The cryptic title of this post will hopefully make sense by the time you have finished reading the material present here.
This week, new research from the USA points towards an increased risk of Parkinson’s (PD) for people that suffer from inflammatory bowel disease (IBD).
That same research, however, also points towards a clinically available treatment that appears to reduce the risk of Parkinson’s in individuals affected by inflammatory bowel disease. That treatment being: anti–tumor necrosis factor antibodies (TNF AB). Is that title making sense yet? If not, read on.
In today’s post, we will outline what inflammatory bowel disease is, review what the new research found, and discuss what is known about TNF in Parkinson’s.
Inflammatory bowel disease. Source: Symprove
Inflammatory bowel disease (or IBD) is one of these umbrella terms that is used to refer to a group of inflammatory conditions of the large and small intestine:
The large and small intestine. Source: Adam
The symptoms of IBD can include abdominal pain, diarrhoea, vomiting, rectal bleeding, severe internal cramps/muscle spasms in the region of the pelvis, and weight loss.
There has been an increased incidence of IBD since World War II, which could be associated with increased awareness and reporting of the condition, but it could also be linked with increases in meat consumption (Click here to read more about this). For example, in 2015, an estimated 1.3% of U.S. adults (3 million) were diagnosed with IBD, which was a large increase on the levels in 1999 (0.9% or 2 million adults – Source: CDC).
This is delightful, but what does it have to do with Parkinson’s?
So this week, an interesting study was published on the Journal of the American Medical Association – Neurology edition website:
In Silicon valley (California), everyone is always looking for the “next killer app” – the piece of software (or application) that is going to change the world. The revolutionary next step that will solve all of our problems.
The title of today’s post is a play on the words ‘killer app’, but the ‘app’ part doesn’t refer to the word application. Rather it relates to the Alzheimer’s disease-related protein Amyloid Precursor Protein (or APP). Recently new research has been published suggesting that APP is interacting with a Parkinson’s disease-related protein called Leucine-rich repeat kinase 2 (or LRRK2).
The outcome of that interaction can have negative consequences though.
In today’s post we will discuss what is known about both proteins, what the new research suggests and what it could mean for Parkinson’s disease.
Seattle. Source: Thousandwonders
In the mid 1980’s James Leverenz and Mark Sumi of the University of Washington School of Medicine (Seattle) made a curious observation.
After noting the high number of people with Alzheimer’s disease that often displayed some of the clinical features of Parkinson’s disease, they decided to examined the postmortem brains of 40 people who had passed away with pathologically confirmed Alzheimer’s disease – that is, an analysis of their brains confirmed that they had Alzheimer’s.
What the two researchers found shocked them:
Title: Parkinson’s disease in patients with Alzheimer’s disease.
Authors: Leverenz J, Sumi SM.
Journal: Arch Neurol. 1986 Jul;43(7):662-4.
Of the 40 Alzheimer’s disease brains that they looked at nearly half of them (18 cases) had either dopamine cell loss or Lewy bodies – the characteristic features of Parkinsonian brain – in a region called the substantia nigra (where the dopamine neurons are located). They next went back and reviewed the clinical records of these cases and found that rigidity, with or without tremor, had been reported in 13 of those patients. According to their analysis 11 of those patients had the pathologic changes that warranted a diagnosis of Parkinson’s disease.
And the most surprising aspect of this research report: Almost all of the follow up studies, conducted by independent investigators found exactly the same thing!
It is now generally agreed by neuropathologists (the folks who analyse sections of brain for a living) that 20% to 50% of cases of Alzheimer’s disease have the characteristic round, cellular inclusions that we call Lewy bodies which are typically associated with Parkinson disease. In fact, in one analysis of 145 Alzheimer’s brains, 88 (that is 60%!) had chemically verified Lewy bodies (Click here to read more about that study).
A lewy body (brown with a black arrow) inside a cell. Source: Cure Dementia
Oh, and if you are wondering whether this is just a one way street, the answer is “No sir, this phenomenon works both ways”: the features of the Alzheimer’s brain (such as the clustering of a protein called beta-amyloid) are also found in many cases of pathologically confirmed Parkinson’s disease (Click here and here to read more about this).
So what are you saying? Alzheimer’s and Parkinson’s disease are the same thing???