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Experts in the field Clinician of the Month Jim Bischoff, M.D.
Natural Killer Cells: Your First Line of Defense Against Disease
JLML: Dr. Bischoff, how did you first get interested in Natural Killer cells?
JB: NK Cells are a critical part of the immune system, and specifically they’re a type of T-cell. We all have hundreds of millions of NK cells, made from stem cells in the bone marrow. Their job is to your first line of defense against invaders or pathogens in your body. This includes viruses, bacteria, fungi and malignant tumor cells. They can detect an invader within minutes and go to work destroying it.
NK cells produce a number of substances called cytotoxins, which are toxic to bacteria, viruses and malignant cells. They seek and destroy. They travel around the body, and when they find, for example, and unfriendly bacteria; they drill a hole in the cell’s membrane, inject it with cytotoxin, and blow it up. And then they can reload and go on and kill another one and another one. One NK cell can kill hundreds of bacteria or viruses.
NK Cells make interferon’s and interluekins, which are part of the immune system, and tumor necrosis factor, which eats tumors. NK cells participate in immune regulation, hematopoiesis [the production and maturation of blood cells from primitive stem cells in the bone marrow], reproduction, and neuroendocrine interaction.
JLML: What happens in the body when NK cell activity is low?
JB: Low or absent NK cell activity is associated with a spectrum of human diseases, and a lowered ability to deal with stressful events. Everyone I’ve tested with those diseases has had a low NK cell activity. Families with a familial history of cancer tend to test low as a family. Families with no cancer tend to run high.
People with herpes, Epstein-Barr virus, chronic colds and flues, Candida overgrowth, auto-immune disease and cancer all tend to have very low NK cell activity. People who have chronic low or border line low chronic anemia also have low NK cell activity. For example, I had a patient whose NK cell activity was 2, which is extremely low, and her hemoglobin was 5, also low, and when we got her NK cell activity up to 56 her hemoglobin came up to 14 in a fairly short period of time. This is because active NK cells stimulate the bone marrow to make red blood cells.
JLML: What can you tell us about NK cell activity and auto-immune diseases such as lupus, multiple sclerosis and rheumatoid arthritis?
JB: An Active NK cell produces chemical messengers that control and program the immune system. If your immune system is attacking our body, and a rheumatoid arthritis, the NK cells will calm them down. People with autoimmune diseases almost always have low levels of NK cell activity.
JLML: How is NK cell activity measured?
JB: What I didn’t realize when I started studying NK cells is that the usual test doctors do is an NK cell count. You can count them because they’re a T-cell, and T-cells count got to be popular because of HIV. However, most of us have a normal count regardless of our health, unless you have HIV or AIDS, were born with immune deficiency disease, or have had chemotherapy or radiation—which kills NK cells.
The relevant test is of NK cell activity.We’ve been able to test the activity of NK cells for 22 years, but it’s much more complicated than doing a simple count. A radioactive isotope of chromium is used to test. Whether your NK cells are active or inactive, functional or nonfunctional. With the count you just use flow cytometry, and every lab has a cytometer. Radioactive material has much stricter regulations, increases the cost, and is less available. The activity test hasn’t been promote or become widely available, yet it’s far more clinically relevant and helpful.
JLML: What are the ranges to look for in a NK cell activity test?
JB: We’ve learned that almost all people with cancer are low—o to 10 or 20. Then they have chemotherapy and radiation, which kills all NK cells, and suppresses their activity for many months and even years afterwards.
The Lancet published an 11-year prospective study just over year ago, the measured the NK cell activity of 3,625 healthy people with no known disease. After 11 years they looked at who got cancer and who didn’t. People with a high NK level had a dramatically lower risk of getting cancer, and those who a low level had a significantly increased risk of cancer.
JLML: Yes, that was a very interesting study. They also reported that higher NK cell activity was associated with keeping body weight closer to the standard, not smoking, increased intake of green vegetables, and moderate alcohol consumption.
JB: Stress, insomnia and depression also lower NK cell activity. NK cells are closely linked to the regulation of stress hormones such as norepinephrine, and when those are low we tend to be depressed. I’m not sure which comes first, the depression or the low NK cell activity. I suspect they go hand in hand. All corticosteriods and all immunosuppressive drugs such as methotrexate suppress NK cell activity. Interferon shots will raise NK cell activity, but they’re very expensive and they tend to create steeps peaks and valleys in the levels.
JLML: What do you use with your patients to raise their NK cell levels?
JB: I use a special type of bovine colostrums called Biomune that comes from dairy cows and goes through a dialysis process that filters out the larger molecules that block absorption. It’s generic name is dialyzable bovine colostrums extract. I’ve done baseline measurement of NK cell activity on many patients, given them this colostrums product, and measured their activity against and have found great success in raising levels and resolving many types of disease.
JLML: What do you find that it works best for?
JB: Any type of chronic infection, from bladder infection to colds, and allergies. I’ve also seen it work well for patients with chronic fatigue, and had some success with auto-immune diseases. Dr. Jesse Stoff of Tucson, Arizona did a clinical of 107 patients who had chronic fatigue, Epstein-Barr virus, staph infections, many types of cancer, and other diseases. He treated them with the Biomune for anywhere from 1.5 to 59 months, and saw a positive response in all of those he treated, and very significant positive responses in the majority of them.
References:
Whiteside TL et al, “Human Natural Killer Cells in Health and Disease,” Clin Diagn Lab Immunol 1994 Mar;1(2):125-33.
Imai K et al, “Natural cytotoxic activity of peripheralblood lymphocytes and cancer incidence: an 11-year follow-up study of a general population,” Lancet2000 Nov 25;356(9244):1795-9.
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