Clinical characteristics and treatment of elderly onset adult-onset Still's disease.

Adult-onset Still's disease (AOSD)-a systemic inflammatory disease-often occurs at a young age. Recently, elderly onset patient proportion has been increasing; however, data are limited. To evaluate the characteristics of elderly patients with AOSD in a multicenter cohort, we retrospectively analyzed 62 patients with AOSD at five hospitals during April 2008-December 2020. Patients were divided into two groups according to age at disease onset: younger-onset (≤ 64 years) and elderly onset (≥ 65 years). Clinical symptoms, complications, laboratory findings, treatment, and outcomes were compared. Twenty-six (41.9%) patients developed AOSD at age ≥ 65 years. The elderly onset group had a lower frequency of sore throat (53.8% vs. 86.1%), higher frequency of pleuritis (46.2% vs. 16.7%), and higher complication rates of disseminated intravascular coagulation (30.8% vs. 8.3%) and macrophage activation syndrome (19.2% vs. 2.8%) than the younger onset group. Cytomegalovirus infections were frequent in elderly onset patients (38.5% vs. 13.9%) but decreased with early glucocorticoid dose reduction and increased immunosuppressant and tocilizumab use. Elderly AOSD is not uncommon; these patients have different characteristics than younger-onset patients. Devising a way to control disease activity quickly while managing infections may be an important goal in elderly AOSD.

Enhanced expression of mRNA for transforming growth factor ß activated kinase 1 in CD34+ cells of the bone marrow in rheumatoid arthritis.

OBJECTIVES: Transforming growth factor ß activated kinase 1 (TAK1) has been found to mediate maladaptive tumour necrosis factor (TNF) signalling, leading to hyperactive downstream nuclear factor Kappa ß (NF-κB) signalling. We explored the expression of TAK1 mRNA in bone marrow CD34+ cells in rheumatoid arthritis (RA) to delineate the mechanism for their abnormal response to TNF-α and differentiate into fibroblast-like cells. METHODS: CD34+ cells were purified from bone marrow samples obtained from 47 RA patients and 27 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The expression of mRNAs for TAK1 and NFκB1 was examined by quantitative RT-PCR. RESULTS: TAK1 mRNA expression in bone marrow CD34+ cells was significantly higher in RA than in OA (TAK1/ß-actin: [11.980 ± 2.380] x 10-3 and [5.593±1.307] x 10-3 [mean ± SEM], respectively; p=0.0238). TAk1 mRNA expression was not different depending on the type of operated joints or on the severity type of RA. Nor was it correlated with serum CRP or rheumatoid factor or with administration of methotrexate, other conventional synthetic disease-modifying anti-rheumatic drugs or oral glucocorticoid. TAK1 mRNA expression was significantly correlated with NFκB1 mRNA expression in RA bone marrow CD34+ cells. CONCLUSIONS: These results indicate that TAK1 mRNA expression is enhanced in bone marrow CD34+ cells independently of the clinimetrics or treatment in RA. It is also suggested that the upregulation of TAK1 mRNA expression might lead to the enhanced expression of NFκB1 mRNA in bone marrow CD34+ cells, but possibly not vice versa, resulting in their abnormal response to TNF-α.

Association of NCF1 polymorphism with systemic lupus erythematosus and systemic sclerosis but not with ANCA-associated vasculitis in a Japanese population.

Genome-wide association studies of systemic lupus erythematosus (SLE) in Chinese and Korean populations demonstrated strong association of single nucleotide polymorphisms (SNPs) located in the GTF2I-NCF1 region, rs73366469 (GTF2I), rs117026326 (GTF2I), rs80346167(GTF2IRD1) and rs201802880 (NCF1). This region has also been associated with susceptibility to Sjögren syndrome and rheumatoid arthritis; however, association studies with systemic sclerosis (SSc) and ANCA-associated vasculitis (AAV) have not been reported. Here we made an attempt to confirm their associations with SLE in the Japanese population, to find the primarily associated SNP, and to investigate whether these SNPs are also associated with susceptibility to SSc and AAV. By genotyping these four SNPs on 842 SLE, 467 SSc, 477 AAV patients and 934 healthy controls, striking association was confirmed in Japanese SLE. In addition, these SNPs were significantly associated with susceptibility to SSc, but not with AAV. Conditional logistic regression analysis revealed that the association of NCF1 rs201802880, a missense SNP encoding p.Arg90His, can account for the association of other SNPs by linkage disequilibrium. These results suggested that GTF2I-NCF1 region is associated with susceptibility to multiple autoimmune rheumatic diseases but not with AAV, and the primarily associated variant may be the missense SNP in NCF1.

