The role of common protective alleles HLA-DRB1*13 among systemic autoimmune diseases.

Associations between human leukocyte antigen (HLA) and susceptibility to systemic autoimmune diseases have been reported. The predisposing alleles are variable among ethnic groups and/or diseases. On the other hand, some HLA alleles are associated with resistance to systemic autoimmune diseases, including systemic sclerosis, systemic lupus erythematosus and rheumatoid arthritis. Interestingly, DRB1*13 alleles are the protective alleles shared by multiple autoimmune diseases. DRB1*13:01 allele is protective in European populations and DRB1*13:02 in Japanese. Because alleles in multiple HLA loci are in strong linkage disequilibrium, it is difficult to determine which of the protective alleles is functionally responsible for the protective effects. Thus far, association studies suggested that DRB1*13:02 represents at least one of the causally associated protective factors against multiple systemic autoimmune diseases in the Japanese population. The protective effect of DRB1*13 alleles appears to overcome the predisposing effect of the susceptible alleles in heterozygous individuals of DRB1*13 and the susceptible allele. A gene dosage effect was observed in the associations of DRB1*13:02 with the protection from systemic autoimmune diseases; thus homozygous individuals are more effectively protected from the systemic autoimmune diseases than heterozygotes. DRB1*13:02 also confers protection against organ-specific autoimmune diseases and some infectious diseases. Several hypotheses can be proposed for the molecular mechanisms of the protection conferred by DRB1*13, some of which can explain the dominant effect of DRB1*13 molecules over the susceptible alleles, but the actual protective function of DRB1*13 requires further study. Understanding of the protective mechanisms of DRB1*13 may lead to the identification of targets for the curative treatment of systemic autoimmune diseases.

Association of IRF5 polymorphism with MPO-ANCA-positive vasculitis in a Japanese population.

Interferon regulatory factor 5 (IRF5) and signal transducer and activator of transcription 4 (STAT4) are shared susceptibility genes for various autoimmune diseases. In this study, we investigated whether these genes also contribute to susceptibility to anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) in a Japanese population. A case-control study was carried out on IRF5 rs10954213 and STAT4 rs7574865 in 232 Japanese myeloperoxidase (MPO)-ANCA-positive AAV patients, including 177 microscopic polyangiitis and 710 healthy controls. IRF5 rs10954213G was significantly increased in MPO-ANCA-positive AAV (additive model, P=0.023, odds ratio=1.27, 95% confidence interval=1.03-1.57). The risk allele was previously shown to be associated with lower mRNA level of IRF5. On the other hand, significant association of STAT4 rs7574865T with AAV was not detected. These observations suggested that IRF5 may contribute to susceptibility to MPO-ANCA-positive AAV in a Japanese population.

A novel HLA-DQB1*04 allele, DQB1*04:10, identified in a Japanese individual.

In this paper, we characterize a novel human leukocyte antigen (HLA) DQB1*04:10 allele.

Association of a single nucleotide polymorphism in the SH2D1A intronic region with systemic lupus erythematosus.

SH2D1A, also known as signaling lymphocytic activation molecule (SLAM)-associated protein (SAP), is an adaptor protein. Recently, it was reported that SAP deficient mice were protected from systemic lupus erythematosus (SLE). In this study, we postulated SH2D1A gene to be a candidate susceptibility gene for SLE and analyzed its association with SLE. A case-control association study was conducted on 5 tag single nucleotide polymorphisms (SNPs) in SH2D1A region in 506 Japanese female SLE patients and 330 healthy female controls. The luciferase assay was performed to determine the functional role of the SNP associated with SLE. One SNP in the intron 2, rs2049995, showed association with SLE (p=0.0110, odds ratio (OR) 1.97, 95% confidence interval (CI) 1.16-3.34, under the dominant model). The association of rs2049995 seemed to be stronger in the subset with the age of onset less than 20 years (p=0.0067, OR 2.65, 95% CI 1.28-5.46). Functional evaluation of rs2049995 showed that reporter gene activity was increased 1.9-fold for the susceptible allele compared with the resistant allele. An intronic SNP of SH2D1A is associated with SLE.

Identification of a novel HLA allele, HLA-DQB1*06:51, in a Japanese rheumatoid arthritis patient.

A novel HLA allele, HLA-DQB1*06:51, was identified in a Japanese rheumatoid arthritis patient.

