Detection of antilymphocyte antibody with two-color method in systemic lupus erythematosus and its heterogeneous specificities against human T-cell subsets.

The two-color method originally described by Van Rood et al. (Van Rood, J. J., A. Van Leeuwen, and J. S. Ploen. 1976. Simultaneous detection of two cell populations by two-color fluorescence and application to the recognition of B-cell determinants. Nature (Lond.). 262: 795-797) for the typing of homologous leukocytic antibodies, D-region was used for the detection of antilymphocyte antibody (ALA) in systemic lupus erythematosus. In this method, surface immunoglobulin-bearing cells were identified with fluorescein isothiocyanate-labeled anti-immunoglobulin and nuclei of killed cells were stained with ethidium bromide. Therefore, cell type (T or B) of the target cells can be identified without fractionating them. ALA was detected in 87% of lupus sera and had a preferential reactivity with T cells. Its major immunoglobulin class was shown to be immunoglobulin (Ig)M. The subspecificity of ALA was further analyzed using fractionated T-cell subsets as target cells. When T lymphocytes were separated into Fc receptor-bearing (Tgamma) and lacking (Tgamma[-]) cells, 64% of ALA showed preferential reactivity with Tgamma cells and 14% with Tgamma(-) cells. The remainder had no selective reactivity against Tgamma or Tgamma(-) cells. Tgamma cells were shown to have suppressor activity, whereas Tgamma(-) cells were indicated to contain helper cells. The above finding was in agreement with the observation that treatment of T cells with ALA that preferentially react with Tgamma cells considerably enhanced immunoglobulin synthesis in vitro, whereas treatment of T cells with ALA reactive with Tgamma(-) cells clearly suppressed the formation of immunoglobulins. Treatment of ALA with no selective reactivity showed variable effects on in vitro immunoglobulin synthesis. These results indicate that ALA in lupus have heterogeneous specificities against human T-cell subsets.

Modified spontaneous and mitogen-stimulated IgG synthesis in lymphocytes from rheumatoid synovial fluid.

Lymphocytes from rheumatoid synovial fluid (RASFL) synthesized lower levels of IgG than normal or rheumatoid peripheral blood lymphocytes (PBL) when cultured in vitro with a plant lectin, pokeweed mitogen (PWM). Conversely, RASFL produced higher levels of IgG than normal or rheumatoid PBL when the plant mitogen was omitted. B cell rich fractions from RASFL showed an enhancement in both spontaneous and PWM-induced IgG synthesis when they were combined with normal PBL T cells, suggesting that the RASFL B cells had already been partially activated in vivo. Presumably, RASFL T cells are defective in that they are not able to assist B cells effectively in the response to PWM stimulus. We also found that rheumatoid synovial fluid contains some humoral factors which render normal PBL T cells capable of helping normal PBL B cells synthesize IgG spontaneously. These findings may contribute to the inflammatory process of rheumatoid synovitis.

Cytokine regulation of hemostatic property and IL-6 production of human endothelial cells.

The effects of four inflammatory cytokines, IL-1, TNF, IFN-gamma, and IL-6, were assessed on the following functions of human vascular endothelial cells (EC) in culture: expression of procoagulant activity (PCA), endothelial cell-associated thrombomodulin (TM), and IL-6 production. Both IL-1 and TNF induced PCA, reduced TM, and induced IL-6 production in a dose-dependent manner. IFN-gamma had a weak but significant reducing effect on TM and an inducing effect on IL-6 production, while it had no effect on PCA expression. IFN-gamma, however, when added in combination with either IL-1 or TNF, modulated the effects of these cytokines; INF-gamma inhibited the PCA expression and enhanced the reduction of TM and the production of IL-6, which were induced by either IL-1 or TNF. In contrast, IL-6 had no significant effect on the EC functions studied. These results suggest that both IL-1 and TNF are the major cytokines affecting the EC functions that determine the association between the coagulation and the inflammatory response, and that IFN-gamma affects this phenomenon predominantly through the modification of the effects of these cytokines.

Inhibitor of interleukin-2 in rheumatoid synovial fluid.

Although large numbers of T cells infiltrate the synovium of patients with rheumatoid arthritis (RA), the responses of these cells, as present in the blood and synovial fluid (SF), to exogenous interleukin-2 (IL-2) and their production of IL-2 are diminished. To investigate this functional defect, RA SF were examined for the presence of inhibitors of IL-1 and IL-2. A factor was found which inhibited the IL-2-induced proliferation of mitogen-stimulated human T cells and the IL-1-induced proliferation of C3H/Hej mouse thymocytes, but not IL-1-induced fibroblast proliferation. On AcA 54 Ultrogel filtration, the inhibitory activity resided in a fraction with an apparent molecular weight of greater than 70 kd and a major pI of 6.8. The inhibitory effect of RA SF on lymphocyte proliferation was partially corrected with IL-2, but not with IL-1. In the presence of RA SF, normal lymphocytes showed not only a decreased response to exogenous IL-2, but also a decreased production of IL-2. The presence of an inhibitor of IL-2 in RA SF could contribute to the IL-2-related T cell defects observed in RA.

