Complement profile in microscopic polyangiitis and granulomatosis with polyangiitis: analysis using sera from a nationwide prospective cohort study.

OBJECTIVE: The complement cascade, especially the alternative pathway of complement, has been shown in basic research to be associated with anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis (AAV). We aimed to elucidate relationships between serum complement components and clinical characteristics in AAV. METHOD: In a nationwide prospective cohort study (RemIT-JAV-RPGN), we measured the serum levels of C1q, C2, C3, C3b/iC3b, C4, C4b, C5, C5a, C9, factor B, factor D, factor H, factor I, mannose-binding lectin, and properdin in 52 patients with microscopic polyangiitis (MPA) and 39 patients with granulomatosis with polyangiitis (GPA). RESULTS: The properdin level of MPA and GPA was significantly lower than that of healthy donors. The properdin level was negatively correlated with the Birmingham Vasculitis Activity Score (BVAS) (ρ = -0.2148, p = 0.0409). The factor D level at 6 months was significantly positively correlated with the Vasculitis Damage Index (VDI) at 6, 12, and 24 months (ρ = 0.4207, 0.4132, and 0.3115, respectively). Patients with a higher ratio of C5a to C5 had higher neutrophil percentage and serum immunoglobulin G levels, and significantly lower creatinine levels. Cluster analysis divided the MPA and GPA patients into three subgroups. A principal component (PC) analysis aggregated 15 types of complements into alternative pathway-related PC 1 and complement classical pathway and common pathway-related PC 2. CONCLUSIONS: The serum levels of properdin and factor D were correlated with the BVAS and the VDI in MPA and GPA, respectively. Our analyses suggested the pathological heterogeneity of MPA and GPA from the aspect of complement components.

Hydroxychloroquine modulates elevated expression of S100 proteins in systemic lupus erythematosus.

OBJECTIVES: We investigated the effect of hydroxychloroquine (HCQ) on S100A8 and S100A9 serum levels in systemic lupus erythematosus (SLE) patients with low disease activity receiving immunosuppressants. METHODS: SELENA-SLEDAI, Cutaneous Lupus Erythematous Disease Area and Severity Index (CLASI) and serum levels of complement factors, anti-dsDNA antibodies, and white blood cell, lymphocyte, and platelet counts were used to evaluate disease activity, cutaneous disease activity, and immunological activity, respectively. Serum S100A8 and S100A9 were measured at HCQ administration and after 3 or 6 months using ELISA. RESULTS: S100A8 and S100A9 serum levels were elevated at baseline and the magnitude of decrease from baseline at 3 and 6 months after HCQ administration was greater in patients with renal involvement than in those without (baseline: S100A8, p = 0.034; S100A9, p = 0.0084; decrease: S100A8, p = 0.049; S100A9, p = 0.023). S100 modulation was observed in patients with (n = 17; S100A8, p = 0.0011; S100A9, p = 0.0002) and without renal involvement (n = 20; S100A8, p = 0.0056; S100A9, p = 0.0012), and was more apparent in patients with improved CLASI activity scores (improved: S100A8, p = 0.013; S100A9, p = 0.0032; unimproved: S100A8, p = 0.055; S100A9, p = 0.055). No associations were observed for immunological biomarkers. CONCLUSION: HCQ may improve organ involvement in SLE by modulating S100 protein levels, especially in patients with renal or skin involvement.

A case of Evans syndrome combined with systemic lupus erythematosus successfully treated with rituximab.

Evans syndrome is a rare autoimmune disorder with unknown aetiology. Although corticosteroids and/or intravenous immunoglobulin (IVIG) are commonly used in its treatment, no standard strategy has been established. We report here a 44-year-old male with refractory Evans syndrome combined with systemic lupus erythematosus (SLE) who responded well to rituximab. He was admitted to our hospital with severe bleeding caused by worsening of Evans syndrome. Despite treatment with a high-dose corticosteroid and IVIG, his thrombocytopaenia and haemolytic anaemia did not improve. We started rituximab at a dose of 375 mg/m(2) once a week for a total of two doses. There was significant improvement in his thrombocytopaenia and anaemia 1 month after administration of rituximab. Although the total immunoglobulin G (IgG) level did not change, the titres of platelet-associated IgG (PA-IgG) and of an indirect antiglobulin test (IAT) decreased under the treatment with rituximab. It is suggested that rituximab would be a powerful candidate in the treatment of refractory Evans syndrome by depleting abnormal clone-producing autoantibody.