Synergistic enhancement of production of proinflammatory cytokines of human peripheral blood monocytes by anti-Sm and anti-RNP antibodies.

The present study was performed to elucidate the roles of serum anti-Sm antibodies in the pathogenesis of systemic lupus erythematosus (SLE). Highly purified peripheral blood monocytes obtained from healthy donors were cultured in the presence of monoclonal anti-Sm antibody (anti-Sm mAb), monoclonal anti-U1-RNP antibody (anti-RNP mAb) or control murine IgG1 or IgG3. After various periods of incubation, levels of IL-6 and TNF-α in the culture supernatants were measured by ELISA and the expression of mRNA for various molecules in monocytes was determined using RT-PCR. Flow cytometry analysis confirmed the bindings of anti-Sm mAb and anti-RNP mAb on viable human monocytes. Both anti-Sm mAb and anti-RNP mAb significantly increased the production of IL-6 and TNF-α of human monocytes in a dose-dependent manner, although the latter was more potent than the former. Of note, anti-Sm mAb synergistically enhanced the production and mRNA expression of IL-6 and TNF-α of human monocytes in the presence of anti-RNP mAb. Notably, anti-RNP mAb, but not anti-Sm mAb, significantly enhanced the mRNA expression of RelA in human monocytes. Finally, anti-Sm mAb still up-regulated the IL-6 production of monocytes in the presence of anti-RNP mAb under the influence of N-acetyl cysteine or pyrrolidine dithiocarbamate that totally abrogated the IL-6 production provoked by anti-Sm mAb alone in the absence of anti-RNP mAb. These results demonstrate that anti-Sm and anti-RNP antibodies synergistically up-regulate the expression of IL-6 and TNF-α in human monocytes. The data also suggest that the effect of anti-Sm in the synergy with anti-RNP might not involve NFkB activation.

Elevation of serum anti-glucose-regulated protein 78 antibodies in neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: Recent studies have demonstrated that autoantibodies directed against glucose-regulated protein 78 (GRP78) on endothelial cells promote blood-brain barrier (BBB) damages. The present study examined whether serum anti-GRP78 antibodies might be involved in the pathogenesis of neuropsychiatric SLE (NPSLE). METHODS: Serum samples were obtained from 129 patients with SLE (58 patients with diffuse psychiatric/neuropsychological syndromes of NPSLE (diffuse NPSLE), 30 with neurological syndromes (focal NPSLE), 21 with lupus nephritis (LN), 20 without NPSLE or LN (SLE alone)), from 35 patients with non-SLE rheumatic diseases (non-SLE RD) and from 24 healthy controls (HC). Anti-GRP78 levels were measured with an ELISA, using recombinant GRP78 as antigens. Cerebrospinal fluid (CSF) samples were also obtained from 88 patients with NPSLE. The BBB function was evaluated by Q albumin ((CSF albumin/serum albumin)×103). RESULTS: Serum anti-GRP78 levels were significantly elevated in SLE compared with non-SLE RD or HC. There were no significant differences in serum anti-GRP78 levels among NPSLE, LN and SLE alone. Of note, serum anti-GRP78 levels were significantly higher in acute confusional state (ACS) than in non-ACS diffuse NPSLE (p=0.0001) or in focal NPSLE (p=0.0002). Finally, serum anti-GRP78 levels were significantly correlated with Q albumin (r=0.294, p=0.0054) in NPSLE. CONCLUSION: These results indicate that anti-GRP78 antibodies are associated with the development of diffuse NPSLE, especially ACS. Thus, the data suggest that anti-GRP78 antibodies might contribute to the development of ACS through the damages of BBB.

The expression of mRNA for peptidylarginine deiminase type 2 and type 4 in bone marrow CD34+ cells in rheumatoid arthritis.

