CD38
From haematologyetc.co.uk
- Summary
- CD38 helps mobilise intracellular calcium to activate a wide array of cell functions. In haematological cell types CD38 it is widely expressed by lymphoid cells B, T and NK) as well as myeloid precursor cells and mature myeloid cells.
- CD38 has particular diagnostic importance for lymphocytes where CD38 expression is acquired as stem cells commit to B-cell lineage, then is lost as mature B cells emerge from bone marrow before being re-acquired at the time of plasma cell differentiation.
What is its diagnostic role?
The wide expression of CD38 limits its diagnostic value except in very specific circumstances:
- The co-expression of CD38 with CD138 can identify normal or neoplastic plasma cells
- Expression of CD38 in chronic lymphocytic leukaemia (>20% of cells) may associated with poorer outcome
Other relevant information: CD38 is a therapeutic target, daratumumab is a monoclonal antibody which binds to CD38 and is used in the treatment of myeloma.
Expression in primitive cell types | |||||||
---|---|---|---|---|---|---|---|
AML | CMML | B ALL | Burkitt | T ALL | ETP ALL <I> | MPAL <I> | Hgns <I> |
2-20%* | 40-80% | 40-80% | 40-80% | 40-80% | 40-80% | 40-80% | 80-100%* |
Notes: * expression correlates with subtype, particularly APML. Expression by haematogones is very high.
Expression in mature B cell neoplasms | |||||||
---|---|---|---|---|---|---|---|
CLL | MCL | FL | MZL | HCL | DLBCL | LPL | PCL |
2-20%* | 80-100% | 80-100% | 80-100% | 2-20% | 80-100%* | 40-80% | 80-100%** |
Notes: Expression level in CLL and DLBCL may have prognostic value, plasma cells express the marker fairly consistently although the levels can vary.
Expression in mature T cell neoplasms | ||||||
---|---|---|---|---|---|---|
ATLL | CTCL/Sezary | T-PLL | T-LGL | NK-LGL | ||
<5% | <5% | <5% | <5% | <5% |