Neopterin in tuberculous and neoplastic pleural fluids

Abstract

Neopterin is derived from guanosine-triphosphate, produced by stimulated macrophages under the influence of gamma interferon of lymphocyte origin. It has been suggested as an excellent marker for activation of the monocyte/macrophage axis in some clinical situations. We evaluated its concentration in the pleural effusions of 25 individuals (10 tuberculous and 15 neoplastic) as well as in the blood of 22 of them (8 tuberculous and 14 neoplastic), comparing these levels with those of a control group in 99 normal individuals. The concentration of neopterin was determined by radioimmunologic assay. This showed a significant increase (p less than 0.001) of neopterin levels in the tuberculous pleural fluid, compared to the neoplastic group (42 +/- 23/17 +/- 9 nmol/L). In the blood, values were nearly identical to the pleural fluid (41.3 +/- 25/15.8 +/- 6.9 nmol/L), although with significant differences between them and in relation to the control group (p less than 0.001), which had a normal serum value (5.11 +/- 1.92 nmol/L). We emphasize the influence of the neopterin levels in the pleural fluid on the diagnosis of causes of pleurisy and its importance as a marker of immunologic cellular activity.

Place of neopterin level in the differential diagnosis of tuberculosis pleurisy

“…Similar results were also found in the malignancy group of Immanuel et al [20]. When compared to each other, Baganha et al [19] found that, the level of neopterin in the serum and in the pleural fluid of malignancy group was lower than that of tuberculosis group. These results are similar to our study.…”

“…In our study, the significant difference in the average age between tuberculosis, malignancy and heart failure seems to be tipping the balance between the groups statistically. But in similar studies with the same age groups, the results were obtained in parallel with us [19,20]. Gender is not a factor that affects the level of neopterin.…”

“…Although CD4/CD8 ratio is normal or decreased in neoplastic effusions, this situation is the result of increased secretion of interferon-α from natural killer cells or the result of the production of tumor necrosis factor-α. This is a result of a response to antigenic stimulation of T cells [19]. In fact, normal or decreased levels of neopterin in most Basic Clin Sci 2013; 2: 65-70…”

The comparative value of pleural fluid adenosine deaminase and neopterin levels in diagnostic utility of pleural tuberculosis

“…In the case of TB, one of the most explored is ADA, which is a polymorphic enzyme that catalyzes the deamination of adenosine to inosine and ammonia (6). In numerous studies ADA has proven to be an accurate and valuable test for differential diagnosis of TB (12)(13)(14)(15)(16)(17). Elevated ADA activity is not specific for TB, but is also seenin parapneumonic effusions and pleural empyemas, rheumatoid effusions, and certain malignant pleural effusions.…”

“…It was reported that neopterin increases in various body fluids in patients with tuberculosis where cellular immunity plays an important role (17)(18)(19)(20). In our study, pleural fluid neopterin levels in the TB group were significantly higher than the malignancy group.…”