The value of adenosine deaminase estimation for the diagnosis of tuberculosis in the serum, pleural and ascitic fluids

Abstract EN

Objective : To study the activity of Adenosine Deaminase enzyme (ADA) in serum, pleural and ascitic fluids in patients with and without tuberculosis (TB), and in serum of control subjects.

Methods : Adenosine Deaminase activity was estimated in seventy six patients with pleural effusion and / or ascites, 32 patients (15 males and 17 females) with suspected tuberculosis and 44 patients (24 males and 20 females) with causes other than tuberculosis.

Serum Adenosine Deaminase was tested and compared with patients group in 90 apparently healthy age and sex matched controls.

Results : Tuberculous patients demonstrated significantly higher activity (P < 0.0001) of ADA in pleural, ascitic fluid and serum when compared with the non-TB patients.

ADA activity was significantly higher (P < 0.0001) in patients with tuberculous fluids than in their corresponding serum (85.1 + 24.7) U / L and (32.9 + 10.7) U / L respectively.

The study has also revealed that the serum ADA activity was higher in TB than non-TB and control groups.

In TB patients ADA activity was (32.9 ± 10.7) U / L, while in non-TB and control groups were (16.9 + 11.2) and (21.3 + 5.5) U / L respectively.

Serum ADA activity of 18 tuberculous patients who completed their treatment showed a highly significant decrease (P < 0.0001) compared to levels before treatment, (16.7+_3.54) U / L to (31.51 + 10.57) U / L.

A cutoff value for ADA of more than 65.3 U / L in pleural fluid and 35.3 U / L in ascitic fluid were used as an indicator for diagnosis of TB, accordingly the sensitivity and specificity for diagnosis of TB in pleural fluid were 96 %, 93 % and in ascitic fluid were 86 %, 100 % respectively.

The serum cutoff value for ADA of more than 32.2 U / L was an indicator for diagnosis of TB with a sensitivity and specificity of 54 %, 85 % in patients with pleural fluid and 66 %, 94 % in patients with ascites.

Conclusions : Estimation of Adenosine Deaminase in pleural and ascitic fluid is a useful and reliable screening test for the diagnosis of tuberculosis, while serum ADA is useful to follow the response of antituberculous treatment.