Leukemia-specific antigen (LSA) (LSA)

Leukemia-specific antigens (LSAs) represent a diverse class of proteins, glycoproteins, or neoantigens that are exclusively or significantly overexpressed on the surface or within malignant leukemic cells relative to healthy hematopoietic tissue (PMID: 28434493). Common examples include surface markers like CD19, CD33, and CD123, as well as intracellular proteins like Wilms Tumor 1 (WT1) or fusion proteins such as BCR-ABL1 resulting from chromosomal translocations (PMID: 22822452). These antigens are prioritized as therapeutic targets for monoclonal antibodies, antibody-drug conjugates (ADCs), and advanced cellular therapies like Chimeric Antigen Receptor (CAR) T-cells, which aim to eliminate leukemic clones selectively (National Cancer Institute). While these targeted approaches have revolutionized the treatment of acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML), they are often limited by 'on-target off-tumor' toxicities where the drug affects healthy cells expressing the same antigen at lower levels (PMCID: PMC7466589). Furthermore, the therapeutic pressure applied to these antigens can lead to antigen escape, where leukemic cells lose or mutate the target protein to evade immune detection, frequently resulting in clinical relapse (PMID: 30143330). Effective management of leukemia via these targets requires rigorous patient screening using flow cytometry or molecular profiling to confirm antigen presence and monitor for minimal residual disease (MRD).

Other names

Leukemia-associated antigenLAATumor-specific antigenTSALeukemia neoantigenMyeloid-associated antigen

Therapeutic agents targeting these antigens utilize monoclonal antibodies to induce direct cell lysis or immune recruitment, antibody-drug conjugates to deliver cytotoxic payloads directly into malignant cells, and CAR-T cells to provide a persistent, antigen-specific immune response against cells expressing the target molecule (PMID: 28434493, PMCID: PMC7466589).