The multiple endocrine neoplasia type 1 gene product, menin, inhibits the human prolactin promoter activity.

Menin is a protein encoded by the gene mutated in multiple endocrine neoplasia type 1 (MEN1) characterized by multiple endocrine tumors of the parathyroid glands, pancreatic islets and the anterior pituitary, especially prolactinoma. In this study, we examined the effects of menin on human prolactin (hPRL) expression. In rat pituitary GH3 cells stably expressing menin, both PRL gene expression/secretion and thymidine incorporation into DNA were inhibited as compared with mock-transfected cells. The transcriptional activity of PRL promoter in GH3 cells co-transfected with menin was significantly decreased. A deletion mutation (569 delC), which we identified in a Japanese MEN1 family, was introduced into menin. When GH3 cells were transfected with a mutant menin expression vector, inhibition of hPRL promoter activity was partially reversed. These observations suggest that menin inhibits hPRL promoter activity and cell proliferation, raising the possibility that menin might play an important role in the tumorigenesis of prolactinoma.

Phosphatidylserine receptor cooperates with high-density lipoprotein receptor in recognition of apoptotic cells by thymic nurse cells.

The thymus contains many apoptotic cells that arise from the process of positive and negative selection. Both thymic macrophages and thymic nurse cells/nursing thymic epithelial cells (nursing TECs), non-professional phagocytes, recognize and ingest apoptotic cells without inflammation or tissue damage. Previously we reported that human scavenger receptor class B (SR-B1) is involved in recognition of apoptotic thymocytes by nursing TECs. In this study, we examined the expression and role of a phosphatidylserine receptor (PSR). This receptor is believed to participate in the clearance of apoptotic cells. PSR was strongly expressed in nursing TECs. Transforming growth factor-beta augmented the expression of PSR leading to enhanced binding of apoptotic cells to nursing TECs. In nursing TECs, suppressed expression of human SR-B1 with anti-PSR antibody decreased binding of apoptotic thymocytes to nursing TECs. Our results suggest that both PSR and SR-B1 are expressed in nursing TECs and these receptors appear to play a major role in the clearance of apoptotic cells from the thymus.

Development of a syngenic brain-tumor model resistant to chloroethyl-nitrosourea using a methylguanine DNA methyltransferase cDNA.

Chloroethyl-nitrosourea (CENU) is one of the most potent chemotherapeutic agents for brain tumors. However, acquired resistance to this drug has become a serious problem in the treatment of brain tumor patients. The main mechanism of the resistance is a recruitment of the O6-methylguanine-DNA- methyltransferase (MGMT) in tumor cells. Many approaches, including treatment with enzyme-depletions, antibodies, antisenses, and a ribozyme, have been reported to successfully overcome the resistance. In order to evaluate these approaches properly, we designed a syngenic rat brain-tumor model resistant to CENU. The 9L rat gliosarcoma cells were retrovirally transduced with MGMT cDNA and stereotactically implanted into the brain parenchyma. In this model, rats inoculated with resistant cells died significantly earlier than did rats with control cells after treatment with CENU. Because of the limited intracranial space, the animals presented a restricted survival. Since the survival was sensitive and reproducible, this system may have a role in the evaluation of approaches to drug-resistant brain-tumors.

Emergence of acute interstitial pneumonia following high dose interferon delta treatment in a case of chronic myelogenous leukemia.

