Inflammation is the earlier event in the multistep mechanism of pleurodesis. Several mediators may regulate the outcome of pleural inflammation, including natural endogenous mediators.
To evaluate the influence of IL-10, an anti-inflammatory cytokine, in the pleurodesis induced by talc (TS) or doxycycline (DX).
Four groups of 10 rabbits received TS (400 mg/kg) or DX (10 mg/kg) via a chest tube, with or without a previous intrapleural injection of IL-10 (200 ng/kg). After 24 hours the pleural fluid was assayed for IL-8, VEGF and lactic dehydrogenase (LD). After 28 days the animals were sacrificed and pleural adhesions were evaluated by a score from 0 to 4. Statistical analysis: t-test.
GroupsAdhesionsIL-8VEGFLDTS2.2 + 0.7594.8+ 123.5562.2 +139.3932.6 + 229.9TS+IL101.1 + 0.2*1095.3 + 343.6#420.0 + 106.31203.6 + 366.3DX3.0 + 0.7240.8 + 128.2331.5 +185.15165.8+2944.2DX+IL102.7 + 0.7341.9 + 33.1305.7 + 127.61240.3 + 465.6Pleural adhesions were significantly (p < 0.05) reduced in the animals that received talc and IL-10 when compared with the animals that received only talc. However no difference was observed in the doxycycline group. The levels of IL-8 they were significantly higher in the animals that received talc plus IL10 compared to those that received only talc. No significant difference was observed in the VEGF or LD levels in all groups.
IL-10 inhibited the pleurodesis induced by talc but not by doxycycline. IL-10 was not capable to reduce the levels of VEGF or IL-8. New studies should be made in attempt to clarify the inflammation and fibrosis mechanisms that are involved in pleurodesis.CLINICAL IMPLICATION: IL-10 an endogenous anti-inflammatory mediator may influence the outcome of talc pleurodesis
L.R. Teixeira, None.