OBJECTIVES: Antibodies directed to citrullinated proteins are highly specific for rheumatoid arthritis (RA). Citrullination is catalyzed by peptidylarginine deiminase (PAD) enzymes. The current study examined the mRNA expression of PADI2 and PADI4 in bone marrow (BM) CD34+ cells from RA patients. METHODS: CD34+ cells were purified from BM samples obtained from 48 RA patients and from 30 osteoarthritis (OA) patients during joint operations via aspiration from the iliac crest. The expression of mRNAs for PADI2, PADI4 and Sp1 was examined by quantitative reverse transcription PCR. RESULTS: The expression of mRNA for PADI2 was significantly higher in RA BM CD34+ cells than OA BM CD34+ cells. The expression of mRNAs for PADI4 and Sp1 in RA BM CD34+ cells appeared to be increased compared to OA BM CD34+ cells, although it did not reach the statistical significance. The levels of mRNAs for PADI2, PADI4 and Sp1 were not correlated with serum C-reactive protein or with the administration of methotrexate or oral steroids. Finally, the level of PADI2 mRNA as well as that of PADI4 mRNA was significantly correlated with the level of Sp1 mRNA in RA BM CD34+ cells. CONCLUSIONS: These results indicate that the mRNA expression of PADI2, PADI4 and Sp1 is upregulated in RA BM CD34+ cells independently of the systemic inflammation or treatment regimen. Moreover, the data suggest that the enhanced mRNA expression of PADI2 and PADI4 in BM CD34+ cells might be a result of the enhanced expression of Sp1 gene in RA BM CD34+ cells.

Differential influences of Fc gamma receptor blocking on the effects of certolizumab pegol and infliximab on human monocytes.

OBJECTIVES: To compare the effects of certolizumab pegol (CZP) and infliximab (IFX) on human monocytes. METHODS: Highly purified monocytes from healthy donors were cultured with CZP, IFX, control IgG1, or polyethylene glycol (PEG) at pharmacological attainable concentrations in culture medium with 10% autologous normal human serum (NHS) or with fetal bovine serum (FBS) for 24 h, after which the supernatants were replaced by fresh culture medium containing LPS. After additional 24 h of incubation, the supernatants were assayed for TNF-α and IL-6. In some experiments, the cells were harvested after 1 h of stimulation with LPS for analysis of mRNA for TNF-α by quantitative PCR. RESULTS: Pre-incubation of monocytes with CZP or IFX reduced the production of TNF-α in subsequent cultures stimulated by LPS in a dose-dependent manner. The suppressive effects of IFX on the TNF-α production were significantly diminished, but those of CZP were rather enhanced, in cultures with autologous NHS compared with in cultures with FBS. Addition of IgG, but not IgG F(ab')2 fragments, significantly inhibited the suppressive effects of IFX on the production of TNF-α and IL-6, whereas either IgG or IgG F(ab')2 fragments had no significant influences on the suppressive effects of CZP. Furthermore, pre-incubation with CZP or IFX significantly inhibited the expression of mRNA for TNF-α and IL-6 in monocytes compared with PEG or IgG. CONCLUSION: These results indicate that the mechanism of action of CZP is different from that of IFX. Thus, CZP suppresses the production of proinflammatory cytokines independently of Fc receptors, whereas the suppressive effects of IFX on human monocytes are almost totally dependent on the interaction with Fc receptors.

Effects of CTLA4-Ig on human monocytes.

BACKGROUND: Abatacept, a CTLA4-Ig fusion protein attenuates T cell activation by inhibiting the CD80/86-CD28 costimulatory pathway that is required for the proper T cell activation and thus displays beneficial effects in the treatment of rheumatoid arthritis (RA). Although some studies have disclosed the in vitro effects of this biological agent on the immune-competent cells, the precise mechanisms of action in RA still remain unclear. The current studies were therefore undertaken to explore the effects of abatacept on monocytes in detail. METHODS: Monocytes from healthy donors were cultured in the presence of staphylococcal enterotoxin B (SEB) with pharmacologically attainable concentrations of abatacept or control IgG-Fc. The expression of CD80 and CD86 and the induction of apoptosis of monocytes were measured by flow cytometry. The expression of CD80 and CD86 messenger RNA (mRNA) was determined by quantitative RT-PCR. RESULTS: Abatacept promoted apoptosis of SEB-stimulated monocytes. The induction of apoptosis of monocytes by these biological agents was reversed by the addition of IgG, but not IgG-F(ab')2 fragments. Furthermore, abatacept significantly suppressed the expression of CD80, but not that of CD86 at protein levels. Finally, abatacept significantly suppressed the expression of mRNA for CD80 of monocytes stimulated with SEB, but not that of CD86. CONCLUSIONS: These results demonstrate that one of the mechanisms of action of abatacept involves the induction of apoptosis of monocytes, which involves interaction with Fc receptor on monocytes. Moreover, the data also demonstrate that abatacept selectively suppresses the expression of CD80 at mRNA levels.

