Low Platelet Count

My 84-year old father has been anemic for three years and has been diagnosed with a low platelet count (90). His other blood counts are normal. He had been diagnosed with hepatitus (hepatitis) in his 20's. Could this much earlier diagnosis be related to his symptoms today? He is unaccountably exhausted and his doctors cannot explain his low platelet count. He's had upper and low GIs - there is no bleeding. He's had injections of Aranespt which seem to have a palliative effect. He takes Cumiden and his health is otherwise excellent