Effect of Recent Antirheumatic Drug on Features of Rheumatoid Arthritis-Associated Lymphoproliferative Disorders.

OBJECTIVE: In this study, we examine how advancements in novel antirheumatic drugs affect the clinicopathologic features of lymphoproliferative disorder (LPD) in patients with rheumatoid arthritis (RA). METHODS: In this multicenter study across 53 hospitals in Japan, we characterized patients with RA who developed LPDs and visited the hospitals between January 1999 and March 2021. The statistical tools used included Fisher's exact test, the Mann-Whitney U-test, the log-rank test, logistic regression analysis, and Cox proportional hazards models. RESULTS: Overall, 752 patients with RA-associated LPD (RA-LPD) and 770 with sporadic LPD were included in the study. We observed significant differences in the clinicopathologic features between patients with RA-LPD and those with sporadic LPD. Histopathological analysis revealed a high frequency of LPD-associated immunosuppressive conditions. Furthermore, patients with RA-LPD were evaluated based on the antirheumatic drugs administered. The methotrexate (MTX) plus tacrolimus and MTX plus tumor necrosis factor inhibitor (TNFi) groups had different affected site frequencies and histologic subtypes than the MTX-only group. Moreover, MTX and TNFi may synergistically affect susceptibility to Epstein-Barr virus infection. In case of antirheumatic drugs administered after LPD onset, tocilizumab (TCZ)-only therapy was associated with lower frequency of regrowth after spontaneous regression than other regimens. CONCLUSION: Antirheumatic drugs administered before LPD onset may influence the clinicopathologic features of RA-LPD, with patterns changing over time. Furthermore, TCZ-only regimens are recommended after LPD onset.

ER-851, a Novel Selective Inhibitor of AXL, Overcomes Resistance to Antimitotic Drugs.

Innate and adaptive resistance to cancer therapies, such as chemotherapies, molecularly targeted therapies, and immune-modulating therapies, is a major issue in clinical practice. Subpopulations of tumor cells expressing the receptor tyrosine kinase AXL become enriched after treatment with antimitotic drugs, causing tumor relapse. Elevated AXL expression is closely associated with drug resistance in clinical samples, suggesting that AXL plays a pivotal role in drug resistance. Although several molecules with AXL inhibitory activity have been developed, none have sufficient activity and selectivity to be clinically effective when administered in combination with a cancer therapy. Here, we report a novel small molecule, ER-851, which is a potent and highly selective AXL inhibitor. To investigate resistance mechanisms and identify driving molecules, we conducted a comprehensive gene expression analysis of chemoresistant tumor cells in mouse xenograft models of genetically engineered human lung cancer and human triple-negative breast cancer. Consistent with the effect of AXL knockdown, cotreatment of ER-851 and antimitotic drugs produced an antitumor effect and prolonged relapse-free survival in the mouse xenograft model of human triple-negative breast cancer. Importantly, when orally administered to BALB/c mice, this compound did not induce retinal toxicity, a known side effect of chronic MER inhibition. Together, these data strongly suggest that AXL is a therapeutic target for overcoming drug resistance and that ER-851 is a promising candidate therapeutic agent for use against AXL-expressing antimitotic-resistant tumors.

Inhibition of FGFR Reactivates IFNγ Signaling in Tumor Cells to Enhance the Combined Antitumor Activity of Lenvatinib with Anti-PD-1 Antibodies.