Association of PHRF1-IRF7 region polymorphism with clinical manifestations of systemic lupus erythematosus in a Japanese population.

Interferon regulatory factor 7 (IRF7) has an essential role in the production of type I interferon. Although recent studies detected association of a single nucleotide polymorphism (SNP) rs4963128 in PHD and ring finger domains 1 (PHRF1)/KIAA1542, located closely to IRF7, and IRF7 rs1131665 (glutamine (Gln) 412 arginine (Arg)) with systemic lupus erythematosus (SLE), causal variants have not been established. In this study, we resequenced exons and introns of IRF7 to screen for all common polymorphisms, and examined whether they were associated with SLE in 416 Japanese patients with SLE and 505 healthy controls. We also tested whether the association of PHRF1 rs4963128 with SLE was replicated in a Japanese population. None of the IRF7 polymorphisms was associated with SLE. PHRF1 rs4963128T was not significantly associated with occurrence of SLE either; however, this allele was significantly increased in SLE with anti-Sm antibodies (6.8%) as compared with healthy controls (3.1%, P = 0.014, odds ratio [OR] 2.31) and SLE without anti-Sm antibodies (3.3%, P =0.041, OR 2.12). This allele was also increased in SLE with renal disorder (5.1%) as compared with those without renal disorder (2.4%, P = 0.047, OR 2.17). These results confirmed recently reported association of PHRF1 rs4963128T with anti-Sm antibody positive SLE in African-American populations, and supported the role of PHRF1-IRF7 region in the genetics of SLE.

Changes of human menisci in osteoarthritic knee joints.

OBJECTIVE: To investigate the changes of knee menisci in osteoarthritis (OA) in human. METHODS: OA and control menisci were obtained from 42 end-stage OA knees with medial involvement and 28 non-arthritic knees of age-matched donors, respectively. The change of menisci in OA was evaluated by histology, and gene expression of major matrix components and anabolic factors was analyzed in the anterior horn segments by quantitative PCR (qPCR). In those regions of menisci, the rate of collagen neo-synthesis was evaluated by [(3)H]proline incorporation, and the change of matrix was investigated by ultrastructural observation and biomechanical measurement. RESULTS: In OA menisci, the change in histology was rather moderate in the anterior horn segments. However, despite the modest change in histology, the expression of type I, II, III procollagens was dramatically increased in those regions. The expression of insulin-like growth factor 1 (IGF-1) was markedly enhanced in OA menisci, which was considered to be responsible, at least partly, for the increase in procollagen gene expression. Interestingly, in spite of marked increase in procollagen gene expression, incorporation of [(3)H]proline increased only modestly in OA menisci, and impaired collagen synthesis was suggested. This finding was consistent with the results of ultrastructural observation and biomechanical measurement, which indicated that the change of meniscal matrix was modest in the macroscopically preserved areas of OA menisci. CONCLUSION: Although the expression of major matrix components was markedly enhanced, matrix synthesis was enhanced only modestly, and the changes of matrix in human OA menisci were rather modest in the non-degenerated areas.

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors.

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

Splice acceptor site mutation of the transporter associated with antigen processing-1 gene in human bare lymphocyte syndrome.

Expression of histocompatibility leukocyte antigen (HLA) class I molecules on the cell surface depends on the heterodimer of the transporter associated with antigen processing 1 and 2 (TAP1 and TAP2), which transport peptides cleaved by proteasome to the class I molecules. Defects in the TAP2 protein have been reported in two families with HLA class I deficiency, the so-called bare lymphocyte syndrome (BLS) type I. We have, to our knowledge, identified for the first time a splice site mutation in the TAP1 gene of another BLS patient. In addition, class I heavy chains (HCs) did not form the normal complex with tapasin in the endoplasmic reticulum (ER) of the cells of our patient.

A multicenter study of leukocytapheresis in rheumatoid arthritis.

