Relationship Between Amyloid Β (aβ) Protein and Inflammatory Markers in Down Syndrome (DS) (98.19)

Brain autopsy data from persons with DS showed that the neuropathology of Alzheimer disease (AD) is always present in DS 40 years of age and older. The core protein of the neuritic plaque is Aβ protein. Studies have suppoted the role of immune abnormalities and inflammation in the pathogenesis of DS. We hypothesized that the levels of TNFα and Cystatin C would be higher in DS than controls, and would correlate with Aβ levels. The study included 40 persons with DS (44±8 years old) and age-matched controls. Plasma levels of Aβ40 and Aβ42 , TNFα and Cystatin C were quantitated by using an ELISA. Aβ40 and Aβ42, TNFα and Cystatin C levels were higher in DS than controls (p<.001). Although there was significant relation between Aβ40 and Aβ42 levels (r=.6; p<.01)in DS, there was no relation between Aβ40 and Aβ42 levels with TNFα or Cystatin C. The higher TNFαand Cystatin C levels indicate a chronic state of immune activation in DS. Because there was no relation between Aβ and TNFα or Cyststin C the data suggests that increases in TNFα and Cystatin C reflect more infections in DS than AD neuropathology.