RESUMO
The diagnosis of tuberculous ascites is often difficult because of the subtle clinical clues, poorly discriminative biochemical assays, delayed results of bacteriological studies and hazards of laparoscopy. Therefore, the role of ascites adenosine deaminase (ADA) activity and interferon-gamma (IFN-delta) level in distinguishing tuberculous from other causes of ascites was examined in 50 patients with ascites. Following bacteriologic culture, seventeen (34%) patients were found to have tuberculous ascites; nine (59.9%) of them had also schistosomal hepatic fibrosis (SHF). Therefore, 36% (9 out of 25) of all patients with SHF included in the study, had coexistent peritoneal tuberculosis despite the presence of transudative ascites and unrecognized clinical features. Ascites ADA activity was significantly higher in tuberculous than in other causes of ascites (P < 0.001) regardless of the presence of an underlying liver disease. A cut-off of 28 U/L reached a sensitivity of 94.4% and a specificity of 100%. A direct correlation was found between ascites ADA activity and total proteins in the tuberculous group (r = 0.613) and the only false-negative result occurred in a patient with SHF and low-ascites protein. Ascites IFN-delta level was also significantly higher in tuberculous ascites with or without SHF than in other causes of ascites (P < 0.05). A cut-off of 26 pg/ml reached a sensitivity of 81% and a specificity of 100%. There was no correlation between ascites ADA activity and IFN-delta level in the tuberculous group (r = 0.329). Based on the results of the present study, it can be concluded that tuberculous ascites should be considered as an important cause of ascites particularly in patients with underlying liver disease. Ascites ADA activity was more sensitive than ascites IFN-delta in diagnosing tuberculosis (TB). It has proved to be an easy, rapid, safe and reliable method for routine use in the early diagnosis of tuberculous ascites.
