Antibodies target microvessels in neuromyelitis optica and multiple sclerosis patients

This study investigated the presence of serum antibodies targeting microvessels in Chinese patients with multiple sclerosis (MS) and neuromyelitis optica (NMO).

Serum samples were collected from 50 patients with NMO, 10 with longitudinally extensive transverse myelitis (LETM), 4 with recurrent optic neuritis, 42 with MS and 27 controls. Serum antibodies binding to microvessels were measured by indirect immunofluorescence (IIF) assay of tissue sections from the brain, stomach and pancreas, and human umbilical vein endothelial cells (HUVEC). Aquaporin-4 (AQP4) antibodies were detected using a cell-based assay.

Indirect immunofluorescence assay of tissue sections from 42 samples (30.4%, 42/138) were positive for microvessel antibodies, where microvessel antibody positivity was 38% (19/50) in patients with NMO, 57.1% (8/14) in high-risk NMO (hrNMO), 26.2% (11/42) in MS, and 14.8% (4/27) in controls. Based on HUVEC analysis, 14 patients with NMO (28%, 14/50), 5 with hrNMO (35.7%, 5/14), 15 with MS (35.7%, 15/42), and 5 controls (18.5%, 5/27) had (AECA). Sixteen patients (32%, 16/50) with NMO, four with hrNMO (28.6%, 4/14), two with MS (4·8%, 2/42), and 0% of controls were positive for antinuclear antibodies (ANA). In MS patients, seropositive AECA MS patients had higher numbers of relapse events and increased spinal lesions than seronegative MS patients (P < 0.05).

Serum microvessel antibodies were present in patients with NMO and MS and the role of microvessel antibodies in diseases may be heterogeneous. This study suggests that AECA may have some significance in MS patients.