On 11 March, a team of researchers published an article on blood phosphorylated tau in immunoglobulin light chain (AL) and transthyretin (ATTR) amyloidosis in the journal Nature Medicine. The study found that serum p-tau181 levels were higher in people with AL and ATTR amyloidosis than in controls, with stronger effects in AL amyloidosis and in people with polyneuropathy.
The researchers analysed phosphorylated tau in serum from four cohorts of people with systemic amyloidosis. In one cohort, they also measured p-tau217 and found similar increases, with p-tau217 distinguishing people with AL and ATTR amyloidosis from controls as well as p-tau181.
The findings are relevant for the interpretation of blood tau biomarkers, as the article suggests that elevated serum p-tau levels are not specific to Alzheimer’s disease. The study also reported that people with non-amyloidosis forms of polyneuropathy did not show elevated p-tau181, and that in presymptomatic genetic ATTR, p-tau181 increased with predicted years from symptom onset.
The authors concluded that elevated serum p-tau levels may also serve as a diagnostic tool for ATTR and AL amyloidosis, with potential use in distinguishing amyloidosis-related polyneuropathy from polyneuropathy of other causes. The article has been published in open access and can be read here: https://doi.org/10.1038/s41591-026-04272-2