Combination therapies consisting of immune checkpoint inhibitors plus anti-VEGF therapy show enhanced antitumor activity and are approved treatments for patients with renal cell carcinoma (RCC). The immunosuppressive roles of VEGF in the tumor microenvironment are well studied, but those of FGF/FGFR signaling remain largely unknown. Lenvatinib is a receptor tyrosine kinase inhibitor that targets both VEGFR and FGFR. Here, we examine the antitumor activity of anti-PD-1 mAb combined with either lenvatinib or axitinib, a VEGFR-selective inhibitor, in RCC. Both combination treatments showed greater antitumor activity and longer survival in mouse models versus either single agent treatment, whereas anti-PD-1 mAb plus lenvatinib had enhanced antitumor activity compared with anti-PD-1 mAb plus axitinib. Flow cytometry analysis showed that lenvatinib decreased the population of tumor-associated macrophages and increased that of IFNγ-positive CD8+ T cells. Activation of FGFR signaling inhibited the IFNγ-stimulated JAK/STAT signaling pathway and decreased expression of its target genes, including B2M, CXCL10, and PD-L1. Furthermore, inhibition of FGFR signaling by lenvatinib restored the tumor response to IFNγ stimulation in mouse and human RCC cell lines. These preclinical results reveal novel roles of tumor FGFR signaling in the regulation of cancer immunity through inhibition of the IFNγ pathway, and the inhibitory activity of lenvatinib against FGFRs likely contributes to the enhanced antitumor activity of combination treatment comprising lenvatinib plus anti-PD-1 mAb. SIGNIFICANCE: FGFR pathway activation inhibits IFNγ signaling in tumor cells, and FGFR inhibition with lenvatinib enhances antitumor immunity and the activity of anti-PD-1 antibodies.

Discovery of 5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine derivatives as novel selective Axl inhibitors.

Axl and Mer are members of the TAM (Tyro3-Axl-Mer) family of receptor tyrosine kinases. Previously, we reported that enzyme-mediated inhibition of Mer by an Axl/Mer dual inhibitor led to retinal toxicity in mice, whereas selective Axl inhibition by compound 1 did not. On the other hand, compound 1 showed low membrane permeability. Here, we designed and synthesized a novel series of 5,6,7,8-tetrahydropyrido[3,4-d]pyrimidine derivatives and evaluated their Axl and Mer inhibitory activities, leading to identification of ER-001259851-000 as a potent and selective Axl inhibitor with drug-likeness and a promising pharmacokinetic profile in mice.

Discovery of a potent and selective Axl inhibitor in preclinical model.

Axl and Mer are a members of the TAM (Tyro3-Axl-Mer) family of receptor tyrosine kinases, which, when activated, can promote tumor cell survival, proliferation, migration, invasion, angiogenesis, and tumor-host interactions. Chronic inhibition of Mer leads to retinal toxicity in mice. Therefore, successful development of an Axl targeting agent requires ensuring that it is safe for prolonged treatment. Here, to clarify whether enzyme inhibition of Mer by a small molecule leads to retinal toxicity in mice, we designed and synthesized Axl/Mer inhibitors and Axl-selective inhibitors. We identified an Axl/Mer dual inhibitor 28a, which showed retinal toxicity at a dose of 100 mg/kg in mice. Subsequent derivatization of a pyridine derivative led to the discovery of a pyrimidine derivative, 33g, which selectively inhibited the activity of Axl over Mer without retinal toxicity at a dose of 100 mg/kg in mice. Additionally, the compound displayed in vivo anti-tumor effects without influencing body weight in a Ba/F3-Axl isogenic subcutaneous model.

Activated FGF2 signaling pathway in tumor vasculature is essential for acquired resistance to anti-VEGF therapy.

Anti-vascular endothelial growth factor (VEGF) therapy shows antitumor activity against various types of solid cancers. Several resistance mechanisms against anti-VEGF therapy have been elucidated; however, little is known about the mechanisms by which the acquired resistance arises. Here, we developed new anti-VEGF therapy-resistant models driven by chronic expression of the mouse VEGFR2 extracellular domain fused with the human IgG4 fragment crystallizable (Fc) region (VEGFR2-Fc). In the VEGFR2-Fc-expressing resistant tumors, we demonstrated that the FGFR2 signaling pathway was activated, and pericytes expressing high levels of FGF2 were co-localized with endothelial cells. Lenvatinib, a multiple tyrosine kinase inhibitor including VEGFR and FGFR inhibition, showed marked antitumor activity against VEGFR2-Fc-expressing resistant tumors accompanied with a decrease in the area of tumor vessels and suppression of phospho-FGFR2 in tumors. Our findings reveal the key role that intercellular FGF2 signaling between pericytes and endothelial cells plays in maintaining the tumor vasculature in anti-VEGF therapy-resistant tumors.

