Ciprofloxacin is one of the new fluoroquinolones which have a strong bactericidal activities and broad antibacterial spectrum. Due to the great potential for the clinical use of these drugs it is important to investigate any possible positive or negat...
Ciprofloxacin is one of the new fluoroquinolones which have a strong bactericidal activities and broad antibacterial spectrum. Due to the great potential for the clinical use of these drugs it is important to investigate any possible positive or negative side effects on the host defense system. We studied to verify the effects of ciprofloxacin on the incorporation of [³H]thymidine, production of interleukin-2 (IL-2), and release of soluble interleukin-2 receptors (IL-2R) in the cultures of phytohemagglutinin stimulated human peripheral lymphocytes for 5 days. After 3 days, After 3 days, [³H]thymidine incorporation was significantly increased in those groups below the 20 ug/ml of ciprofloxacin with dose dependent manner. At 80 ug/ml of ciprofloxacin, however, the [³H]thymidine incorporation was almost completely inhibited all the time.
On the other hand, IL-2 assay in culture supernatants shows that ciprofloxacin strongly increase the production of IL-2. After 3 days, IL-2 activity in culture supernatants are 160.7, 93.3, 4.0, and 40.4 IU/ml at concentrations of ciprofloxacin 80, 20, 5, and 1.25 ug/ml respectively, and 2.3 IU/ml that does not contain drug, as measured by enzyme immunoassay. The effect was significant at clinically achievable concentrations (below 5 ug/ml).
The release of IL-2R was not affected below the 20 ug/ml of ciprofloxacin, but significantly decreased at 80 ug/ml of ciprofloxacin.
These data show that quinolones increased IL-2 synthesis by mononuclear leukocytes and it suggests that the potential usefulness of these antibiotics, not only as antimicrobial agents, but also as modulators of immune responses.