Molecular markers in subclinical acute rejection of renal transplants.
In this study, we evaluated the expression of molecular markers of acute rejection in protocol biopsies of patients with and without subclinical acute rejection (SAR). Protocol biopsies were performed at 2 months (n = 21) and 12 months (n = 14) after kidney transplantation in patients with stable allograft function. After biopsy tissue RNA isolation, reverse transcription and polymerase chain reaction (RT-PCR) for the glyceraldehyde 3-phospate dehydrogenase (GAPDH), perforin, granzyme B and Fas ligand genes were performed. The Banff 97 classification was used for histological diagnosis. Creatinine concentrations at 2 months were significantly higher in patients with SAR (1.46 +/- 0.27 x 1.18 +/- 0.24; p < 0.02). Perforin transcripts were found in 15 biopsy specimens, 10 of which had histological signs of SAR (p = 0.06). Granzyme B expression was found in 10 specimens, nine of which had SAR (p < 0.01). Fas ligand was expressed in seven specimens, and six of them were classified as SAR (p < 0.01). Perforin expression had the highest sensitivity (81%) for the diagnosis of SAR. Granzyme B and Fas ligand had specificity of 90%. At 12 months, there was no significant difference in creatinine concentrations for patients with and without previous SAR (1.63 +/- 0.57 x 1.28 +/- 0.31; p = 0.10). Molecular analysis revealed that there was no statistically significant difference in the expression of perforin and granzyme B in patients with and without SAR. Fas ligand expression was observed in five samples, four of which had histological signs of SAR (p = 0.03). At 12 months, perforin expression had the highest sensitivity (83%), and Fas ligand, the highest specificity (88%) for the diagnosis of SAR. We concluded that the expression of genes that encode proteins involved in the cytolytic attack against the allograft is increased in kidneys with SAR. These findings support the understanding that SAR is an active immune process potentially deleterious to renal allografts.
Aquino Dias
Esther Cristina
EC
Post-Graduation Medical Sciences, Nephrology Program, School of Medicine, Universidade Federal do Rio Grande do Sul, Renal Division, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Veronese
Francisco José Veríssimo
FJ
Santos Gonçalves
Luiz Felipe
LF
Manfro
Roberto Ceratti
RC
D000208:Acute Disease; D001706:Biopsy; D005819:Genetic Markers; D006084:Graft Rejection / Q000235:genetics* / Q000276:immunology*; D006801:Humans; D007668:Kidney / Q000276:immunology / Q000473:pathology*; D016030:Kidney Transplantation / Q000009:adverse effects / Q000276:immunology*
D005819:Genetic Markers