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L Rostaing

Publications and source records attributed to L Rostaing.

117 records · Page 7Linked to original sources

[Study of CD45 isoforms on T CD8 lymphocytes, in the peripheral blood and the graft in patients after kidney transplantation].

We report characterization of CD45 isoforms expressed by CD8+ lymphocytes in peripheral blood and in the graft of 40 kidney transplanted patients who underwent kidney biopsy on the basis of clinical signs suggesting rejection. Standard histological examination of the biopsy fragments and three-color cytofluorimetric analysis of lymphocytes extracted from the same fragments by mechanical and enzymatic treatment were performed simultaneously and compared to the peripheral blood lymphocytes. In 14/40 biopsies where lymphocyte extraction succeeded, the predominant subset was CD8 (CD4/CD8 mean ratio was 0.53). Almost all CD8+ cells were activated: among these CD8+ cells, 55 percent were HLA-DR+, and 68 percent CD45RO+, i.e. of a memory cell type with cytotoxic activity. This situation resembles the in vitro observation made during mitogenic stimulation of lymphocytes by phytohemagglutinin, OKT3 or CML ("culture mixte lymphocytaire"). Beside their evident interest for the diagnosis, these data could be useful for our understanding of the physiopathology of the rejection crisis.

Biopsy, Needle↗

[Optimization of renal transplantation].

In 1990, 1,949 renal transplantations were performed in France, with a graft survival rate of 89% at one year and 70% at five years. To improve on these results it would be necessary to pursue a dynamic policy in all fields of transplantation: in view of the ever growing number of patients on the transplantation list, more kidneys should be collected; hyperimmunized recipients should undergo reinforced exchanges to have compatible kidneys; immunosuppression must be optimized: just a using cyclosporin and monoclonal antibodies has resulted in a significant advance, so should the discovery of new drugs, such as FK 506, or of more specific monoclonal antibodies, be a source of progress; the complications of immunosuppression must be controlled: prevention protocols and antiviral treatments have considerably reduced the incidence of viral infections. The emergence of malignant tumours directly related to the degree of immunosuppression can be prevented by a rational use of immunosuppressants and by systematic detection. All these advances make it possible to extend the indications of renal transplantation to subjects at risk, notably patients more than 60 years old, and diabetic patients who can successfully benefit from a dual kidney-pancreas transplantation.

France↗

[Crescent: structure, evolution, pathogenesis].

Extracapillary crescent is an elementary lesion which can be superimposed to any type of glomerulonephritis, or constitute the main lesion as in vasculitis, or appear to be idiopathic. One must oppose cellular crescent which is partially reversible, to irreversible fibrous crescent. Cellular composition of crescents has been much controversial: initially considered as having an epithelial-cell origin, then an exclusive macrophagic origin, crescents are in fact composed of epithelial cells, monocytes-macrophages and lymphocytes all together. The former are prevailing when Bowman's capsule (BC) is intact, whereas macrophages predominate when there is extensive damage of GBM and of BC. The initial event in crescent formation appear to be breaches in glomerular capillary wall, leading the deposition of fibrin within Bowman's space. The consequence is the proliferation of parietal epithelial cells and of activated macrophages followed by a production, in series, of cytokines and growth factors.

Animals↗

[Influence of angiotensin on the secretion of aldosterone in idiopathic hyperaldosteronism].

The purpose of study was to investigate the role of angiotensin II in idiopathic primary aldosteronism (IPA) and to evaluate the interest of angiotensin converting enzyme inhibitors (ACEI) in its management. The study concerned 10 hypertensive patients, mean 49 +/- 11 years with idiopathic primary aldosteronism due to bilateral adrenal hyperplasia: plasma renin activity (PRA) less than 1.5 ng/ml/h and plasma aldosterone (PA) greater than 25 ng/100 ml. Adrenal venography and adrenal vein aldosterone levels demonstrated bilateral hyperplasia. PRA and PA were evaluated in recumbent position, then after 4 hours in upright posture. The next day, a "captopril screening test" was performed with PA assays before and three hours after a single oral administration of captopril (1 mg/kg). Upright PRA and PA were slightly increased and acute administration of captopril reduced significantly PA levels in all patients. Blood pressure (BP was unmodified under captopril. These hormonal results demonstrated that adrenal glomerulosa remained sensitive to low concentrations of angiotensin II, and underlined the potential interest of ACEI in the management of IPA. Brown R. demonstrated already an increase of adrenal sensitivity to angiotensin II infusions, and isolated an aldosterone-stimulating factor (ASF). Plasma aldosterone levels were related to increased ASF concentrations but there was no link between PRA and ASF. Carey R. suggested that ASF acts through an increase of the sensitivity of aldosterone production to angiotensin II.(ABSTRACT TRUNCATED AT 250 WORDS)

Aldosterone↗

Combined use of tacrolimus and sirolimus in de novo renal transplant patients: current data.

The concomitant use of calcineurin inhibitors (CNIs) with mTOR inhibitors, that is, either sirolimus (SRL) or everolimus (ERL), in de novo renal transplant patients is still debated. Prescription of full doses of cyclosporine A (CsA) with either SRL or ERL in that population leads to impaired renal function and hyperlipidemia compared with a regimen using mycophenolate mofetil (MMF) with CsA. The current data for the use of SRL doses, ranging from 0.5 to 2 mg/d, or SRL troughs ranging from 8 to 12 ng/mL with conventional doses of tacrolimus, are associated with reduced renal function, higher blood pressure, and an increase in serum lipids compared with MMF/tacrolimus therapy.