Differential activation mechanisms of serum C5a in lupus nephritis and neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To explore the role of C5a in the pathogenesis of neuropsychiatric systemic lupus erythematosus (NPSLE) and lupus nephritis (LN). METHODS: Sera were obtained from 29 patients with NPSLE, 25 with LN, 26 without NPSLE or LN [SLE alone], and 21 healthy donors. Cerebrospinal fluid (CSF) was obtained from 29 NPSLE patients. C5a and C5 were measured by ELISA. Blood-brain barrier (BBB) function was evaluated by Q albumin ([CSF albumin/serum albumin] × 103). RESULTS: Serum C5a, but not C5, was significantly increased in SLE compared with healthy control. Serum C5a, but not C5, was significantly higher in NPSLE and in LN than in SLE alone. Serum C4, but not C3, was lower in LN than in NPSLE. Q albumin was significantly higher in diffuse NPSLE than in focal NPSLE, whereas there were no significant differences in CSF or serum C5a between both groups. Notably, CSF C5 and C5a were significantly correlated with Q albumin, whereas serum C5a, but not C5, appeared to be inversely correlated with Q albumin. CONCLUSION: These results disclosed that serum C5a was elevated not only in NPSLE but also in LN through different mechanisms. Moreover, it is suggested that C5a might be consumed during BBB damages.

Association of HLA-G 3' Untranslated Region Polymorphisms with Systemic Lupus Erythematosus in a Japanese Population: A Case-Control Association Study.

HLA-G plays a role in fetal-maternal tolerance as well as immunoregulation, and has been suggested to be involved in autoimmune diseases and cancers. HLA-G encodes two potentially functional polymorphisms in the 3' untranslated region, 14bp insertion/deletion (14bp indel, rs371194629) and a single nucleotide polymorphism rs1063320, previously reported to affect HLA-G expression level or splicing isoform and to be associated with susceptibility to systemic lupus erythematosus (SLE). However, the results of SLE association studies are inconsistent, probably due to the small sample size of each study and lack of consideration of linkage disequilibrium (LD) with HLA-class II haplotypes in each population. In this study, we performed association studies of these polymorphisms on 843 patients with SLE and 778 healthy controls in a Japanese population, in many of whom HLA-DRB1 alleles have been genotyped at the four-digit level. LD was detected between DRB1*13:02, protective against multiple autoimmune diseases in the Japanese, and the rs1063320 G (D' = 0.86, r2 = 0.02) and with 14bp del (D' = 0.62, r2 = 0.01), but not between SLE-susceptible DRB1*15:01 and HLA-G. Although significant association with overall SLE was not detected, 14bp ins allele was significantly associated with SLE with the age of onset <20 years, when compared with healthy controls (P = 0.0067, PFDR = 0.039, OR 1.44, additive model) or with SLE patients with the age of onset ≥20 (P = 0.033, PFDR = 0.0495, OR 2.09, additive model). This association remained significant after conditioning on DRB1*13:02 or DRB1*15:01. On the other hand, significant association was detected between rs1063320 C and anti-RNP antibody and anti-Sm antibody positive SLE, which was dependent on negative LD with DRB1*13:02. eQTL analysis showed reduced HLA-G mRNA level in 14bp ins/ins individuals. In conclusion, our observations showed that HLA-G 14bp ins allele represents a genetic contribution on early-onset SLE independent of DRB1.

Human Leukocyte Antigen and Systemic Sclerosis in Japanese: The Sign of the Four Independent Protective Alleles, DRB1*13:02, DRB1*14:06, DQB1*03:01, and DPB1*02:01.