Immunomodulatory activity of lenvatinib contributes to antitumor activity in the Hepa1-6 hepatocellular carcinoma model.

Angiogenesis inhibitors such as lenvatinib and sorafenib, and an immune checkpoint inhibitor (ICI), nivolumab, are used for anticancer therapies against advanced hepatocellular carcinoma (HCC). Combination treatments comprising angiogenesis inhibitors plus ICIs are promising options for improving clinical benefits in HCC patients, and clinical trials are ongoing. Here, we investigated the antitumor and immunomodulatory activities of lenvatinib (a multiple receptor tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 1-3, fibroblast growth factor receptor 1-4, platelet-derived growth factor receptor α, KIT and RET) and the combined antitumor activity of lenvatinib plus anti-programmed cell death 1 (PD-1) antibody in the Hepa1-6 mouse HCC syngeneic model. We found that the antitumor activities of lenvatinib and sorafenib were not different in immunodeficient mice, but lenvatinib showed more potent antitumor activity than sorafenib in immunocompetent mice. The antitumor activity of lenvatinib was greater in immunocompetent mice than in immunodeficient mice and was attenuated by CD8+ T cell depletion. Treatment with lenvatinib plus anti-PD-1 antibody resulted in more tumor regression and a higher response rate compared with either treatment alone in immunocompetent mice. Single-cell RNA sequencing analysis demonstrated that treatment with lenvatinib with or without anti-PD-1 antibody decreased the proportion of monocytes and macrophages population and increased that of CD8+ T cell populations. These data suggest that lenvatinib has immunomodulatory activity that contributes to the antitumor activity of lenvatinib and enhances the antitumor activity in combination treatment with anti-PD-1 antibody. Combination treatment of lenvatinib plus anti-PD-1 antibody therefore warrants further investigation against advanced HCC.

The 23-valent pneumococcal polysaccharide vaccine in patients with rheumatoid arthritis: a double-blinded, randomized, placebo-controlled trial.

BACKGROUND: Pneumococcal pneumonia is the most frequent form of pneumonia. We herein assessed the effectiveness of the 23-valent pneumococcal polysaccharide vaccine (PPSV23) in the prevention of pneumonia overall in rheumatoid arthritis (RA) patients at risk for infections. We hypothesized that PPSV23 vaccination is superior in preventing pneumococcal pneumonia compared with placebo in RA patients. METHODS: A prospective, multicenter, double-blinded, randomized, placebo-controlled (1:1) trial was conducted across departments of rheumatology in Japanese National Hospital Organization hospitals. RA patients (n = 900) who had been treated with biological or immunosuppressive agents were randomly assigned PPSV23 or placebo (sodium chloride). The primary endpoints were the incidences of all-cause pneumonia and pneumococcal pneumonia. The secondary endpoint was death from pneumococcal pneumonia, all-cause pneumonia, or other causes. Cox regression models were used to estimate the risk of pneumonia overall for the placebo group compared with the vaccine group. RESULTS: Seventeen (3.7%) of 464 patients in the vaccine group and 15 (3.4%) of 436 patients in the placebo group developed pneumonia. There was no difference in the rates of pneumonia between the two study groups. The overall rate of pneumonia was 21.8 per 1000 person-years for patients with RA. The presence of interstitial pneumonia (hazard ratio: 3.601, 95% confidence interval: 1.547-8.380) was associated with an increased risk of pneumonia in RA patients. CONCLUSION: PPSV23 does not prevent against pneumonia overall in RA patients at relative risk for infections. Our results also confirm that the presence of interstitial lung disease is associated with pneumonia in Japanese patients with RA. TRIAL REGISTRATION: UMIN-CTR UMIN000009566 . Registered 17 December 2012.

Pneumococcal polysaccharide vaccination in rheumatoid arthritis patients receiving tacrolimus.

