A team at the Van Andel Research Institute recently led a study on the relationship between Parkinson’s disease and the appendix.
Viviane Labrie of Grand Rapids-based VARI served as the senior author of the study that found removing the appendix early in life reduces the risk of developing Parkinson’s disease by 19 to 25 percent.
The findings were published last week in Science Translational Medicine.
The findings show the appendix acts as a major reservoir for proteins closely linked to Parkinson’s onset and progression, which Labrie said points to the appendix as an origin site for the disease and provides a path for devising new treatment strategies.
The study, funded through Labrie’s VARI faculty startup package, involved analyzing health data of nearly 1.7-million people from two databases: the Swedish National Patient Registry, a one-of-a-kind database that contains de-identified medical diagnoses and surgical histories for the Swedish population beginning in 1964; and Statistics Sweden, a Swedish governmental agency responsible for official national statistics.
The data showed a reduced risk for Parkinson’s — which Labrie said affects less than 1 percent of the population — only when the appendix was removed early in life, years before the onset of the disease. Removal of the appendix after the disease process starts, however, had no effect on disease progression.
Analysis of the general population for the databases showed those who had undergone the operation were 19 percent less likely to develop Parkinson’s, while those in rural areas were 25 percent less likely. VARI said Parkinson’s is often more prevalent in rural populations, a trend that has been associated with increased exposure to pesticides.
The study also found the operation can delay disease progression in people who later develop Parkinson’s, pushing back diagnosis by an average of 3.6 years.
Because there are no definitive tests for Parkinson’s, VARI said people are often diagnosed after motor symptoms arise, when the disease is typically advanced and has already caused brain damage.
No apparent benefit was shown in people whose disease was linked to genetics, fewer than 10 percent of cases.
Labrie and her team also found clumps of the protein in the appendixes of healthy people of all ages, as well as those with Parkinson’s, raising new questions about how the disease forms and progresses.
Next, Labrie said the plan is to look at what factors “tip the scale in favor of Parkinson’s.”
A number of Labrie's colleagues at VARI and scientists at Michigan State University, Northwestern University, Lund University and the Paris-Saclay Institute of Neuroscience were involved in the study:
Bryan Killinger, Ph.D.
Zachary Madaj, M.S.
Patrik Brundin, M.D., Ph.D.
Lena Brundin, M.D., Ph.D.
Michigan State University
Honglei Chen, M.D., Ph.D.
Proteomics Center of Excellence at Northwestern University
Jacek Sikora, Ph.D.
Paul Thomas, Ph.D.
Daniel Lindqvist, M.D., Ph.D.
Paris-Saclay Institute of Neuroscience
Nolwen Rey, Ph.D.