| Abstract [eng] |
The aim of this study was to analyze the effect of photodynamic therapy (PDT)for the local treatment of inflammed knees in case of antigen induced arthritis. For our tests we have chosen the model of antigen induced arthritis (AIA), characterized by the features of monoarthritis. AIA was provoked in rabbits (n=17) by injecting an ovalbumin (OA) solution in the right knee of previously immunized animals using OA and Freund’s adjuvant solution. Different concentrations of 5-aminolevulinic acid, a precursor of PpIX, were injected intraarticulary or intravenously. The measurements of the knee have been performed, the body weight was measured, blood test results (i.e. ESR., the number of erythrocytes and leukocytes) were evaluated. The accumulation of PpIX was determined by measuring fluorescence spectra. In the first stage of the experiment the development and suitability of AIA model (n=17) was evaluated. The process of inflammation was characterized by statistically significantly increased ESR following the immunization, furthermore, after intraarticulary injection with OA, ESR at day 3 was 20 times increased as compared with the healthy animals. The number of erythrocytes had the tendency to decrease due to the inflammation (control group -4.48 ×1012L, at day three after the injection – 3.8 ×1012L). On the contrary, the number of leukocytes was increasing (control group – 7.27×109L, after the injection with OA – 21.74×109L). A significant feature of AIA model is the difference in the size between the inflamed right knees and the control left ones, that makes about 2 cm, as measured on the first and the second days following the antigen injection. During the second stage of this study in order to induce the process of photosensibilization in the inflammed synovia the different concentrations of 5-aminolevulinic acid, were injected. The animals for the treatment were injected with 1 ml ALA solution into the right knees (n=5) and the second group (n=4) was injected with 1 ml of ALA into the right knees and 1 ml of ALA into the ear vein. The control group of animals were treated with analogical ALA doses (n=3 and n=2) and physiological solution injections into the right knees (n=3). The comparison of inflammed and healthy knees showed the highest aggregation of PpIX in the right knees after 3 hours of immunization. Photosensitized therapy (irradiation dose of 18 J/cm2) has been applied for the treatment of ill animals. The third step of our work was analyzing of PDT effect in the period of 20 days. ESR in the group receiving the PDT therapy was found to be statistically significantly decreased. The comparison of ESR dynamics did not reveal any differences between the groups investigated. PT effect for the process of inflammation was not significant as revealed by measuring the size of right and left knees at the day of PDT application and after the next 20 days. The difference of 2 cm remained unchanged. Histological analysis of right knee tissue did not reveal any statistically significant changes too. To summarize, we can state, that the dose of irradiation might have not been sufficient enough therefore we did not receive the expected effect of impaired monoarthritis at the final stage of our experiment. It is confirmed by the histological tests as well. |
