Brown J, Coles A, Jones J. First use of alemtuzumab in Balo’s concentric sclerosis: a case report. Mult Scler. 2013 Jul 25. [Epub ahead of print]
Balo’s concentric sclerosis (BCS) is a rare demyelinating disorder of the central nervous system. The humanised monoclonal antibody alemtuzumab has shown efficacy in another demyelinating disorder, relapsing-remitting multiple sclerosis. We aimed to explore its efficacy in treatment-refractory BCS. A 52-year-old male with radiologically confirmed progressive BCS resistant to steroids, plasmapharesis and cyclophosphamide was administered a standard protocol of alemtuzumab. Treatment failed to slow his decline; he died 6 months after administration. Why alemtuzumab induced no clinical or radiological impact may be multifactorial.
Balo concentric sclerosis is a demyelinating disease similar to standard multiple sclerosis, but with the particularity that the demyelinated tissues form concentric layers. It was believed that the prognosis was similar to Marburg multiple sclerosis, but now they know that patients can survive, or even have spontaneous remission and asymptomatic cases.
The rings may be caused by a physiological hypoxia in the lesion, which is in turn countered by expression of stress proteins at the border. This expression and counter-expression forms rings of preserved tissue within the lesion and rings of demyelinated tissue just beyond where the previous attack had induced the protective stress proteins. Hence, subsequent attacks form a concentric ring.
It is also common that the clinical course is primary progressive is this why alemtuzumab did not stop the progress of disease.