RESUMO
BACKGROUND: Injuries in kidney transplant is currently diagnosed by needle biopsy. A noninvasive test that sensitively detects these injuries would benefit the patients. METHODS: Urine samples were collected from healthy controls and kidney transplant recipients. Urine samples were screened first with an antibody array consisting of 120 chemokines and cytokines and then with a multiplex beads assay. Representative parameters, including macrophage inflammatory protein-1Delta, osteoprotegerin, monokine induced by interferon-gamma (IFN), and IFN-gamma-induced protein of 10 kDa, were simultaneously determined by a quadruplex assay in urine samples from 84 patients with renal allograft injury, 29 patients with stable graft function, and 19 healthy individuals. RESULTS: Twenty-three cytokines/chemokines were found to be elevated in urine samples of patients with acute rejection by the antibody array. The second round of screening confirmed that 11 of the 23 parameters were elevated in the patients but not in the healthy controls. Induced protein of 10 kDa and monokine induced by IFN-gamma were significantly elevated in urine samples of patients with acute renal injury, and macrophage inflammatory protein-1Delta and osteoprotegerin were significantly elevated in patients with both acute and chronic renal injuries. The combination of the four parameters had a high positive detection rate (97.6%) for renal transplant injury and could differentiate between acute and chronic injury. CONCLUSION: These results might indicate that the present multiplex assay provides a basis to establish a noninvasive method for the diagnosis and monitoring of renal transplant injury.
Assuntos
Quimiocinas/urina , Creatinina/sangue , Citocinas/urina , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/urina , Transplante de Rim/patologia , Biomarcadores/sangue , Biomarcadores/urina , Biópsia por Agulha , Quimiocina CXCL10/genética , Quimiocina CXCL10/urina , Quimiocinas/genética , Citocinas/genética , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/patologia , Humanos , Transplante de Rim/imunologia , Análise de Sequência com Séries de Oligonucleotídeos , Osteoprotegerina/genética , Osteoprotegerina/urina , Valores de Referência , Reprodutibilidade dos Testes , Transplante Homólogo/patologiaRESUMO
A noninvasive urinary test that diagnoses acute renal allograft dysfunction would benefit renal transplant patients. We aimed to develop a rapid urinary diagnostic test by detecting chemokines. Seventy-three patients with renal allograft dysfunction prompting biopsy and 26 patients with stable graft function were recruited. Urinary levels of CXCR3-binding chemokines, monokine induced by IFN-gamma (Mig/CXCL9), IFN-gamma-induced protein of 10 kDa (IP-10/CXCL10), and IFN-inducible T-cell chemoattractant (I-TAC/CXCL11), were determined by a particle-based triplex assay. IP-10, Mig and I-TAC were significantly elevated in renal graft recipients with acute rejection, acute tubular injury and BK virus nephritis. Using 100 pg/mL as the threshold level, both IP-10 and Mig had diagnostic value (sensitivity 86.4%; specificity 91.3%) in differentiating acute graft dysfunction from other clinical conditions. In terms of monitoring the response to antirejection therapy, this urinary test is more sensitive and predictive than serum creatinine. These results indicate that this rapid test is clinically useful.
