New PET agent detects earliest signs of Alzheimer’s disease

A new highly selective PET agent can detect overexpression of monoamine oxidase-B (MAO-B) in cognitively impaired individuals with high levels of amyloid beta (Ab), one of the earliest signs of Alzheimer’s disease, according to a study published in October. issue of Art Journal of Nuclear Medicine.

radio tracer, ¹⁸F-SMBT-1 allows for better understanding of the role of inflammation in Alzheimer’s disease, allowing for more accurate staging and earlier prognosis. Brain inflammation that accompanies Alzheimer’s disease involves reactive astrocytes, which are cells that overexpress MAO-B.

Recently developed ¹⁸The F-SMBT-1 radiointerface is highly selective for MAO-B and consequently enhances binding to reactive astrocytes. “This increased attachment is indicative of that ¹⁸F-SMBT-1 could potentially be used as a surrogate marker for reactive astrogliosis in Alzheimer’s disease,” said Victor Willeman, MD, professor of psychiatry at the University of Pittsburgh in Pittsburgh, Pennsylvania.

The study aimed to characterize ¹⁸Binding of F-SMBT-1 to reactive astrocytes across the Alzheimer’s disease continuum. The study participants included three clinical groups: 57 control participants without cognitive impairment, 12 subjects who met the criteria mild cognitive impairment (MCI), and eight subjects meeting criteria for Alzheimer’s disease.

The participants underwent several types of visualization, including ¹⁸F-SMBT-1 PET, Ab PET, tau PET and MRI. Images were normalized and statistical analysis was performed for evaluation ¹⁸F-SMBT-1 binding as a function of pathological Ab and tau load. ¹⁸F-SMBT-1 was found to correlate strongly with Ab load and much less with tau load.

The three clinical groups were then classified based on their Ab status (either Ab+ or Ab-). Significant differences in ¹⁸F-SMBT-1 binding was detected among Ab- participants in the control and MCI groups. In Ab+ subjects with Alzheimer’s disease, ¹⁸F-SMBT-1 binding was significantly higher. the main thing ¹⁸F-SMBT-1 binding was significantly higher in Ab+ control group compared to the Ab control group.

“It should be noted that areas of the brain where we saw it above ¹⁸F-SMBT-1 binding in controls are areas known for early Ab deposition. This suggests that reactive astrocytes are associated with early AT deposition in the preclinical stages of Alzheimer’s disease and likely play a role in clinical progression,” Willeman said.

He continued, “Implementation ¹⁸F-SMBT-1 will elucidate the role of reactive astrogliosis in neurodegenerative diseases, not just Alzheimer’s disease, and its potential independent and/or synergistic effects on pathology, neurodegeneration, cognition and disease progression. This has the potential to define and clarify the diagnostic, staging and prognostic role of reactive astrogliosis in these conditions.”