Gut microbiome (GM) is acquiring increasing importance in human health and disease. GM influences hematopoiesis and immune cells types differentiation. Patients with cancer are characterized by dysbiosis and compromised immunity. In the case of Chronic Myeloid Leukemia (CML), treatment with Tyrosine Kinase Inhibitors (TKIs) restores immunosurveillance; in particular deep molecular response (DMR) is associated with increased levels of NK and CD8+ Tcells. There is no literature on the effects of GM on CML outcomes. This project aims to identify a microbial signature associated with a higher probability of achieving DMR.

Philadelphia positive Chronic Myeloid Leukemia (CML) is a myeloproliferative disorder originating from pluripotent hematopoietic cells. Treatment typically involves tyrosine-kinase inhibitors (TKIs), which have significantly improved long-term survival. While generally well-tolerated, TKIs can cause side effects, particularly gastrointestinal issues (diarrhea, constipation, abdominal pain, malabsorption, bleeding) and liver/pancreatic enzyme increases, which may persist and affect quality of life. Additionally, cardiovascular events, often linked to metabolic changes (e.g., glucose intolerance, diabetes, hypertension), occur more frequently during treatment. These side effects raise concerns about TKIs potentially inducing a chronic inflammatory response.

Recent research on the human microbiota highlights its importance in health. The microbiota plays a critical role in gut health, immune function, and metabolic processes, and its imbalances (dysbiosis) can contribute to a range of diseases. Factors such as diet, age, physical activity, and medication use can disrupt the microbiota. However, the relationship between gut microbiota and TKIs in CML patients remains unexplored.

The current study will evaluate by whether different CML gut microbiota genotypes influence TKI treatment responses, whether microbiota alterations cause inflammation or metabolic disorders, and whether microbiota, along with dysmetabolism and dysimmunity, contribute to variations in treatment efficacy and tolerance

Inclusion Criteria:

• Age > 18 years old
• Chronic Myeloid Leukemia Patients
• Any stage of the disease

Exclusioni Criteria:

none

All hematologic patients of the the Hematology Division of the AO Ordine Mauriziano di Torino with a diagnosis of Philadelphia positive Chronic Myeloid Leukemia (CML) will be included.