One cool November morning I drove from San Diego South in a battered rental car. I had with me a standard set of journalistic supplies (voice recorder, camera, notebook and pencils) lying on the passenger seat, as well as instructions on how to get to the meeting place — the last turn in front of Mexico city. In addition, I took with me a printout of a recent blood test — proof that I have no anemia, that I am not infected with hepatitis or HIV, and therefore healthy enough to participate in the upcoming experiment.
As I drive, the radio commentator recounts the horrific details of the recent bloodshed in Tijuana, where I’m going: two bodies hanging from a bridge, a third decapitated, a fourth shot. My thoughts, however, are not so much occupied by these terrible, incessant atrocities as by parasites-helminths that migrate through the body, penetrate the lungs, crawl into the larynx and dig into the sensitive innards. Any other traveller might be concerned about the possibility of finding such a home while abroad, but I am going to Mexico precisely to get not one, but a whole colony of such satellites. Today in Tijuana, I deliberately introduce to your body ankylostoma “necator American” (necator americanus “American murderer”).
This dubious honor will cost me quite expensive — a one-time fee of $ 2,300. Having received twenty microscopic larvae, I will pay $ 115 for each of the parasites, which in the first decades of the twentieth century were considered in the South of America a real disaster. It was believed (I would like to add, devoid of any arrogance) that Ancylostoma makes southerners are stupid and lazy, and that this helminth is holding back social and economic development of half of the country. Made at the time the photographs of people in poor rural areas, were at the mercy of these parasites are clearly visible consequences of necatoroz, or hookworm: protruding collarbone, clouded eyes, the haggard expression indifferent entities. In these photos, the people look like something is eating away.
As a result of efforts to destroy the ankylostomy (it is also called krivogolovka), undertaken over a long period in the early twentieth century, this parasite has almost disappeared in the United States. However, in poor tropical countries, where ankylostoma is still widespread, it can cause anaemia, stunting, amenorrhea, and even mental retardation in children. This parasite infected from 576 to 740 million people. And for all the reasons listed above, the health system considers parasitic worm infestation to be “a tropical disease that is not given due attention”. Helminths (as these parasites are called) do not lead to such obviously disastrous consequences as, say, malaria, but their constant impact on viability is very insidious. These parasites prevent children from going to school and their parents from working. It is believed that they contribute to a self-reinforcing cycle of ill health and poverty that afflicts entire countries.
So why did I decide to let this horrible creature into my system? In our time, scientists have formed a dual attitude to parasites. Some consider them the embodiment of evil. Others note that, while the above-mentioned effects do occur, today most people infected with parasites (more than 1.2 billion, between one fifth and one sixth of the world’s population) have no obvious symptoms. Representatives of this camp began to suggest that in fact parasitic worms can bring some benefit to people who have become their owners.
Already in the 1960s (by this time in the United States ankylostoma was almost destroyed), scientists were trying to understand why some people have no symptoms of infection with these parasites. “People who receive adequate food, in many cases, are carriers of helminths, which does not bring them obvious harm, — said one doctor in 1969. — In this regard, it is possible to question the feasibility of treating such infections, especially through chemotherapy drugs that have toxic properties”.
For decades, immunologists have carefully studied the mechanisms that allow one creature to dwell in another, which is clearly contrary to the principles of recognition of “his” and “alien”, which was considered to be the basis of the functioning of the immune system. As a result, they learned a lot not only about how insidious parasitic worms are, but also how the human immune system actually works. Parasites such as Ancylostoma, in the process of evolution is widely spread. Can the human body in some sense expect their presence or even need it? And can their absence be one of the reasons for a number of curious ailments of our time?
That’s the motive for my adventure: the results of an increasing number of scientific studies suggest that parasites can prevent allergic and autoimmune diseases. And I have both.
At eleven, my hair started falling out. My grandmother noticed it for the first time when one summer I was staying with my grandfather in a beach house. She called me to her, examined the back of my head and said that I had a bald head the size of a coin. Soon we all forgot about it. When there’s sand and waves and sun, it doesn’t seem that important.
