Microtubule-associated protein tau (phosphorylated at Threonine 217) (pTau-217)

pTau-217 is a specific phosphorylated isoform of the microtubule-associated protein tau (MAPT), characterized by phosphorylation at the threonine 217 residue [1, 16]. In healthy neurons, tau protein stabilizes microtubules; however, in Alzheimer's disease (AD), it undergoes hyperphosphorylation, leading to its dissociation from microtubules and the formation of toxic neurofibrillary tangles [3, 5]. pTau-217 has emerged as a premier blood-based biomarker for AD due to its high sensitivity and specificity, often rising up to 20 years before clinical symptoms appear and correlating strongly with amyloid-beta and tau PET imaging results [2, 8, 39]. Beyond its diagnostic utility, pTau-217 is a significant therapeutic target for monoclonal antibodies, such as posdinemab (JNJ-63733657), which aim to clear pathological tau species and inhibit the transneuronal spread of tau seeds [20, 21, 23]. By targeting this specific epitope, researchers hope to slow the progression of neurodegeneration and cognitive decline in patients with early-stage Alzheimer's disease [22, 26].

Other names

Phospho-tau217p-tau217Tau phosphorylated at Thr217pT217p217+tau

Passive immunotherapy targeting the pT217 epitope to clear pathological tau and inhibit seed propagation [20, 23].