SN also induced a systemic response, with increases in serum LDH, IL-8, and VEGF levels. The serum LDH level increased 6 h after injection, and decreased after 24 and 48 h. The serum levels of IL-8 were higher than those of animals injected with saline solution at all three time periods, and were higher than those of animals injected with TL at 6 and 24 h. The serum VEGF levels in the SN group were significantly greater than those in the control group or in animals injected with saline solution.
There have been only a limited number of previous studies that examined changes in the blood or serum after the intrapleural injection of sclerosing agents. In one study in rabbits, the intrapleural injection of TL led to a significant increase in the angiotensin-converting enzyme activity in serum, whereas the intrapleural injection of doxycycline led to increases in liver function enzymes and produced lung toxicity for 30 days. In a clinical study, the intrapleural injection of both TL and tetracycline induced significant increases in serum C-reactive protein levels 48 h after the injection, but the increases after TL injection were significantly greater than the increases after tetracycline injection. In the same study, the intrapleural injection of TL, but not of tetracycline, led to decreased levels of oxygen saturation and to decreases in lung clearance, as measured by a 99mTc-diethylenetriaminepenta-acetate scan 48 h after the injection. antiviral eye drops
The mechanisms by which TL induces a systemic inflammatory response remain unknown. One possible mechanism is the migration of TL particles to other organs such as the lung, spleen, liver, and kidneys, where its presence could elicit an inflammatory response. Indeed, after the intrapleural administration of TL in rats and rabbits, TL particles have been found in various organs. Moreover, TL particles were found disseminated throughout the body in one patient who died of ARDS following TL administration.