Medications that are normally taken by people who have received an organ transplant to prevent rejection of the organ may also help to stave off Alzheimer’s disease.
The two drugs, tacrolimus and cyclosporine, are considered calcineurin inhibitors and transplant patients must take them for the rest of their lives. Calcineurin is an enzyme that controls communications between brain cells and the formation of memories.
Researchers at the University of Texas Medical Branch at Galveston (UTMB) previously demonstrated that the enzyme plays a key role in the formation of toxic beta-amyloid protein and that elevated levels of calcineurin are present in Alzheimer’s patients. Their earlier research also showed that in a mouse model of Alzheimer’s, blocking calcineurin helped to restore memory.
In their latest study, the UTMB researchers examined the medical records of more than 2,600 patients who received organ transplants and were given tacrolimus or cyclosporine. The rate of Alzheimer’s disease in this group was compared against a national dataset from the Alzheimer’s Association.
Overall, no matter what the age group examined, the patients who were taking one of the two drugs had far less prevalence of Alzheimer’s and dementia than the general public, the researchers reported in the Journal of Alzheimer’s Disease. For example, while 15.3% of the general population over the age of 75 had dementia, just over 0.6% of the study group did.
“We are currently working on devising treatment strategies to obtain the same beneficial effects in [Alzheimer’s disease] humans using low doses of calcineurin inhibitors that result in minimal or no immunosuppression, thus limiting possible undesired side effects,” senior author Giulio Taglialatela, PhD, director of UTMB’s Mitchell Center for Neurodegenerative Diseases, said in a statement.
Taglialatela G, et al. Reduced Incidence of Dementia in Solid Organ Transplant Patients Treated with Calcineurin Inhibitors. J Alzheimers Dis. 2015; doi: 10.3233/JAD-150065.