RESOURCE: The subclinical rejection is defined as finding of histological signs of rejection on well functioning grafts. Its diagnostic domain remains protocol biopsy. The diagnostic value of ultrasound scaning in subclinical rejection has not been studied yet.

AIM: The aim of our study was to detect the incidence of subclinical rejection in protocol biopsies in the first three months after kidney transplantation and to find out the ultrasound correlation to histological picture of subclinical rejection with special accent on ultrasound signs of parenchymal oedema, quantity and quality of perfusion emphasising their changes in process of time.

METHODS: Sixty six protocol graft biopsies were performed on 36 recipients of cadaveric renal transplants in Transplant Centrum Olomouc between July 1999 and September 2000. The biopsies were carried out 21 +/- 2 days and 90 +/- 5 days after transplantation. Subclinical rejection was defined as t2 i2 v0 (IA) rejection infiltrate by Banff 97 histological classification at the same time with serum creatinine in normal range and ultrasound signs of parenchymal oedema.

RESULTS: In the group of subclinical rejection the ultrasound findings of graft parenchymal oedema correlated with 81% sensitivity and 90 % specificity with histological diagnosis. The duplex picture of parenchymal hyperaemia blush - had 100 % specificity but low sensitivity. The resistive indices were in the wide range 0,61 - 0,80 without diagnostic value.

CONCLUSION: The high sensitivity and specificity of ultrasound prospective follow up was found in the subclinical rejection diagnosis. Parenchymal hyperaemia indicated high specificity but low sensitivity in evaluation of subclinical rejection. No benefit of resistive indices was found. Larger sample of patients has to be established to gain more exact review anyway.

Keywords: Adult; Aged; Biopsy; Female; Graft Rejection /diagnosis/; Humans; Kidney /diagnostic imaging/; Kidney Transplantation; Male; Middle Aged; Predictive Value of Tests; Sensitivity and Specificity; Ultrasonography