Acute liver rejection: accuracy and predictive values of doppler US measurements--initial experience.
OBJECTIVE
To prospectively evaluate accuracy and predictive values of Doppler ultrasonographic (US) measurement of portal blood velocity (PBV) and splenic pulsatility index (SPI) in diagnosis of clinically relevant acute rejection in patients with clinicobiochemical hepatic dysfunction after orthotopic liver transplantation (OLT).


METHODS
Study was approved by the institutional review board, and protocol conformed to ethical guidelines of Declaration of Helsinki. Patient informed consent was obtained. In 27 patients with OLT (23 men, four women; mean age, 48 years; range, 27-64 years), PBV and SPI were measured at Doppler US within 48 hours before or after liver biopsy for clinically suspected acute rejection. Biopsy specimens were assigned scores according to Banff method, and rejection activity index (RAI) was calculated. RAI score of 4 or greater was considered clinically relevant acute rejection. Doppler US parameters were analyzed as absolute values and as percentage point changes with respect to values obtained at last examination before rejection was suspected. Information from two Doppler US parameters was combined; Doppler US composite index was calculated. Statistical tests were conducted to assess accuracy, sensitivity, specificity, and predictive values of Doppler US parameters in diagnosis of graft rejection.


RESULTS
Clinically relevant acute rejection was diagnosed in nine patients. Median time from OLT until histologic diagnosis of acute rejection was 8 days (range, 5-20 days). Rejection was associated with a marked reduction in mean PBV (-43% +/- 5 [standard error of the mean]) and a slight increase in SPI (+12% +/- 16). The calculated Doppler US composite index was strictly related to severity of rejection (P < .001). When applied retrospectively, this index had good accuracy (88%) for prediction of rejection (specificity, 89%; sensitivity, 86%; negative predictive value, 94%).


CONCLUSIONS
During the first weeks after OLT, a marked decrease in PBV associated with increased SPI supports suspicion of clinically relevant acute rejection.
Bolognesi
Massimo
M
Department of Clinical and Experimental Medicine, Institute of General Surgery, Clinica Medica 5, Policlinico Universitario, University of Padua, Via Giustiniani 2, 35128 Padua, Italy. massimo.bolognesi@unipd.it
Sacerdoti
David
D
Mescoli
Claudia
C
Nava
Valeria
V
Bombonato
Giancarlo
G
Merkel
Carlo
C
Merenda
Roberto
R
Angeli
Paolo
P
Rugge
Massimo
M
Gatta
Angelo
A
D000208:Acute Disease; D000328:Adult; D001706:Biopsy; D001783:Blood Flow Velocity / Q000502:physiology; D005260:Female; D006084:Graft Rejection / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008099:Liver / Q000098:blood supply* / Q000473:pathology; D016031:Liver Transplantation / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011169:Portal Vein / Q000000981:diagnostic imaging; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011673:Pulsatile Flow / Q000502:physiology; D012039:Regional Blood Flow / Q000502:physiology; D012680:Sensitivity and Specificity; D013154:Spleen / Q000098:blood supply*; D014463:Ultrasonography