Aim of the work This study was conducted to evaluate the
role of serum adenosine deaminase (ADA) level in the
diagnosis of pulmonary tuberculosis (TB) and its relationship
with clinical, radiological, and laboratory parameters.
Patients and methods This study was performed on 70
individuals: 60 patients with tuberculous and nontuberculous
pulmonary diseases and 10 apparently healthy individuals as
a control group. The participants were divided into four
groups: group I included 30 patients with active pulmonary TB
who were subdivided into group IA, which included 20
patients with sputum smear-positive pulmonary TB, and
group IB, which included 10 patients with sputum smearnegative
pulmonary TB (culture positive); group II included 10
patients with tuberculous pleural effusion; group III included
20 patients with nontuberculous lung diseases (five cases
with pneumonia, five cases with pyogenic lung abscess, five
cases with bronchiectasis, three cases with lung cancer, and
two cases with mesothelioma); and group IV included 10
apparently healthy individuals as a control group. Patients
were subjected to history taking, clinical examination, plain
chest radiography posterior–anterior view, three consecutive
sputum smears for acid-fast bacilli (AFB), sputum culture for
AFB using BACTEC TB-460 system in group IB, laboratory
investigations, tuberculin skin test, serum ADA level
evaluation in all participants, and pleural ADA level evaluation
in cases of tuberculous pleural effusion.
Results Serum ADA showed high percentage positivity (90%)
in the diagnosis of pulmonary TB, followed by tuberculin skin
test (83.3%), chest radiography (73.3%), erythrocyte
sedimentation rate (70%), sputum for AFB (66.6%), toxic
symptoms (53.3%), and hemoptysis (36.3%). Serum ADA
sensitivity and specificity at cut-off point 30.15 μ/l were 95 and
86.7%, respectively, with a positive predictive value of 90.5%,
negative predictive value of 92.2%, and accuracy of 91.4%.
Conclusion Serum ADA level shows higher percentage
positivity compared with clinical, radiological, and laboratory
parameters in the diagnosis of pulmonary TB. |
