Yasuyuki Tomita

Elevation of Serum Soluble Tumour Necrosis Factor Receptors in Patients with Polymyositis and Dermatomyositis

Abstract: The aim of the study was, to examine the relationship between serum levels of soluble tumour necrosis factor receptors (sTNF-R) and the gene expression of two types of receptor for TNF (TNF-R), a 55 kDa receptor (TNF-R1) and a 75 kDa receptor (TNF-R2), in peripheral blood mononuclear cells (PBMC) from patients with polymyositis and dermatomyositis (PM/DM). Soluble tumour necrosis factor receptor 1 (sTNF-R1) and soluble tumour necrosis factor receptor 2 (sTNF-R2) levels in sera from patients were measured by enzyme-linked immunosorbent assay. Expression of TNF-R1 and TNF-R2 mRNAs in PBMC was analysed by Northern blotting. Serum sTNF-R1 and sTNF-R2 levels were elevated significantly in 25 patients with active-stage PM/DM, compared to those in 18 patients with inactive-stage PM/DM and 32 normal controls. Serum concentrations of sTNF-R1 and sTNF-R2 were correlated with PM/DM disease activity. TNF-R1 gene expression was enhanced in freshly isolated PBMC from patients with active-stage PM/DM. In contrast, TNF-R2 mRNA was expressed constitutively in patients with active-stage PM/DM and in normal controls. The expression of TNF-R1 and TNF-R2 mRNAs in PBMC and elevation of their soluble forms in the sera of patients with active-stage PM/DM suggest increased proteolytic cleavage of cell surface TNF-R from PBMC in patients with active-stage PM/DM, and that sTNF-R may regulate TNF-α-mediated muscle fibre damage in PM/DM.

Elevated levels of soluble ICAM-1 in sera from patients with bronchial asthma

We measured the levels of soluble intercellular adhesion molecule‐1 (sICAM‐1) in sera from patients with bronchial asthma. sICAM‐1 levels in sera from atopic asthmatic patients in stable conditions were higher than in normal control subjects. Furthermore, the sICAM‐1 levels in sera obtained during bronchial asthma attacks were higher than those in sera obtained in stable conditions. These results suggest that higher levels of sICAM‐1 in sera reflect the upregulation of ICAM‐1 expression in allergic inflammation.

Impaired tumour necrosis factor‐α (TNF‐α) production and abnormal B cell response to TNF‐α in patients with systemic lupus erythematosus (SLE)

We examined the TNF‐α activity in culture supernatants of monocytes isolated from the peripheral blood of patients with SLE and of normal individuals. The monocytes from patients with SLE stimulated with silica particles, lipopolysaccharide or Staphylococcus aureus Cowan I secreted significantly lower amounts of TNF‐α than did normal monocytes. A decreased TNF mRNA expression was observed in peripheral blood mononuclear cells stimulated by mitogens from patients with SLE. Furthermore, we examined the effect of recombinant TNF‐α (rTNF‐α) on the B cell function in SLE patients. rTNF‐α inhibited the spontaneous Bcell proliferation of SLE, but tended to enhance the normal Bcell proliferation. Spontaneous IgM production from SLE Bcells was inhibited by rTNF‐α, but that from normal B cells was not. Spontaneous IgG production was unaffected by rTNF‐α. Also, rTNF‐α did not affect the viability of B cells. These findings suggest that an impaired TNF‐α production and an abnormal B cell response to TNF‐α play a role in the immunological dysfunction in patients with SLE.

Interaction of the cell-binding domain of fibronectin with VLA-5 integrin induces monokine production in cultured human monocytes

