[Effect of actipol on interferon level in tears (clinico-laboratory study)]

High interferon-inducing activity of a new antiviral drug actipol (0.007% para-aminobenzoic acid) instilled into the eye was demonstrated in animal experiments. In the present study the effect of actipol on interferon production in ocular tissues was investigated clinically. Interferon (IFN) content was measured in washings from the conjunctiva in 20 patients with herpetic keratitis, treated by actipol. Actipol was instilled frequently or injected subconjunctivally parabulbarly. The reference group consisted of 7 patients with herpetic keratitis treated with acyclovir locally. IFN titer was the last dilution of the sample ensuring 50% cell protection in comparison with complete cell destruction in the virus control. The samples were collected before, on days 1, 2, 3, 7 of treatment, and after clinical cure. Time course of IFN concentrations was wave-like in all the patients. The peak of IFN content surpassed the initial level 2-4-fold in all patients (26.13 +/- 5.9 vs. 58.9 +/- 4.4 U/ml, p < 0.01), which seems to be due to actipol induction of IFN production in the surface structures of the eyeball. In the reference group IFN content did not increase in comparison with the control during treatment. Hence, actipol induces the production of IFN in the surface eyeball structures in patients with various forms of herpetic keratitis.