Blood Pressure↗

Ex vivo flow cytometry determination of intracytoplasmic expression of IL-2, IL-6, IFN-gamma, and TNF-alpha in monocytes and T lymphocytes, in chronic hemodialysis patients.

AIMS: To determine the intracytoplasmic expression of TNF-alpha, IL-2, IL-6 and IFN-gamma, ex vivo and in vitro, in both monocytes and T lymphocytes by flow cytometry after appropriate stimulation using phorbol myristate acetate (PMA)/ionomycin or lipopolysaccharides (LPS) in the presence of monensin, in order to assess the bio(in)compatibility of different dialysis membranes. METHODS: We examined monocytes and T lymphocytes taken from chronic hemodialysis patients (using either cuprophane (CUP), n = 6; polyacrylonitrile (AN 69), n = 6; or polysulfone (PS), n = 6 membranes), before and after a dialysis session. We compared the results with those obtained from end-stage chronic renal failure patients (n = 3) and healthy volunteers (n = 11). RESULTS: Before any stimulation there was a statistically significant difference in the percentages of TNF-alpha, IL-6, and IFN-gamma- expressing monocytes with respect to the dialysis membrane used. The highest percentages were observed for CUP and AN69 patients with figures of around 30% for each cytokine; the lowest percentages were found in PS patients and healthy volunteers. One hour after LPS stimulation the patterns remained unchanged for TNF-alpha and IFN-gamma, whereas the percentages of IL-6-expressing cells in PS patients and in healthy volunteers reached the figures obtained in the other groups. When we examined the percentage of IFN-gamma-, TNF-alpha- and IL-6-expressing monocytes in patients before and after a dialysis session, before any stimulation, we found that the results were significantly different for the three membranes (p = 0.01). Thus, a dialysis session with polysulfone membranes had no significant effect on the precentages of IFN-gamma-, TNF-alpha-, and IL-6-expressing monocytes, whereas percentages were significantly lower after the dialysis session when using cuprophane or AN69 membranes, suggesting a release of these cytokines by the monocytes during dialysis. A significant number of IFN-gamma- and IL-2-expressing T lymphocytes were only detected after 18 hours of PMA/ionomycin stimulation. The percentages of IFN-gamma-expressing T cells recorded for the different membranes were not statistically different from those recorded for healthy subjects or pre-dialysis patients, i.e., they were between 11.5 and 20%. However, the percentages of IL-2-expressing T lymphocytes were significantly different between the 5 groups, i.e., 31.3, 30.5, 18.6, 13.9 and 7. 6%, respectively, for CUP patients, pre-dialysis patients, healthy volunteers, PS and AN69 patients. This suggests that pre-dialysis and CUP patients have, at baseline, a stimulation of their T lymphocytes. Finally, a 4-hour dialysis session had no impact on the percentages of IL-2-expressing T lymphocytes, whereas it was associated with a significant decrease in the percentage of IFN-gamma-expressing cells, but only when cuprophane membranes were used. CONCLUSION: Cytokine flow cytometry enables one to study, ex vivo, i.e., without any stimulation of the cells, and in vitro after appropriate stimulation, the bio(in)compatibility of dialysis membranes assessed by the intracytoplasmic cytokine profiles of TNF-alpha, IFN-gamma, IL-6 and IL-2, evaluated at the single cell level.

Adult↗

Lack of effect of chronic hepatitis C virus infection on T-cell cytokine production in chronic hemodialysis patients.

It has been shown that chronic hemodialysis modifies, to some extent, the normal immune response by both T and B lymphocytes elicited by antigenic stimulation, e.g. by impairing the T-cell-dependent response after vaccination. A new technique, i.e. flow cytometry, enables to assess intracytoplasmically, at the single cell level, the production of a given cytokine. By using it, we studied in healthy volunteers (HV) and in chronic hemodialysis (CHD) patients, with respect to their hepatitis C virus (HCV) status, the production by the T lymphocytes of type 1, and type 2 cytokines. We studied the following cytokines (CK): IL-2, IL-4, IL-5, IL-6, IL-10, IFN-gamma and TNF-alpha in the T-cell lymphocytes (whole, CD4+ and CD8+). There were 13 HV and 59 CHD patients (36 HCV(-) and 23 HCV(+)). Amongst the latter, there were 32 men and 27 women, aged 59.5 +/- 2 years, undergoing CHD since 70 +/- 9.4 months. We found that: (1) the total number of lymphocytes as well as those expressing CD3, CD4, or CD19 were significantly decreased in CHD patients as compared to those from HV; (2) the total number of lymphocytes as well as their different subsets were similar in HCV(+) and in HCV(-) CHD patients; (3) the frequency of T-cell-expressing IL-5 or IL-10 was always low (<1%) in both HV and CHD groups; (4) overall in CHD patients, the mean percentages of T lymphocytes expressing IL-2, IL-4, IFN-gamma or TNF-alpha were respectively 31 +/- 13, 2.5 +/- 1.3, 28 +/- 12 and 34 +/- 11% and were not statistically different between HCV(+) and HCV(-) patients; (5) IL-2 was mainly produced by CD4+ T cells, whereas IFN-gamma was produced by CD8+ T cells, in both HV and CHD groups, and (6) the lymphocytes of CHD patients produced significantly more IL-2 and IL-4 than those from HV, suggesting an activation of their T lymphocytes. We conclude that using the cytokine flow cytometry assay, our study demonstrated that in HCV(+) CHD patients, as opposed to what has been described for HCV(+) patients with normal renal function, there was no impairment in the production of type 1 cytokines by peripheral blood mononuclear cells when compared to HCV(-) CHD patients. Conversely to HV, T lymphocytes from CHD patients are activated.

Adult↗