From the Guidelines
Yes, myelofibrosis can cause low platelets (thrombocytopenia). Myelofibrosis is a type of bone marrow cancer that disrupts the normal production of blood cells by replacing healthy bone marrow with fibrous scar tissue. This scarring interferes with the bone marrow's ability to produce adequate numbers of platelets, along with other blood cells. According to a study published in the Journal of Clinical Oncology in 2011 1, some patients with primary myelofibrosis may experience severe thrombocytopenia or neutropenia, in addition to severe anemia. The low platelet count occurs because the scarred bone marrow cannot produce enough platelets, and the enlarged spleen (splenomegaly) that often accompanies myelofibrosis can trap and destroy platelets.
Key points to consider in patients with myelofibrosis-related thrombocytopenia include:
- Monitoring for bleeding risks
- Treatment approaches may include JAK inhibitors, thrombopoietin receptor agonists, or in severe cases, platelet transfusions
- The severity of thrombocytopenia often correlates with disease progression and can be an important factor in determining treatment strategies and prognosis
- Patients may also experience other clinical issues, such as marked hepatosplenomegaly, nonhepatosplenic extramedullary hematopoiesis, thrombohemorrhagic complications, and profound constitutional symptoms, as outlined in the study 1.
Overall, the management of myelofibrosis-related thrombocytopenia requires a comprehensive approach that takes into account the patient's overall clinical condition and disease progression.
From the Research
Myelofibrosis and Low Platelets
- Myelofibrosis (MF) is a chronic myeloproliferative neoplasm that can cause thrombocytopenia (low platelet count) due to bone marrow fibrosis, splenic sequestration, and myelosuppression from an inflammatory microenvironmental milieu 2.
- Thrombocytopenia is a common feature of MF, occurring frequently at diagnosis and worsening with disease progression, and is an independent adverse prognostic factor 2, 3.
- The mechanisms underlying thrombocytopenia in MF are poorly understood, but recent studies have identified distinct genetic etiologies, including U2AF1 Q157 mutation, deletion 20q, molecular complexity, and high-risk karyotype 4.
Prevalence and Prognostic Impact
- Thrombocytopenia is a disease-related feature of MF that portends a poor prognosis, impacting overall survival (OS) and leukemia-free survival 5.
- Patients with MF and thrombocytopenia are considered high-risk by most prognostic models, but recent studies have shown that thrombocytopenia in MF is not uniformly high-risk 4.
- Genetic mutations affecting the genes SRSF2 and TP53 are uniquely problematic in MF patients with thrombocytopenia, as is a low serum albumin level 4.
Treatment Options
- Currently, there are limited therapeutic options for MF patients with thrombocytopenia, and treatment is often focused on improving cytopenias or alleviating systemic symptoms and splenomegaly 2, 3.
- JAK2 inhibitors have moved to the forefront of MF therapy, but are advised against in patients with severe thrombocytopenia (platelets < 50 × 10^9/L) 5.
- Danazol therapy has been shown to be effective in improving anemia in MF patients, and may also increase platelet counts in some patients with moderate thrombocytopenia 6.