Bone marrow hypoplasia and fibrosis following interferon treatment.

Interferon treatment is known to cause hematologic changes such as thrombocytopenia, anemia and granulocytopenia or combinations thereof. Patients previously treated with chemotherapeutic drugs followed by alpha interferon treatment developed even more severe pancytopenia and aplasia. Case reports of two patients who received treatment with alpha interferon 2a are reported here. Both patients were previously treated with chemotherapy, but with a long interval before starting IFN administration. Patient one developed life-threatening bone marrow hypoplasia and aplasia after interferon treatment and died. Patient two showed similar but less severe changes in bone marrow, i.e. thrombocytopenia, mild leukopenia and anemia. The clinical course of both patients was followed by routine peripheral blood tests and bone marrow biopsies and permit some reflection on the pathogenesis of marrow hypoplasia. Myelosuppressive effects of interferon treatment are discussed in the context of chemotherapy effects, cytokine actions and potential additional influences of herpesvirus infections.