Correct!
5. All of the above
The abundance of mast cells producing histamine, tryptase and a variety of other substances lead to the symptoms of SM. The symptoms are similar to anaphylaxis since the pathophysiology is similar. However, in contrast to anaphylaxis, tryptase levels remain elevated after resolution of the acute event. Our patient’s tryptase level after his recovery was > 200 ng/mL (normal 1-10 ng/mL). CD25 is a portion of an interleukin-2 receptor expressed on the surface of mast cells in the bone marrow of patients with SM. This interleukin-2 receptor is involved in inflammatory or cell-mediated immune responses and not seen on normal mast cells. D816V/KIT is a mutation of the stem cell receptor CD117 commonly associated with SM and its presence leads to overstimulation of the receptor resulting in overgrowth of mast cells. A reference laboratory later confirmed the presence of D816V/KIT mutation in our patient.
The patient had previously had a skin biopsy which showed an abundance of mast cells consistent with SM. A bone marrow biopsy was performed which demonstrated multiple large aggregates of spindle-shaped mast cells that were CD25+ consistent with the diagnosis of systemic mastocytosis (Figure 2).
Figure 2. Bone marrow biopsy showing a low power view (Panel A) and a high power view (Panel B) of the typical spindle-shaped mast cells in the bone marrow. The cells were CD25 + on monoclonal antibody peroxidase staining (Panel C).
Which of the following are used for treatment of SM?