OBJECTIVE: To evaluate the efficacy and safety of leukocytapheresis (LCAP) in patients with rheumatoid arthritis (RA) that is refractory to disease modifying antirheumatic drugs (DMARDs), we conducted a prospective, multicenter, open-label clinical trial. METHODS: We enrolled 38 active RA patients, including 32 patients who showed an inadequate response to > or = 2 DMARDs and 6 patients with rapidly progressive RA. All patients continued drug therapy and were treated with 5 LCAP sessions conducted at 1-week intervals. The clinical response was evaluated at baseline before starting LCAP and at 4 weeks after the completion of all the LCAP sessions using the American College of Rheumatology (ACR) criteria and the 28-joint disease activity score (DAS28) of the European League Against Rheumatism (EULAR). RESULTS: Of the 35 patients who fulfilled the study's eligibility criteria, 24 (69%), 10 (29%), and 23 (66%) patients achieved 20% (ACR20), 50% (ACR50), and DAS28-C-reactive protein (CRP) EULAR improvement, respectively. The mean DAS28-CRP score of the 35 patients decreased significantly from 5.99 +/- 0.92 at baseline to 4.54 +/- 1.39 after treatment. Comparison analysis of the ACR20 responders and non-responders to LCAP revealed that 22 of 24 responders (92%) concomitantly received methotrexate, whereas significantly fewer, that is, 6 of 11 non-responders (55%) received methotrexate. Less frequent and transient mild-to-moderate adverse events, including nausea and headache, were seen in 12 of 189 LCAP sessions (6.3%). CONCLUSION: These results demonstrate the usefulness of LCAP in combination with DMARDs, particularly methotrexate, as an effective and safe treatment for refractory RA.

Expression and distribution of CD11a/CD18 and CD54 during human T cell-B cell interactions.

Interactions between intercellular adhesion molecule 1 (ICAM-1, CD54) and leukocyte function-associated antigen 1 (LFA-1, CD11a/CD18) play a critical role in T cell-B cell collaboration. The current experiments were carried out to determine the expression and distribution of these adhesion molecules on human peripheral T cells and B cells during T cell-B cell collaboration. Resting CD4+ T cells were largely ICAM-1 negative, whereas immobilized anti-CD3 monoclonal antibody (mAb) rapidly induced ICAM-1 expression. By contrast, most B cells expressed ICAM-1 before activation, and further increases in density were noted with stimulation. Both B cells and CD4+ T cells expressed LFA-1 before activation, although the density on CD4+ T cells was considerably greater. A double staining method for electron microscopic analysis was developed that permitted analysis of the expression and distribution of ICAM-1 to be assessed during T cell-B cell collaboration. Under the experimental conditions examined, B cells showed a uniform distribution of ICAM-1. In contrast, ICAM-1 was highly mobile on the surface of CD4+ T cells. If the T cells were not fixed, staining, even at 4 degrees C, caused rapid redistribution of ICAM-1 into aggregates. However, by fixing cells before the staining procedures, the distribution of ICAM-1 on CD4+ T cells could be accurately assessed. Most (85%) of the fixed activated CD4+ T cells showed a uniform distribution of ICAM-1. However, when activated CD4+ T cells were cocultured with B cells, redistribution of ICAM-1 on CD4+ T cells but not B cells occurred, such that the majority (85%) was found at or immediately adjacent to the point of attachment to the B cells. No redistribution of LFA-1 on either T cells or B cells was found. These findings suggest that rapid changes in density of ICAM-1 expression and the mobility of ICAM-1 on activated T cells may play a role in providing activation signals to B cells during T cell-B cell collaboration.

Tolerance of NK and LAK activity for HLA class I-deficient targets in a TAP1-deficient patient (bare lymphocyte syndrome type I).

NK cells recognize target cells that lack HLA class I molecules and lyse them, according to the 'missing self' hypothesis. It was previously reported that a TAP2-deficient patient with an HLA class I-deficiency, had a normal number of NK cells but that the lymphocytes of this patient had lost their NK activity against K562 cells. In this study, we investigated the HLA class I-recognizing NK receptor expressions and the NK and LAK activities of the lymphocytes of a TAP1-deficient patient. The patient had a normal number of NK cells. Although the lymphocytes showed LAK activity against class I expressing targets following IL-2, IL-12 and IL-15 stimulation for 3 days, neither NK nor LAK activity against targets lacking class I molecules was induced. The NK cells of the patient expressed class I-recognizing NK receptors, although the percentages of such cells were low. However, no differences were observed in the expression levels of inhibitory and activating NK receptors between lymphocytes of the patient and those of healthy controls, suggesting that the modulation of the NK receptor expression is not primarily responsible for this tolerance. These results also suggest that the lymphocytes of the patient are defective in the recognition of class I-deficient target cells in order to promote the induction of self tolerance.