Here we report a 58-year-old man with chronic myelogenous leukemia in the chronic phase, who developed acute respiratory failure following administration of high dose natural interferon delta (6,300 x 10(4) units/week). Radiological and histological findings were consistent with acute interstitial pneumonia (AIP). Although the pathogenesis remains unclear, it is important to watch for the possible development of AIP when employing interferon delta therapy, especially at high doses.

[Multiple myeloma associated with phenytoin (diphenylhydantoin) therapy].

The occurrence of multiple myeloma is described in a patient receiving phenytoin (diphenylhydantoin) for 43 years. In this article, five cases of multiple myeloma and one of immunoblastic lymphadenopathy associated with diclonal gammopathy diagnosed after longterm phenytoin therapy are reviewed. These cases are characterized by lymphadenopathy, hepatosplenomegaly, and no or equivocal bone lesions, which are quite unusual in multiple myeloma. Because of the association of lymphomas with phenytoin, the role of the drug in the etiology of multiple myeloma or plasma cell dyscrasias is still in controversy, but highly suspected. It is suggested that a periodic examination of patients receiving phenytoin may be useful in an early detection of M-component. The possibility of reversing multiple myeloma by removal of phenytoin early in the course of the disease should be investigated.

[Clonal deletion and clonal anergy as the mechanism of self-tolerance induction].

In the immune system, it is most important to discriminate self from nonself and to acquire and maintain the unresponsiveness to self antigens, self-tolerance. Recently, the transgenic animals provides the evidence of the mechanism of self-tolerance induction. Self-tolerance is established mainly by elimination, clonal deletion, and functional inactivation, clonal energy, of the autoreactive T cells and B cells. Clonal deletion and clonal anergy are involved not only in the central tolerance, in thymus or bone marrow, but also in the peripheral tolerance. The failure of self-tolerance involves the induction of auto-immune disease.

[An imbalance between Th1 and Th2-like cytokines in patients with autoimmune diseases--differential diagnosis between Th1 dominant autoimmune diseases and Th2 dominant autoimmune diseases].

An imbalance between T helper cell (Th)1 and Th2-like cytokines has been described in several autoimmune diseases. Organ specific autoimmune diseases such as multiple sclerosis (MS) and inflammatory bowel diseases (IBD) are caused by Th1 dominant immune responses. On the contrary, systemic autoimmune diseases such as systemic lupus erythematosus (SLE) and Sjögren's syndrome(SS) are characterized by Th2 dominant imbalance of cytokine production. It might be useful for differential diagnosis among patients with various autoimmune diseases such as SLE, SS, IBD, and MS to measure the serum levels of cytokines such as IL-10, IFN gamma, and TNF alpha using ultrasensitive enzyme-linked immunosorbent assay system.

Transient erythrophagocytosis in Diamond-Blackfan anemia.

We report on a 4-month-old Japanese infant girl with Diamond-Blackfan anemia (DBA) as shown by congenital macrocytic pure red cell hypoplasia with marked reduction of erythroid precursors in bone marrow, reticulocytopenia, increased fetal hemoglobin, and elevated adenosine deaminase activity in peripheral blood. She responded poorly to conventional doses of corticosteroids, however, with high-dose corticosteroids she responded with reticulocytosis and an elevation of hemoglobin level above 12 g/dL. Erythrophagocytosis was noted during the tapering period of prednisone when her hemoglobin level declined to 7.6 g/dL and reticulocyte level to 0.4%. At that time, the erythrophagocytosis was noted in about 60% of marrow histiocytes. These findings were not observed prior to or during the high dose prednisone therapy. We speculate that one of the causes of pure red cell aplasia and reticulocytopenia in DBA is mediated by erythrophagocytosis.

The liver as a crucial organ in the first line of host defense: the roles of Kupffer cells, natural killer (NK) cells and NK1.1 Ag+ T cells in T helper 1 immune responses.

