Serum IgG to brain microvascular endothelial cells in multiple sclerosis

Area of Science:

• Neuroimmunology
• Vascular Biology

Background:

• Multiple sclerosis (MS) involves immune system attacks on the central nervous system.
• The integrity of the blood-brain barrier (BBB) is crucial in MS pathogenesis.
• Brain microvascular endothelial cells (BMECs) form the BBB and may be targets of autoimmune responses.

Purpose of the Study:

• To investigate the presence and significance of serum IgG antibodies against BMECs in patients with multiple sclerosis.
• To determine if anti-BMEC antibodies correlate with disease activity and MRI findings in MS.

Main Methods:

• Sera from 50 MS patients, 24 with other neurological diseases, and 30 healthy controls were analyzed.
• Indirect immunofluorescence on BMEC cultures was used to detect anti-BMEC IgG.
• Specificity was confirmed using human umbilical vein endothelial cells and brain pericytes.
• Correlation with Gadolinium-enhanced MRI lesions was assessed in 36 MS patients.

Main Results:

• Anti-BMEC IgG was detected in active relapsing-remitting (RR) MS (12/16) and relapsing-progressive (RP) MS (1/8), but not in inactive RR or primary progressive (PP) MS patients or controls.
• Antibodies were significantly associated with the presence of Gadolinium-enhanced MRI lesions (9/12 with lesions vs. 1/24 without).
• Immune reaction specificity for brain endothelium was confirmed.

Conclusions:

• Serum IgG against BMECs is a potential biomarker for active disease in relapsing-remitting and relapsing-progressive MS.
• Anti-BMEC antibodies may help differentiate active MS (RR/RP) from primary progressive MS.
• These antibodies might indicate BBB involvement or serve as a marker of disease activity, irrespective of their direct pathogenetic role.