- Pesquisadores da University College London defendem que terapias contra o Alzheimer devem mirar o gene Apoe, em especial duas variantes de risco: Apoe3 e Apoe4.
- O estudo, com mais de quatrocentos e cinquenta mil pessoas de ascendência europeia, aponta que, sem os efeitos dessas variantes, entre setenta e dois e noventa e três por cento dos casos de Alzheimer e cerca de quarenta e cinco por cento de todo o dementia não ocorreriam.
- Fármacos que removem proteínas tóxicas do cérebro já chegaram ao mercado, mas oferecem benefícios modestos e foram rejeitados pela National Institute for Health and Care Excellence (Nice) para uso amplo no Reino Unido.
- O Apoe é essencial para o transporte de colesterol e outras gorduras no corpo e no cérebro; eliminá-lo completamente geraria problemas. Futuras terapias poderiam editar ou reduzir a atividade das variantes, porém não são imediatas nem isentas de risco.
- Existem visões diferentes: alguns especialistas destacam a importância de entender fatores de risco para tratamentos eficazes, enquanto outros ressaltam que mais de 99% das pessoas carregam Apoe3 ou Apoe4, o que torna o tratamento amplo um desafio.
Researchers from University College London (UCL) defend a shift in Alzheimer’s therapy strategy, focusing on the Apoe gene. They argue that blocking the harmful effects of its variants could prevent most cases of the disease.
The team analyzed medical records from over 450,000 individuals of European ancestry to assess how Apoe variants influence risk. Apoe has three main forms: Apoe2, Apoe3 and Apoe4, inherited from both parents.
Already, Apoe4 is known to raise risk, while Apoe3 is usually neutral and Apoe2 is often protective. The study reframes risk by suggesting that both Apoe3 and Apoe4 contribute to the likelihood of developing Alzheimer’s.
If interventions could neutralize the detrimental effects of Apoe3 and Apoe4, researchers say a large share of Alzheimer’s and other dementias might be preventable. The authors caution that this is a big if.
Apoe is essential for transporting fats in the body and brain, so complete removal could cause problems. Future therapies might tweak the variants or dampen their activity, but such approaches are not ready for clinical use and carry risks.
The work notes that more than half a million people in the UK and over 40 million worldwide live with Alzheimer’s. Widespread treatment would affect a substantial portion of the population, raising practical and ethical questions.
The study received mixed reactions. Some experts compare the potential impact to broad changes in road safety, while others emphasize the need for careful risk assessment and further research before clinical application.
Alzheimer’s Research UK highlights that Apoe3’s role in risk is significant, but not definitive for all individuals. They stress that many factors, including non-genetic risks, influence dementia outcomes.
The researchers acknowledge the complexity of Apoe-related risk and call for further study on diverse populations. They also note that Apoe testing is not routinely available through public health services in the UK.
Fonte: estudo de UCL, com contribuições de especialistas em genética e neurodegeneração. As informações devem ser verificadas por institutos de saúde para orientações clínicas futuras.
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