In a small number of patients, CLL can sometimes change (transform) into other different diseases. These include:
- Prolymphocytic leukaemia (PLL): This is a rare and aggressive type of leukaemia characterised by an excessive growth of lymphocytes. It occurs in less than 1% of chronic leukaemia patients. Ibrutinib as initial therapy for B-PLL Ibrutinib has shown positive responses (Moore et al 2020). Current treatment options for T-cell PLL are inadequate.
- Richter’s transformation: CLL transforms into a fast-growing lymphoma called diffuse large B-cell lymphoma (DLBCL). This aggressive lymphoma is a serious complication of CLL as it is often very difficult to treat. It affects approximately 2-10% of CLL patients at any time during the course of their disease. Treatment is similar to that used for DLBCL, i.e., chemotherapy, chemoimmunotherapy or CAR T-cell therapy.
- Autoimmune haemolytic anaemia: With this condition, patients’ immune systems do not recognise their own red blood cells and destroy them, causing anaemia. Occasionally, a similar problem may affect the platelets which is called autoimmune thrombocytopenic purpura. Specific treatment for these autoimmune problems are required usually starting with steroid therapy.