Immunological mechanism of peripheral neuropathy induced by Campylobacter jejuni-Incidences of experimental peripheral neuropathy induced by Pen19 and Pen43

Abstract

Recent studies have suggested that Campylobacter jejuni (CJ) may be the most common pathogen causing Guillain-Barre syndrome (GBS). Fifteen to seventy-five percent of patients with GBS had had a recent CJ infection. The serotypes of CJ isolated from stool usually are Penner (Pen) 19, Pen4, Pen41, and so on. Although some serotypes of CJ have been proved to associate with GBS, the directly evidence from the animal model is needed. Objective To clarify the association of peripheral neuropathy with GBS by using the different serotypes of CJ to immunize Wistar rats respectively. Methods Sixty Wistar rats were divided into three groups: CJ-Pen 19 group, CJ-Pen43 group and normal saline control group. Each rat was immunized repeatedly with Freund′s adjuvant and inactivation antigen of CJ-Pen19, Pen43 and normal saline, respectively. The serum titers of specific anti-CJ antibodies were detected by ELISA. The pathologic examination of sciatic nerves was performed at different time points: 1, 2, 3, 4 and 5 weeks, respectively after the immunization. Results (1) Compared with the normal saline group, the serum titer of anti-CJ IgG elevated after immunization and sustained at a higher level after the 3rd-4th week in the CJ-Pen19 and Pen43 groups of rats. (2) The incidences of pathologic nerves and fibers in CJ-Pen19 group (60.0% and 17.7%, respectively) were much higher than those of CJ-Pen43 group (10.0% and 0.5%, respectively) and of normal saline group (5.0% and 0.5%, respectively, P 0.05). (3) At the initial stage, the type of pathologic fibers was mostly axon degeneration. The ratio of axon degeneration to demyelination was 3.4% to 0.7%. But at advanced stage, the proportions of demyelination increased rapidly and the ratio of axon degeneration to demyelination was 5.3% to 24.1%. (4) There was a positive correlation between the antibody titer of specific anti-CJ IgG and the incidence of axon degeneration (r=0.801) compared with the demyelination. There was no correlation between the IgM level and the incidence of axon degeneration or demyelination (r=0.253 and 0.281, respectively). Conclusions (1) The incidence of experimental peripheral neuropathy might depend on CJ serotypes; (2) The majority of pathologic fibers showed axonal degeneration at the initial stage and remarkable demyelination at the later stage. (3) The specific anti-CJ IgG antibody might act as an important pathogenic factor in the process of axon degeneration. Key words: Campylobacter jejuni; Peripheral nervous system diseases