's syndrome (SS), we examined the expression of PD-1 and its ligand PD-L1 in salivary lymphocytes and salivary glands from patients with SS.

METHODS

Flow cytometry analysis was used to determine expression of PD-1 in SS salivary lymphocytes. Intracellular staining of interleukin 10 (IL-10) was performed after stimulation with PMA and ionomycin. Indirect immunohistochemistry was used to investigate the expression of PD-1 and PD-L1.

RESULTS

The mean fluorescence intensity of PD-1 expression in SS salivary lymphocytes was significantly higher than that from healthy controls and patients with RA or systemic lupus erythematosus. PD-1-positive SS salivary lymphocytes expressed IL-10 intracellularly upon PMA/ionomycin stimulation. Immunohistochemical analysis showed that PD-1 was expressed on infiltrating lymphocytes in salivary gland from 52% of SS patients, and PD-L1 was expressed on ductal and acinar epithelial cells from 68% of SS patients. In vitro analysis using HSG cells revealed that PD-L1 was induced by interferon-gamma but not by tumor necrosis factor-alpha and IL-1beta.

CONCLUSION

PD-1 is expressed on T lymphocytes and PD-L1 on epithelial cells from inflamed salivary glands of patients with SS, which suggests that dysfunction of the PD-1/PD-L1 pathway may be related to tolerance for lymphocytes, which causes SS.

Combination of cytoplasmic and nuclear patterns on Hep-2 antinuclear antibody is useful as a screening test for anti-synthetase syndrome

OBJECTIVE

This study aimed to establish a screening model for differentiating anti-synthetase syndrome (ASS) from other ANA-associated rheumatic diseases (AARDs) using a combination of cytoplasmic and non-cytoplasmic ANA (ncANA) patterns.

METHODS

: This retrospective observational study included patients with AARDs such as SLE, SSc, SS, MCTD and PM/DM who underwent ANA screening between April 2012 and December 2021. Variables included age, sex, ANA patterns (Cytoplasmic and ncANA) and titres. Logistic regression analysis of Cytoplasmic and ncANA patterns was performed to differentiate ASS from other AARDs.

RESULT

: The 981 diagnosed cases of AARDs consisted of SS (n = 451), SSc (n = 264), SLE (n = 201), PM/DM (n = 104), MCTD (n = 52) and ASS, including PM/DM (n = 64). Of these, 155 patients had ≥2 overlapping diseases; however, there was no overlap between AARDs and ASS. ASS is more likely to occur when the cytoplasmic titre is positive and the ncANA <320. Receiver operating characteristic analysis of the Cytoplasmic and ncANA range revealed an area under the receiver operating characteristic curve of 0.885 (95% CI: 0.844-0.927).

CONCLUSION

: It is important to detect cytoplasmic patterns as an ANA screening test for ASS diagnosis, even if the titre is low. Additionally, combining the cytoplasmic and ncANA patterns yields more accurate ASS screening results.

CD4+ PD-1+ T cells accumulate as unique anergic cells in rheumatoid arthritis synovial fluid

OBJECTIVE

The PD-1 receptor, whose deficiency in mice causes autoimmune diseases such as arthritis, is considered to be a negative regulator of activated T cells and to play a crucial role in peripheral tolerance. To clarify the involvement of the PD-1 system in rheumatoid arthritis (RA), we investigated PD-1 expression on synovial fluid (SF) T cells from patients with RA.

METHODS

FACS analysis for PD-1 was performed on SF T cells from 44 patients with RA and 6 with osteoarthritis (OA), and also on peripheral blood (PB) T cells from 12 RA patients and 7 healthy controls. Two-color analysis of cell surface PD-1 expression and the intracellular concentration of cytokine production was used to investigate CD4+ T cells from SF of patients with RA and PB from controls.

RESULTS

Scarcely any PD-1 expression was detected on control PB T or OA SF T cells. In contrast, PD-1+ cells made up 20.9 +/- 8.6% (mean +/- SD) of RA SF T cells. In RA SF, PD-1 was expressed more predominantly on CD4+ T cells than on CD8+ T cells. As well as expressing CD45RO and CXCR3, CD4+ PD-1+ T cells were mostly CTLA-4 positive and CD26 negative, and were enriched in CD45RB(low) cells. Intracellular cytokine staining revealed that CD4+ PD-1+, but not CD4+ PD-1-, T cells produced interleukin 10 (IL-10), and that CD4+ PD-1+ T cells produced less IL-2 than CD4+ PD-1- T cells.

CONCLUSION

PD-1+ T cells in RA SF are enriched, and phenotypic analysis suggests that these cells constitute a unique anergic T cell subset in RA SF.

AB0136 ASSESSING THE RELATIONSHIP AMONG OBESITY, GENETIC POLYMORPHISM, AND CLINICAL PARAMETERS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background:

Several study suggested body mass index(BMI) may influence development of rheumatoid arthritis(RA). There are conflicting reports concerning the impact of high BMI on development of RA, but several reports of obese on drug resistance and functional impairment. The relationship of genetic polymorphism on obesity is unclear in RA.

Objectives:

To examine the relationship among BMI, genetic polymorphism of obesity, disease activity of RA, laboratory parameters, and therapeutic agent of RA.

Methods:

We have carried out a retrospective observational study by systematically analyzing medical records of total 289 patients diagnosed with RA in Shinko Hospital between March 2016 and December 2019. We also conducted genotyping single nucleotide polymorphisms (SNPs) including FTO (rs1558902 and rs9939609), UCP1 (rs1800592), ADR2(rs1042713) and ADR3(rs4994) after informed consent. Obesity was defined as BMI over than 25 and patients were divided between obese (“Ob”) and non-obese (“non-Ob”). These SNPs, DAS28CRP, laboratory parameters, methotrexate dose, use of biological DMARDs were compared between Ob and non-Ob patients.

Results:

Of these 289 patients, 82.7% was female, mean age was 61.9 years and BMI was 22.4. Univariate logistic regression showed differences (p<0.1) between Ob and non Ob groups in UCP1 gene mutation(63.6% vs 78%, P=0.018), DAS(2.24 vs 1.99, P=0.033),triglyceride abnormality(23.8% vs 9.3%, P=0.021), HDL(56 vs 71, P=0.00009), HbA1c abnormality(26.5% vs 12.1%, P=0.019),γGTP(32 vs 21, P=0.00037), ALP (253 vs 230, P=0.0058), ALT (26.5 vs 20, P=0.029),and MTX dose(6 vs 8, P=0.066). Multivariate logistic regression showed that Ob group was significantly associated with HDL(OR=0.976, 95%CI 0.958 to 0.995), UCP1 gene mutation(OR=0.446, 95%CI 0.202 to 0.984), γGTP(OR=2.321, 95%CI 1.269 to 4.245), and MTX dose(OR=0.866, 0.784 to 0.957).

Conclusion:

Obesity in patients with RA had significant positive correlation with γGTP, and negative correlation with HDL, UCP gene mutation and MTX dose.

Disclosure of Interests:

None declared

Usefulness of position emission tomography/computed tomography in a case of sarcoidosis with multiorgan involvement

Sarcoidosis, a systemic inflammatory disease of unknown etiology, can affect any site in the body. A bone lesion was unexpectedly detected by fluorodeoxyglucose position emission tomography/computed tomography (FDG PET/CT) in a patient with multiorgan sarcoidosis. FDG PET/CT should be considered for the detection of clinically silent lesions of sarcoidosis.