OBJECTIVE: Several studies on associations between human leukocyte antigen (HLA) allele frequencies and susceptibility to systemic sclerosis (SSc) have been reported. Anti-centromere antibodies (ACA) and anti-topoisomerase I antibodies (ATA) are found in SSc patients. Here, we sought to identify HLA alleles associated with SSc in Japanese, and explored their associations with SSc phenotypes including the presence of autoantibodies. METHODS: Associations of HLA-DRB1, DQB1, and DPB1 were analyzed in 463 Japanese SSc patients and 413 controls. RESULTS: We found that DRB1*13:02 (P = 0.0011, Pc = 0.0319, odds ratio [OR] 0.46, 95% confidence interval [CI] 0.29-0.73), DRB1*14:06 (P = 6.60X10-5, Pc = 0.0020, OR 0.05, 95%CI 0.01-0.41), DQB1*03:01 (P = 0.0009, Pc = 0.0150, OR 0.56, 95%CI 0.40-0.79), and DPB1*02:01 (P = 5.16X10-6, Pc = 8.77X10-5, OR 0.52, 95%CI 0.39-0.69) were protectively associated with SSc. In addition, these four alleles seemed to be independently associated with the protection against the susceptibility of SSc. On the other hand, we could not find predisposing alleles for overall SSc. With respect to SSc subsets, a tendency for these four alleles to be protectively associated was observed. However, there was a significant association between DRB1*01:01, DRB1*10:01, DQB1*05:01, and DPB1*04:02 and the susceptibility to SSc with ACA. On the other hand, the presence of DRB1*15:02, DQB1*06:01, DPB1*03:01, and DPB1*09:01 was associated with SSc with ATA. CONCLUSION: Thus, the present study has identified protective associations of the four HLA class II alleles with overall Japanese SSc and predisposing associations of HLA class II alleles with Japanese SSc subsets.

Association of antibodies to the NR1 subunit of N-methyl-D-aspartate receptors with neuropsychiatric systemic lupus erythematosus.

OBJECTIVE: To determine epitope reactivity of autoantibodies to N-methyl-D-aspartate (NMDA) receptor NR1 subunit and their association with neuropsychiatric systemic lupus erythematosus (NPSLE). METHODS: Paired serum and CSF specimens were obtained from 41 patients with NPSLE (22 with diffuse psychiatric/neuropsychological syndromes [diffuse NPSLE] and 19 with neurologic syndromes or polyneuropathy [focal NPSLE]), 21 patients with various rheumatic diseases other than SLE (non-SLERD). Sera were also obtained from 27 SLE patients without neuropsychiatric manifestations (non-CNS SLE). Antibodies to murine NR1 (mNR1) or to 4 different preparations of synthetic 25-amino-acid (AA) peptides of human NR1 were measured by enzyme-linked immune sorbent assay (ELISA). RESULTS: Serum anti-mNR1 levels were significantly higher in NPSLE than in non-SLERD. Sera from NPSLE patients bound efficiently to the AA residues 19-44 from the N-terminus of NR1 (NR1-A) or 56-81 (NR1-C). Accordingly, serum anti-NR1-A and anti-NR1-C were also elevated in NPSLE compared with non-SLERD. Of note, anti-NR1-A as well as anti-NR1-C levels in CSF, but not in sera, were significantly elevated in diffuse NPSLE compared with focal NPSLE or with non-SLERD. CONCLUSION: These results suggest that autoantibodies to NMDA receptor NR1, especially to the AA residues 19-44 and 56-81 from the N-terminus play a pivotal role in the pathogenesis of diffuse NPSLE.

Transverse myelitis extended to disseminated encephalitis in systemic lupus erythematosus: Histological evidence for vasculitis.