INTRODUCTION: In rheumatoid arthritis (RA) patients receiving immunosuppressive treatments, vaccination against Streptococcus pneumoniae is recommended. The objective of the study was to evaluate the effects of tacrolimus (TAC) on immune response following administration of a 23-valent pneumococcal polysaccharide vaccine (PPSV23) in patients with established RA. METHODS: Patients with RA (n = 133) were vaccinated with PPSV23. Patients were classified into TAC (n = 29), methotrexate (MTX) (n = 55), control (n = 35), and TAC/MTX (n = 14) treatment groups. We measured the concentrations of pneumococcal serotypes 6B and 23F by using an enzyme-linked immunosorbent assay and determined antibody functionality by using a multiplexed opsonophagocytic killing assay, reported as the opsonization index (OI), before and 4 to 6 weeks after vaccination. A positive antibody response was defined as at least a twofold increase in the IgG concentration or as at least a 10-fold increase in the OI. RESULTS: IgG concentrations and OIs were significantly increased in all treatment groups after PPSV23 vaccination. The TAC treatment group appears to respond in a manner similar to that of the RA control group in terms of 6B and 23F serotype concentration and function. In contrast, the MTX group had the lowest immune response. Patients who received a combination of TAC and MTX (TAC/MTX) also had a diminished immune response compared with those who received TAC alone. CONCLUSIONS: TAC monotherapy does not appear to impair PPSV23 immunogenicity in patients with RA, whereas antibody production and function may be reduced when TAC is used with MTX. Thus, PPSV23 administration during ongoing TAC treatment should be encouraged for infection-prone TAC-treated patients with rheumatic diseases. TRIAL REGISTRATION: University Hospital Medical Information Network Clinical Trials Registry: UMIN000009566. Registered 12 December 2012.

MCRIP1, an ERK substrate, mediates ERK-induced gene silencing during epithelial-mesenchymal transition by regulating the co-repressor CtBP.

The ERK pathway not only upregulates growth-promoting genes, but also downregulates anti-proliferative and tumor-suppressive genes. In particular, ERK signaling contributes to repression of the E-cadherin gene during epithelial-mesenchymal transition (EMT). The CtBP transcriptional co-repressor is also involved in gene silencing of E-cadherin. However, the functional relationship between ERK signaling and CtBP is unknown. Here, we identified an ERK substrate, designated MCRIP1, which bridges ERK signaling and CtBP-mediated gene silencing. CtBP is recruited to promoter elements of target genes by interacting with the DNA-binding transcriptional repressor ZEB1. We found that MCRIP1 binds to CtBP, thereby competitively inhibiting CtBP-ZEB1 interaction. When phosphorylated by ERK, MCRIP1 dissociates from CtBP, allowing CtBP to interact with ZEB1. In this manner, the CtBP co-repressor complex is recruited to, and silences, the E-cadherin promoter by inducing chromatin modifications. Our findings reveal a molecular mechanism underlying ERK-induced epigenetic gene silencing during EMT and its dysregulation in cancer.

N-terminal hydrophobic amino acids of activating transcription factor 5 (ATF5) protein confer interleukin 1ß (IL-1ß)-induced stabilization.

Activating transcription factor 5 (ATF5) is a stress-response transcription factor that responds to amino acid limitation and exposure to cadmium chloride (CdCl2) and sodium arsenite (NaAsO2). The N-terminal amino acids contribute to the destabilization of the ATF5 protein in steady-state conditions and serve as a stabilization domain in the stress response after CdCl2 or NaAsO2 exposure. In this study, we show that interleukin 1ß (IL-1ß), a proinflammatory cytokine, increases the expression of ATF5 protein in HepG2 hepatoma cells in part by stabilizing the ATF5 protein. The N-terminal domain rich in hydrophobic amino acids that is predicted to form a hydrophobic network was responsible for destabilization in steady-state conditions and served as an IL-1ß response domain. Furthermore, IL-1ß increased the translational efficiency of ATF5 mRNA via the 5' UTRα and phosphorylation of the eukaryotic translation initiation factor 2α (eIF2α). ATF5 knockdown in HepG2 cells up-regulated the IL-1ß-induced expression of the serum amyloid A 1 (SAA1) and SAA2 genes. Our results show that the N-terminal hydrophobic amino acids play an important role in the regulation of ATF5 protein expression in IL-1ß-mediated immune response and that ATF5 is a negative regulator for IL-1ß-induced expression of SAA1 and SAA2 in HepG2 cells.