The effect of fibronectin on IL‐1α, IL‐1β, tumour necrosis factor‐alpha (TNF‐α), and IL‐6 production was investigated with cultured monocytes isolated from human peripheral blood. Monokine concentrations were determined by both ELISA and bioassay. Fibronectin markedly stimulated the secretion of IL‐1α, IL‐1β, TNF‐α and IL‐6 from cultured monocytes in a dose‐dependent manner, with the maximal effect apparent within 24 h. Northern blot analysis revealed a marked increase in the abundance of mRNA specific for each monokine on exposure of monocytes to fibronectin. Monoclonal antibodies to the α chain of very late antigen (VLA)‐5, the β1 integrin, the α chain of Mac‐1, and the β2 integrin, as well as the synthetic peptide of GRGDSP (which corresponds to the cell‐binding domain of fibronectin), inhibited (>50%) fibronectin‐induced monokine production. Monoclonal antibodies to the α chain of VLA‐4, and the α chain of LFA‐1, as well as the synthetic peptide CS‐1 (which corresponds to the alternatively spliced connecting segment of fibronectin) and the control peptide GRADSP, had no inhibitory effect on monokine production. A MoAb, R60, that recognizes an epitope of the fibronectin molecule that includes the RGD sequence, inhibited monokine production, whereas the MoAb Y16, which recognizes another epitope of fibronectin not including RGD, did not. These results indicate that fibronectin‐induced production of IL‐1α, IL‐1β, TNF‐α and IL‐6 from cultured monocytes is mediated predominantly by interaction of the cell‐binding domain of fibronectin with VLA‐5, although Mac‐1 also may contribute to this effect of fibronectin. Our results indicate that the interaction of fibronectin with integrins may contribute to the cytokine network in inflammatory response.

Mechanism of calcium ionophore and phorbol ester-induced T-cell activation : accessory cell requirement for T-cell activation

We examined (he role of monocytes in T‐cell activation induced by phorbol myristate acetate (PMA) and calcium ionophore ionomycin. Depletion of monocytes from peripheral blood mononuclear cells (PBMC) was associated with the loss of inlerleukin‐2 (IL‐2) production, IL‐2 receptor (1L‐2 RI expression and proliferation, in response to cither PMA or ionomycin. Addition of monocytes to highly purified T cells resulted in the complete R‐constitution of IL‐2 production. 1L‐2R expression and proliferation by PMA‐stimulated lymphocytes. Exogenous IL‐2, but not interleukin‐l (IL‐l), could reconstitute the T‐cell responsiveness. Addition of monocytes to highly purified T cells stimulated with ionomycin resulted in partial reconstitution of IL‐2 production. II,‐2R expression and proliferation. Similarly, (he addition of exogenous lL‐2 to ionomycin‐stimulated T cells only partially reconstituted the response compared with PBMC, These results suggest that monocyte‐T‐cell interactions contribute to IL‐2 production and IL‐2R expression and are crucial events for PMA‐induced T‐cell proliferation. With ionomycin, monocytes play a role, in part, in inducing IL‐2 production, IL‐2R expression and proliferation. However, IL‐2 is not a sufficient signal to induce T‐cell proliferative response lo ionomycin, suggesting that an IL‐2‐independent mechanism may exist in ionomycin‐induced T‐cell proliferation.

Antithymocyte Globulin for a Patient with Systemic Lupus Erythematosus Complicated by Severe Pancytopenia

The clinical use of antithymocyte globulin is rarely reported in patients with rheumatic diseases. We describe the use of this agent in a patient with systemic lupus erythematosus who concomitantly developed severe pancytopenia. High-dose methylprednisolone therapy had been unsuccessful in controlling either the disease exacerbation or the pancytopenia. Antithymocyte globulin and cyclosporin A were therefore administered to achieve immunosuppression. The exacerbation of disease activity was gradually lessened, except for persistent thrombocytopenia and anaemia. Severe and persistent immunosuppression, however, led to a fatal brain abscess. The combined use of both antithymocyte globulin and cyclosporin A induced potent immunosuppression, and should be confined to selected patients with systemic lupus erythematosus, and administered under detailed monitoring.

Cultured human monocytes secrete fibronectin in response to activation by proinflammatory cytokines.

We studied the effects of the cytokines IL‐1α, IL‐6, tumour necrosis factor‐alpha (TNF‐α), IL‐4, IL‐10, IL‐13 and transforming growth factor‐beta (TGF‐β) on fibronectin (FN) production by cultured‐human monocytes. IL‐1α, IL‐6 and TNF‐α all increased FN production, an indicator of monocyte activation. These cytokines increased FN production in a dose‐dependent fashion, with a 4‐h treatment being sufficient to measure FN production by radioimmunoassay. Conversely, IL‐4, IL‐10 and IL‐13 strongly inhibited cytokine‐induced FN production, while TGF‐β only partially inhibited FN production. The combination of suboptimal doses of cytokines (IL‐1α+ IL‐6, IL‐1α+ TNF‐α, IL‐6 + TNF‐α), which could not singly induce substantial amounts of FN, were able to induce FN production by cultured monocytes. Northern blot analysis with a cDNA specific for FN confirmed the expression of FN mRNA in cultured monocytes stimulated with a single cytokine or a combination of cytokines. Our data demonstrate that monocytes may not always require high concentrations of cytokines for activation in vitro, and that the synergistic or additive action of low levels of cytokines on monocyte activation may be sufficient to promote immune or inflammatory reactions. Our data also suggest that certain T cell cytokines may regulate monocyte activation.

