Archive for the ‘General’ category

Carabin

January 29, 2007

white blood cell, lymphocyteThe BBC is reporting that John’s Hopkins researchers have discovered one of the ways the immune system naturally restricts its own activity. Carabin is a protein produced by white blood cells, and places a drag on the immune reponse to an infection. Why would the body want to cripple its own immune response? How could it be useful for the body to hold back when an infection is in play? If you have an autoimmune disease, you already know the answer. When unrestricted, the immune system can be as much an enemy as a friend.

Researchers hope that this discovery will yield benefits for transplant patients in controlling the rejection of new organs, and possibly in the treatment of autoimmune diseases as well. However the protein, because of its size, will not be easy to incorporate into a drug.

Story

Update: M.S. and Parasites

January 19, 2007

parasiteEarlier I reported some confusion as to the explanation given by the South Coast Today regarding the effects of stomach parasites on the course of M.S. in an Argentinian study.

Wednesday’s BBC report on the same subject was more informative. The comparison between the accounts is equally illuminating. When explaining the cause of the results, the BBC explained it thusly:

The scientists said it was possible that the parasites were able to influence the production of T-cells – cells which “dampen down” immune reactions within the body, both ensuring their success, and reducing “autoimmune” illnesses such as MS.

No confusion there. The supposition is that the parasites are suppressing the immune system’s production of immune agents, presumably including both the particular types of T-cells that attack that parasite and those that attack the body’s own myelin surrounding the nervous system. Now read the South Coast Today explanation:

The finding suggests that when the body’s immune system is occupied with an external threat, it might be less likely to misfire, which happens in conditions known as autoimmune disorders.

That explanation posits that any time the immune system is engaged in fighting infection, it doesn’t have the resources to engage in self-destruction. The problem is that the resources the immune system would use to fight a parasitic infection are not the same resources it would use to attack its own myelin. Every T-cell is “keyed”, so that it can only attack a certain type of cell. When it comes into contact with that cell, it divides, increasing the supply of that particular keying of T-cell. If the body’s (insert specific parasite name here) parasite attacking T-cells are busy fighting the parasite infection, it has no effect (that I can think of) on the body’s supply of myelin attacking T-cells.

Only the more general immune suppression ability of parasites that the BBC describes makes sense in explaining the results arrived at. In comparing the accounts, the second lesson we arrive at today is the dependability of sources. The BBC took the time to record a reason that makes sense, even if it is only supposition. The South Coast Today didn’t bother. The latter’s style has the advantage of being ready for the ‘presses’ two days earlier. The former’s style has the advantage of being plausible.

South Coast Today
BBC report

Krauthammer’s Stem Cell Showdown

January 17, 2007

stem cellOver the past couple of years the news has been full of the unbounded promise that exists in the world of embryonic stem cell research. Nary a voice in the mainstream exists that would forgive any limitations on stem cell research. It shows promise for understanding cancer, it shows promise in treating nerve damage, even spinal cord damage. It probably wouldn’t be very nice to press for details, because most stories don’t bother with them.  It is problematic that in a profession that values curiousity, there just aren’t many questions asked about the viability of the research or the immediacy of the promise.

Krauthammer broaches the topic after the discovery of the usefulness of stem cells found in amniotic fluid. The thrust of the column is that a source of stem cells that doesn’t create a moral delimma could end the showdown over funding.

You don’t need religion to tremble at the thought of unrestricted embryo research. You simply have to have a healthy respect for the human capacity for doing evil in pursuit of the good.

Once we have taken the position of many stem cell advocates that embryos are discardable tissue with no more intrinsic value than a hangnail or an appendix, then all barriers are down. What is to prevent us from producing not just tissues and organs, but human-like organisms for preservation as a source of future body parts on demand?

South Korea enthusiastically embraced unrestriced stem cell research. The subsequent greatly heralded breakthroughs – accompanied by lamentations that America was falling behind – were eventually exposed as a swamp of deception, fraud and coercion.

There’s no doubt that the media has been grossly irresponsible in its reporting on the topic. Whether amniotic fluids stem cells could solve the problem or not remains to be seen.

Column

Mysterious Still

January 14, 2007

t-cellIn the Febuary issue Nature Immunology, Dana-Farber Cancer Institute researchers uncover one immune system mystery and claim more lurk in the distance.

The question is this, How does the small intestine, a veritable biosphere of helpful (but still foreign) bacteria escape the heavy hand of the immune system that is supposed to repel foreign microbes? This Science Daily article is full of immune system education.

It describes how agents of the immune system, T-cells, have different levels of alert. Dendritic cells act as informants, preventing T-cells from attacking familiar cells, self-product. In this study, stromal cells are found to be fulfilling the same function for the small intestine. T-cells take their direction from stromal cells and leave the small intestine be.

I recommend the article.  I think the relevance to autoimmunity, hinted at in the intro to the story, is that unknown systems of creating immune system tolerance to foreign agents could lead to treatments that would protect cells the immune system should not be attacking, like islet cells in diabetes patients, myelin in M.S. patients, or synovial fluid in R.A. patients.

Story: Science Daily

Why do bad things happen to good cells?

January 14, 2007

T cell in actionDisease is often associated with weakness and inability.  While an infection signals that your immune system is falling behind the microbes that are always in our bodies, autoimmune diseases signal exactly the opposite, that your immune system is fully operational.  At least the final execution stage is.  It’s in such good shape it need not limit itself to attacking disease, it can branch out and attack you as well.

The methods by which the body trains the immune system to sort the good cells (your own) from the bad (foreign cells) is still a mystery.  But in people with autoimmune diseases there is something wrong with the training process.  Your immune system fails to properly sort the good from the bad and attacks your body.  Many very different diseases, from arthritis to diabetes to skin diseases have their root in an overactive immune system.

The Era we now live in is one of rampant scientific discovery. Never before has science been so well funded.  Never before has technology advanced so quickly.  This blog will serve as an information depot pointing you to advances and news regarding autoimmune diseases, collecting the experiences and telling the stories of those afflicted.  Part of my mission is to learn more about these diseases.  Hopefully in the process, I can spread the wealth and help explain what these diseases are and what we know about them.

Medical advice will not be given here and no information provided by this blogger or commentors should be relied on as medical advice.  If you are suffering from an autoimmune disease or think you might be, seek medical attention and rely on your doctor’s advice and your own research.   I’m a writer, not a doctor.

Your input is welcome.  Stop in and leave your suggestions, comments or corrections in the comments section.