Baseline anti-citrullinated peptide antibody (ACPA) titers and serum interleukin-6 (IL-6) levels possibly predict progression of bone destruction in early stages of rheumatoid arthritis (ERA).

A prospective study was made to seek for a convenient biomarker to predict progression of bone destruction (PBD) in early stages of rheumatoid arthritis (ERA). All participated patients had definite RA and their radiographic stages were mild less than stage II of the Steinbrocker classification, naïve for treatment of any DMARDs or corticosteroids. After the entry, they were treated according to the 2002 ACR management guideline for RA. The candidate biomarkers (RF-IgM, RF-IgG, CARF, ACPA, CRP, ESR, NTx, MMP-3, IL-6 and osteopontin) were measured at the entry. PBD was assessed radiographically by interval changes in the modified Sharp scores (ΔSHS) for 24 months. The associations between ΔSHS and baseline biomarkers were assessed statistically by multivariate regression analyses. Both the baseline ACPA and IL-6 levels correlated with PBD, suggesting that they could predict PBD in ERA.

Regulation of stress-activated MAP kinase pathways during cell fate decisions.

Mammalian cells are frequently exposed to a variety of environmental stresses, such as ultraviolet rays, ionizing radiation, genotoxins, heat shock, and oxidative stress. In coping with the barrage of these and other stresses, multi-cellular eukaryotic organisms have developed a strategy as to how damaged cells will respond to stresses. In general, if the intensity of the damage is moderate, the cell will seek to repair the damage. If, however, the damage to a cell is too severe to be repaired, the affected cells are eliminated by apoptosis. This cell death reduces the risk to the organism as a whole, such as development of a cancer. Such a crucial decision between survival and death is, at least in part, mediated by the stress-activated MAP kinase (SAPK) pathways. SAPKs are a group of serine/threonine protein kinases that convert extracellular stress stimuli into diverse cellular responses, including cell cycle arrest, apoptotic cell death, and cytokine production, through phosphorylation of specific target proteins. Recent progress in the identification of molecules that participate in the SAPK pathways, such as GADD45 proteins and Wipl, has provided new insights, not only into the molecular basis of the cellular response to environmental stress, but also into the etiology of human diseases including cancer.

A multicentre trial of bucillamine in the treatment of early rheumatoid arthritis (SNOW study).

In this study, we enrolled early rheumatoid arthritis (RA) patients at multiple institutes who fulfilled the American Rheumatism Association 1987 revised criteria for the classification of RA, and followed the clinical results of disease-modifying anti-rheumatic drug (DMARD) treatment prospectively. With the aim of developing therapeutic guidelines using the disease activity score 28 (DAS28) as disease indices, we investigated the usefulness of bucillamine (BUC), one of the most widely used DMARDs in Japan. Eighty-one patients with early RA who had not previously been treated with DMARDs were suitable for BUC therapy as first-choice treatment. After 24 months of treatment, at least moderate improvement was seen in 87.5% of patients using the DAS28 erythrocyte sedimentation rate (ESR). After 24 months of BUC therapy, 7 patients (43.8%) met the remission criterion of DAS28 (ESR) <2.6. The 24-month BUC continuation rate was 60.5% (49/81, monotherapy + combination therapy), of which 59.2% (29/49) were on BUC monotherapy. From the efficacy and safety viewpoints alike, BUC was useful as first-choice treatment for early RA.

Stress-induced translation of ATF5 mRNA is regulated by the 5'-untranslated region.