The liver remains a hematopoietic organ after birth and can produce all leukocyte lineages from resident hematopoietic stem cells. Hepatocytes produce acute phase proteins and complement in bacterial infections. Liver Kupffer cells are activated by various bacterial stimuli, including bacterial lipopolysaccharide (LPS) and bacterial superantigens, and produce interleukin (IL)-12. IL-12 and other monokines (IL- 18 etc.) produced by Kupffer cells activate liver natural killer (NK) cells and NK1.1 Ag+ T cells to produce interferon-gamma and thereby acquire cytotoxicity against tumors and microbe-infected cells. These liver leukocytes and the T helper 1 immune responses induced by them thus play a crucial role in the first line of defense against bacterial infections and hematogenous tumor metastases. However, if this defense system is inadequately activated, shock associated with multiple organ failure takes place. Activated liver NK1.1 Ag+ T cells and NK cells also cause hepatocyte injury. NK1.1 Ag+ T cells and another T-cell subset with an intermediate T-cell receptor, CD 122+CD8+ T cells, can develop independently of thymic epithelial cells. Liver NK cells and NK1.1 Ag+ T cells physiologically develop in situ from their precursors, presumably due to bacterial antigens brought from the intestine via the portal vein. NK cells activated by bacterial superantigens or LPS are also probably involved in the vascular endothelial injury in Kawasaki disease.

Thrombocytopenia with absent radii syndrome: studies on serum thrombopoietin levels and megakaryopoiesis in vitro.

PURPOSE: The pathogenesis of thrombocytopenia in patients with thrombocytopenia with absent radii (TAR) syndrome has not been clarified yet. PATIENTS AND METHODS: This is the first report of a Japanese patient with TAR syndrome. We studied his megakaryopoiesis in vitro and serum levels of thrombopoietin (TPO). RESULTS: Serum levels of TPO in the patient with TAR syndrome were comparable with those of an age-matched control. The bone marrow cells from the patient with TAR syndrome actually generated megakaryocyte colonies in the presence of TPO and the numbers were significantly greater than those from the age-matched control marrow. However, megakaryocyte colonies from the marrow cells with TAR syndrome contained a much lower number of cells per colony and the size of the individual megakaryocytes appeared to be smaller. CONCLUSION: These data suggest that megakaryocyte progenitors from patients with TAR syndrome may have decreased proliferative and differentiative capacity to respond to TPO, leading to thrombocytopenia.

Combined use of cyclosporine A and methotrexate in refractory polymyositis.

Polymyositis is an inflammatory muscle disease with unknown cause that is characterized by progressive weakness of the proximal muscles. Limited information is available concerning the effectiveness of the combination therapy with cyclosporine A and methotrexate in reducing myositis activity. We describe here a female patient with polymyositis who showed resistance to pulse corticosteroid therapy. Neither the combination of azathioprine (100 mg/day) nor methotrexate (10 mg/week) with corticosteroids decreased the value of creatine phosphokinase. Normalization of the creatine phosphokinase level as well as improvement of muscle strength was obtained only when low-dose cyclosporine A (3 mg/kg/day) was combined with methotrexate.

Activation of mouse liver natural killer cells and NK1.1(+) T cells by bacterial superantigen-primed Kupffer cells.

Although bacterial superantigens have been well characterized as potent stimulators of T cells, their role in natural killer (NK)-type cells remains largely unknown. In the present study, we examined the effect of bacterial superantigens on mouse liver NK cells and NK1.1 Ag(+) (NK1(+)) T cells. C57BL/6 mice were intravenously injected with staphylococcal enterotoxin B (SEB) or streptococcal pyrogenic exotoxin A (SPE-A), and mononuclear cells (MNC) of various organs were obtained from mice 4 hours after being injected with superantigen. MNC were cultured for 48 hours, and interferon gamma (IFN-gamma) levels of supernatants were measured. The antitumor cytotoxicities of the liver and spleen MNC were also evaluated 24 hours after the mice were injected with superantigen. Liver MNC produced more IFN-gamma than did splenocytes, and peripheral blood and lung MNC did not produce any detectable IFN-gamma. In addition, liver MNC acquired a potent antitumor cytotoxicity by the SEB injection, and both NK cells and NK1(+)T cells but not cluster of differentiation (CD)8(+) T cells were responsible for the cytotoxicity as demonstrated by either in vivo or in vitro cell depletion experiments, and the NK-type cells were partly responsible for the increased serum IFN-gamma. Activation of liver NK-type cells was also supported by the fact that liver NK cells proportionally increased and NK1(+) T cells augmented their CD11a expressions after SEB injection. The pretreatment of mice with anti-IFN-gamma Ab and/or with anti-interleukin-12 (IL-12) Ab diminished the SEB-induced cytotoxicity of liver MNC. Furthermore, the in vivo depletion of Kupffer cells decreased the SEB-induced cytotoxicity of liver MNC. Consistent with these results, liver MNC stimulated with superantigens in the presence of Kupffer cells in vitro produced a greater amount of IFN-gamma than did the liver MNC without Kupffer cells or splenocytes. Our results suggest that bacterial superantigen-primed Kupffer cells produce IL-12 and other monokines, while also nonspecifically activating both NK cells and NK1(+) T cells to produce IFN-gamma.