However, after a few months, by the time the school started, the bald spot became bigger. The dermatologist diagnosed it as “alopecia areata” (autoimmune disease). My immune system, which under normal circumstances should protect the body from infectious agents, for some reason mistook friends for enemies and began to attack the hair follicles. Scientists did not know what provokes alopecia, but it was believed that stress plays a role in this. At first glance, it made sense: at the time, my parents were in the process of a long, difficult divorce. Besides, I went to a new school. I really seemed to have something to worry about.
I also had other, more well-known immune-related health problems. As a child, I suffered from quite severe asthma, as well as food allergies to peanuts, sesame and eggs. (Over time, it’s only allergic to eggs.) At least twice a year, usually during periods of high pollen in the air, I found it so difficult to breathe that my lips and fingers were blue and my parents rushed me to the hospital. The doctors injected me with bronchodilators and, in the case of heavy attacks pumped immunosuppressive steroids.
“Yeah!”— said the dermatologist, learning about all this. He explained that there was a relationship between allergies, asthma and alopecia. No one knew for sure why this was happening and what it meant, but the presence of an allergic disease such as asthma increased the likelihood of developing alopecia.
Many years later, I learned that the joint appearance of these two diseases indicates, in all likelihood, the presence of one initial disorder in the body. However, at eleven, I accepted the fact that if there is one problem, there are likely to be others. So what to do? Given my age and the relatively small size of the bald spot, the doctor recommended to watch and wait. He said that over time, alopecia usually passes itself.
A month later there was another bald spot on the right side of the head. And then left. It’s like a big bald spot on top of your head overnight. The more new bald spots appeared, the faster this process went. Every morning my mother combed my hair and fixed it with gel to hide the growing areas of bare skin, but soon it became impossible to hide my bald skull. The bald spots began to connect with each other. I started to go bald.
We went back to the dermatologist. This time his conclusion was less optimistic. The more the disease progresses, he noted, the less likely it is to recover. And the chances were that only one or two percent of the population has focal alopecia in the form of a pair of bald spots, which over time again overgrown with hair [4]. However, much more people with focal alopecia (about 7% of the population) have chronic hair loss. Some of them develop total alopecia — all the hair on the head falls out. At this point, the likelihood of a full recovery is significantly reduced. Whatever mistake the immune system makes, it is a long-term mistake. And in some cases, people develop universal alopecia — hair loss throughout the body. Then recovery is almost impossible.
In all these scenarios, there was nothing good, especially given the fact that I was getting closer to the total, and maybe (who knows?), and to universal alopecia. There were two methods of treatment, none of which provided a guaranteed result: inhibition of the immune system and irritation of the immune system. Steroids inhibit the immune response and, in fact, withdraw the “watchdogs” of the immune system, making hair again have the opportunity to grow. On the other hand, immunostimulation works in a somewhat more mysterious way. The inflammatory process caused by an irritant distracts the immune system from less relevant projects, such as an attack on the hair follicles. Irritation should have given them a break. Since neither of these approaches was a win-win, the dermatologist advised me to try both.
So I did, but none of these methods provided the desired result — although I had a oozing blister where I used the stimulus. My alopecia has progressed to until sixteen years in my body not a single hair. I became a member of a select group of people (about 0.1% of the population) suffering from universal alopecia. I put on a headdress (and wore it, almost without removing, to twenty-odd years) and tried to somehow adjust my life in adolescence.
It was only in my early thirties that I decided to find out what the scientists had found out in the twenty years since the first bald spot appeared on my head. I did not have much hope: if a method of treatment was found, I would certainly know about it. As I planned to have children, I began to worry about what was hidden in my genes. The results of the first genome-wide Association search, published in 2010, showed that the disease (the most common autoimmune disease in the United States) has the same gene variants as a number of much more devastating autoimmune diseases, such as rheumatoid arthritis, type 1 diabetes and celiac disease (gluten enteropathy). Soon after that, I had my first child, a girl. Now the results of my research have found concrete application. If alopecia meant a tendency to damage the immune system, and if that trend could be reversed, I needed to know how to play the cards. I wanted to protect my children from both allergic and autoimmune diseases.
I was right about one thing. Methods of treatment of alopecia have not improved since my childhood. They continued to be limited to the use of stimuli and immunosuppressors, and since neither approach provided for the elimination of the underlying disorder, they both required lifetime use. Long-term exposure to both treatments created a number of secondary problems. For example, repeated injections of steroids were not only extremely painful, but also led to thinning and discoloration of the skin. One strong immunosuppressor — cyclosporine, increased the risk of skin cancer.
