[Pleural thickening in tuberculous pleural effusion. The associated factors]

We aimed to determine which factors were related to the development of residual pleural thickening (RPT) after completion of prescribed treatment. Sixty-two patients with pleural tuberculosis (PTB) were assigned to 2 groups according to the presence or absence of RPT > 2 mm in the side and lower portion of a chest film after completion of prescribed treatment. No patient had been given corticoids. Thickening developed in 72.6%, more often in men (OR, 4.06; p = 0.034), in older patients (36 +/- 21 versus 27 +/- 12 years; p = 0.05). Smoking, size of effusion, duration of symptoms, encapsulation, PPD, pleural biopsy, bacteriology and pH, glucose, proteins and cholesterol in pleural fluids, as well as their respective pleura/serum coefficients, were similar in both groups. Pleural LDH (LDHp) and its pleura/serum coefficient (LDHp/LDHs) were 454.3 +/- 234.6 U/l and 3.21 +/- 1.67 U/l in the group with RPT and 306.0 +/- 137.2 U/l and 2.00 +/- 1.16 in the group with no sequelae (p = 0.004 and p = 0.016, respectively). Using 2.10 as the cutoff for LDHp/LDHs, sensitivity was 78.9% and specificity was 71.4%, giving a positive predictive value of 88.2% and a negative predictive value of 55.5%. We conclude that RPT a) is a frequent complication, b) is mainly found in men, c) is age-related and d) can be fairly safely predicted using 2.10 as the cutoff for LDHp/LDHs.