TREATMENT OF VIRAL-INFECTIONS WITH 5-AMINOLEVULINIC ACID AND LIGHT

Background and Objective: When B-aminolevulinic acid (ALA) is exogenou sly supplied, protoporphyrin IX (PpIX) is accumulated in various cells and makes them light sensitive. The possibility of using such an appr oach for the treatment of viral infections was studied in this work. S tudy Design/Materials and Methods: ALA was added to cultured cells inf ected with human immunodeficiency virus (HIV). Accumulation of PpIX in the cells as well as virus infectivity after photodynamic treatment ( PDT) were assessed. For in vivo studies, guinea pigs were infected wit h herpes simplex virus (HSV) and then administered ALA at intervals af ter infection. The animals were exposed to PDT at the site of infectio n 3 hours after ALA administration. Clinical observations and virus ti tration were made daily. For clinical studies, two patients with Mollu scum contagiosum and Verrucae vulgares were treated with ALA fortified with an iron chelating agent and dimethylsulfoxide, followed 4 hours later by PDT. Results: Cells that are infected with HIV accumulated Pp IX upon addition of ALA in vitro. This accumulation was enhanced - two -fold in the presence of an iron chelator. Subsequent exposure to red light PDT drastically reduced the virus titer (> 99% for U1 cells late ntly infected with HIV). In guinea pigs infected with HSV, subsequent administration of ALA and exposure of the lesions to red light shorten ed the duration of vesicles' appearance from more than a week to a few days and reduced HSV titer in the lesions by greater than or equal to 5 log(10). ALA-PDT treated AIDS patient suffering from Molluscum cota giosum or a kidney transplant patient with Verrucae vulgares showed gr eatly improved clinical symptoms one month after treatment. Conclusion : It is concluded that ALA-PDT could be effective in treating certain viral infections, particularly those resulting in warts. (C) 1997 Wile y-Liss, Inc.