concanavalin-a and Nephrotic-Syndrome

Glucocorticoids (GC) represent the mainstay of treatment of idiopathic nephrotic syndrome (INS) and might be involved in the pathogenesis of the disease. We evaluated basal secretion of cortisol, number and affinity of glucocorticoid receptors, dexamethasone (Dex)-mediated inhibition of concanavalin-A (Con-A)-stimulated peripheral blood mononuclear cell (PBMC) proliferation, and cytokine secretion in patients with INS.. Blood and saliva were obtained from 20 INS patients in relapse and 11 control patients. Cortisol concentrations were measured by radioimmunoassay. PBMC were isolated for binding and in vitro GC sensitivity assays. Cytokines were measured in supernatants of PBMC culture by enzyme-linked immunosorbent assay (ELISA).. Salivary cortisol concentrations were similar in INS patients and control patients. Density and affinity of GC receptors were similar in steroid-sensitive (SS) patients and control, whereas in steroid-resistant (SR) patients they were variable. Lymphocyte proliferation after Con-A stimulation was inhibited by Dex in a dose-dependent manner in control and SS patients. Control and all clinically SS patients were steroid-sensitive by in vitro test, but control patients significantly presented more suppression of PBMC proliferation compared with SS patients. Basal- and Con-A-stimulated interleukin (IL)-6, IL-10, interferon (IFN)-gamma, and tumor necrosis factor (TNF)-alpha levels were similar in control and INS patients, and all cytokines but IL-10 were significantly inhibited by Dex 10-6 mol/L. In SR patients, cytokine secretion remained elevated after treatment with high doses of Dex.. Abnormalities of number and affinity of the GC receptor and altered secretion of cytokines may be involved in tissue sensitivity to GC in INS patients.

Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Cytokines; Dexamethasone; Female; Glucocorticoids; Humans; Hydrocortisone; In Vitro Techniques; Infant; Interferon-gamma; Interleukin-10; Interleukin-6; Leukocytes, Mononuclear; Male; Nephrotic Syndrome; Prospective Studies; Receptors, Glucocorticoid; Saliva; Tumor Necrosis Factor-alpha

The characteristic function of interleukin (IL)-15 appears to be its ability to mimic the stimulatory action of IL-2 on lymphocytes by utilizing part of the IL-2 receptor complex. To gain insight into the immunoregulatory properties of this cytokine in patients with minimal-change nephrotic syndrome (MCNS), we analyzed effects of IL-15 on vascular permeability factor (VPF) release in vitro. Peripheral blood mononuclear cells (PBMC) were isolated from 16 patients with MCNS, 16 patients with IgA nephropathy (IgAN) and 16 healthy controls. Cells were stimulated with concanavalin A (Con A) and the VPF was assessed using the method of Lagrue with minor modifications. PBMC secreted significantly increased amounts of VPF under stimulation with Con A in patients with MCNS and IgAN patients with the nephrotic syndrome as compared with normal controls. Here we have demonstrated, for the first time, that addition of IL-15 to PBMC obtained from nephrotic patients as well as from normal controls increased Con A-induced release of VPF by 250%. This stimulatory effect was found highly significant and was dose-dependent. The effect of IL-15 on the secretion of VPF was specific, since a complete reversion was obtained with a neutralizing antibody to human IL-15. Our findings reveal that IL-15 has the potential to function as an immunoregulatory molecule of PBMC VPF release. In addition, IL-15 had similar effects to IL-2 in terms of its capacity to upregulate VPF release. Taken together, our data emphasize a positive regulatory role for IL-15 in inducing the release of VPF when present at optimal levels. Therefore, IL-15 antagonists may provide a basis for immune intervention in the pathophysiology of VPF.

