Acute leukaemia is a clonal ( derived from a single cell) malignant disorder characterised by the accumulation of immature blast cells in the BM, which replace normal marrow tissue, including haemopoietic precursor cells.
This results in BM failure, reflected by peripheral blood cytopenias and circulating blast cells. Infiltration of various organs is also a
(a) acute lymphoblastic leukaemia (ALL ), in which the abnormal proliferation is in the lymphoid progenitor cells ( immature lymphocytes)
(b) acute myeloid leukaemia (AML ), which involves the
myeloid lineages ( cells from which neutrophils,
eosinophils, monocytes, basophils, megakaryocytes, etc. are derived). The distinction between the two leukaemias is based on morphological, cytochemical, immunological and cytogenetic differences and is of paramount importance as the treatment and prognosis are usually different
usually but not invariably shows reduced Hb conc. and platelet count. The WBC can vary from 1000 to 200000, and the differential WBC is often abnormal, with neutropenia and the presence of blast cells . The anaemia is a normochromic, normocytic anaemia, and the
Prophylactic PLT transfusions are given if PLT count is 10000.
Clotting abnormalities may result from a DIC where infusions of FFP and cryoprecipitate may be beneficial.
Packed red cell transfusions are given for symptomatic anaemia, though these are contraindicated if the WBC is extremely high. In most patients a central venous catheter is inserted to facilitate blood product support, administration of chemotherapy and antibiotics, and frequent blood sampling.
Serious infection is a common cause of death in patients with acute leukaemia, as BM failure due to the leukaemia and to chemotherapy often results in profound neutropenia for 2 weeks or more. Reverse-barrier nursing techniques should therefore be used for such patients, and
iv antimicrobial agents should be started as soon as there is a fever or other sign of infection.
Pseudomonas infection of skin and nail bed in patient having treatment for AML
The aim is initially to induce a remission (5% blasts in the BM) and then to eradicate the residual leukaemic cell population by further courses of consolidation therapy. The drugs damage the capacity of the leukaemic cells to divide and replicate, and using cyclical combinations of three or more drugs increases the cytotoxic effect, improves the chance of remission after the initial “induction” period, and reduces the emergence of drug resistance.
In ALL the induction course is followed by two or more consolidation periods and by treatment directed at the CNS, followed by long term maintenance or continuation treatment for up to two years. This has been shown to improve long term cure rates in ALL, though not in AML.
treated with 4 or 5 courses of intensive chemotherapy when there is intent to cure. Each course consists of 10 days of chemotherapy. Subsequent courses are started after cell counts have recovered and response to treatment is established. In AML M3 the drug ATRA (all-trans-retinoic acid) is used as an adjunct to
chemotherapy as it causes differentiation of the malignant clone.
The treatment or prevention of leukaemic cells in CNS is part of all treatment protocols in childhood leukaemia and adult ALL, but not in adults with AML unless they have symptoms or blasts in the CSF. Treatment:
regular intrathecal chemotherapy (usually methotrexate), high dose intravenous methotrexate, or cranial irradiation.
Up to 85% of patients who initially achieve a complete remission will subsequently relapse. Transplantation reduces relapse risk but has been associated with high procedural mortality. The development of peripheral rather than BM stem cell harvest has reduced procedural
Nausea and vomiting, mucositis, hair loss, neuropathy, and renal and hepatic dysfunction.
Myelosuppression, resulting in profound neutropenia for two or more weeks with resultant opportunistic infection. Febrile neutropenic episodes require prompt use of broad spectrum antibiotics. Many patients also develop fungal infection requiring treatment with systemic antifungal drugs. Viral infection is predominantly seen in the post-transplant setting.