Nevertheless, my attention was drawn to the patterns inherent in immune-mediated diseases. Recently, there has been an increase in autoimmune and allergic diseases, and this time, as far as one could judge from the scientific literature, this trend was alarming. Scientists often used the word epidemic to describe the increasing prevalence of certain diseases (especially asthma), although the word was usually used to describe infectious diseases such as debilitating and killing cholera in one day, epidemics which horrified the world in the XIX century. However, in fact, there was no asthma bacteria or autoimmune virus. There were no new agents of infection that would trigger the pandemic. The impression was that instead we had a tendency to disorders of the immune system.
If I had glasses through which I could see the usually inconspicuous cases of allergic and autoimmune diseases, I would be amazed at how many people have similar problems. For example, while walking on new York Broadway, I would see that one in ten of the children passing by has asthma; one in six has an itchy rash or even blisters — atopic dermatitis, and one in five passers-by suffers from hay fever. [6] About 3,500 people die each year from asthma attacks in the United States. If I could look at allergic antibodies (immunoglobulin E, IgE), I would see that half the people around me are sensitive to dust mites, wood pollen, peanuts, and other essentially harmless proteins. I would see that many people carry inhalers in their pockets, and Allergy medications in their bags (for passers-by with the most severe form of these diseases, these would be pills of potent immunosuppressants, such as prednisone).
Americans spend about ten billion dollars a year on anti-asthma drugs and visiting doctors. The total direct and indirect costs of asthma are around $ 56 billion. I would see these funds flow from the wallets of people with asthma and allergies to the pockets of doctors and pharmaceutical companies. Also, I would pay attention to what the money are being lost because of sick leave, reduce the overall level of performance, and the opportunities lost for life.
If I had the opportunity to take the same walk with glasses to recognize autoimmune diseases, I would notice that every twentieth passer-by has one of eighty such diseases, often causing serious harm to health [7]. One in 250 passers-by would suffer from debilitating pain in the intestine, that is, from the so-called inflammation of the intestine (to meet such a person, say, in times square, it would take about a minute) [8]. I would see intestines with scars and constrictions, and in the most severe cases — traces of removal of fragments of intestines, colostomy (surgically made holes for the withdrawal of the contents of the intestine) and attached to them colostomy bags (containers for the withdrawal of waste products), hidden under clothing.
In every thousand passers-by I would notice one person who is difficult to move his legs or hands. In such people, multiple sclerosis is a progressive autoimmune disease of the Central nervous system. When they read the signs, the letters blur before their eyes. It is difficult for them to coordinate the movements of the legs. Of course, in the most severe cases, these people do not appear on the street. They stay at home, maybe in wheelchairs, maybe even bedridden.
I would see blood glucose meters on one of every three children frolicking in Central Park playgrounds — they have autoimmune diabetes, which usually debuts in childhood. I would notice in these babies traces of daily insulin injections that need to be done to avoid coma and death.
If I had not only glasses but also headphones, I would hear a cacophony of anxiety and despair: asthma-stricken teenagers wondering if they could play baseball with friends; teenagers with more severe asthma cases focused on walking slowly and not starting to suffocate; those suffering from atopic dermatitis would constantly remind themselves not to scratch, and those who still scratched themselves would scold themselves for it.
People suffering from intestinal inflammation would be absorbed in thinking about the pain (sometimes aching, sometimes sharp) that has become an integral part of their lives since diagnosis. And when their thoughts are not occupied with painful cramps in the intestine, they think about the acts of defecation that occur too often, imperative urges to them are extremely painful, and excrement sometimes contain blood. People with multiple sclerosis wonder: after what time I will not be able to walk? And all of them constantly ask: why doctors can’t cure it? Where did that come from? Why me?
According to the National institutes of health, 1.7 to 23.5 million Americans, or five to eight percent of the population, suffer from autoimmune diseases. According to the American Association of autoimmune diseases, this figure is more than twice as high — 50 million Americans. In the United States, autoimmune diseases are among the ten most common causes of female mortality. This corresponds to the scenario described above, in which I did not mention this fact for the sake of simplicity. About three-quarters of those suffering from autoimmune diseases are women. In other words, being in autoimmune glasses, I would see mostly women.
