부산대학교 도서관

The involvement of cellular immunity in alveolar echinococcosis (AE) due to E. multilocularis is strongly suggested by the intense granulomatous infiltration observed around the hepatic parasitic lesions, and a progressive decrease of specific cellular immunity has been described in murine AE. However, specific cellular immunity against E. multilocularis has never been documented in human AE. The reactivity to phytohacmagglutinin (PHA) and E. multilocularis antigens of peripheral blood mononuclear cells (PBMC) from 48 patients with AE and 35 control subjects was evaluated by incorporation of ³H-methylthymidine into DNA. A sequential measurement of the proliferative response of PBMC was performed in 20 patients 2 years later, and again in live of them 4 years after the first determination. After stimulation by PHA, the mean proliferation index (P1) of the patients with AE was somewhat higher than that observed in the uninfected controls, but the difference was not significant. The P1 obtained with E. multilocularis antigens was higher than the threshold value in all the patients but one, and in five control subjects. The difference between the P1 values in the patients with AE and those obtained in the control subjects was highly significant. There was no correlation between the lymphocyte proliferation indices and the specific antibodies assessed using the Em 2-ELISA, or the volume of the parasitic lesions. All the five 'positive' control subjects were living in areas endemic for AE. A previous contract of these subjects with E. multilocularis in the past, followed by a spontaneous elimination of the parasite is possible. The long-term persistence of lymphocyte reactivity to parasite antigens was emphasized by the results of the follow-up of 20 patients with AE: reactivity of PBMC decreased progressively but persisted more than 4 years after complete resection of the parasitic lesions in the patients who underwent a radical surgical procedure. Conversely, an increase in the P1 was shown to be usually associated with a progression of the liver lesions. [ABSTRACT FROM AUTHOR]