br Discussion Mycobacterium tuberculosis infection

Discussion Mycobacterium tuberculosis infection is a main threat to mankind, with one third of the world population being infected. [9] Over nine million new cases of tuberculosis and two million deaths from this disease occur yearly worldwide. [10] The rising incidence of tuberculosis over the last decade has increased the need to define the host factors that control the resistance to tuberculosis. The chance of developing active disease after M. tuberculosis infection is about 10% in a lifetime in the non HIV infected host. The major risk factor for developing active tuberculosis is immunodeficiency. Worldwide, malnutrition and starvation are major causes of immunosuppression and increased susceptibility to infectious diseases like tuberculosis [11], [12]. Adenosine deaminase (ADA) is an enzyme involved in purine catabolism. The enzyme catalyzes the hydrolytic and irreversible deamination of adenosine to inosine and deoxyadenosine to deoxyinosine. Two isoenzymes, ADA1 and ADA2 have been described [5], [6]. ADA is an enzyme found in the majority of cells, but particularly in AZD-9291 sale and monocytes. Its concentration is inversely related to the degree of differentiation [8]. High ADA activity has been used as a valuable marker for the diagnosis of tuberculous pleural effusion. As ADA is also high with other diseases, such as bronchogenic cancer, systemic lupus erythematousis, lymphoproliferative disorders, empyema, mesothelioma and rheumatoid arthritis, the sensitivity of the test is high and its specificity is low [13]. In the current study there was a statistically significant difference between the three studied groups regarding sputum ADA. The mean value of sputum ADA in tuberculous patients was 159.76±16.95U/L, the mean value of sputum ADA in pneumonia patients was 84.34±6.87U/L and the mean value of sputum ADA in bronchogenic carcinoma patients was 67.30±7.47U/L. There was a statistically significant difference between the three studied groups regarding sputum ADA (F=25.65, P=0.0001). There was a significant increase in sputum ADA in group I than group II and group III and there was a significant increase in sputum ADA in group II than group III (F=25.65, P1=0.0001, P2=0.0001, P3=0.0001, respectively). In accordance with our findings Dimakou et al. [14] tried to evaluate the diagnostic value of sputum ADA, ADA1 and ADA2 activity in pulmonary tuberculosis and found Brachydactyly sputum total ADA activity was significantly higher in TB than in lung cancer patients (median 18U/L [range 3–70] vs. 6U/L [2–16]; P<0.001) respectively and sputum ADA2 activity was significantly higher in TB compared to lung cancer patients (9U/L [0–65] vs. 5U/L [0–12]; P=0.001) respectively. There was a statistically significant difference between the three studied groups regarding serum ADA. The mean value of serum ADA in tuberculous patients was 31.99±8.85U/L, the mean value of serum ADA in patients with pneumonia was 24.15±4.22U/L and the mean value of serum ADA in patient with bronchogenic carcinoma was 14.84±2.43U/L (F=10.65, P=0.001). There was a significant increase in serum ADA in group I than group II and group III and group II show a significant increase than group III (P<0.01) (F=10.65, P1=0.0022, P2=0.0001, P3=0.0001, respectively). Afrasiabian et al. [15] found that the average (SD) of serum ADA in TB and non-TB patients were 20.88 (±5.97) and 10.69 (±2.98)U/L, respectively (P value<0.05). The best cut-off point was 14U/L. The calculated area under the receiver operating characteristic (ROC) curve was 0.955 (95% CI, 0.914–0.995); sensitivity was 92.7% (95% CI, 84.7–100) and specificity was 88.1% (95% CI, 78.3–97.8) (P<0.001). There was a statistically significant positive correlation between sputum and serum ADA (r=0.75, P=0.0001). In the present study, there was no statistical significant difference between the three studied groups regarding ratio ADA sputum/serum (P 0.0685, 0.208 and 0.11, respectively).