A 42-year-old woman was admitted due to systemic lupus erythematosus complicated with glomerulonephritis and pulmonary hypertension. During the treatment for these complications, she presented motor paresis and sensory loss caused by transverse myelitis. In spite of methyl prednisolone pulse therapy, she further developed acute confusional state due to disseminated encephalitis and fell into respiratory arrest. On laboratory examination, elevation of anti-NR2 antibodies in serum as well as in cerebrospinal fluid was noted. Although she recovered from the disseminated encephalitis after extensive treatment with high doses of corticosteroid and intravenous cyclophosphamide, she suddenly died of pulmonary hypertension. Autopsy findings confirmed the presence of liquefaction necrosis in the entire circumference of the whole spinal cord along with intimal hyperplasia and obliteration of the small arteries, accompanied by mononuclear cell infiltration and disruption of internal elastic lamina. It is therefore most likely that our patient developed longitudinal transverse myelitis through spinal cord vasculitis, which extended to brainstem and brain parenchyma, leading to the development of disseminated encephalitis.

Effects of anti-IL-6 receptor antibody on human monocytes.

OBJECTIVE: To explore the effects of anti-IL-6 receptor antibody, tocilizumab on function of human monocytes. METHODS: Monocytes from healthy donors were cultured in the presence of staphylococcal enterotoxin B (SEB) with pharmacologically attainable concentrations of tocilizumab or control IgG. The expression of IL-6 mRNA was determined using quantitative RT-PCR. The expression of CD80 and CD86 and the induction of apoptosis of monocytes were measured using flow cytometry. RESULTS: Tocilizumab promoted apoptosis of SEB-stimulated monocytes. The induction of apoptosis of monocytes by tocilizumab were reversed by addition of IgG, but not IgG F(ab')2 fragments. Tocilizumab significantly suppressed the expression of CD80, but not that of CD86, on SEB- stimulated monocytes. Finally, tocilizumab significantly suppressed the expression of mRNA for IL-6 of monocytes stimulated with SEB. CONCLUSIONS: These results demonstrate that one of the mechanism of action of tocilizumab involves the induction of apoptosis of monocytes, which requires interaction with Fc receptor on monocytes. Moreover, the data also indicate that tocilizumab inhibit IL-6 production of monocytes at mRNA levels.

Brain MRI in patients with diffuse psychiatric/neuropsychological syndromes in systemic lupus erythematosus.

BACKGROUND: Manifestations in neuropsychiatric systemic lupus erythematosus (NPSLE), especially active diffuse NPSLE syndromes, are some of the most difficult complications of the disease. For the evaluation and the diagnosis of central nervous system manifestations, including NPSLE, MRI is a very useful tool to detect the various abnormalities. However, the relationship between brain MRI findings and clinical variables has not yet been clarified in patients with diffuse NPSLE. OBJECTIVES: The aim of this study is to investigate the pathogenesis of diffuse NPSLE, by comparing various parameters such as serum autoantibodies and cytokines in cerebrospinal fluid (CSF) with abnormal findings revealed on brain MRIs in patients with diffuse NPSLE. METHODS: Fifty-three patients with diffuse NPSLE admitted to our University Hospital from 1992 to 2012 were exhaustively enrolled in this study. Their medical charts and brain MRI scans were reviewed. The relationship of MRI abnormalities with various parameters was analysed. RESULTS: As many as 25 of 53 patients (47.2%) had abnormal MRI findings. MRI findings improved after treatment in 10 of 17 patients for whom follow-up studies were available. MRI abnormalities were not correlated with age at the onset of diffuse NPSLE. However, the disease duration of SLE was significantly longer in patients with abnormal MRI findings (p=0.0009). MRI abnormalities were not significantly associated with serum autoantibodies. However, there were significant elevations of the CSF protein level (p=0.0106) and the CSF interleukin 6 level (p=0.0225) in patients with abnormal MRI findings. Patients with MRI abnormalities showed significantly higher overall mortality (p=0.0348). CONCLUSIONS: The results revealed that MRI abnormalities in diffuse NPSLE might be heterogeneous with regard to their reversibility. These data also indicate that patients with diffuse NPSLE and MRI abnormalities have more severe inflammation in the central nervous system related to the activity of diffuse NPSLE, as evidenced by poorer prognosis.

Association of functional polymorphisms in interferon regulatory factor 2 (IRF2) with susceptibility to systemic lupus erythematosus: a case-control association study.