Efficacy of Lansoprazole against Peptic Ulcers Induced by Nonsteroidal Anti-Inflammatory Drugs: Endoscopic Evaluation of Ulcer Healing

Beyond the obvious step of limiting use of non-steroidal anti-inflammatory drugs (NSAIDs), the treatment of ulcers induced by NSAIDs remains controversial. We evaluated the efficacy of the proton-pump inhibitor lansoprazole on NSAID-induced ulcers. Ulcers were endoscopically diagnosed in 47 NSAID users. These patients received 30 mg/day lansoprazole, orally, for 6 or 8 weeks (6 weeks for duodenal ulcers and 8 weeks for other ulcers). Ulcer healing was assessed using an established classification system. The presence of immunoglobulin G antibody against Helicobacter pylori was also evaluated. The antibody was present in the sera of 51% of patients (24/47). Most of the ulcers reached scarring stages S1 (healing) or S2 (good healing), and the S2 healing rate was 35%. Two H. pylori seropositive patients did not reach these stages; their ulcers were improved by H. pylori eradication therapy, followed, in one case, by medication with misoprostol. Lansoprazole seemed to be useful for most patients with NSAID-induced ulcers, but a few needed additional treatments.

Successful methotrexate therapy for adult Still's disease with Marked thrombocytopenia

A 34-year-old Japanese woman developed spiking fever, splenomegaly, arthritis, neutrophilia, hyperferritinaemia (22517 ng/ml), elevated C-reactive protein (9.1 mg/ml) and severe thrombocytopenia (1.7×104/μl). The patient had depressed antithrombin III activity and abnormally high concentrations of both fibrin degradation products and thrombin-antithrombin complexes. This condition was resistant to high-dose prednisolone therapy (120 mg/day) and non-steroidal anti-inflammatory drugs. We initiated oral methotrexate therapy (7.5 mg/week, orally) with a favourable outcome. The patients spiking fever subsided on the first day of methotrexate administration. Elevated levels of ferritin and C-reactive protein in the sera rapidly normalised. Methotrexate rapidly improved the disease state which suggested that methotrexate act via modulation of cytokine production or secretion.

TNF-alpha regulates GM-CSF-, IL-3- or M-CSF-induced Fc epsilon RII/CD23 gene expression and soluble Fc epsilon RII release by human monocytes.

The authors examined the regulatory effects of tumour necrosis factor‐α (TNF‐α) on granulocyte macrophage colony stimulating factor (GM‐CSF)‐, interleukin‐3 (IL‐3)‐ or macrophage colony stimulating factor (M‐CSF)‐induced gene expression of the low affinity receptor for IgE (Fc ε RII) on human monocytes and GM‐CSF‐, IL‐3‐ or M‐CSF‐induced soluble Fc ε RII (sFc ε RII) release from monocytes. The expression of GM‐CSF‐, IL‐3‐ or M‐CSF‐induced Fc ε RII on the surface of monocytes was reduced by TNF‐α. The present analysis was designed to examine whether or not TNF‐α could suppress GM‐CSF‐, IL‐3‐ or M‐CSF‐induced Fc ε RII messenger RNA (mRNA) expression and enhance the release of sFc ε RII induced by these cytokines. The addition of TNF‐α to monocyte cultures with GM‐CSF, IL‐3 or M‐CSF significantly reduced Fc ε RII expression on the surface of monocytes and significantly increased sFc ε RII release from monocytes. These results suggest that TNF‐α‐dependent reduction of GM‐CSF‐, IL‐3‐ or M‐CSF‐induced Fc ε RII expression on the surface of monocytes resulted, at least in part, from the suppression of Fc ε RII mRNA and the enhancement of sFc ε RII release.