In vitro production of interleukin-1 receptor antagonist in chronic renal failure, CAPD and HD.

Dialysis-related symptoms are believed to be mediated, at least in part, by monocyte/macrophage-derived pro-inflammatory cytokines including interleukin-1 (IL-1) and tumor necrosis factor (TNF). Measuring the production of interleukin-1 receptor antagonist (IL-Ra), a naturally occurring inhibitor of IL-1, opens avenues to study the balance between these two cytokines in patients. We studied the cell content and production of IL-1 beta and IL-Ra by unstimulated and endotoxin- or IgG-stimulated peripheral blood mononuclear cells (PBMC) in undialyzed patients with chronic renal failure (CRF), patients on continuous ambulatory peritoneal dialysis (CAPD) and patients on chronic hemodialysis with reuse cuprophan membranes (HD), and compared them to healthy controls. IL-1 beta and IL-Ra were measured by specific radioimmunoassay. IL-1 beta was undetectable in freshly harvested PBMC from healthy controls, CRF, CAPD or HD. In contrast, the content of IL-Ra in HD patients (2828 +/- 466 pg/ml) was significantly higher than that in healthy controls (643 +/- 53 pg/ml, P < 0.01), CRF (1097 +/- 320 pg/ml, P < 0.01) or CAPD (1398 +/- 390 pg/ml, P < 0.05). In endotoxin-stimulated PBMC, IL-1 beta production by HD patients (9375 +/- 1687 pg/ml) was not significantly different from healthy controls (8429 +/- 1621 pg/ml). However, endotoxin-stimulated IL-Ra production by HD patients (32,350 +/- 8276 pg/ml) was greater than that from healthy controls (11,284 +/- 1250 pg/ml, P < 0.001), CRF (12,263 +/- 2680 pg/ml, P < 0.01) or CAPD patients (11,822 +/- 1797 pg/ml, P < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)     

Production and kinetics of interleukin-1 in hemodialysis. In vivo and in vitro study

Interleukin-1-beta (IL-1-beta) was measured in the plasma and peripheral blood mononuclear cell lysates of uremic patients undergoing maintenance hemodialysis by means of either cuprophane or polysulfone membranes. Basal plasma levels of IL-1-beta in hemodialyzed patients were strikingly higher than those of uremic patients on conservative treatment or of healthy subjects. Plasma levels of IL-1-beta in uremic patients increased significantly after 3 and 6 months of hemodialysis. The study of the kinetics of IL-1-beta concentration during a single hemodialysis session revealed that the concentration of IL-1-beta fell to 21 and 22% of the predialysis level with cuprophane and polysulfone, respectively. Hemodialysis patients also had a significantly higher intracellular IL-1-beta level than normal controls. During the hemodialysis session, an increase in cell-associated IL-1-beta was seen regardless of the membrane employed. In a parallel study, normal mononuclear cells were subjected to closed-loop in vitro dialysis with either cuprophane or polysulfone membranes, with or without acetate buffer. After 120 min of recirculation, an increase in cell-associated IL-1-beta was detected, but no changes were seen in the circulating medium. IL-1-beta production was not significantly influenced by either membrane or the dialysate composition. Hemodialysis has been associated with high plasma- and cell-associated IL-1 levels. The kinetics of intradialytic changes of IL-1-beta levels make IL-1 an unlikely cause of acute complications in hemodialysis. On the other hand, a chronic elevation of IL-1 in plasma of patients on maintenance hemodialysis may contribute to the development of some of the long-term complications of this treatment.     

In vitro studies on the human renal calices.

Smooth muscle preparations taken from the minor calices of human kidneys were investigated by an isolated tissue technique. The existence of alpha-adrenoceptor and muscarinic receptor sites were demonstrated and it was shown that stimulation with the appropriate agonist resulted in an excitatory response. No evidence could be found to support the presence of beta-adrenoceptors in such tissues. The results of transmural electrical stimulation of similar preparations were highly suggestive of an effective innervation of the alpha-adrenoceptors.     

