The involvement of specific anti myelin basic protein antibody-forming cells in multiple sclerosis immunopathology

Irrespective of the large body of literature on the putative role of antibodies in the development of multiple sclerosis (MS), the detection of specific antibody-forming B cells (AFCs) in the central nervous system (CNS) tissues has not been described. In this study we show that autoantigen-specific AFCs can be found in CSN tissue sections of MS patients. Applying a newly developed myelin basic protein (MBP)-enzyme conjugate technique, we have detected MBP-specific AFCs in autopsy periventricular white matter and cerebellum tissue sections of MS patients. We demonstrated the presence of MBP-specific AFCs in CNS tissue sections in five out of 12 MS patients. No MBP-specific AFCs were detected in CNS tissue sections of 11 patients with other neurological diseases, such as Parkinson's and Alzheimer's disease, or in brain tissue sections of eight deceased persons without neurological diseases. In MS patients, anti-MBP AFCs were present in brain tissue sections both with and without plaques. The proportion of MBP-specific AFCs in some of the MS patient brain tissues reached over 50% of all AFCs. The high relative frequency of the anti-MBP AFCs and their localization in periventricular white matter and cerebellum of MS patients only, suggests that anti-MBP AFCs represent a cell population, which could play an important role in MS immunopathology.