Has anyone been diagnosed with Thrombocythemia MPN. This is linked I understand with GCA, which I was diagnosed with 8 years ago. I lost the sight in my left eye and have been on prednisolone. I am now on 7 mgs, trying to reduce to 6 mg without much success. A few weeks ago during a routine blood test (ESR and CRP) hospital noticed that my platelet count was abnormally high (720) and further blood tests were carried out. It now transpires that I have Thrombocythemia MPN. At present no medication has been given, but I return to Oncology on the 9th March for the full outcome. If anyone has this complaint I would like to know what medication they are on, and how it affects their GCA. Symptoms are those similar to relapse in PMR and GCA so has been very confusing for GP and myself. I haven't been on the forum for sometime as I thought my GCA was definitely on the way out, but then something else hits you.