HLA-DR: Difference between revisions
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: | ::HLA-DR is considered a pan-B lineage marker in leukaemia and in cases where lineage is ambiguous the expression of HLA-DR may contribute to (but not prove) the assignment of B cell lineage. The molecule is also expressed by myeloid blasts, but rarely by promyelocytes so has value in identification of acute promyelocytic leukaemia (APL). | ||
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:<span style="color:navy">'''Background'''</span> | :<span style="color:navy">'''Background'''</span> | ||
: | :HLA-DR presents antigen to T-helper cells and is typically expressed by cells involved in antigen processing and recognition - including macrophages, B-cells and dendritic cells. HLA-DR is also expressed by early myeloid progenitor cells but expression is lost as they mature to promyelocytes. | ||
:<span style="color:navy">'''Diagnostic Use'''</span> | :<span style="color:navy">'''Diagnostic Use'''</span> | ||
* | *Acute myeloid leukaemias generally express HLA-DR, but expression is expected to be absent from mature myeloid leukaemias such a APL and erythroid leukaemia | ||
*B-lineage leukaemias and lymphomas each will usually express HLA-DR, although expression is generally lost as they mature to plasma cells | |||
*T-lineage ALL is generally HLA-DR negative, although rarely mature T-cell neoplasms may express HLA-DR | |||
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Latest revision as of 18:36, 16 May 2023
- Summary
- HLA-DR is considered a pan-B lineage marker in leukaemia and in cases where lineage is ambiguous the expression of HLA-DR may contribute to (but not prove) the assignment of B cell lineage. The molecule is also expressed by myeloid blasts, but rarely by promyelocytes so has value in identification of acute promyelocytic leukaemia (APL).
- Background
- HLA-DR presents antigen to T-helper cells and is typically expressed by cells involved in antigen processing and recognition - including macrophages, B-cells and dendritic cells. HLA-DR is also expressed by early myeloid progenitor cells but expression is lost as they mature to promyelocytes.
- Diagnostic Use
- Acute myeloid leukaemias generally express HLA-DR, but expression is expected to be absent from mature myeloid leukaemias such a APL and erythroid leukaemia
- B-lineage leukaemias and lymphomas each will usually express HLA-DR, although expression is generally lost as they mature to plasma cells
- T-lineage ALL is generally HLA-DR negative, although rarely mature T-cell neoplasms may express HLA-DR