Dr RG Wiseman Pinto
A newly approved blood test offers a promising, non-invasive approach to support the early diagnosis of Alzheimer's disease in adults aged 55 years and above.
Alzheimer's disease is named after Dr Alois Alzheimer (Dr. Aloysus Alzheimer), a German psychiatrist, neuroanatomist and neuropathologist, who lived from June 14, 1864 to December 19, 1915. In 1906, he observed characteristic changes in the brain of a woman who had died after suffering from an unusual mental illness. In 1910, Emil Kraepelin published a book in which he introduced the term Alzheimer's disease. Dr Alzheimer passed away in 1915 at the age of 51.
A significant advance in the early diagnosis of Alzheimer's disease is the introduction of a new blood test by Fujirebio Diagnostics. The test, known as Lumipulse G, is performed on the Lumipulse G600II instrument. Recently approved by the US Food and Drug Administration (FDA), it was launched in the United States in June 2025.
The blood test is intended to support the early diagnosis of Alzheimer's disease in patients aged 55 years and above. It uses chemiluminescent enzyme immunoassay technology, which offers high precision and sensitivity.
The test measures the ratio of two important biomarkers in the blood. The p-Tau 217 protein is associated with the neurofibrillary tangles seen in Alzheimer's disease, while beta amyloid 1-42 is responsible for the formation of amyloid plaques. The ratio of p-Tau 217 to beta amyloid 1-42 provides valuable information to assist in diagnosis.
The results of this blood test should always be interpreted along with the patient's clinical findings and other relevant medical information. It is a non-invasive investigation and is meant to support clinical assessment rather than replace it. Importantly, it is not a screening test.
Clinical trials evaluating this test included 500 patients with mild cognitive impairment. Six additional biomarkers were also studied: Volumetric MRI, PET-FDG, EEG, cerebrospinal fluid (CSF), APOE apolipoprotein genotype and blood APOE.
Currently, Alzheimer's disease is diagnosed using cognitive tests, memory assessment, brain imaging such as MRI and PET scans, and cerebrospinal fluid (CSF) analysis obtained through a spinal tap.
Alzheimer's disease remains a major global health burden. Around 50 million people worldwide are affected, including 7 million in the United States. It is estimated that 10% of the world's population above 65 years of age suffers from Alzheimer's disease, and this figure is expected to double by 2050.
The drugs currently used in the treatment of Alzheimer's disease include Leqembi (lecanemab) and Kisunla (donanemab).
(The writer is a Professor of Pathology, former Head of Department at Goa Medical College, former Dean of Goa University, and the current President of the Asian Society of Cytopathology)