Interferon regulatory factor 2 (IRF2) negatively regulates type I interferon (IFN) responses, while it plays a role in induction of Th1 differentiation. Previous linkage and association studies in European-American populations suggested genetic role of IRF2 in systemic lupus erythematosus (SLE); however, this observation has not yet been confirmed. No studies have been reported in the Asian populations. Here we investigated whether IRF2 polymorphisms contribute to susceptibility to SLE in a Japanese population. Association study of 46 IRF2 tag single nucleotide polymorphisms (SNPs) detected association of an intronic SNP, rs13146124, with SLE. When the association was analyzed in 834 Japanese patients with SLE and 817 healthy controls, rs13146124 T was significantly increased in SLE compared with healthy controls (dominant model, P = 5.4×10(-4), Bonferroni-corrected P [Pc] = 0.026, odds ratio [OR] 1.48, 95% confidence interval [CI] 1.18-1.85). To find causal SNPs, resequencing was performed by next-generation sequencing. Twelve polymorphisms in linkage disequilibrium with rs13146124 (r2: 0.30-1.00) were identified, among which significant association was observed for rs66801661 (allele model, P = 7.7×10(-4), Pc = 0.037, OR 1.53, 95%CI 1.19-1.96) and rs62339994 (dominant model, P = 9.0×10(-4), Pc = 0.043, OR 1.46, 95%CI 1.17-1.82). The haplotype carrying both of the risk alleles (rs66801661A-rs62339994A) was significantly increased in SLE (P = 9.9×10(-4)), while the haplotype constituted by both of the non-risk alleles (rs66801661G-rs62339994G) was decreased (P = 0.0020). A reporter assay was carried out to examine the effect of the IRF2 haplotypes on the transcriptional activity, and association of the IRF2 risk haplotype with higher transcriptional activity was detected in Jurkat T cells under IFNγ stimulation (Tukey's test, P = 1.2×10(-4)). In conclusion, our observations supported the association of IRF2 with susceptibility to SLE, and the risk haplotype was suggested to be associated with transcriptional activation of IRF2.

Human leukocyte antigens and systemic lupus erythematosus: a protective role for the HLA-DR6 alleles DRB1*13:02 and *14:03.

Many studies on associations between human leukocyte antigen (HLA) allele frequencies and susceptibility to systemic lupus erythematosus (SLE) have been performed. However, few protective associations with HLA-DRB1 alleles have been reported. Here, we sought protective, as well as predispositional, alleles of HLA-DRB1 in Japanese SLE patients. An association study was conducted for HLA-DRB1 in Japanese SLE patients. Relative predispositional effects were analyzed by sequential elimination of carriers of each allele with the strongest association. We also explored the association of DRB1 alleles with SLE phenotypes including the presence of autoantibody and clinical manifestations. Significantly different carrier frequencies of certain DRB1 alleles were found to be associated with SLE as follows: increased DRB1*15:01 (P = 5.48×10⁻¹°, corrected P (Pc) = 1.59×10⁻8, odds ratio [OR] 2.17, 95% confidence interval [CI] 1.69-2.79), decreased DRB1*13:02 (P = 7.17×10⁻5, Pc = 0.0020, OR 0.46, 95% CI 0.34-0.63) and decreased DRB1*14:03 (P = 0.0010, Pc = 0.0272, OR 0.34, 95% CI 0.18-0.63). Additionally, the "*15:01/*13:02 or *14:03" genotype tended to be negatively associated with SLE (P = 0.4209, OR 0.66), despite there being significant positive associations with *15:01 when present together with alleles other than *13:02 or *14:03 (P = 1.79×10⁻¹¹, OR 2.39, 95% CI 1.84-3.10). This protective effect of *13:02 and *14:03 was also confirmed in SLE patients with different clinical phenotypes. To the best of our knowledge, this is the first report of a protective association between the carrier frequencies of HLA-DRB1*13:02 and *14:03 and SLE in the Japanese population.

Association of increased frequencies of HLA-DPB1*05:01 with the presence of anti-Ro/SS-A and anti-La/SS-B antibodies in Japanese rheumatoid arthritis and systemic lupus erythematosus patients.

