CD13
From haematologyetc.co.uk
Normal expression and function
CD13 is an enzyme which cleaves eutral amino acids from the N terminus of small peptides. The function of CD13 appears to vary with the tissue and the precise function in myeloid cells is unclear. The pattern of expression that is similar to other pan-myeloid markers (CD117 and CD33), but with levels generally increasing during maturation (contrasting with CD33 whose expression decreases). Maturation of myeloid cells may be partly identified through the relative CD33/13 expression.
Diagnostic role
- Together with other markers (CD117, CD33 and MPO) CD13 identifies myeloid lineage, particularly acute myeloid leukaemia. CD13 is also found on myelomonocytic and monocytic leukaemias.
- Expression is often absent on more primitive AML, erythroid or megakaryoblastic AML
- Aberrant expression by ALL occurs in around 30% of patients (at the 20% threshold)
- Overall high sensitivity, but may be less specific than CD117 or MPO.
Other relevant information:
Outside the haematopoietic system CD13 is particularly expressed on small intestinal and renal tubular epithelial cells and synaptic membranes from the CNS.
SUMMARY TABLES
Expression of CD13 by cells with early differentiation: ALL and haematogones | |||||||
---|---|---|---|---|---|---|---|
pro-B ALL | early pre-B ALL | pre-B ALL | B-ALL | pro T-ALL | mat T-ALL | AML | Hgns |
poss | poss | poss | rare | rare | rare | strg | freq |
* low expression correlates with subtype e.g. APML
Expression of CD38 by mature B cells: B-lymphoproliferative disorders | |||||||
---|---|---|---|---|---|---|---|
CLL | MCL | FL | HCL | HCv | MZL | LPL | PCL |
rare | rare | rare | rare | rare | rare | rare | rare |
*May indicate adverse prognostic when present on more than 20% of cells
**May be weak
1. Colour key: - the likelihood of any individual case expressing this marker, indicated by colour:
Rare (<5%) | Possible (5-20%) | Likely (20-40%) | Frequent (40-80%) | Expected (80-100%) |
2. Text key: - where expression level is characteristic of a disorder this is indicated by text:
abs = absent expression, wk = weak expression, mod = moderate expression, stg = strong expression, sub = expression may be on a sub-population of cells
SUMMARY TABLES
Expression by acute leukaemias and by haematogones
- Poss.png
B lineage ALL
- Rare.png
T lineage ALL
- Rare.png
ETP ALL
- Hi.png
AML
- Freq.png
Haemato-gones
Notes
In ALL the expression of CD13 is more likely in B-ALL but is also seen in T-ALL
In AML CD13 is expressed in around 80% of cases
In haematogones expression of CD13 is very frequent
Expression by B-lymphoproliferative disorders
- Rare.png
CLL
- Rare.png
PLL
- Rare.png
MCL
- Rare.png
FL'
- Rare.png
HCL
- Rare.png
HCLv
- Rare.png
MZL
- Rare.png
LPL
- Rare.png
PCs
Expression of CD13 by cells with early differentiation: ALL and haematogones | |||||
---|---|---|---|---|---|
B ALL | T ALL | AML | ETP ALL | MPAL | Hgns |
rare | freq | strg | strg | freq |
Expression of CD38 by mature B cells: B-lymphoproliferative disorders | |||||||
---|---|---|---|---|---|---|---|
CLL | MCL | FL | HCL | HCv | MZL | LPL | PCL |
rare | rare | rare | rare | rare | rare | rare | rare |
KEY
The indicated expression frequency, indicates the approximate frequency of occurrence in each particular disease type.
rare (<5%)
possible (5-20%)
likely (20-40%)
frequent (40-80%)
expected (>80%)
Where expression level is unusual or characteristic of a disorder this is indicated by text: