RESUMEN
BACKGROUND: Human leukocyte antigen (HLA)-C is expressed on nucleated cells and platelets in lower levels than HLA-A,B, and its antigens are in linkage disequilibrium with HLA-B antigens. Therefore, HLA-C antibody detection is difficult. The authors questioned whether HLA-C could serve as a target in clinical kidney transplantation using a newly developed assay. METHODS: Flow cytometry was performed with sera from patients (n=34) awaiting a kidney retransplant using nine cell lines expressing a single HLA-C antigen (single-antigen lines [SAL]). RESULTS: The SAL were validated with HLA-C-specific alloantisera and human monoclonal antibodies against HLA-A, -B, and -C. The results were in agreement with the specificities previously reported. Exceptions, because of new HLA-C specificities used here, could be explained by epitope sharing between the antigens. With respect to patient sera, 15 of the 34 patients tested (44%) showed serum reactivity toward one or more HLA-C SAL. CONCLUSIONS: In contrast to peripheral blood lymphocytes, SAL are excellent targets for detecting HLA-C-reactive alloantibodies by flow cytometry. This preliminary analysis revealed that HLA-C-reactive antibodies are frequently present in sera of retransplant patients, serving as possible targets in clinical transplantation.
Asunto(s)
Antígenos/inmunología , Antígenos HLA-C/inmunología , Trasplante de Riñón/inmunología , Leucocitos/inmunología , Anticuerpos/sangre , Biomarcadores/análisis , Línea Celular , Epítopos/análisis , Humanos , Selección de Paciente , Reproducibilidad de los ResultadosRESUMEN
Interleukin 18 (IL-18) is a potent proinflammatory cytokine involved in the host defence by upregulating both innate and acquired immune responses and may be of particular importance also in mechanisms of kidney allograft rejection. Immunohistochemical staining of protocol biopsies showed constitutive IL-18 expression in the epithelium of distal tubules with the induction of immunoreactivity in acute rejection patients where also proximal tubules, infiltrating leukocytes, and endothelium were strongly positive. Furthermore, serum levels of IL-18 were significantly elevated in patients with acute rejection of kidney allograft (1247+/-389 pg/l) as compared to patients with uncomplicated outcome of kidney transplantation (444+/-164 pg/l) and subjects with acute tubulointerstitial nephropathy (385+/-155 pg/l, p<0.0001 for both comparisons). Tissue culture model of renal epithelial cells expressed IL-18 mRNA constitutively and released mature IL-18 in response to TNF-alpha and IFN-gamma. We assume that upregulation of epithelial IL-18 plays an important role in immune and immunopathological reactions in renal parenchyma and contributes to rejection mechanisms of kidney allograft.
Asunto(s)
Rechazo de Injerto/genética , Interleucina-18/metabolismo , Trasplante de Riñón , Regulación hacia Arriba , Biopsia , Línea Celular , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Humanos , Inmunohistoquímica , Interferón gamma/farmacología , Interleucina-18/genética , Riñón/metabolismo , Riñón/patología , Riñón/cirugía , ARN/genética , Trasplante HomólogoRESUMEN
BACKGROUND: Renal ischaemia/reperfusion (I/R) injury and hypertension represent major alloantigen-independent factors contributing to the development of chronic allograft nephropathy of renal allografts. In the present study, we investigated the effect of the anti-proliferative immunosuppressant, sirolimus (SIR), in a model of accelerated renal injury in hypertensive transgenic rats (TGRs). Twenty anaesthetized uninephrectomized TGRs with renin overproduction [TGR(mREN2)27] and 20 normotensive Han SD (SD) rats as genetic controls had their renal pedicles clipped for 45 min and were subsequently treated with either SIR (0.5 mg/kg per day, orally) or placebo ( n=10 in each group) for 16 weeks, after which time the kidneys were harvested for morphological and immunohistochemical analysis. High-renin hypertension aggravated the functional and structural changes induced by I/R in SD animals: both SIR-treated and untreated TGRs exhibited significantly greater proteinuria and suffered from more severe glomerulosclerosis ( P<0.01) and vasculopathy ( P<0.01), as well as compensatory renal hypertrophy ( P<0.01) and tissue TGF-beta1 expression, than both normotensive SD groups ( P<0.01). SIR-treated SD rats showed reduced proteinuria ( P<0.01), glomerulosclerosis ( P<0.01), and TGF-beta1 expression in the glomerular epithelium and proximal tubuli ( P<0.05) compared with placebo-treated SD rats. SIR-treated TGRs had significantly lower proteinuria at week 4 after I/R ( P<0.01) than placebo-treated TGRs, but there were no significant differences thereafter. Morphological patterns were similar in treated and untreated TGRs at week 16. High-renin-induced hypertension aggravated the renal injury induced by I/R. Sirolimus treatment ameliorated some late functional and morphological changes induced by I/R injury in hypertensive TGRs but, particularly, in normotensive SD rats.