Thrombosis and hemorrhage in chronic myeloproliferative disorders

TKI-Related Platelet Dysfunction Does Not Correlate With Bleeding in Patients With Chronic Phase-Chronic Myeloid Leukemia With Complete Hematological Response

Bleeding has been reported in patients with chronic myeloid leukemia (CML) using tyrosine kinase inhibitors (TKIs). In this study, we aimed to evaluate platelet functions and associated bleeding symptoms in patients with CML using TKIs. A standardized questionnaire that was developed for inherited bleeding disorders (ISTH/SSC Bleeding Assessment Tool) was used to score bleeding symptoms in 68 chronic phase patients with CML receiving imatinib (n = 47), dasatinib (n = 15), or nilotinib (n = 6). Light transmission aggregometry was used for platelet function testing. None of the patients had major bleeding (score > 3). Minor bleeding was observed in 25.6% and 20% of the patients in imatinib and dasatinib treatment groups. Impaired/decreased platelet aggregation was observed in 29.8% of imatinib treatment group, 50% of nilotinib group, and 40% of dasatinib group. A secondary aggregation abnormality compatible with the release defect was observed in 26% of patients with CML; 25.5%, 33.3%, and 16.7% of patients receiving imatinib, dasatinib, and nilotinib, respectively. No correlation was found between bleeding symptoms and the impaired platelet function. We can conclude that TKIs may impair in vitro platelet aggregation but this impairment is not associated with bleeding diathesis.

The therapeutic goals of essential thrombocythemia under the clouds of over-treatment and under-treatment

INTRODUCTION

Therapeutic stratification after the accurate essential thrombocythemia (ET) diagnosis is made based on the medical history (age, previous thrombosis), clinical assessments (cardiovascular [CV] risk factors, comorbidities, systemic diseases), laboratory examinations (leukocytosis, extreme thrombocytosis, anemia) and if available further sophistical analyses (CD34 count, JAK2V617F homozygosity, and mutant allele burden).

AREAS COVERED

Current conventional therapeutic tools for reaching those goals are observation, low-dose aspirin, hydroxyurea, anegrelide and interferon alpha. Those treatment modalities are used alone or in combination to get the therapeutic goals in ET patients. The ET literature search was made in PubMed with particular focus on the clinical trials, recommendations, guidelines and expert opinions.

EXPERT OPINION

The most important step for the therapeutic decision of ET in the clinic is the risk assessments. Clinical decision making starts with the detection of the age and the prior thrombosis history of the ET patient. Treatment goals in ET are to avoid thrombosis and bleeding, to treat ET-related symptoms, improve quality of life and to minimize risk of malignant transformation and/or post-ET myelofibrosis.