Anthony fauchy, Director of the National Institute for the study of allergic and infectious diseases, once said that the direct and indirect costs of autoimmune diseases have reached an astounding $ 100 billion per year. (For comparison, we spent $ 57 billion on cancer and $ 200 billion on cardiovascular disease.) These numbers may seem huge, but don’t forget that autoimmune diseases, which are chronic, usually affect a person in the Prime of life and require expensive symptomatic treatment for decades.
These statistics cover the richest countries at the beginning of the twenty-first century. However, immune-mediated diseases have not always been so widespread. If we leave aside the first cases of autoimmune diseases during the 19th century, we will see that the epidemic of allergies and asthma picked up pace in the 1960s, in the 1980s this rate accelerated, and in the early 2000s remained at the same level. The results of studies involving different groups of the population show an increase in the incidence of asthma and allergies in developed countries in two and three times during this period.
At the end of the twentieth century, some autoimmune diseases show even greater growth. A 2009 study showed that the prevalence of undiagnosed celiac disease (inflammation of the intestine caused by the protein found in cereals) increased almost fourfold since the mid-20th century [10]. The incidence of multiple sclerosis has almost tripled. And the onset of some of these diseases is gaining momentum. According to some estimates, the incidence of type 1 diabetes, which tripled at the end of the twentieth century, will double by 2020.
What happened? In 2002, the French scientist Jean-françois Bach published a fundamental work of interest to those who ask this question [11]. In an article published in the new England Journal of Medicine, two graphs were presented side by side, one showing a gradual decline in the incidence of past common infectious diseases (such as hepatitis A, measles, mumps, and tuberculosis) since the 1950s, and the other showing an increase in the prevalence of autoimmune and allergic diseases in developing countries over the same period. In 1950, almost all were sick with mumps and measles. In 1980, almost no one was ill with them. Vaccines have almost completely destroyed both of these viruses. The number of new cases of hepatitis A infection has decreased to one fifth of the previous level even in a shorter period (since 1970). And during that time, the number of new cases of asthma, multiple sclerosis and Crohn’s disease increased two, three and four times, respectively.
The dependence so vividly demonstrated by Bach (a decrease in the incidence of infectious diseases along with an increase in the prevalence of immune system disorders) is manifested simultaneously in the respective regions and population groups. The prevalence of allergic diseases in countries with the highest and lowest levels of diseases of this kind is at least twenty times. For example, in Albania, very few children are allergic, while in Australia a quarter of children are allergic [12]. The incidence of type 1 diabetes is even more significant: 350 times between Finland, which has the highest level, and China, which has the lowest level [13]. Are some ethnic groups more vulnerable to such diseases than others? That’s possible. However, when migrants move from low-risk countries to high-risk countries, children born in their new homeland almost always suffer from immunocompromised diseases as often as the local population. So, if it’s not genetics, what explains the big gap?
In the past, epidemiologists have argued that in the General case, the prevalence of diseases of this kind increases as you move from the equator to the poles: in sub-Saharan Africa to sub-Saharan Africa, these diseases are rare; in the UK they are quite common. It seemed an undeniable truth thirty years ago. However, data on the recent dramatic increase in asthma incidence in countries such as Brazil and Peru (as well as in cities in other developing countries) refuted this generalization, made in the past with full confidence in its truth. Today, more often you can hear about the existence of a correlation between allergic and autoimmune diseases, on the one hand, and gross domestic product — on the other. The richer the country you call home (or, in some cases, the higher your social class in that country), the more likely you are to get asthma, intestinal inflammation, or multiple sclerosis.
Critics reject these large-scale statistics because they are taken from questionnaires. They emphasize that the results of surveys are invariably influenced by past experiences and cultural biases. However, in smaller studies that use more objective indicators (such as the results of diagnosis of bronchial obstruction and skin injection tests, as well as tests for the presence of autoimmune antibodies), a similar basic pattern has repeatedly been found: the frequency of autoimmune diseases increases in direct proportion to the level of material well-being and Westernization. The more the habitat resembles the environment in which human evolution took place (an environment teeming with infections and what one scientist calls “animals, excrement and dirt”), the lower the prevalence of such diseases.