CHAPTER: Clonal Haematopoiesis Assessment: Prevention, Treatment and Research

Inclusion Criteria: 1. Aged 55 years and above 2. Confirmed CH or possible CH, with possible CH defined by: a. Persistent, non-severe cytopenia, characterised by one or more of the following, present on at least 2 occasions, at least 4 months apart (WHO criteria): i. Absolute neutrophil count (ANC) \< 1.8 x 109/L ii. Haemoglobin (Hb) \< 120 g/L in females, \< 130 g/L in males iii. Platelet count \< 150 x 109/L 3. Provision of written informed consent prior to any study-related assessments or procedures being carried out. Exclusion Criteria: 1. Severe cytopenia as defined by one or more of the following: 1. ANC \< 0.5 x109/L 2. Hb \< 80 g/L 3. Platelet count \< 50 x 109/L 2. Multilineage cytopenias: a. Marked trilineage cytopenia with all the following present: i. ANC \< 1.0 x 109/L AND ii. Hb \< 110 g/L AND iii. Platelet count \< 100 x 109/L b. Marked bilineage cytopenia, with two or more of the following present: i. ANC \< 1.0 x 109/L ii. Hb \< 110 g/L iii. Platelet count \< 100 x 109/L Note: People with possible CH, with the above characteristics will be excluded from referral to the CH clinic and will instead have urgent investigation as an inpatient or in the haematology clinic. However, if no definite cause for cytopenia is identified, including CH, then individuals may be referred for CH screening at the CH clinic the discretion of the study PI