Topics: Adult; Cells, Cultured; Concanavalin A; Endothelial Growth Factors; Female; Glomerulonephritis, IGA; Humans; Interleukin-15; Interleukin-2; Kidney; Kinetics; Lymphocyte Activation; Lymphocytes; Lymphokines; Male; Nephrotic Syndrome; Reference Values; Steroids; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

The vascular permeability factor (VPF) is a lymphokine that has been shown to play a role in minimal-change nephrotic syndrome (MCNS). A better understanding of the mechanisms that upregulate VPF release is of basic importance to control the immune system in nephrotic syndrome (NS). Interleukin (IL)-15 is a key inducer of differentiation of uncommitted T helper cells, which regulates cellular immunity. The cytokine IL-15 appears to mimic the stimulatory activity of IL-2 on T cells.. In the present report, we studied the ability of IL-15, alone or in combination with IL-12, to influence the release of VPF by peripheral blood mononuclear cells (PBMC) from nephrotic patients. We have analyzed the release of VPF by concanavalin-A- (Con A) stimulated PBMC in normals, 16 patients with MCNS and 16 patients with IgA nephropathy (IgAN).. In both patient groups 50% had a proteinuria below 0.8 g/day. We demonstrate that nephrotic, but not non-nephrotic patients (both MCNS and IgAN), exhibit a high VPF release, which can be stimulated further by IL-15 + IL-12. To determine the specificity of the stimulatory effect, neutralizing anti-IL-15 and anti-IL-12 antibodies were preincubated with IL- 15 and IL-12 prior to the addition of responder cells, respectively. The antibodies completely inhibited the effects of IL-15 and IL-12.. These results indicate that IL-15 plus IL-12 acted additively to augment VPF release. These biological interactions between IL-15 and IL-12 may be important in the pathophysiology of VPF in vitro.

Topics: Adolescent; Adult; Cells, Cultured; Concanavalin A; Drug Synergism; Endothelial Growth Factors; Female; Glucocorticoids; Humans; Interleukin-12; Interleukin-15; Leukocytes, Mononuclear; Lymphokines; Male; Nephrosis, Lipoid; Nephrotic Syndrome; Prednisolone; Protein Isoforms; Reference Values; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

We investigated serum levels of interleukin-6 (IL-6), interferon-gamma (IFN-gamma), and tumor necrosis factor alpha (TNF alpha) from patients with systemic lupus erythematosus (SLE) and its various clinical manifestations of disease and from patients with rheumatoid arthritis (RA) and other rheumatic diseases. The serum levels of IL-6 and IFN-gamma were highly elevated from patients with SLE associated with lymphadenopathy (LN) or nephrotic syndrome (NS). On the contrary, the serum levels of TNF alpha were elevated from most patients with SLE associated with thrombocytopenia (TP). However, serum levels of TNF alpha were in the normal range from patients with SLE associated with NS, LN, or central nervous system disease. Of interest, patients with SLE associated with humoral immunodeficiency disorder, hypogammaglobulinemia, had highly elevated levels of serum IL-6. The concanavalin A-stimulated mononuclear cells (MNC) of patients with SLE associated with TP secreted highly elevated levels of TNF alpha compared to other patient groups. We suggest that abnormal production of various cytokines in SLE is an intrinsic defect of MNC and the immune system that may be the key element for a variety of clinical manifestations of this disease.

Topics: Adolescent; Adult; Arthritis, Rheumatoid; Behcet Syndrome; Concanavalin A; Cytokines; Female; Humans; Interferon-gamma; Interleukin-6; Lupus Erythematosus, Systemic; Lymphadenitis; Male; Middle Aged; Nephrotic Syndrome; Polymyalgia Rheumatica; Rheumatic Diseases; Sjogren's Syndrome; Thrombocytopenia; Tumor Necrosis Factor-alpha

Idiopathic nephrotic syndrome (INS) is associated with a disorder of T-lymphocyte function, and an enhanced production of a vasoactive lymphokine, the vascular permeability factor (VPF). In an attempt to evaluate lymphocyte activation in various phases of INS, we measured beta 2-microglobulin (beta 2m) levels in lymphocyte culture supernatants (LCS). In 23 cases of untreated active INS, beta 2m levels in unstimulated LCS were significantly increased in comparison with those of 13 cases of untreated INS in complete remission (p less than 0.001), of 17 cases of active membranous nephropathy (p less than 0.01) and of 14 controls (p less than 0.001). In 13 patients treated with cyclosporine (Cs) (3-4.5 mg/kg/d) during 3 months, beta 2m levels were within the normal range. Although the beta 2m of 7 Cs patients without proteinuria was lower than 5 Cs patients with residual proteinuria, the difference was not statistically significant. In 15 prednisone(Pr)-treated INS patients, beta 2m levels were normalized. However their beta 2m levels were lower in 8 cases of complete remission than in 7 cases of persistent proteinuria (p less than 0.05). Concanavalin-A stimulation increased beta 2m amounts in all groups with a similar magnitude. In vitro addition of Cs (100 ng/ml) inhibited both beta 2m and VPF elevations observed in active INS. beta 2m level and VPF activity were significantly correlated (r = 0.54, p less than 0.01). High levels of beta 2m in LCS from INS are the consequence of an enhanced cellular synthesis and they are inhibited by Pr and Cs. Thus beta 2m increase in INS indeed reflects lymphocyte activation.

