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Immunology

John Cohen, MDCM, PhD


Q: It has been suggested to me that when you have one or more autoimmune conditions, you do not pick up many "ordinary" illnesses like colds and flu. The suggestion implied that my immune system is so revved up that it fights off those every day illnesses, Is there any evidence supporting that?
A: I don’t think that observation holds up. Most people with a true diagnosis of autoimmunity are on some form of therapy, and those are, to be effective, somewhat immunosuppressive; so people being treated that way may be more, not less, susceptible to infections. The immune system is not so much revved up, as unregulated.

Q: Has there ever been any research into the possibility of nutritional causes of autoimmune disorders?
A: Oh, yes. But except in specific cases like celiac disease, there has been no smoking gun. Newer studies, looking into the different bacterial populations that live in our intestines, may offer exciting new insights.

Q: How do drugs like Humira work for Crohn's Disease?
A: Humira (adalimumab) is a therapeutic monoclonal antibody directed against the inflammatory molecule called “TNF.” As an antibody, it circulated and binds to TNF wherever it finds it, neutralizing its action. It is quite effective at doing this! The major downsides are that is can increase risk of some infections, and it’s very expensive.

Q: How would a proposed cancer vaccine work? How can self-tolerance be overcome?
A: Cancer cells are recognized by the immune system, a fact that surprises many people; that’s because they express mutated proteins (which are new to the body, therefore “foreign” from the immune system’s standpoint), or they greatly overexpress a normal protein to the point where even a weak immune response against it may be effective. But tumor cells, as the tumor develops, learn to evade most of the attempts of the immune system to attack them. Cancer immunologists are pretty smart, too, and are developing fascinating approaches to immune stimulation.

Q: How is rheumatoid arthritis linked to the immune system?
A: Although we don’t know all the answers, in RA we can readily detect activated T cells—like the ones that destroy tuberculosis—directed against collagen and other constituents of the joints. Why did they occur? The answer is: genetics, environment, and bad luck. We’re still learning the details of those three.

Q: What is serum sickness? Do you use antibodies for snake venom?
A: Yes, the only treatment we have for snake bites is antibody to the venom. In most cases these antibodies are from immunized animals. The dose required is large, and the antibodies are foreign to the human immune system, which makes its own antibodies against the animal antibodies! They make complexes which settle out in the joints, the skin, and the kidneys: serum sickness. Once the foreign proteins are gone the patient can recover, but it’s a rocky road.

Q: How can asthma be outgrown? Personal anecdote that my brother outgrew his chronic asthma when he was 13.
A: Good for him! That’s not uncommon. All we can guess is that the immune system changes throughout life, and sometimes that’s not so good, but often it is.

Q: How can you help your immune system?
A: Eat plenty of pizza. There isn’t any specific food or vitamin that you need, just a well-balanced diet; sorry, health food stores, but you are fooling a lot of nice people with all your so-called Immune Strengtheners.

Q: Can you explain shingles as the latent chicken pox virus?
A: When you get chicken pox, some of the virus goes “latent” in nerve structures along the spinal cord called the dorsal root ganglia. There they are dormant, so the immune system doesn’t see them. Much later, they may wake up, reproduce, and move down the nerve roots to the skin, where they infect, causing shingles. The immune system now sees them and attacks (that’s part of the painfulness of shingles) and the virus finally goes back to hide. But nerve damage can happen, leading to the painful and persistent “post-herpetic neuralgia.”

Q: In a nutshell, what exactly is AIDS?
A: Infection with the virus called HIV leads to the condition called AIDS when there are serious “opportunistic” infections (ones that cannot make a person with a healthy immune system sick) or the number of helper T cells in the blood falls below 200 per cubic millimeter (normal is about 1000).

Q: Do you believe the immune system can be reset, i.e. if early bio markers suggest RA, can anything be done (like short-term immune suppression)??
A: That is a topic seriously being debated among immunologists and rheumatologists. At this time, resetting the immune system might have to involve destroying what you have with drugs and radiation, and then repopulating the body from stem cells. This is a lot too rough for someone at the beginning of a disease which is rarely, by itself, fatal.

Q: Does polio make a person sterile?
A: No. Mumps can, if a male gets it after puberty because he was not immunized as a child (this isn’t known by most vaccine refusers). Extensive nerve damage in polio might make a person impotent, but not sterile. Some religious leaders in certain countries have claimed the polio vaccine makes boys sterile; but this is their way (I think) of exerting their authority over the people, while ignoring the damage it can cause.

Q: What can you tell us about the progress being made in treating "flesh-eating bacteria"?
A: Necrotizing fasciitis is the medical term for a so-called flesh-eating bacterial infection. It is an infection of the deep skin and underlying tissues, including a layer of connective tissue or fascia. The infection moves rapidly as the fascia provides a plane along which the organisms can spread. Many different bacteria, including Strep and Staph, can cause it; they have in common the production of cell-killing toxins (the bacteria do not actually eat flesh). Treatment has to consist of surgery to remove infected tissue, and antibiotics to try to kill the bacteria. Hyperbaric chambers, if available locally, can help keep tissue alive. There is really nothing new, except a strong educational push so that diagnosis can be made early (which improves results considerably). Fever, nausea, pain, skin discoloration, and the presence of a wound, are all early signs; but in many cases there is no detectable wound. Immunocompromised and chronically ill people are at increased risk.