Ashimycins A and B, new streptomycin analogues.

Detailed analysis of the fermentation broth of Streptomyces griseus strain FT3-4 resulted in the identification of two new streptomycin analogues named ashimycins A and B. Their structures have been determined by NMR spectral analysis and chemical degradations.

Neutrophil CD64 expression in the diagnosis of local musculoskeletal infection and the impact of antibiotics.

We examined the usefulness of neutrophil CD64 expression in detecting local musculoskeletal infection and the impact of antibiotics on its expression. Of 141 patients suspected of musculoskeletal infection, 46 were confirmed by microbiological culture to be infected and 95 had infection excluded. The median CD64 count of patients with localised infection was 2230 molecules per cell (interquartile range (IQR) 918 to 4592) and that of the patients without infection was 937 molecules per cell (IQR 648 to 1309) (p < 0.001). The level of CD64 correlated with the CRP level in patients with infection, but not in those without infection (r = 0.59, p < 0.01). Receiver operator characteristic curve analysis revealed that CD64 was a good predictor of local infection. When the patients were subdivided into two groups based on the administration of antibiotics at the time of CD64 sampling, the sensitivity for detecting infection was better in those who had not received antibiotics. These results suggest that measurement of CD64 expression is a useful marker for local musculoskeletal infection.

Methotrexate-related lymphomatoid granulomatosis: a case report of spontaneous regression of large tumours in multiple organs after cessation of methotrexate therapy in rheumatoid arthritis.

We describe a 54-year-old female patient with rheumatoid arthritis (RA) and Sjögren's syndrome (SS) who presented with right chest pain and a large mass visible in the upper right field of a chest X-ray. Computed tomography (CT) showed multiple tumours in both lungs, the liver, and the spleen. The right lung tumour was 8 cm in diameter with a cavity. Biopsy of the lung and liver revealed lymphomatoid granulomatosis (LG) and diffuse large B-cell lymphoma (DLBCL). These lesions spontaneously regressed after withdrawal of methotrexate without any therapy for the lymphoma. This is the first report of self-limiting LG in a patient, complicated with methotrexate-treated RA.

Analysis of the mechanisms of T cell-dependent polyclonal activation of human B cells. Induction of human B cell responses by fixed activated T cells.

Coculture of resting human B cells with T cells stimulated with immobilized mAb to the CD3 molecular complex induces polyclonal activation and the production of Ig of all isotypes. The current experiments were carried out to determine the nature of the signals provided to B cells by the anti-CD3-activated T cells. For these experiments, fresh T cells or T cell clones were activated with immobilized mAb to CD3 and then fixed with 1% paraformaldehyde. Upon coculture, the fixed activated T cells or T cell clones induced B cell RNA synthesis and IL-2R expression, but only minimal DNA synthesis and no Ig production. Induction of B cell RNA synthesis by fixed activated T cells was not inhibited by mAb to the alpha-chain of the IL-2R, and was not enhanced by supplementing cultures with IL-2, IL-4, IL-6, or supernatants of mitogen-activated T cells. Upon the addition of IL-2, but not IL-4 or IL-6, to cultures of B cells and fixed activated T cells, sustained proliferation was noted along with the production of Ig. Control fixed T cells or T cell clones did not induce any of these responses. The presence of cycloheximide or cyclosporin A during the activation with anti-CD3 prevented T cells from developing the capacity to provide help for B cells. The use of mAb to a variety of cell surface molecules indicated that several T cell surface molecules including CD11a/CD18, CD44, CD54, and class I MHC molecules are involved in the induction of B cell responses. Among the mAb that inhibited B cell DNA synthesis and/or Ig production, only mAb to CD11a, CD18, or CD54 inhibited initial B cell activation as assessed by RNA synthesis. Even though mAB to CD11a/CD18 inhibited the capacity of fixed activated T cells to induce B cell responses, the finding that fixed activated CD18 deficit clones provided help for B cells indicated that expression of the beta 2 family of integrins by T cells was not necessary. These results indicate that activated T cells acquire the capacity to stimulate B cells polyclonally and induce cytokine responsiveness, proliferation, and Ig production by utilization of a variety of surface molecules. Moreover, these results indicate that the initial activation of the B cell is independent of the metabolic activity of the T cell and the production of cytokines.