Topics: Adolescent; Adult; Aged; beta 2-Microglobulin; Cells, Cultured; Concanavalin A; Cyclosporins; Female; Humans; Lymphocyte Activation; Lymphocytes; Male; Middle Aged; Nephrotic Syndrome; Proteinuria; Time Factors

Soluble immune response suppressor (SIRS) is an immunosuppressive protein produced by human and murine suppressor cells activated by a variety of agents. Because histamine has been reported to activate suppressor cells, the possibility that it also induced SIRS production was investigated. Human lymphocytes treated with 10(-4) M histamine for less than 1 hr released a suppressive substance into culture supernatants that was physically, functionally and antigenically similar to human SIRS. Cimetidine and ranitidine, structurally distinct histamine type II (H-2) receptor antagonists, prevented histamine-induced SIRS production. In further experiments, suppression of human polyclonal IgM PFC responses by Con A and interferons, substances that activate the SIRS pathway, was inhibited by H-2 receptor antagonists. Activation of lymphocytes to produce SIRS by Con A or interferons was blocked by cimetidine or ranitidine. These data demonstrate that production of SIRS is induced by histamine, and raise the possibility that H-2 receptor binding may play a role in the SIRS pathway.

Topics: Antibody Formation; Antigens, Differentiation, T-Lymphocyte; Antigens, Surface; Cimetidine; Concanavalin A; Histamine; Humans; Immune Tolerance; Interferons; Lymphokines; Nephrotic Syndrome; Ranitidine; Receptors, Histamine H2; Suppressor Factors, Immunologic; T-Lymphocytes, Regulatory

Recent evidence suggests that transferrin has immunoregulatory functions. In the nephrotic syndrome, excessive urinary losses can produce hypotransferrinemia. Whether low serum transferrin concentration in children with the nephrotic syndrome is related to their decreased immunoglobulin concentrations and to the decreased in vitro response of lymphocytes to a mitogen was studied. Twenty patients, 2 to 15 years of age, were studied. Fifteen patients had the nephrotic syndrome and 5 had other renal disorders. Of 13 patients with nephrotic syndrome in relapse, serum transferrin and gamma-globulin concentrations were decreased in 10 and 11 patients, respectively. Transferrin levels correlated with the concentrations of total protein (r = 0.87, P less than 0.001), albumin (r = 0.91, P less than 0.001), and gamma-globulin (r = 0.78, P less than 0.001). Urinary electrophoretic analyses suggested that hypogammaglobulinemia was not explained simply by urinary losses. In order to determine whether decreased serum transferrin concentrations might limit immunoglobulin synthesis, the effect of hypotransferrinemic sera on lymphocyte proliferation in vitro was tested. At low concentrations of serum, tritiated thymidine uptake was directly proportional to the serum transferrin concentration (r = 0.86, P less than 0.001 at 0.02% serum concentration). Addition of transferrin completely restored the ability of patients' sera to support lymphocyte proliferation. These results suggest that hypotransferrinemia might influence in vivo lymphocyte function and immunity in the nephrotic syndrome.

