Cerebrospinal Fluid p‑Tau181/Amyloid Beta 42 Ratio Identifies Lymphatic-Venous Anastomosis Patients Who Respond to and Benefit from the Surgery for Relief of Cognitive Impairment with a Diagnostic Accuracy of 0.744

Responders (R) and Non-Responders (NR) to lymphatic-venous
anastomosis
(LVA) surgery for relief of cognitive impairment show significant
difference in their p-tau181/Aβ42 ratios via enzyme-linked immunosorbent
assay (ELISA) of their cerebrospinal fluid (CSF). LVA involves the
conjugation of a lymph vessel to a small vein in the neck to facilitate
lymph flow. The R and NR groups were classified using five standard
cognitive assessment tools: Mini-Mental State Examination (MMSE),
Montreal Cognitive Assessment (MoCA), Alzheimer’s Disease Assessment
Scale – Cognitive subscale (ADAS-Cog), Activities of Daily
Living (ADL) and Clinical Dementia Rating (CDR), and augmented by
clinical assessments. ELISA results for 43 patients were available.
Welch’s t test and Mann–Whitney U-test
revealed significant difference between R and NR’s p-tau181
value and p-tau181/Aβ42 ratio. Using a p-tau181/Aβ42 cutpoint
of 0.0923 allows patient selection for LVA with a specificity of 0.800,
sensitivity of 0.667, positive predictive value (PPV) of 0.706, and
negative predictive value (NPV) of 0.769. The diagnostic accuracy
is 0.744. The receiver operating characteristic (ROC) curve gives
an area under the curve (AUC) of 0.793, which compares well with those
of biomarker tests currently in use: prostate specific antigen (PSA),
Straticyte and Oncotype DX. The p-tau181/Aβ42 ratio could serve
to predict LVA’s effectiveness in alleviating AD patients’
symptoms and to rule-in patients for LVA, once validation from a larger
patient cohort is available.