Activating transcription factor (ATF) 5 is a transcription factor belonging to the ATF/cAMP-response element-binding protein gene family. We previously reported that ATF5 mRNA expression increased in response to amino acid limitation. The ATF5 gene allows transcription of mRNAs with at least two alternative 5'-untranslated regions (5'-UTRs), 5'-UTRalpha and 5'-UTRbeta, derived from exon1alpha and exon1beta. 5'-UTRalpha contains highly conserved sequences, in which the upstream open reading frames (uORFs) uORF1 and uORF2 are found in many species. This study was designed to investigate the potential role of 5'-UTRs in translational control. These 5'-UTRs differentially determined translation efficiency from mRNA. The presence of 5'-UTRalpha or 5'-UTRbeta represses translation from the downstream ATF5 ORF. Moreover, 5'-UTRalpha-regulated translational repression is released by amino acid limitation or NaAsO(2) exposure. This release was not seen for 5'-UTRbeta. Mutation of uAUG2 in the uORF2 of 5'-UTRalpha restored the basal expression and abolished the positive regulation by amino acid limitation or arsenite exposure. We demonstrated that phosphorylation of eukaryotic initiation factor 2alpha was required for amino acid limitation-induced translational regulation of ATF5. Furthermore, arsenite exposure activated the exogenously expressed heme-regulated inhibitor kinase and induced the phosphorylation of eukaryotic initiation factor 2alpha in nonerythroid cells. These results suggest that translation of ATF5 is regulated by the alternative 5'-UTR region of its mRNA, and ATF5 may play a role in protecting cells from amino acid limitation or arsenite-induced oxidative stress.

[Prolonged complete response obtained by single agent S-1 in a case of peritoneal metastasis from gastric remnant cancer].

A 58-year-old man underwent cholecystectomy and partial resection of the stomach with the preoperative diagnosis of acute cholecystitis and submucosal tumor of the stomach. The submucosal tumor was found postoperatively to be a T3 stage gastric cancer with well-differentiated phenotype through histopathologic examination of the resected specimen. The patient rejected a subsequent offer of either reoperation or chemotherapy, and underwent close follow-up. Serum tumor markers rose a few months later, and cancer recurrence was confirmed by the finding of a measurable peritoneal metastasis by computed tomography. He was treated with single agent S-1, obtained a complete response 10 months later, and went on to receive the drug for 42 months. He remains disease-free for over 30 months after cessation of S-1. S-1 is recommended as a first-line chemotherapy for recurrent gastric cancer, but the treatment schedule and follow-up schedule after obtaining a complete response remain an issue.

[A case of recurrent gastric cancer with peritoneal dissemination responding to doxifluridine/paclitaxel combination chemotherapy as third-line treatment].

A 50-year-old man had undergone total gastrectomy and splenectomy for advanced gastric cancer in October 2000, and was then treated with postoperative adjuvant chemotherapy for 2 years. In June 2005, we made a diagnosis of recurrent gastric cancer with peritoneal dissemination. Although the chemotherapy with TS-1/CPT-11 was started, it was discontinued after 2 courses because of subileus. Despite a change to second-line chemotherapy with CPT-11/CDDP, progressive disease due to a large amount of ascites was confirmed after 3 courses. Therefore, chemotherapy with doxifluridine (5'-DFUR)/paclitaxel (PTX) was selected as third-line treatment. After completion of 3 courses, abdominal computed tomography revealed a marked decrease of ascites. After 8 courses we discontinued 5'-DFUR/PTX chemotherapy, so the increase of ascites was remarkable. All response time was 197 days. The patient had good quality of life. 5'-DFUR/PTX combination chemotherapy can be expected to improve patient quality of life and show good therapeutic efficacy against recurrent gastric cancer with peritoneal dissemination.

Antigenic structures recognized by anti-beta2-glycoprotein I auto-antibodies.

Beta2-glycoprotein I (beta2-GPI) is a major antigen for anti-cardiolipin antibodies and their epitopes are cryptic. Conformation of each domain of beta2-GPI was optimized from its crystal structure by energy minimization and by molecular dynamics simulation. Three electrostatic interactions, i.e. D193-K246, D222-K317 and E228-K308, were observed between domains IV and V in the optimized structure that was constructed based on the consensus sequences obtained by the phage-displayed random peptide library. Antigenic structures determined by the epitope mapping mainly consisted of hydrophobic amino acids located on two discontinuous sequences in domain IV. These amino acid clusters, as an epitope, were covered by domain V and were of a hidden nature. A similar but incomplete counterpart to the epitopic clusters was found in domain I but was not in domains II or III. Binding of anti-beta2-GPI auto-antibodies to solid-phase beta2-GPI was significantly reduced either by L replacement for W235, a common amino acid component for the epitopes, or by V replacement for all of D193, D222 and E228. Structural analysis indicated a hypothesis that these electrostatic interactions between domains IV and V retained exposure to W235 and that epitope spreading occurred in the region surrounding W235. Thus, epitopic structures recognized by anti-beta2-GPI auto-antibodies are cryptic and inter-domain electrostatic interactions are involved in their in exposure.

