Autoimmune disease in Cats

Autoimmune disease in Cats

Autoimmune disease and allergies

Question: Kitty Ranger has an autoimmune disease, like lupus or whatever. Now I'm wading towards the deep end, here, but I've been surfing for information about various aspects of this problem and have come across two different and interesting possibilities:

1. According to a bunch of cites on Medline, parasitic infections can trigger autoimmune responses in humans.

2. Some paper I saw recently (the NYT? I'll try to find it and send it along) suggested that deliberately infecting patients with non-invasive parasites (the researcher used a form of worms that don't colonize in humans) can actually lessen symptoms of autoimmune diseases.

Are these contradictory or merely aspects of the same thing? Anyway. When I got him, Ranger had tapeworms (and fleas, and ear fungus) but no stomatitis. Could the tapeworms have been a factor? Could they have (a) caused the present lymphocytic stomatitis or (b) suppressed the stomatitis while they were active?

Like I said, deep end. But I am faced with a cat who is in pain when he eats and has not responded to oral prednisone so will probably need regular injections for the foreseeable future, if THOSE even work any more. I'm just trying to figure out WHY and/or HOW.

Thanks for bearing with me, S.

Answer: S.

A long time ago I attended a seminar on allergies and the speaker (I think it was Dr. Ihrke from UCD) said that allergies were very uncommon in the Amazon river basin, presumably because the people and pets in that region are heavily infested with parasites. The reasoning behind this thinking is that allergies are associated with the same portion of the immune system whose job it is to fight off parasites. When there are no parasites, there may be some chance that the immune system becomes "bored" and looks for a job to do. When there is none, it creates one -- allergies! This may also hold true for immune mediated disease, if the entire white blood cell system is considered.

I honestly don't know if it is true that allergies are less common in people in the Amazon river basin and I don't know if the current treatments with non-lethal parasites will prove to be a good thing in the long run. I do think that if this theory does hold true for disorders of the gastrointestinal tract it may be that a stronger link to allergies as an underlying cause of the problems seen is likely to be present than we are currently aware of.

The flip side of this story is immune system disease that is triggered by parasites. There is almost no question that this can occur, especially with blood borne parasites. In this case, what usually happens is that a parasite has an affinity for a particular cell type (red blood cells) and invades them. The body's defense mechanism identifies the invader but also identifies the red blood cell it is attached to as a problem -- and begins to destroy red blood cells. Once this process is started it can be very hard to stop. It is likely that parasites that infect other cells or migrate through the body will occasionally cause similar problems.

At present, I also do not know if anyone really has any idea what the underlying cause of lymphocytic/plasmacytic gingivitis is. It is hard for me to believe that parasites trigger this particular reaction but I have been wrong about other things in the past so I recognize that I could be wrong about this, too.

I'll try to keep an eye out for more definite information on the possible causes of this condition for you.

Mike Richards, DVM 10/15/99