Monocyte dysfunction in Sydenham's chorea patients

Until now, there are no conclusive data about the mechanisms involved in motor symptoms of Sydenham's chorea (SC). Taking into account the autoreactive antibody-mediated hypothesis of SC pathogenesis, the SC may be associated with uncontrolled immune mechanisms. Besides the antibody hypothesis, the innate immune system has been underappreciated. Hence, we evaluated the activation state of monocytes, cells that are precursors of macrophages, to characterize the inflammation profile of patients. We assessed the surface molecules CD80, CD86, and human leukocyte antigen DR expression in patients with SC by flow cytometry analysis. Our results showed a decreased CD14⁺ (monocyte) frequency, with concomitant increased CD14^- frequency inside monocyte population. Although monocyte population showed a decreased human leukocyte antigen DR and CD86 frequencies, the CD14^- population showed an increased frequency of CD80⁺ monocyte from SC compared with controls. These data suggest that monocytes showed a reduced costimulatory potential in SC.