Gettysburg Medical News
The Clinical View
by P.E. Hoffsten, MD
18 April 2007

WHAT IS ITP?

             A lady came to the clinic with her 18 year old daughter wanting a second opinion.  The daughter had gone away to college in the fall and in January had developed multiple bruises.  The daughter didn’t have a clue how these might have happened with bruises on her abdomen, her legs, her arms and her shoulders.  The bruises were not large or unusually painful but they were certainly something different than what the daughter was used to.  She went to the college dispensary where the doctor checked several blood tests and found that she had a very low platelet count.  She was referred to the local university hospital where a diagnosis of ITP was made.  The daughter was told this was a very serious condition and it would require large doses of cortisone and perhaps other steps in care to be effectively treated.   The daughter didn’t feel sick; she started taking the medicine as her doctors at the University Hospital had instructed but did not alert her parents that anything might be wrong.  When she came home for a spring break in late February, the daughter’s face was very round and she had put on a great deal of weight.  Mother was very upset.  She wanted to know what ITP was, why her daughter was getting such large doses of cortisone which she knew as bad, and what the future held.

            On examination, the daughter had no bruises at this time.  She did indeed have a round face and looked as though she had been taking large doses of cortisone for more than a month. The clinic record documented a 15 pound weight gain since she had gone to college.  A blood test was done and the patient’s platelet count was found to be slightly low but nothing dangerous at this time.  The daughter’s dose of cortisone has been dropped to 20 mg of day of Prednisone which is a cortisone-like drug.  In fact, this dose is not particularly excessive although it can have significant long term side effects.

            There was just a lot of explaining to do at this point.  I first explained to the mother and the daughter that there is a normal component in the blood called a platelet.  Platelets are fragments of a special cell from the bone marrow.  Platelets circulate in the blood and are an essential part of forming a blood clot.  If a person has an injury, platelets stick to the damaged tissue and prevent bleeding.  If there is a cut and blood vessels are severed, bleeding needs to be stopped and platelets are the backbone essential component of forming a blood clot so that the person doesn’t bleed to death.  Without platelets dangerous bleeding can occur and bruising is very common. 

            Next, I explained what the letters ITP meant.  The “I” stands for idiopathic.  The prefix “idio” stands for “we don’t know”.  The second half of the word is “pathic” and it means disease.  So idiopathic means there is a disease that we don’t understand why it occurs.  The letter “T” stands for thrombocytopenic.  The first part of that word is “thrombo” which has to do with clotting.  The middle part is “cyto” and it stands for cell parts.  The last part of the word is “penic” and it means that “there isn’t much”.  So thrombocytopenic means there aren’t many platelets.  The letter “P” stands for “purpura” which is a medical word for bruising.  So idiopathic thrombocytopenic purpura is a disease in which the person doesn’t have many platelets, gets a lot of bruises and we don’t know why.

            The name of this disease was coined many years ago before we found out what causes the disease.  In the 1950’s, two doctors working at Washington University in St. Louis, Missouri were studying patients with ITP.  They hypothesized that there must be some kind of agent in the blood that damaged the platelets and thereby decreased the number of platelets in the blood.  So the two doctors took some serum from a patient that had ITP and injected it into themselves.  Within a few hours these two doctors had almost no platelets at all in themselves.  Doctors do some crazy things but at least they did prove that the basic problem was an antibody in the patient’s blood that damaged the patient’s platelets and theirs, too.  Fortunately, the doctors’ platelets grew back in a few days and there no permanent ill effects.

            While those doctors’ work demonstrated the cause of the low platelet count there was no explanation as to why the person would develop an antibody to their own platelets.  This had to do with a condition called “autoimmunity”.  Autoimmunity means that the person becomes allergic or immune to some part of their own body.  In patients with ITP, they become allergic to their own platelets and try to kill them all off.  We have no idea why.

            Based on the work that the doctors above did, it just became logical that cortisone could be used to treat this condition by suppressing the person’s own immunity.  It is the same principle that we use to treat patients with a kidney transplant or a heart transplant.  Indeed, cortisol is still the backbone of treatment 50 years later.

            As I was explaining all of this to the patient’s mother it was apparent that there wasn’t much comfort developing.  The mother wanted to know what was going to happen and how long the daughter would have to be on cortisone and what would happen if she stopped it.  I explained that for some patients, the cortisone dose can be slowly tapered down over several months time and the condition may not come back.  But for most patients, that doesn’t work.  Often as the prednisone dose is tapered down, the platelet count drops and the person gets back in trouble again.  Then there a number of other medications that might be used.  Eventually, a surgical procedure called a splenectomy in which the spleen has to be removed is carried out.  Sometimes, some of the newer modern medications can be used to achieve a permanent cure for the disease but there is no treatment that is predictably perfect.  I explained to the mother that the doctors at the University Hospital were quite up-to-date on what the problems were and how to deal with their daughter’s illness and that their daughter could continue through college as she was presently doing.  Indeed the daughter would have to be careful to control her weight and avoid situations such as over fatigue and body abuse which sometimes happens to college students.  I told her that the disease is rarely fatal but it is a nuisance that requires careful medical attention to avoid complications that can be fatal if not attended to. 

            Actually the physicians and nurse practitioners and physician assistants at your local clinics are aware of this problem and how to maintain a person over an extended period of time with this condition.  Referral to specialists is necessary periodically but the backbone of treatment for this condition is done through your local clinics.  The mother did gain new respect for the care that the daughter had received thus far.  The internet is often a good source for learning about conditions such as ITP.  Once one gets on the internet type in “National Library of Medicine” and there is more information than you can ever absorb.