Vnitr Lek 2008, 54(11):1054-1058

Subclinical acute rejections in protocol biopsies at 3 months after kidney transplantation

I. Matl^1,*, E. Honsová², A. Lodererová², V. Lánská³, O. Viklický¹

¹ Klinika nefrologie IKEM Praha, přednosta doc. MUDr. Ondřej Viklický, CSc.

² Pracoviště klinické a transplantační patologie IKEM Praha, přednostka prim. MUDr. Eva Honsová, Ph.D.

³ Oddělení lékařské statistiky IKEM Praha

Aim:
The primary aim of the study was detection of subclinical acute rejection and borderline changes in protocol biopsies at 3 months after transplantation, and assessment of possible clinical and laboratory associations.

Methods:
Biopsy was carried out in 194 patients with stabilized graft function. Patients were treated with immunosuppressive regimen based on cyclosporine A (n = 34), tacrolimus (n = 152), or sirolimus/everolimus (n = 10). Samples were processed by standard paraffine technique, and stained according to laboratory protocol. All samples were tested by immunofluorescence or immunohistochemical procedures for C4d presence as a sign of humoral rejection.

Results:
Of 192 representative samples, subclinical acute rejection and borderline changes were found in 24 samples (12.5%). In patients with this finding, the mean serum creatinine was significantly higher (185.2 ± 2.2 μmol/L), than in patients with normal finding (128.2 ± 28.3 μmol/L) p < 0.001. Using the ROC curve analysis of serum creatinine, the cut-off point 170 μmol/L was found to discriminate normal findings from subclinical rejection and borderline changes. A significant correlation between acute rejections before protocol biopsy and subclinical acute rejections together with borderline changes in protocol biopsy was found. C4d positivity was found in 6 samples. Immunosuppressive therapy (cyclosporine versus tacrolimus) did not have any impact on subclinical acute rejections and borderline changes prevalence.

Conclusions:
The main conclusion of this study is a finding, that acute rejection early after renal transplantation and serum creatinine ≥ 170 μmol/l at three months after transplantation are risks for development of subclinical acute rejection, even of humoral type, or borderline changes.

Keywords: kidney transplantation; protocol biopsy; subclinical acute rejection; borderline changes; immunosuppressive therapy

Received: May 21, 2008; Accepted: August 15, 2008; Published: November 1, 2008  Show citation