[Asymptomatic pneumatosis cystoides intestinalis in a patient with systemic lupus erythematosus].

Pneumatosis cystoides intestinalis (PCI) is a rare condition characterized by the presence of gas-filled cysts in the submucosa or subserosa of gastrointestinal tract. PCI has been widely recognized as a late manifestation of systemic sclerosis but seldom reported to take place in patients with systemic lupus erythematosus (SLE). We reported here a 13-year-old female who had been diagnosed to have SLE based on the following findings; malar rash, discoid erythema, proteinuria, positive antinuclear antibody and anti-DNA antibody. She had been treated with various immunosuppressive drugs including pulse use of corticosteroid, cyclophosphamide and cyclosporin A. She was referred to our hospital because of proteinuria and numbness on her right fifth toe, refractory to above treatment. On admission, the activity of her disease was already low and she had no abdominal symptoms. Plain X-ray film showed multiple round translucencies along the wall of the ascending and transverse colon. Colonoscopy revealed multiple firm-walled cysts distributing in the terminal ileum as well. A diagnosis of PCI was made and she was successfully treated with oral antibiotics and laxatives. The association of PCI with SLE is reviewed briefly.

Inhibition of IL-12 synthesis of peripheral blood mononuclear cells (PBMC) stimulated with a bacterial superantigen by pooled human immunoglobulin: implications for its effect on Kawasaki disease (KD).

The aim of this study was to further assess the role of pooled human immunoglobulin (PHIG) on cytokine production from PBMC stimulated with a bacterial superantigen. Human PBMC were cultured with Streptococcus pyrogenic exotoxin A (SPE-A) with or without PHIG and several proinflammatory cytokine levels of culture supernatants were measured. Serum cytokine levels of KD patients before and after PHIG therapy were also examined. PHIG greatly reduced the production of IL-12, interferon-gamma (IFN-gamma) and other cytokines from SPE-A-stimulated PBMC, while exogenous IL-12, but neither IL-1 nor tumour necrosis factor-alpha (TNF-alpha), restored IFN-gamma production inhibited by PHIG. Although PHIG partially adsorbed SPE-A, its inhibitory effect on cytokine production was not played by anti-SPE-A antibody. Although purified CD4+ T cells cultured with human HLA-DR-transfected mouse L cells and SPE-A could not effectively produce IFN-gamma, they produced large amounts of IFN-gamma if exogenous IL-12 was introduced. KD patients in the acute phase had higher levels of serum IFN-gamma than did controls and patients with bacterial infection. Although IL-12 levels of children with or without KD were not significantly different, IL-12 levels of children were much higher than those of adults. However, serum levels of IL-12 of KD patients were transiently but significantly decreased by PHIG therapy and IFN-gamma amounts subsequently reverted to basal levels thereafter. These findings indicate that PHIG inhibits IL-12 production of SPE-A-activated monocytes and thereby decreases IFN-gamma synthesis by T cells and suggest that inhibition of IL-12 and IFN-gamma production is an important part of the mechanisms underlying PHIG therapy on KD.