In vitro immunoglobulin production in long-term renal transplant recipients

The difference in immunoregulation between stable renal transplant recipients and patients undergoing chronic rejection is unknown. In stable transplant recipients humoral responses to the allograft are controlled, but in patients with chronic rejection this control appears to be lost. In this study we evaluate B cell function in 24 stable transplant recipients and 5 patients with chronic rejection, using pokeweed mitogen (PWM)-stimulated in vitro lymphocyte production of immunoglobulin (Ig). Stable patients and patients with chronic rejection were similar with respect to time posttransplant, age, degree of HLA-A and B matching and immunosuppressive therapy. Unstimulated immunoglobulin production and serum immunoglobulin levels were similar in both groups and within the normal range. PWM stimulated IgG, and IgM production was significantly depressed in stable patients compared with normal controls and patients with chronic rejection. Patients with chronic rejection had normal PWM-stimulated Ig production. Mononuclear cell subsets--as determined by the monoclonal antibodies T4, T8, T11, B1, and M02, as well as the ratio of T4 to T8--were similar in the two patient groups and within the normal range. There was no correlation between decreased Ig production and decreased T4/T8 ratio. We conclude that stable renal transplant recipients have impaired in vitro humoral responses that may be important in maintaining allograft tolerance. In patients with chronic rejection PWM-stimulated responses have escaped control, and this may be important in the pathogenesis of antibody-mediated graft damage. Impaired Ig production in stable patients may be due to a suppressor cell mechanism--however, quantitative measurements of suppressor cells and the T4/T8 ratio do not predict humoral unresponsiveness.     

In vivo description of dendritic cells in human renal cell carcinoma.

PURPOSE: Dendritic cells (DCs) are efficient and effective antigen-presenting cells that play a major role in initiating the primary immune response. They are the most potent stimulators of T-cell activation and would thus be expected to be of great importance in the antitumoral immune response. Although DC phenotype and function have been described under in vitro conditions, their in vivo characteristics are less well detailed. Human renal cell carcinoma (RCC) is an excellent model to explore tumor infiltrating dendritic cells (TiDCs) because of rare clinical spontaneous regressions and the association of high numbers of tumor infiltrating lymphocytes (TiLs), suggesting a strong immune response. MATERIALS AND METHODS: We determined the in situ phenotype of mature CD83+ TiDCs using monoclonal antibodies to known activation molecules (CD86 [B7.2], CD80 [B7.1], CD40, CD54, CD1a and HLA-DR). Seventeen primary RCCs, representing four distinct histologies, were evaluated using double-staining immunohistochemical techniques and light microscopy. RESULTS: CD83+ TiDCs were found in all tumors. Expression of CD40 correlated with expression of CD1a on CD83+ TiDCs. Expression of CD54 (ICAM-1) correlated with a lower expression of CD86 (B7.2) as well as a decrease in CD3+ and CD8+ TiLs. CONCLUSIONS: These data suggest a de novo lipid or sugar-based immunogenic antigen presentation by TiDCs. Also, the data support an impaired antigen-presenting capability for CD54+ TiDCs based on the decreased coexpression of CD86 (B7.2) and the decrease of associated CD8+ TiLs.     

In vitro and in vivo effects of ribavirin on human respiratory epithelium.

The effects of ribavirin, a broad spectrum antiviral agent, on the structure and function of normal human nasal epithelium have been studied in vitro, as has also the in vivo effect of treatment with nebulised ribavirin on nasal mucociliary clearance of saccharin in four patients. Ciliary beat frequency was measured by a photometric technique, and changes in epithelial and ciliary ultrastructure were assessed by transmission electron microscopy. Ribavirin solution at the recommended concentration of 20 mg/ml had no adverse effects on ciliary activity in vitro; at concentrations of 50 mg/ml and above it slowed ciliary beating significantly and at 60 mg/ml caused ciliostasis associated with epithelial disruption. Nasal inhalation of ribavirin at 60 mg/ml for up to 20 minutes, however, did not slow nasal mucociliary clearance, nor did it adversely affect the ciliary beating or structure of nasal ciliated epithelium examined in vitro immediately after inhalation.     

Plasma proteins in human cortical bone:In vitro binding studies

Summary Studies on the interaction of serum a₂ HS-glycoprotein, a₁ acid-glycoprotein, and IgE within vitro-generated calcium phosphate precipitates, bone powder, hydroxyapatite, and collagen demonstrated selective binding of a₂ HS-glycoprotein to all substrates except collagen. IgE and a₁ acid-glycoprotein did not bind to any of these materials and were not detected at enhanced levels in a single bone specimen. These results may account for the enrichment of a₂ HS-glycoprotein in bone but question the reported concentration of IgE and a₁ acid-glycoprotein in this tissue.     

