ASCITIC FLUID ADENOSINE-DEAMINASE INSENSITIVITY IN DETECTING TUBERCULOUS PERITONITIS IN THE UNITED-STATES

Tuberculous peritonitis, although common in Third World countries, rem ains an uncommon cause of ascites in the United States, Ascitic fluid adenosine deaminase (ADA) activity has been proposed as a useful diagn ostic test, The aim of this retrospective study was to determine the c linical utility of ascitic fluid ADA activity in diagnosing tuberculou s peritonitis in a U,S, patient population, A total of 368 ascitic flu id specimens from a well-characterized ascitic fluid bank, including t uberculous peritonitis (n = 7), tuberculous peritonitis in the setting of cirrhosis (n = 10), and consecutive specimens of widely varied eti ologies (n = 351) were analyzed for ADA activity by ultraviolet spectr ophotometry at 265 nm, The overall sensitivity of the ADA determinatio n in diagnosing tuberculous peritonitis was only 58.8%, and the specif icity was 95.4%, The accuracy of ADA determination (93.8%) compared fa vorably with that of the common ascitic fluid tests of white blood cel l (WBC) count (>500/mm(3)), total protein (>2,5 g/dL), and combined WB C count and total protein (45.8%, 74.4%, and 81.3%, respectively), How ever, ADA was only 30% sensitive in detecting tuberculous peritonitis in the setting of cirrhosis, and cirrhosis was present in 59% Of the t uberculous peritonitis patients in our population, In addition, malign ancy-related ascites (13%) and bacterial peritonitis specimens (5.8%) occasionally yielded false-positive results, In conclusion, our result s indicate that the ascitic fluid ADA activity has good accuracy but p oor sensitivity and imperfect specificity in a U,S, patient population in which the prevalence of tuberculosis is low and underlying cirrhos is is common.