Dear Dr. Roach: What can you tell me about the cause and treatment of immune thrombocytopenia purpura (ITP)? I am a 71-year-old male, and after lab results showed a low blood platelet count, I underwent a spleen and liver scan as well as a bone marrow biopsy. They all showed normal function, and no infection (viral or bacterial) has been found. Thus, I have been diagnosed with ITP.

My platelet count dropped to 11,000 before I was put on 35 mg of prednisone daily by my hematologist. After one week on prednisone, my platelet count rose to 84,000. Going forward, I have been advised that if prednisone continues to increase my platelet count, I can be weaned off of it and monitored.

I am concerned about the high dose of prednisone, even though it may be temporary. There has also been discussion about a splenectomy if prednisone must be continued. I have a quadricuspid aortic valve, and I was diagnosed with endocarditis and recovered from it in 2014.

In addition, I am concerned about infections (among other things) if my spleen is removed. According to my cardiologist, I may need heart valve replacement at some point due to the anomaly of my aortic valve and a moderate to severe heart murmur that was found in this valve. — J.V.

Answer: You have one fairly common condition (ITP) and one very rare condition (a quadricuspid aortic valve).

ITP affects about 5 people per 10,000. It can be associated with other conditions that are hematologic (leukemia) or rheumatic (lupus), as well as viral infections. But in many people, no other identifiable cause can be found, so this is termed “primary ITP.”

Treatment is often not necessary, but your platelet count got very low. (The normal number is between 200,000-400,000, and spontaneous bleeding can occur under 50,000. A level below 10,000 is considered high-risk for bleeding.) Treatment was appropriate, and your hematologist treated you with the most common treatment, glucocorticoids (steroids), that are at a relatively low dose.

Most experts would treat you for one to two weeks, then taper the medicine off over a few weeks. The side effects of this dose of steroids are modest if it does not need to be frequently repeated.

It’s not clear whether you will have further episodes of very low platelets. Some people have few episodes that respond to steroids, while others require additional treatments. Because of the side effects from recurrent courses of steroids, there are other options, but each has its own potential for harm.

Removing the spleen gives the best chance of long-term freedom from recurrences without medication, but it does increase the risk of certain infections. However, infections after heart valve surgery are uncommon, even in people who don’t have a spleen.

The normal aortic valve has three leaflets (tricuspid). Bicuspid (two) valves are not uncommon, and they are at a higher risk for becoming leaky valves. Valves with four leaflets (quadricuspid) are very rare, with only a few hundred cases that were ever reported in the world’s literature.

Quadricuspid valves are sometimes (between 18% to 32%) associated with other unusual heart anatomies, including abnormal arteries that supply blood to the heart. The majority of people with quadricuspid valves will develop leaky valves. You are at an even higher risk for needing a valve replacement due to the history of heart valve infections (endocarditis).

Because of the combination of conditions you have, your hematologist could consider treatment with medication to increase your platelets without suppressing the immune system, such as a TPO receptor agonist. (This is the body’s own system to stimulate platelet production.) Hopefully, though, you will not need it, and hematologists generally wait a year before considering additional therapy to see whether the person will go into remission.