Bullous systemic lupus erythematosus with cutaneous mucinosis and leukocytoclastic vasculitis.

A 38-year-old man with systemic lupus erythematosus had nodular cutaneous mucinosis, leukocytoclastic vasculitis, and a vesiculobullous eruption. Immunopathologic study of a bullous lesion revealed granular deposits of IgA and IgG along the basement membrane zone. Localization of immune deposits to the lamina and sublamina densa was confirmed by immunoelectron microscopy.

T cell inhibitor secreted by macrophages and endothelial cells.

On stimulation with lipopolysaccharide (LPS), normal human macrophages (M phi) and endothelial cells (EC) produced factors which inhibited interleukin 2 (IL-2)-dependent lymphocyte proliferation and PHA plus interleukin 1 (IL-1)-dependent mouse thymocyte proliferation but not IL-1-dependent human fibroblast proliferation, suggesting that they were inhibitors of the IL-2 response. In addition, these factors inhibited the production of IL-2 by normal human peripheral blood mononuclear cells (PBMC). The factors also inhibited PBMC proliferation in response to PHA and concanavalin (Con A) but did not inhibit the proliferation of EC, U937 cells, or Epstein-Barr virus-transformed B cells. On Sephadex G200 gel filtration, the inhibitory factors from both M phi and EC were detected almost entirely in a 130- to 150-kDa fraction, but active material was also detected in a 15- to 20-kDa fraction. On isoelectric chromatofocusing of the 130- to 150-kDa fraction, inhibitory activity was associated with fractions eluted at three isoelectric points, pH 7.0, 5.4, and 4.8. The isoelectric fractions isolated from M phi and EC showed similar patterns of inhibition. When 130- to 150-kDa fractions from Sephadex G200 of the M phi and EC supernatants were treated with an antibody against a macrophage-derived suppressor factor produced by the human monocytic leukemia cell line THP-1, the activity of both fractions was neutralized. The above findings suggest that normal M phi and EC secrete an identical or closely related inhibitor of IL-2 synthesis and IL-2 response, and this inhibitor regulates these IL-2-related functions by a suppressive action on the T lymphocyte.

[Denopamine responsive pulmonary hypertension in a patient with collagen disease].

We report a 52-years-old female patient with collagen disease and pulmonary hypertension. Denopamine, beta-adrenergic agonist, decreased her high pulmonary arterial pressure and improved dyspnea on exercise after long term use. She had suffered from Raynaud's phenomenon, pulmonary fibrosis, shortening of lingual frenulum and positive ANA and RA test. Although her pulmonary fibrosis had been well controlled by azathioprine, dyspnea on exercise became worse, so she admitted to our hospital for further examination in Feb 1988. Right heart catheterization revealed her high pulmonary arterial pressure (mean 29 mmHg). Under right heart catheterization, denopamine markedly decreased her pulmonary arterial pressure and increased her cardiac output. After about 6 weeks' use of denopamine, her mean pulmonary arterial pressure decreased to 15 mmHg, PO2 increased from 43 to 62 mmHg and dyspnea improved. Denopamine has been regarded as a selective beta 1-adrenergic agonist. In this case, denopamine might have beta 2-agonist effect to dilate pulmonary vasculature, or have secondary effect to increase PO2 by the improvement of cardiac function. Denopamine might be useful for pulmonary hypertension with collagen diseases.

Inhibitor of interleukin-2 synthesis and response in rheumatoid synovial fluid.

We studied the effects of a factor present in rheumatoid arthritis (RA) synovial fluid (SF) on interleukin-2 (IL-2)-dependent cell proliferation and on the production of IL-2 by mitogen-stimulated peripheral blood mononuclear cells. RA SF suppressed the responsiveness of a mouse T cell line (HT-2) to IL-2, indicating that it contained an inhibitor of the IL-2 response. When RA SF was fractionated by Sephadex G-200 gel filtration, the inhibitory activity was detected mainly in fractions with a molecular weight of approximately 150,000, but was also found in a 15-19-kd fraction. Removal of IgG from the 150-kd fraction, by means of an anti-IgG affinity column, did not reduce the activity of the fraction, nor was activity found in the eluted IgG. The inhibitory fractions reduced mouse thymocyte proliferative responses to IL-1 in the presence of phytohemagglutinin, and reduced the production of IL-2 by human peripheral blood mononuclear cells, but did not inhibit IL-1-induced human foreskin fibroblast proliferation; this suggests that the factor was not an IL-1 inhibitor. The inhibitory activity of the RA SF factor was blocked by an antibody against an inhibitor of IL-2 that was purified from a culture of the human monocytic leukemia cell line, THP-1. This finding also supports the conclusion that RA SF contains an IL-2 inhibitory factor. The observed inhibition of both IL-2 synthesis and IL-2 response suggests that the target of the inhibition was the T lymphocyte.