Biomarkers in spinal fluid of patients with dementia

BACKGROUND: We wanted to assess whether biomarkers abeta42, tau and p-tau could differentiate between Alzheimer's disease and other dementia illnesses. MATERIAL AND METHODS: Following systematic Pubmed searches, 25 articles which reported sensitivity and specificity for Alzheimer's disease and other dementias were included. RESULTS: Most studies showed significant differences for all three markers between Alzheimer's disease and other dementia illnesses, except abeta42 which did not differ between Alzheimer's disease and dementia with Lewy bodies. Alzheimer's disease was distinguished from vascular dementia with sensitivities and specificities 77 % - 87 % and 62-80 % (abeta42); 79-100 % and 14-100 % (tau); and 78-80 % and 63-96 % (p-tau181). Alzheimer's disease and dementia with Lewy bodies were differentiated by tau and p-tau181 with sensitivities and specificities of 72-94 % and 53-92 %, and of 68-85 % and 61-85 %. Markers separated Alzheimer's disease from frontal lobe dementia with sensitivities and specificities of 37-91 % and 59-92 % (abeta42), 58-88 % and 68-92 % (tau) and 44-91 % and 79-100 % (p-tau181). INTERPRETATION: Methodological weaknesses impede the interpretation. CSF markers are not yet sufficient to differentiate between Alzheimer's disease and other forms of dementia.