Your Immune System: In Sickness and Health...

If your brain is the air traffic control system for your body, your immune system is the combined offensive and defensive team against infections, cancer and autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, Crohn’s disease, and lupus. You are born with an innate section of your immune system organized to do battle on your behalf as soon as you are delivered. Over time, your so-called “adaptive” immune system learns via exposure to viruses, bacteria and fungi. Your system develops a bank of T-cell and B-cell antibodies that work together that assist you in fighting infections over a lifetime. 

A riddle of the coronavirus situation is as follows: Why does influenza affect the young and the old, whereas coronavirus preferentially only kills the elderly? Find the answer at the end of this piece.

As we age into our 50s and beyond, the immune system begins to lose some of its robustness in a process called “immunosenescence”. This decline in immune function is hastened by poor nutrition and chronic diseases such as diabetes, COPD and cancer. A question I want to explore further is the connection between stress, both acute and chronic, and the functioning of the immune system.

Living well contributes to living longer...

The incidence of and mortality from cancer increases after age 65 and levels off at around age 85. This reflects the activity of the immune system and its complex interactions with an individual’s environment that may include helpful and harmful activities. Harmful activities include smoking, eating a poor diet high in saturated fat and sugar, obesity, excessive alcohol intake and likely chronic stress. Helpful activities that augment the immune system’s ability to do its job and fight infections include regular exercise, good diet, adequate sleep, low weight, dental health and probably lower stress levels. Regarding cancer, the immune system plays a key role in detecting and suppressing malignant cells.

There are interesting links between “chronic inflammation” and the risk for earlier morbidity and mortality. Not to get too technical, but inflammation can be measured in the blood with tests including C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha). There is mounting evidence that chronic stress – not acute stress – accelerates the process of immunosenescence. So, in plain English, living well contributes to living longer!

...but who says what is scientifically true?

Let me turn for a moment to how science works. We have all heard the saying, “They say…” (fill in the blank) Who is they? In your mind perhaps “they” are a group of hard-working scientists in white coats holed up in a lab coming up with results. It doesn’t really work that way. 

The path to scientific discovery (either in the lab or through statistical analyses of large amounts of data in clinical trials) is littered with setbacks, blind alleys and counterintuitive findings. Let me give two examples. 

For years, we have heard that “moderate” alcohol consumption is healthy – a finding I personally wish to believe is correct. However, just recently a paper came out suggesting that any amount of alcohol is harmful to adults. I am convinced that the science about any amount of alcohol being harmful to pregnant mothers and their babies is true. I am not convinced that any amount of alcohol is harmful to other adults. Who knows where the truth lies: the devil is deeply in the details and the jury is still out.

Another example is the data around screening for breast cancer. For most of my early years in medical practice, I was taught that screening for average risk women should begin at age 40. More recently the data shows that screening is of no benefit to average risk women until they are age 50. And on and on these debates go. Just look at the debates about what constitutes a “healthy diet”!

Let me know bring these two threads of the complex immune system and the pursuit of scientific truth together. A company like Arcadia holds medical data on many millions of patients. Though it is not our core business, we are occasionally asked to do research projects leveraging our database. Recently we identified the prevalence of a serious skin disorder called hidradenitis suppurativa and figured out which co-morbidities were likely to march along with this diagnosis. Now think about the kind of research we could do on the immune system if we powered up all our data, including claims and electronic health record data. We have longitudinal records on millions of patients over many years. As we begin to look at correlations between immune system diseases, the environment and any number of co-morbidities, pieces of the puzzle might begin to emerge. And think for a moment, if we were able to pool the resources of companies, insurers and the government that hold mountains of data for research for the public good. 

The immune system is complicated. Science is complicated. And politics is sometimes complicated, standing in the way of cooperation between data holding entities. As a physician and chief medical officer, my hope is that we can think big and overcome our narrow agendas in the service of improving the health of our entire population.

Now back to coronavirus. Can you get re-infected with coronavirus? Some evidence suggests this is possible, but it may be a false data point relative to abnormal test results. Time will tell.

And why do young people get sick and die with influenza but rarely with coronavirus? This is because the immune system is activated in different ways by these two different viruses. With influenza, the immune system in young people gets so overactivated that the super-hot immune response contributes to lung damage and the onset of ARDS – acute respiratory distress syndrome. With coronavirus, the immune system in young people is activated, but usually not to the super highly detrimental level that occurs with influenza. We are still learning…