Teen
Thrombocytopenia is a diagnosis of exclusion. Sometimes it is secondary to a disease/condition/medication but if no other reasons are known primary ITP is diagnosed. It used to be diagnosed as idiopathic thrombocytopenic purpura (ITP), idiopathic means no recognised cause. In 2007 to idiopathic was changed to immune. For a good description of the reason for name change and ITP in general see this link
www.ncbi.nlm.nih.gov/pmc/articles/PMC3410635/
A group of medications called Thrombopoietin Receptor Agonists [TPORAs] such as Romiplostim (N Plate), Eltrombopag (Promacta or Revolade) and Avatrombopag (Doptelet) used to treat ITP carry a
small risk of developing bone marrow fibrosis. Last year a study called 'Thrombopoietin Receptor Agonists: Ten Years Later' was published, see this link
www.haematologica.org/content/104/6/1112
I have copied the most relevant bits from it regarding bone marrow fibrosis (which is graded MF0-MF3) below
"Early concerns were raised regarding the possible induction of bone marrow fibrosis because of sustained stimulation of megakaryopoiesis .... results of the published trials showing that, in most patients, grade of fibrosis did not change during treatment....while a slight, non-progressive reticulin fibrosis (MF-1) was observed in 10-50% of patients. In one study, a moderate increase in fibrosis (MF-2) was observed in 18% at median time of treatment of 2.5 years,48 whereas in three other studies, fibrosis progressed ..or developed ≥MF-2 during the study periods in less than 10%.... Severe grades of fibrosis (MF-3) were extremely rare in all studies...... In general, it does not seem that TPO-RA induce substantial fibrosis ...... fibrosis regressed in most patients after discontinuation treatment; in a few patients, fibrosis regressed despite continuing therapy.....
There is no consensus for patients on TPO-RA as to whether or how to monitor bone marrow (BM) fibrosis. At the moment, hardly any centers perform routine BM biopsy in TPO-RA treated patients. However, if a biopsy is performed and MF3 or collagen is discovered, then it is recommended that TPO-RA be discontinued. With moderately increased fibrosis, e.g. MF 2, a patient may continue TPO-RA but may need a repeat biopsy in six months. Older age and splenectomy could be associated with higher grades of BM fibrosis; fibrosis was not associated with type, dose or duration of treatment"
I hope you find the links useful. I have been taking taking Eltrombopag for over 3 years and have no signs of fibrosis.