Ontology highlight
ABSTRACT: Background
The mechanism of action of oral cladribine, recently licensed for relapsing multiple sclerosis, is unknown.Objective
To determine whether cladribine depletes memory B cells consistent with our recent hypothesis that effective, disease-modifying treatments act by physical/functional depletion of memory B cells.Methods
A cross-sectional study examined 40 people with multiple sclerosis at the end of the first cycle of alemtuzumab or injectable cladribine. The relative proportions and absolute numbers of peripheral blood B lymphocyte subsets were measured using flow cytometry. Cell-subtype expression of genes involved in cladribine metabolism was examined from data in public repositories.Results
Cladribine markedly depleted class-switched and unswitched memory B cells to levels comparable with alemtuzumab, but without the associated initial lymphopenia. CD3+ T cell depletion was modest. The mRNA expression of metabolism genes varied between lymphocyte subsets. A high ratio of deoxycytidine kinase to group I cytosolic 5' nucleotidase expression was present in B cells and was particularly high in mature, memory and notably germinal centre B cells, but not plasma cells.Conclusions
Selective B cell cytotoxicity coupled with slow repopulation kinetics results in long-term, memory B cell depletion by cladribine. These may offer a new target, possibly with potential biomarker activity, for future drug development.
SUBMITTER: Ceronie B
PROVIDER: S-EPMC5937883 | biostudies-literature | 2018 May
REPOSITORIES: biostudies-literature
Ceronie Bryan B Jacobs Benjamin M BM Baker David D Dubuisson Nicolas N Mao Zhifeng Z Ammoscato Francesca F Lock Helen H Longhurst Hilary J HJ Giovannoni Gavin G Schmierer Klaus K
Journal of neurology 20180317 5
<h4>Background</h4>The mechanism of action of oral cladribine, recently licensed for relapsing multiple sclerosis, is unknown.<h4>Objective</h4>To determine whether cladribine depletes memory B cells consistent with our recent hypothesis that effective, disease-modifying treatments act by physical/functional depletion of memory B cells.<h4>Methods</h4>A cross-sectional study examined 40 people with multiple sclerosis at the end of the first cycle of alemtuzumab or injectable cladribine. The rela ...[more]