Adenosine deaminase activity and its isoenzymes in the sputum of patients with pulmonary tuberculosis

• Published in: The international journal of tuberculosis and lung disease Vol. 13; no. 6; pp. 744 - 748
• Main Authors: DIMAKOU, K, HILLAS, G, BAKAKOS, P
• Format: Journal Article
• Language: English
• Published: Paris, France IUATLD 01.06.2009; International Union against Tuberculosis and Lung Disease
• Subjects: Ada; Adenosine Deaminase - metabolism; Bacterial diseases; Bacterial diseases of the respiratory system; Biological and medical sciences; Case-Control Studies; Female; Human bacterial diseases; Humans; Infectious diseases; Isoenzymes - metabolism; Male; Medical sciences; Middle Aged; Mycobacterium; Pneumology; Respiratory system : syndromes and miscellaneous diseases; Sensitivity and Specificity; Sputum; Sputum - enzymology; Tuberculosis; Tuberculosis and atypical mycobacterial infections; Tuberculosis, Pulmonary - diagnosis; Tuberculosis, Pulmonary - enzymology; Human; Lung disease; Enzyme; Respiratory disease; Pulmonary tuberculosis; tuberculosis; Activity; Mycobacterial infection; Adenosine deaminase; Infection; Sputum; Bacteriosis; Hydrolases; ADA; Pneumology
• ISSN: 1027-3719; 1815-7920

BACKGROUND: Adenosine deaminase (ADA) has been widely used for the diagnosis of tuberculous pleural effusion. Two isoenzymes have been described, ADA1 and ADA2.OBJECTIVE: To evaluate the diagnostic value of sputum ADA, ADA1 and ADA2 activity in pulmonary tuberculosis (TB).DESIGN: We measured total ADA, ADA1 and ADA2 activity in the sputum of 27 patients with pulmonary TB (11 had a negative Ziehl-Neelsen stain for acid-fast bacilli [AFB]). Nineteen patients with lung cancer were used as controls.RESULTS: Sputum total ADA activity was significantly higher in TB than in lung cancer patients (median 18 U/l [range 3-70] vs. 6 U/l [2-16]; P < 0.001). Sputum ADA2 activity was significantly higher in TB compared to lung cancer patients (9 U/l [0-65] vs. 5 U/l [0-12]; P = 0.001). Sputum ADA2 was significantly higher than ADA1 in TB patients (P = 0.001). Sputum ADA and ADA2 were higher in both AFB-positive and AFB-negative TB patients. Using a cut-off level of respectively 16 UI/l and 5UI/l for sputum total ADA and ADA2, sensitivity and specificity were 55.6% and 100% for total ADA and 81.5% and 63.2% for ADA2.CONCLUSION: Sputum total ADA and ADA2 levels are elevated in patients with pulmonary TB. As they are elevated even in AFB-negative patients, they may assist in the early diagnosis of pulmonary TB.