Table 4.
Cellular Distribution of pSTAT5 in Bone Marrow Sections in Mastocytosis and Controls
| Cell type | Predominantly cytoplasmic pSTAT5 staining protocol
|
Predominantly nuclear pSTAT5 staining protocol
|
||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Normal/reactive BM | CM | ISM | ASM/MCL | SM-AHNMD | Normal/reactive BM | CM | ISM | ASM/MCL | SM-AHNMD | |
| Megakaryocytes | ++ | ++ | ++ | ++ | ++ | +** | +** | +** | +** | +** |
| Myeloid progenitors | + | + | + | + | + | +** | +** | +** | +** | +** |
| Neutrophil granulocytes | − | − | − | − | − | − | − | − | − | − |
| Eosinophil granulocytes | − | − | − | − | − | − | − | − | − | − |
| Erythroid progenitors | − | − | − | − | − | − | − | − | − | − |
| Mast cells | n.d.* | n.d.* | + | + | + | n.d.* | n.d.* | + | + | + |
Bone marrow sections were stained with antibody AX1 as described in the text.
Score: −, negative; +, positive; ++, strongly reactive; BM, bone marrow; CM, cutaneous mastocytosis; ISM, indolent systemic mastocytosis; ASM, aggressive systemic mastocytosis; MCL, mast cell leukemia; SM-AHNMD, systemic mastocytosis with an associated clonal hematologic non MC-lineage disease; n.d., not determined.
*
In these cases, only a few diffusely spread mast cells were found.
**
In most patients and controls, pSTAT5 was found to be expressed in the cytoplasmic compartment in the ’predominantly nuclear’ staining protocol, often exceeding the nuclear staining-reaction.