Significance of valine/leucine247 polymorphism of beta2-glycoprotein I in antiphospholipid syndrome: increased reactivity of anti-beta2-glycoprotein I autoantibodies to the valine247 beta2-glycoprotein I variant.

OBJECTIVE: To clarify the consequences of the valine/leucine polymorphism at position 247 of the beta(2)-glycoprotein I (beta(2)GPI) gene in patients with antiphospholipid syndrome (APS), by investigating the correlation between genotypes and the presence of anti-beta(2)GPI antibody. The reactivity of anti-beta(2)GPI antibodies was characterized using recombinant Val(247) and Leu(247) beta(2)GPI. METHODS: Sixty-five Japanese patients with APS and/or systemic lupus erythematosus who were positive for antiphospholipid antibodies and 61 controls were analyzed for the presence of the Val/Leu(247) polymorphism of beta(2)GPI. Polymorphism assignment was determined by polymerase chain reaction followed by restriction enzyme digestion. Recombinant Val(247) and Leu(247) beta(2)GPI were established to compare the reactivity of anti-beta(2)GPI antibodies to beta(2)GPI between these variants. The variants were prepared on polyoxygenated plates or cardiolipin-coated plates, and the reactivity of a series of anti-beta(2)GPI antibodies (immunized anti-human beta(2)GPI monoclonal antibodies [Cof-19-21] and autoimmune anti-beta(2)GPI monoclonal antibodies [EY1C8, EY2C9, and TM1G2]) and IgGs purified from patient sera was investigated. RESULTS: A positive correlation between the Val(247) allele and the presence of anti-beta(2)GPI antibodies was observed in the patient group. Human monoclonal/polyclonal anti-beta(2)GPI autoantibodies showed higher binding to recombinant Val(247) beta(2)GPI than to Leu(247) beta(2)GPI, although no difference in the reactivity of the immunized anti-beta(2)GPI between these variants was observed. Conformational optimization showed that the replacement of Leu(247) by Val(247) led to a significant alteration in the tertiary structure of domain V and/or the domain IV-V interaction. CONCLUSION: The Val(247) beta(2)GPI allele was associated with both a high frequency of anti-beta(2)GPI antibodies and stronger reactivity with anti-beta(2)GPI antibodies compared with the Leu(247) beta(2)GPI allele, suggesting that the Val(247) beta(2)GPI allele may be one of the genetic risk factors for development of APS.

Diagnostic value of antiagalactosyl IgG antibodies in rheumatoid arthritis.

Our objective in this study was to explore the diagnostic value of antiagalactosyl IgG antibodies in rheumatoid arthritis (RA). The study comprised 266 Japanese patients with systemic autoimmune diseases, including 60 with RA. Human agalactosyl IgG was prepared enzymatically, and the serum levels of antiagalactosyl IgG antibodies were determined using a lectin enzyme immunoassay. Serum IgG and IgM rheumatoid factors (RF) were measured using laser nephelometry for IgM (LN-RF) and an enzyme-linked immunosorbent assay for IgG (IgG-RF). Antiagalactosyl IgG antibodies were significantly more common in patients with RA than in those without (78% vs. 18%, odds ratio (OR) 16.51, 95% confidence interval (CI) 8.12-33.58, p<0.0001). Patients with RA also had a higher frequency of LN-RF than those without RA (75% vs. 28%, OR 7.81, 95% CI 3.91-15.58, p< 0.001). The specificity of antiagalactosyl IgG antibodies for RA was significantly higher than that of LN-RF (82% vs. 72%, p<0.0011). There was a significant correlation between titers of antiagalactosyl IgG antibodies and C-reactive protein levels. Antiagalactosyl IgG antibodies are more specific markers for RA than conventional LN-RF, and may provide useful information for the diagnosis of RA.