Topics: Adolescent; Blood Proteins; Child; Child, Preschool; Concanavalin A; gamma-Globulins; Humans; Immunoglobulins; Iron; Lymphocyte Activation; Nephrosis, Lipoid; Nephrotic Syndrome; Transferrin

Topics: Adolescent; Child; Child, Preschool; Chronic Disease; Concanavalin A; Glomerulonephritis; Humans; Lymphocyte Activation; Nephrotic Syndrome; Receptors, Fc; Rosette Formation; T-Lymphocytes, Regulatory

Serum from patients with idiopathic minimal-change nephrotic syndrome (INS) inhibited concanavalin A (Con A) - induced lymphocyte proliferative response and rosette formation of lymphocytes with sheep erythrocytes (E). The inhibitory effect on Con A response was observed in not only INS serum but also in hyperlipidemic serum from some glomerulonephritis and hyperlipoproteinemia and was related to the serum lipid level. However, the inhibitory effect on E rosette formation was more specific for INS and was not related to the serum lipid level. Low density lipoprotein (LDL) from INS serum was more effective than that from normal serum in the inhibition of Con A response. On E rosette formation, only LDL from INS serum had inhibitory activity. Lipoprotein depleted serum did not inhibit either Con A response or E rosette formation. From these results, we speculated that LDL of INS serum contains some specific immunosuppressive factors different from those in normal LDL.

Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Glomerulonephritis; Humans; Immune Tolerance; Lipoproteins; Lipoproteins, LDL; Lymphocyte Activation; Nephrotic Syndrome; Rosette Formation

Suppressor cell activity (SCA) was analyzed in 8 patients with focal glomerular sclerosis (FGS) and 11 patients with chronic proliferative glomerulonephritis (CGN). We have assessed the ability of peripheral blood lymphocytes (PBL) stimulated by concanavalin A (Con A) to inhibit the proliferative response of normal allogeneic lymphocytes by both Con A and phytohemagglutinin (PHA). It was found that the FGS patients with nephrotic syndrome (NS) had significantly increased levels of suppression index when compared to the values obtained with normal controls. In contrast, the mean suppression values in the PBL from FGS patients in remission and CGN patients with or without NS, whether the mitogen used was Con A or PHA, were similar to those of the control subjects. Thus, the majority of FGS patients with NS demonstrated an alteration in Con A-induced SCA. The possible significance of these phenomena in the pathophysiology of FGS is discussed.

Topics: Adolescent; Adult; Chronic Disease; Concanavalin A; Female; Glomerulonephritis; Glomerulosclerosis, Focal Segmental; Humans; Male; Middle Aged; Nephrotic Syndrome; Phytohemagglutinins; T-Lymphocytes, Regulatory

Serum from 5 patients with idiopathic nephrotic syndrome (INS) inhibited markedly lymphocyte proliferative response with Con A and rosette formation with sheep erythrocytes (E). The inhibitory effect was not due to a cytotoxic activity of INS serum. The expression of the inhibitory activity on Con A response required the preincubation of lymphocytes with INS serum before Con A stimulation and the inhibitory effect was reversed by washing of lymphocytes exposed to INS serum. Furthermore, lymphocytes from INS patients responded normally to Con A. However, the inhibition of rosette formation with E was not reversed by washing of lymphocytes exposed to INS serum. Although the mechanism of the inhibition of immune response with INS serum was not clearly identified, it seems to be an interaction between INS serum and lymphocyte membranes which may cause the modulation of membrane structures or may influence the metabolic events of lymphocytes.

Topics: Animals; Concanavalin A; DNA Replication; Erythrocytes; Humans; Immunosuppression Therapy; Kinetics; Lymphocyte Activation; Nephrotic Syndrome; Reference Values; Rosette Formation; Sheep

Topics: Adolescent; Child; Child, Preschool; Concanavalin A; Female; Humans; Immunosuppression Therapy; Lymphocyte Activation; Male; Nephrotic Syndrome; Rosette Formation

Sera from patients with the nephrotic syndrome due to minimal change nephropathy (11 patients), membranous nephropathy (14 patients) and focal glomerulosclerosis (15 patients) inhibited the response of normal lymphocytes to the mitogen Concanavalin A. Although there was a tendency for the sera of patients with minimal change nephropathy to be more inhibitory than sera from the other two forms of nephrotic syndrome, this effect of nephrotic sera on normal lymphocytes is not confined to minimal change nephropathy. Until the exact nature of the inhibitor(s) is established, it is therefore not possible to state that impaired lymphocyte transformation by serum plays a pathogenetic role specifically in minimal change nephropathy. The susceptibility of nephrotic patients to infection may be due in part to the sera of the patients causing reduced lymphocyte function in vivo which leads to a defective immune response.

Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Concanavalin A; Glomerulosclerosis, Focal Segmental; Humans; Lymphocyte Activation; Middle Aged; Nephrosis, Lipoid; Nephrotic Syndrome

Inhibitory activity on PHA- and Con A-induced lymphocyte proliferation was observed in the serum of 29 patients with nephrotic syndrome (NS); this inhibitory activity was present both in steroid-sensitive nephrotic syndrome (SSNS; 18 patients) and in NS due to other glomerulopathies (11 patients). In order to characterize the inhibitory activity, peripheral blood lymphocytes from normal donors were stimulated with various concentrations of Con A in culture medium supplemented with: (1) 20% SSNS serum, (2) various concentrations (1, 5 and 20%) of either SSNS serum or normal human serum (NHS) and (3) 20% of a serum prepared by mixing different proportions of SSNS and NHS. The results suggest that the inhibitory activity is due to at least two different factors: (a) inhibitor(s) acting competitively with the lectin Con A, and (b) inhibitor(s) neutralized by factor(s) present in NHS. A disturbance in the normal equilibrium between inhibiting and enhancing factors which results in overall inhibition might well be a consequence of the marked alteration in serum proteins characteristic of NS.

Topics: Adolescent; Adult; Blood; Cell Division; Cells, Cultured; Child; Child, Preschool; Concanavalin A; Dose-Response Relationship, Drug; Humans; Infant; Lymphocyte Activation; Lymphocytes; Nephrotic Syndrome; Phytohemagglutinins

Topics: Adolescent; Adult; B-Lymphocytes; Child; Concanavalin A; Female; Humans; Immunity, Cellular; Kidney Diseases; Leukocyte Count; Lymphocyte Activation; Lymphocytes; Male; Middle Aged; Nephrotic Syndrome; Phytohemagglutinins; Pokeweed Mitogens; Rosette Formation; T-Lymphocytes

Topics: Concanavalin A; Hot Temperature; Humans; Hypoproteinemia; Lymphocyte Activation; Lymphocytes; Mitogens; Nephrotic Syndrome; Phytohemagglutinins; Time Factors

Stimulation of human lymphocytes with Con A resulted in the liberation of a soluble lymphokine that increased the permeability of guinea pig skin capillaries. This factor, termed vascular permeability factor (VPF), was characterized by physicochemical methods. Upon gel filtration chromatography on Sephadex G-100, it eluted in a narrow peak with an apparent molecular weight of 12,000 daltons. The sedimentation rate of VPF, estimated by sucrose density gradient ultracentrifugation, was 1.8 S. Polyacrylamide gel electrophoresis showed the biologic activity to migrate in the beta region; the factor displayed a pI of 6.4 upon isoelectric focusing. These characteristics allow VPF to be distinguished from other human lymphokines.

Topics: Capillary Permeability; Cell Separation; Concanavalin A; Humans; Lymphocyte Activation; Lymphokines; Nephrotic Syndrome; Phagocytes

P.H.A. and Concanavalin A stimulated lymphocytes culture supernatants were comparatively studied in 23 volontary normals and in 46 patients with nephrotic syndrome. Intradermal injections to guinea-pig demonstrated a permeability increasing and pro-inflammatory factor. Vascular permeability (immediate reaction) is determinated by blue Evans technique. Delayed reaction is assesed by the cutaneous inflammatory process (erythema, induration); pathologically it is defined as polymorphonuclear and mononuclear infiltration. Differences are highly significant between nephrotic patients and normal subjects. This biological activity is not observed with control supernatants (medium plus normal human serum and P.H.A. or Conca A). Positive results were also found with M.E.M. eagle culture supernatants of nephrotic stimulated lymphocytes. To date lymphokines have been studied especially in animals. In human, they have been found only after concentration. Variations in lymphokine production may be present in some pathologic states.

Topics: Animals; Capillary Permeability; Cells, Cultured; Concanavalin A; Guinea Pigs; Humans; Inflammation; Lectins; Lymphocytes; Lymphokines; Nephrotic Syndrome