Elevated adenosine deaminase activity in patients with HIV and tuberculous peritonitis.

Objective To evaluate the diagnostic potential of the ADA T , ADA isoenzymes (ADA 1 and ADA 2 ) and the interferon-γ (IFN-γ) test in HIV-seropositive patients with tuberculous peritonitis. Methods Ascitic ADA T , ADA 1 , ADA 2 and IFN-γ were prospectively evaluated in HIV-seronegative patients with tuberculous peritonitis (n = 17), HIV-seropositive patients with tuberculous peritonitis (n = 6) and in patients with cirrhosis (n = 22) and malignancy (n = 5). Results ADA T and ADA 2 isoenzyme activities of HIV-seronegative (ADA T = 109 U/l; ADA 2 = 94 U/I) and HIV-seropositive (ADA T = 109.5 U/l; ADA 2 = 95.5 U/I) patients with tuberculous peritonitis, respectively, were significantly different (P < 0.001) from patients with cirrhosis (ADA T = 10.5 U/l; ADA 2 = 8 U/I) and malignancy (ADA T = 13 U/l; ADA 2 = 11 U/I). There was no significant difference in ADA T and ADA 2 activities between HIV-seropositive and seronegative patients with tuberculous peritonitis. There was no significant correlation between ADA, its isoenzymes and IFN-γ. Conclusions The diagnosis of tuberculous peritonitis can be made by a sensitive, relatively non-invasive procedure in both HIV-seronegative and seropositive patients with minimal risk to the patient and the investigator. The diagnostic value of ADA T is not enhanced by measuring ADA isoenzymes or IFN-γ.