INTRODUCTION: @entity195 ( @entity195 ) is characterized by the deposition of tau and amyloid in the brain. Although the core cerebrospinal fluid (CSF) @entity195 biomarkers amyloid b peptide 1-42 (Ab1-42), total tau (t-tau) and phosphorylated tau 181 (p-tau181) show good diagnostic sensitivity and specificity, additional biomarkers that can aid in preclinical diagnosis or better track disease progression are needed. Activation of the complement system, a pivotal part of @entity32 , occurs at very early stages in the @entity195 brain. Therefore, CSF levels of complement proteins that could be linked to cognitive and structural changes in @entity195 may have diagnostic and prognostic value. METHODS: Using xMAP   technology based assays we measured complement 3 ( @entity4417 ) and @entity4050 ( @entity4050 ) in the CSF of 110 controls (CN), 187 @entity73 ( @entity73 ) and 92  @entity195 subjects of the @entity195 Neuroimaging Initiative (ADNI) at baseline. All ADNI @entity1 underwent clinical follow-up at 12  month intervals and @entity73 subjects had additional visits at 6 and 18  months. The association between CSF biomarkers and different outcome measures were analyzed using Cox proportional hazard models (conversion from @entity73 to @entity195 ), logistic regression models (classification of clinical groups) and mixed-effects models adjusted for age, gender, education, t-tau/Ab1-42 and @entity2204 presence (baseline and longitudinal association between biomarkers and cognitive scores). RESULTS: Although no association was found between the complement proteins and clinical diagnosis or cognitive measures, lower levels of @entity4417 (b   =   -0.12, p   =   0.041) and @entity4050 (b   =   -0.075, p   =   0.041) were associated with faster @entity73 in @entity73 subjects as measured by the @entity195 Assessment Scale-cognitive subscale (ADAS-Cog) test. Furthermore, lower @entity4050 levels were associated with larger lateral ventricular volume (p   =   0.024), which is indicative of @entity1010 . CONCLUSIONS: Our study confirms a lack of suitability of CSF C3 and @entity4050 as diagnostic biomarkers of @entity195 , but points to their modest potential as prognostic biomarkers and therapeutic targets in @entity73 @entity1 .

Low levels of cerebrospinal fluid complement 3 and XXXX predict faster @entity73 in @entity73 .

@entity1 :: ('9606', 'Species') :: ['participants', 'patients'] @entity32 :: ('MESH:D007249', 'Disease') :: ['inflammation'] @entity2204 :: ('348', 'Gene') :: ['APOE   4'] @entity73 :: ('MESH:D003072', 'Disease') :: ['cognitively impaired', 'cognitive decline', 'MCI', 'mild cognitive impairment'] @entity4417 :: ('718', 'Gene') :: ['C3'] @entity1010 :: ('MESH:C566985', 'Disease') :: ['brain atrophy'] @entity195 :: ('MESH:D000544', 'Disease') :: ['AD', "Alzheimer's disease"] @entity4050 :: ('3075', 'Gene') :: ['factor H', 'FH']
@entity4050 :: (3075,Gene) :: ['factor H']