INTRODUCTION: Autoantibodies to ribonucleoprotein are associated with a variety of autoimmune diseases, including rheumatoid arthritis (RA). Many studies on associations between human leukocyte antigen (HLA) alleles and RA have been reported, but few have been validated in RA subpopulations with anti-La/SS-B or anti-Ro/SS-A antibodies. Here, we investigated associations of HLA class II alleles with the presence of anti-Ro/SS-A or anti-La/SS-B antibodies in RA. METHODS: An association study was conducted for HLA-DRB1, DQB1, and DPB1 in Japanese RA and systemic lupus erythematosus (SLE) patients that were positive or negative for anti-Ro/SS-A and/or anti-La/SS-B antibodies. RESULTS: An increased prevalence of certain class II alleles was associated with the presence of anti-Ro/SS-A antibodies as follows: DRB1*08:03 (Pc = 3.79×10(-5), odds ratio [OR] 3.06, 95% confidence interval [CI] 1.98-4.73), DQB1*06:01 (Pc = 0.0106, OR 1.70, 95%CI 1.26-2.31), and DPB1*05:01 (Pc = 0.0040, OR 1.55, 95%CI 1.23-1.96). On the other hand, DRB1*15:01 (Pc = 0.0470, OR 3.14, 95%CI 1.63-6.05), DQB1*06:02 (Pc = 0.0252, OR 3.14, 95%CI 1.63-6.05), and DPB1*05:01 (Pc = 0.0069, OR 2.27, 95% CI 1.44-3.57) were associated with anti-La/SS-B antibodies. The DPB1*05:01 allele was associated with anti-Ro/SS-A (Pc = 0.0408, OR 1.69, 95% CI 1.19-2.41) and anti-La/SS-B antibodies (Pc = 2.48×10(-5), OR 3.31, 95%CI 2.02-5.43) in SLE patients. CONCLUSION: HLA-DPB1*05:01 was the only allele associated with the presence of both anti-Ro/SS-A and anti-La/SS-B antibodies in Japanese RA and SLE patients.

Role of FK506 binding protein 5 (FKBP5) in osteoclast differentiation.

OBJECTIVES: We previously disclosed the enhanced expression of FK506 binding protein 5 (FKBP5) messenger RNA (mRNA) in bone marrow (BM) CD34(+) cells in rheumatoid arthritis (RA), in which systemic osteoporosis takes place. Since BM CD34(+) cells are precursors of osteoclasts, it is possible that FKBP5 overexpression might lead to osteoporosis by affecting osteoclastogenesis. We therefore explore the influences of FKBP5 in osteoclast differentiation. METHODS: Stable transfectants of RAW264.7 overexpressing murine FKBP5 gene were established. Osteoclast differentiation was induced by receptor activator of nuclear factor kappa B (NF-κB) ligand and was evaluated by tartrate-resistant acid phosphatase (TRAP) staining and pit formation assay. RESULTS: FKBP5 transfectants of RAW264.7 generated higher numbers of TRAP-positive multinucleated cells with increased activity of pit formation on calcium phosphate-coated culture slides than mock transfectants. The enhancement of osteoclast differentiation of FKBP5 transfectants was only partially inhibited by N-acetyl L-cysteine. Finally, glucocorticoid enhanced FKBP5 mRNA expression as well as osteoclast differentiation of RAW264.7 cells in a dose-dependent manner. CONCLUSIONS: These results indicate that FKBP5 promotes osteoclast differentiation by a mechanism distinct from NF-κB activation. Moreover, the data suggest that FKBP5 might play a role in bone destruction and development of osteoporosis in RA as well as in glucocorticoid-induced osteoporosis.

[An adult case of acute pericarditis and glomerulonephritis associated with human parvovirus B19 infection].

We report herein on a 52-year-old Japanese woman with acute pericarditis and glomerulonephritis associated with human parvovirus B19 infection, who had no significant medical history. The patient was admitted for progressive edema and upper abdominal pain. On physical examination, she had hypertension, generalized edema and upper abdominal tenderness. Urinalysis revealed protein (1+), and occult blood (+/-), with cellular casts. Echocardiography revealed pericardial effusion measuring 3-9mm in diameter. A serological test showed elevation of serum IgM antibodies for parvovirus B19. At the end of two weeks, generalized edema and glomerulonephritis improved spontaneously, and pericardial effusion was resolved three weeks after admission. This case would appear to be a very rare case indicating a direct relationship between human parvovirus B19 infection and acute pericarditis in a healthy adult patient.