In vivo effect of 1 alpha-hydroxyvitamin D3 on interleukin-2 production in hemodialysis patients

The immunoregulatory effect of 1 alpha-OHD3, a precursor form of active vitamin D3 1,25 (OH)2D3, was examined in hemodialysis patients. Peripheral blood mononuclear cells (PBM) from hemodialysis patients produced significantly less interleukin-2 (IL-2) than those from normal controls. Four weeks of oral administration of 0.5 micrograms/day of 1 alpha-OHD3 enhanced the IL-2 production of PBM from the patients. This fact suggests that 1 alpha-OHD3 therapy may be useful for the restoration of IL-2 production in hemodialysis patients, and that the vitamin D3 deficiency may be responsible for the impairment of cellular immunity associated with IL-2 production disorder in hemodialysis patients.     

In vivo and in vitro humoral immunity in surgical patients.

In vivo and in vitro humoral immunity was studied in surgical patients. Laboratory controls (LC), delayed type hypersensitivity (DTH) skin test reactive (HR), and anergic (HA) patients were immunized with tetanus toxoid. Maximum in vivo antibody levels occurred 14 days after immunization. Eighty-six, 47, and 17% of LC, HR, and HA subjects, respectively, showed a positive response (X2(2) = 21.1 with Yates, p less than 0.0005). Peak in vitro antibody production in unstimulated lymphocyte cultures occurred at day 6 after immunization. Antibody responses in vitro were reduced in all surgical patients, worst in HA, and correlated quantitatively with in vivo antibody responses at day 14 (Spearman rank correlation = 0.794, p less than 0.001). Total IgG production in vitro was not decreased; 595, 1080, and 1538 ng IgG/culture were produced by LC, HR, and HA, respectively. These data demonstrate decreased in vivo and in vitro humoral immunity in all surgical patients, worst in those with decreased DTH responses. There is a kinetic and quantitative correlation between in vivo and in vitro responses, the latter being a biologic reflection of the integrity and magnitude of the in vivo process. Finally, failure to produce specific antibody is not due to failure of total IgG synthesis.     

Mechanisms underlying somatosensory cortical dynamics: I. In vivo studies.

The experiments of this study demonstrate that relatively modest rates of repetitive tactile stimulation are accompanied by rapid and reversible modifications (either increases or decreases) in the response of SI neurons. Complete recovery occurs in a few minutes following cessation of stimulation. The modifications are reproducible (1) if stimulus parameters remain the same and (2) if time for recovery is provided between successive exposures. In contrast, repetitive tactile stimuli identical to those that modify SI neuron response rarely lead to changes in the response of cutaneous mechanoreceptive afferents. SI neuron functional properties conventionally regarded as immutable [e.g., directional selectivity, and distribution of sensitivity within the receptive field (RF)] also modify with repetitive stimulation. While the changes in RF organization differ in detail from one neuron to the next, they are similar in form: the response generated by stimulus contact with one (or more rarely, several) RF region(s) becomes enhanced relative to the response the same stimulus evokes from neighboring regions. Neurons in the same column (sampled in the same radial penetration) exhibit very similar changes in the distribution of sensitivity within the RF, whereas neurons sampled in tangential penetrations exhibit diverse, apparently unrelated changes in RF organization in response to the same repetitive stimulus. Simultaneous multichannel recordings reveal that a repetitive tactile stimulus exerts similar effects on the response and RFs of the neurons within local (no more than 100 microns) neuron groupings. A model that incorporates a manner of SI topographical organization (segregate organization) and well-known aspects of neocortical cellular, neurotransmitter/receptor, and connectional architecture accounts for the changes in SI neuron behavior observed during repetitive stimulation.     

In vitro production of interleukin-1 from blood mononuclear cells of patients on chronic hemodialysis therapy.

A monocyte defect is thought to be involved in the impaired immune response in patients on regular hemodialysis therapy. As an indicator of cell function, we studied in vitro IL-1 beta production of mononuclear cells from hemodialysis patients in comparison to normal controls. Mononuclear cells were stimulated with endotoxin or Staphylococcus epidermidis in parallel with control incubations in tissue culture medium alone. Spontaneous as well as stimulated total IL-1 beta production (cell-associated plus extracellular) did not differ significantly in cells obtained from patients compared to those from normal controls. However, the relative amounts of IL-1 beta released into the cell supernatants were significantly reduced in mononuclear cells from hemodialysis patients when stimulated with endotoxin but not with Staphylococcus epidermidis. These data indicate a stimulus-dependent defect in the mechanism of IL-1 beta release. As IL-1 is necessary for T-cell activation this alteration in mononuclear cell function may play a role in the impaired cellular immunity observed in patients on chronic hemodialysis therapy.