Experimental neuropathy induced by IgG from Acute Inflammatory Demyelinating Polyradiculoneuropathy plasma

This study investigated whether purified plasma IgG from patients diagnosed with Acute Inflammatory Demyelinating Polyradiculoneuropathy (AIDP) were able to transfer disease into Lewis rats. A mild adoptive transfer experimental allergic neuritis was induced in all recipient animals prior to the intravenous injection of purified AIDP or control IgG or saline. Physical and histological examination revealed that there were significant increases in neurological dysfunction and primary demyelination in 5 of the 10 AIDP IgG samples tested compared to saline alone whereas none were observed after injection of purified IgG from normal blood-bank donors. Paralysis occurred within 48 hours of active AIDP IgG injection, concurrently the somatosensory evoked potential amplitudes decreased rapidly and the latency was prolonged. The magnitude of the change was significantly greater than in the rats injected with control IgG or saline. Further investigation revealed a high proportion of AIDP donors had serum IgG reactive with peripheral nerve myelin whereas normal blood bank donors, other inflammatory neuropathies and other neurological disease cases did not. This demonstrates the pathogenic effects of AIDP IgG in vivo, inducing loss of ambulation and peripheral nerve pathology in a whole animal model in which the blood nerve barrier is compromised.