Prevalence of amyloid PET positivity in XXXX syndromes: a meta-analysis.

@entity1 @entity2204 @entity303 @entity146 @entity1294 @entity1832 @entity195 @entity4943
IMPORTANCE: Amyloid-b positron emission tomography (PET) imaging allows in vivo detection of fibrillar plaques, a core neuropathological feature of @entity195 ( @entity195 ). Its diagnostic utility is still unclear because amyloid plaques also occur in @entity1 with non- @entity195 . OBJECTIVE: To use individual @entity1 data meta-analysis to estimate the prevalence of amyloid positivity on PET in a wide variety of @entity303 syndromes. DATA SOURCES: The MEDLINE and Web of Science databases were searched from January 2004 to April 2015 for amyloid PET studies. STUDY SELECTION: Case reports and studies on neurological or @entity146 diseases other than @entity303 were excluded. Corresponding authors of eligible cohorts were invited to provide individual @entity1 data. DATA EXTRACTION AND SYNTHESIS: Data were provided for 1359 @entity1 with clinically diagnosed @entity195 and 538 @entity1 with non- @entity195 . The reference groups were 1849 healthy control @entity1 (based on amyloid PET) and an independent sample of 1369 @entity195 @entity1 (based on autopsy). MAIN OUTCOMES AND MEASURES: Estimated prevalence of positive amyloid PET scans according to diagnosis, age, and @entity2204 ( @entity2204 )   4 status, using the generalized estimating equations method. RESULTS: The likelihood of amyloid positivity was associated with age and @entity2204 status. In @entity195 , the prevalence of amyloid positivity decreased from age 50 to 90 years in @entity2204 noncarriers (86% [95% CI, 73%-94%] at 50 years to 68% [95% CI, 57%-77%] at 90 years; n   =   377) and to a lesser degree in @entity2204 carriers (97% [95% CI, 92%-99%] at 50 years to 90% [95% CI, 83%-94%] at 90 years; n   =   593; P   <   .01). Similar associations of age and @entity2204 with amyloid positivity were observed in @entity1 with @entity195 at autopsy. In most non- @entity195 @entity303 , amyloid positivity increased with both age (from 60 to 80 years) and @entity2204 carriership ( @entity303 with @entity1832 : carriers [n   =   16], 63% [95% CI, 48%-80%] at 60 years to 83% [95% CI, 67%-92%] at 80 years; noncarriers [n   =   18], 29% [95% CI, 15%-50%] at 60 years to 54% [95% CI, 30%-77%] at 80 years; @entity4943 : carriers [n   =   48], 19% [95% CI, 12%-28%] at 60 years to 43% [95% CI, 35%-50%] at 80 years; noncarriers [n   =   160], 5% [95% CI, 3%-8%] at 60 years to 14% [95% CI, 11%-18%] at 80 years; @entity1294 : carriers [n   =   30], 25% [95% CI, 9%-52%] at 60 years to 64% [95% CI, 49%-77%] at 80 years; noncarriers [n   =   77], 7% [95% CI, 3%-18%] at 60 years to 29% [95% CI, 17%-43%] at 80 years. CONCLUSIONS AND RELEVANCE: Among @entity1 with @entity303 , the prevalence of amyloid positivity was associated with clinical diagnosis, age, and @entity2204 genotype. These findings indicate the potential clinical utility of amyloid imaging for differential diagnosis in early-onset @entity303 and to support the clinical diagnosis of @entity1 with @entity195 and noncarrier @entity2204 status who are older than 70 years.
