Lysozyme levels for the diagnosis of tuberculous effusions in children

Lysozyme level was measured in the fluid and serum of 42 tuberculous (25 pl eural, 11 ascites and 6 pericardial) and 29 non-tuberculous (5 malignant, 9 empyema thoracis, 10 transudative ascites and 5 pyopericardium) effusions, The mean fluid lysozyme level was significantly raised in tuberculous pleu ral, ascites, and pericardial effusions in comparison to malignant pleural (p < 0.001), transudative ascites (p < 0.001), and pyopericardium (p < 0.02 ) cases, respectively. The mean fluid/serum lysozyme ratio did not differ s ignificantly between tuberculous and their corresponding non-tuberculous ef fusions, The confirmed tuberculous pleural effusion patients had significan tly higher mean fluid lysozyme level and fluid/serum lysozyme ratio when co mpared with clinical cases (p < 0.05), The cut-off fluid lysozyme level of greater than or equal to 50/Ul(-1) and fluid/serum lysozyme ratio of greate r than or equal to1.1 were considered for the diagnosis of tuberculous effu sions; the sensitivity and specificity of fluid lysozyme and fluid/serum ly sozyme ratios were 100, 100 per cent, and 97.6, 33.3 per cent, respectively , on excluding the patients with purulent effusions, A significant correlat ion was observed between the fluid and serum lysozyme levels in tuberculous effusions (r = 0.39,p < 0.01), Thus, fluid lysozyme was found to be a bett er and reliable test than fluid/serum lysozyme ratio for the diagnosis of t uberculous effusions in children.