When various forms of news media last week reported the cause of death of Harold Ramis, the writer/director/actor, as complications from the "rare autoimmune disorder vasculitis," I can promise you there were many people who read that and said, "Huh?" for very personal reasons. These are people who, like me, knew that these reports weren't quite right. Vasculitis is actually a family of at least 15 forms of this disease group and one not so rare when all those who have some form (perhaps as many as 3 million) are added together.
Research and clinical trials on vasculitis have been carried on in a handful of centers around the world. One long-time investigator in this area, also a teacher and clinician, is here at Stanford: Cornelia Weyand, MD, PhD, division chief of immunology and rheumatology. Wayand's e-mail box was flooded last week, so we asked her to answer some basic questions here about the vasculitis family.
I understand the vasculitides are a family of diseases. Is there something all forms have in common?
A diagnosis of vasculitis means that there is inflammatory disease in the blood vessels.
All organ systems in the body have blood vessels. Therefore, all organ systems can be affected by vasculitis. Blood vessels provide oxygen and nutrients to the tissues. Inflamed blood vessels have a tendency to become blocked. In that case, the tissues do not get blood supply anymore, causing serious complications. In some cases, the inflamed blood vessel bursts, causing life-threatening bleeding. This complication is particularly serious if the body’s largest blood vessel, the aorta, is affected. A leak in the aorta is incompatible with life.
What insights into vasculitis have we gotten from research?
My research team has been involved in vasculitis research for the last decade. We have been trying to find answers to the questions most patients ask at one point in the course of their disease:
A. Why did I get this disease?
Vasculitis results from a faulty immune response. Cells of the immune system attack the blood vessel and cause tissue injury. The blood vessel responds to the attack by either closing up or by rupturing. We have been able to identify the immune cells that initiate and sustain vasculitis. Remarkably, cells that induce disease are identical to cells that protect the body. We have also learned that blood vessels have specialized sensor cells in them that keep a dialogue with the immune system and start the inflammation.
B. How can my disease be treated or prevented?
We cannot prevent vasculitis, but since the disease takes a course of flares and remission, we may be able to prevent the next disease flare.
Vasculitis is treated by suppressing the immune system. One of the most effective drugs is cortisone. Some patients need it in large doses and we are very cognizant of side effects.
We have devoted our research effort to develop new means of therapy. To accomplish that goal, we have developed a system in which we can induce vasculitis and then test new therapies. This system involves the transplantation of human blood vessels into mice. If such mice are supplied with immune cells from our patients, vasculitis develops in the engrafted blood vessel. We can treat that inflammation in the mice and can easily take a biopsy from the blood vessel to check what we have achieved and how therapy actually works.
C. How do you know whether my disease is active or not?
This is one of our greatest challenges as we take care of our patients. We cannot just go and take a tissue biopsy of our patients every time they come and see us. We have a research project in place which is aimed at developing biomarkers of vasculitis in a blood sample. We isolate out the immune cells of the patient and, by applying cutting edge technology, we assess these immune cells to get information how likely or unlikely these cells would cause inflammation.
Are these conditions often misdiagnosed - and, if so, why?
I've learned from my patients that misdiagnosis occurs quite frequently. The reason is that each vasculitis by itself is a rare disease. Thus, physicians may only see a few cases in their practice and are just not familiar with the disease. The other reason is that vasculitis can easily mimic another condition, making it difficult to “nail down” that there is blood vessel inflammation. Yet, another reason is that we don't have highly specific blood tests to help with the diagnosis. In some forms of vasculitis, we have autoantibody tests, that are helpful, but in other forms different diagnostic testing has to be applied. Finally, many different organ systems can be involved, e.g. the eyes, the ears, the nose, the lungs, the heart, the gut, the kidneys, the nerves, the skin, the brain, etc. Thus, patients are seen by many different specialists.
If one person in a family has a form of vasculitis, does this mean others have an increased risk?
There is genetic risk that contributes to vasculitis, but its impact is relatively small. Most patients we see in Vasculitis Clinic do not have a family member that has a similar disease. The genetic risk may be more visible on the population level. Certain populations are at higher risk to be affected by vasculitis. One example is giant cell vasculitis which occurs with the highest frequencies in individuals of Scandinavian origin and thus is seen more frequently in Iceland, Norway, Sweden, and Denmark.
Can you tell us more about treatments, and which ones have proven most effective?
As mentioned above, corticosteroids remain the cornerstone of therapy for almost all vasculitides. Depending on the type of vasculitis, we now have an armamentarium of other drugs, which we use as “steroid-sparing agents”. That means we combine them with corticosteroids to be able to reduce the dose of Prednisone much faster.
All medications used in the therapeutic management of vasculitis have in common that they suppress the immune system, they are so-called immunosuppressants. That means that our patients are at risk to acquire infections and we have to be very careful.
A major challenge is that vasculitides often have to be treated over many years. Most patients will receive several different treatment regimens over the course of their disease.
The art of vasculitis management lies in the Goldilocks Rule: treat enough to suppress the disease, don’t treat too much to avoid loss of protection for the patient.
