UNDERSTANDING LEUKAEMIA- AN INTEGRATIVE REVIEW OF PATHOGENESIS, DIAGNOSIS, AND EMERGING THERAPIES

This review article provides a panoramic description of Leukaemia, where unusual WBC growth is observed. It outlines the classification of leukaemia into acute and chronic types (AML, ALL, CML, CLL) based on clinical course and cell origin, and the molecular mechanisms underlying its aetiology, such as chromosomal changes, genetic predisposition, and environmental factors. The article follows the history of development of leukaemia treatments, from initial chemotherapy protocols to recent advances such as TYK inhibitors (e.g., Imatinib) for CML, monoclonal antibodies (e.g., Rituximab) for B-cell malignancies, and CAR-T cell therapy. It also covers the histopathology and pathophysiology of leukaemia, outlining the multistep leukemogenesis process driven by genetic and epigenetic lesions, clonal evolution, and microenvironment pressures. Some genetic mutations, e.g., the BCR-ABL1 fusion gene in CML, and drug resistance mechanisms are discussed. The review also points out the role of signaling pathways like Notch, Wnt, and JAK/STAT in leukaemia stem cell maintenance and drug resistance. It also touches upon developments in diagnostic techniques, e.g., blood tests, bone marrow examination, and molecular tests like karyotyping and FISH.