Immunoprotective Aspects of Infectious Diseases

This recent study showed an association between childhood infection with mumps and a reduction by about 20% in future risk of contracting ovarian cancer. Mumps is an acute childhood viral infection that typically results in swollen salivary glands and occasionally can affect testes (potentially causing sterility) or cause encephalitis (a very rare severe complication). It is estimated that over 14,000 women will die of ovarian cancer in the US in 2018. If we use this study as a predictive tool, our public health intervention of immunizing our population may be causing an excess of more than 2800 ovarian cancer deaths every year. Are we causing more harm than good with the mumps vaccination? The problem is the blinders we use in funding science- there are few studies looking at these associations that are chronic and long term.

The study on mumps is important in that it did not only look for (and find) an association, it also found plausible mechanisms relating to immune system surveillance. In a fascinating interplay, in an acute mumps infection, the inflamed salivary gland expresses antigens that our immune system primes itself against. Mumps patients have elevated anti-MUC1 antibodies. MUC1 also happens to be expressed by ovarian cancer and it is thought that the MUC1 antibodies are able to help very early recognition and elimination of ovarian cancer in women with anti-MUC1. In fact, MUC1 is expressed in breast tissue and these researchers previously found that mastitis has a protective effect against ovarian cancer, also through the same pathway. I wonder if injections of mistletoe for ovarian cancer might be most beneficial if delivered in breast tissue. 

Fifty Shades of Immunity

The idea that exerting influence on one part of a system might impact other parts of that system, potentially dramatically, cannot be captured with our current Public Health movement. Health communication is aimed at the lowest common denominator using short slogans and dumbing messages down to entire populations. The state of a living biologic system is complicated and impossible to describe in a sound byte or slogan. For example there are several cancers caused by infections- stomach cancer being the most common (caused by H. pylori). There are several infections that can cause cancer. The noteworthy thing is they are all chronic infections. HPV is not simply an acute infection- it lingers forever in the human body causing underlying inflammation that can lead to cervical cancer. 

Infections can also cure cancer. Mumps and west Nile virus have been associated with remissions. William Coley noted cellulitis or other acute infections preceded the series of cancer remissions he examined- then he harnessed the immune stimulation by creating Coley’s Toxins- the first immunotherapy for cancer. Mistletoe is used in cancer as an immunostimulant and one component- the mistletoe lectin has a similar form to a toxin found in Shigella bacteria. 

This interesting paper explores “fifty shades of immunity”- the various roles our immune system’s interaction with infections can relate to cancer. The immune system works in two main ways. The Th1 arm is inflammatory and works by directly patrolling and killing pathogens and abnormal cells- self vs other (usually viral infected or cancer cells). The Th2 arm works through antibodies (one can see these as “memory proteins”). Both arms should work together in a healthy immune system. Th1 gone too far can lead to your immune cells attacking your own self- usually one organ or cell type is the “victim” such as the beta cells of the pancreas in Type 1 Diabetes. Th2 gone too far leads to asthma, eczema and other autoimmune issues. Th2 dominant people tend to do worse with cancer. There is ample evidence that childhood infections play a role in the healthy balance of Th1 and Th2. Childhood infections have typically been linked with decreased likelihood of cancer later in life. 

The balancebetween Th1 and Th2 is important and will be covered again in more detail. The use of lemon/quince extract for allergies can shift the balance favorably. 

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