We finally know what causes childhood leukemia—and how to prevent it

[phands]

I really hope this is true. All the ingredients seem right, but I'm wary of such a grandiose claim....

The cause of the most common type of childhood cancer has been a century-long debate among those in the medical community. Now, thanks to the work of Prof. Mel Greaves, of the Institute of Cancer Research in London, the mystery is at its end. Acute lymphoblastic leukemia (ALL) affects 1 in 2,000 children. Ironically, it’s our modern germ-free lifestyle, particularly our high level of cleanliness, that contributes to the disease’s formation. What’s really exciting is that we may even have the knowledge we need to make ALL a thing of the past.

To make this breakthrough, Prof. Greaves conducted a meta-analysis, combing through 30 years of medical literature and gathering data from colleagues all across the globe. His search included research on genetics, epidemiology, immunology, cellular biology, and much more. Along this journey, Prof. Greaves ruled out chemicals in the environment, ionizing radiation, electromagnetic waves, and the influence of high tension wires (electrical cables) as possible causes.

Putting together so many disparate puzzle pieces and eliminating false causes allowed him to formulate a “unified theory of leukemia.” Although a horrifying condition for a child and parents to endure, Prof. Greaves’ analysis, published in the journal Nature Reviews Cancer, has a bright spot. This type of leukemia may be wholly preventable.

The rest of the article is here....

 

[T.G.G. Moogly]

It sounds right to me. But it will always be a two-edged sword when it comes to germs.

 

[barbos]

Great, but I think I read about it before, can't be absolutely sure they were specifically mentioning leukemia. But basically hypothesis says young children (few month old) must be exposed to certain amount of filth or their immune system will not get properly calibrated. And by "filth" they understand pathogens which are fairly harmless and very common in the environment and have been around humans since the time mammals first appeared, so tens of millions years.
In any case, simply comparing statistics from developing countries to western ones can give you an idea.
So yeah, people have been living in filth for so long that it is required for normal development.

 

[phands]

Great, but I think I read about it before, can't be absolutely sure they were specifically mentioning leukemia. But basically hypothesis says young children (few month old) must be exposed to certain amount of filth or their immune system will not get properly calibrated. And by "filth" they understand pathogens which are fairly harmless and very common in the environment and have been around humans since the time mammals first appeared, so tens of millions years.
In any case, simply comparing statistics from developing countries to western ones can give you an idea.
So yeah, people have been living in filth for so long that it is required for normal development.

This article does specifically mention ALL, the most common form of childhood Leukemia, but yes, the idea has been looked at for a while now.

A lot of research has shown links between an over-sterile environment and allergies, asthma and others. Another factor seems to be that Cesarean Section births have a similar problem - the baby doesn't get coated in the mother's vaginal secretions, which include a lot of beneficial bacteria which help start priming the infant's immune system. So much so, that some hospitals are manually swabbing Cesarean babies with their mother's secretions as soon as the infant is out.

We all know that a properly balanced micro-biome is essential for good health, so this is further confirmation of the general idea. A further confirmation comes from the fact that fecal transplants are showing very good results in a number of clinical scenarios.

 

[J842P]

Great, but I think I read about it before, can't be absolutely sure they were specifically mentioning leukemia. But basically hypothesis says young children (few month old) must be exposed to certain amount of filth or their immune system will not get properly calibrated. And by "filth" they understand pathogens which are fairly harmless and very common in the environment and have been around humans since the time mammals first appeared, so tens of millions years.
In any case, simply comparing statistics from developing countries to western ones can give you an idea.
So yeah, people have been living in filth for so long that it is required for normal development.

It's absolutely no surprise that a non-pathological development assumes a certain amount of exposure to pathogens. I've heard similar ideas regarding exposure to certain types of parisites and the development of various allergies and autoimmune disorders.

I don't think people appreciate how incredibly complex the immune system is. I mean, it evolved a mechanism that uses an evolutionary algorithm to mediate adaptive immunity, allowing us to evolve resistance at the same time scales as bacteria and other pathogens.

 

[phands]

I don't think people appreciate how incredibly complex the immune system is. I mean, it evolved a mechanism that uses an evolutionary algorithm to mediate adaptive immunity, allowing us to evolve resistance at the same time scales as bacteria and other pathogens.

Complex indeed, but your second point isn't accurate. We don't evolve (resistance) at anything like the rate of bacteria or viruses. This is noticeable when, for instance, every few years, a new strain of Flu appears, and we scramble for vaccines. Similarly, we haven't evolved immunity to a large number of bacteria, so we need antibiotics to treat them - even as they evolve quickly to be antibiotic resistant. Vaccinations help, but they have to be administered to each new generation.

The longest running bacterial evolution experiment has been going since 1988, and has examined over 60000 generations, sampling at 500 generation intervals. They found some very interesting things about appearance of beneficial mutations. The point for this discussion is that 30 years is barely 1 generation for humans, maybe 2 if you're from a religious state ;-) There hasn't been a chance for us to evolve resistance. Part of the good news is that the mutations which allow survival don't always occur in ways that change the organism's external proteins which our immune systems use to identify targets. If they do, our immune system will no longer recognize them as enemies - hence flu strains.

 

[Underseer]

Isn't that also supposed to be the cause of allergies?

 

[J842P]

I don't think people appreciate how incredibly complex the immune system is. I mean, it evolved a mechanism that uses an evolutionary algorithm to mediate adaptive immunity, allowing us to evolve resistance at the same time scales as bacteria and other pathogens.

Complex indeed, but your second point isn't accurate. We don't evolve (resistance) at anything like the rate of bacteria or viruses. This is noticeable when, for instance, every few years, a new strain of Flu appears, and we scramble for vaccines. Similarly, we haven't evolved immunity to a large number of bacteria, so we need antibiotics to treat them - even as they evolve quickly to be antibiotic resistant. Vaccinations help, but they have to be administered to each new generation.

The longest running bacterial evolution experiment has been going since 1988, and has examined over 60000 generations, sampling at 500 generation intervals. They found some very interesting things about appearance of beneficial mutations. The point for this discussion is that 30 years is barely 1 generation for humans, maybe 2 if you're from a religious state ;-) There hasn't been a chance for us to evolve resistance. Part of the good news is that the mutations which allow survival don't always occur in ways that change the organism's external proteins which our immune systems use to identify targets. If they do, our immune system will no longer recognize them as enemies - hence flu strains.

No, I am not talking about human populations evolving, but populations of lymphocytes evolving the ability to recognize pathogens which occurs at a similar scale as bacterial evolution (of course, yes, not *as* rapid, but i'll take an immune cycle over a couple of human generations).

This is why vaccines *work*.