Thalhammer-Scherrer et al used a battery of monoclonal immunostains to characterize blasts from adults with myeloperoxidase-negative acute leukemia. These can be used to separate patients with AML Type M0 from ALL. The authors are from the University of Vienna in Austria.
Cases: Adults with myeloperoxidase-negative acute leukemia. Patients with AML Types 1 to 6 usually could be recognized based on morphologic or cytochemical findings.
Battery of immunostains:
(1) intracytoplasmic CD79a
(2) intracytoplasmic CD3
(3) CD117
(4) CD13
(5) CD33
(6) CD10
(7) CD19
(8) CD2
|
Immunostain |
Finding |
Points for Myeloid Score |
Points for Lymphoid Score |
|
cy79a OR cyCD3 |
positive |
0 |
2 |
|
cy79a AND cyCD3 |
negative |
2 |
0 |
|
CD117 |
positive |
1 |
0 |
|
|
negative |
0 |
1 |
|
CD13 |
positive |
1 |
0 |
|
|
negative |
0 |
1 |
|
CD33 |
positive |
1 |
0 |
|
|
negative |
0 |
1 |
|
CD10 OR CD19 OR CD2 |
positive |
0 |
1 |
|
CD10 AND CD19 AND CD2 |
negative |
1 |
0 |
myeloid score =
= SUM(points for all of the immunostains)
lymphoid score =
= SUM(points for all of the immunostains) =
= 6 – (myeloid score)
Interpretation:
• minimum score: 0
• maximum score: 6
|
Diagnosis |
Myeloid Score |
Lymphoid Score |
|
AML Type M0 |
>= 4 |
<= 3 |
|
ALL |
<= 3 |
>= 4 |
Ambiguous case: 1 patient with T-cell ALL scored 3 on both the myeloid and lymphoid scores (I am not sure how this could happen based on the scoring scheme). This case was characterized using additional immunostains (CD5, CD7, CD1a, CD4, CD8, CD10, surface CD3).
Specialty: Hematology Oncology, Clinical Laboratory
