High salt diet ameliorates functional, electrophysiological and histological characteristics of murine spontaneous autoimmune polyneuropathy.

Background: It was previously reported that high salt dietary conditions can drive autoimmunity and worsen severity and symptoms of autoimmune diseases. Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a common autoimmune condition of the peripheral nervous system which leads to progressive paralysis and sensory deficits due to a demyelination and secondary axonal loss of peripheral nerves. We used a previously described model with a knockout of CD86 in non-obese diabetic mice (CD86 NOD), which results in the spontaneous development of an autoimmune peripheral neuropathy similar to CIDP and investigated the influence of a high salt diet on functional impairment, electrophysiological parameters, demyelination and neuroinflammation in these mice.

Methods: At seven weeks of age, asymptomatic female CD86 NOD mice were randomly assigned to a normal or high salt diet containing 4% sodium chloride in food and 1% in water. The diet was continued for a total of 30 weeks.

Results: Mice on the high salt diet showed a delayed onset of clinical symptoms and an ameliorated disease course with a reduced decline of locomotor function. Furthermore, electrophysiological parameters of neuropathy and demyelination were attenuated in mice on the high salt diet, which was confirmed with histological analysis. Additionally, we observed a reduced immune cell infiltration of sciatic nerves in mice which had received the high salt diet.

Conclusions: We demonstrate beneficial effects of high salt diet regarding disease progression, functional, electrophysiological and histological parameters in a transgenic mouse model of spontaneous autoimmune neuropathy.