Neurological features and anti-myeloperoxidase antibodies in rheumatoid arthritis patients

ABSTRACT

To determine if there is a relation between the level of anti-myeloperoxidase antibodies [AMP] and the occurrence of peripheral neuropathy [PN] in rheumatoid arthritis [RA] patients. Serum levels of C3, C4 and circulating immune complex [CIC] were also assayed to determine whether their levels are related to RA activity or not. The levels of AMP antibodies as well as that of C3, C4 and circulating immune complex [CIC] were measured in 48 RA patients. All patients underwent electrophysiological studies for both median and radial nerves in the upper limbs and the sural nerve in the lower limbs to detect peripheral neuropathy. Peripheral neuropathy was found in thirteen out of 48 patients. There was a significantly higher level of serum AMP antibodies in patients with PN, the mean being 11.4 +15.1 microg/ml as compared to patients without PN [4.5 + 2.1 microg/ml]. Serum level of C4 was significantly lower in patients with PN [30.9 +10.4 IU/ml] than those without PN [37.2+ 17.1 IU/ml]. No significant difference was found as regards either C3 or CIC between the two groups. Also, a significant correlation was found between AMP and clinical vasculitis. Peripheral neuropathy seems to be a common complication of RA. The high level of AMP anti-bodies in RA complicated with PN suggests that PN is associated with vasculitis that may be fatal if it involves other main organs