The significance of diagnosing associated clonal mast cell diseases in patients with venom-induced anaphylaxis and the role of bone marrow investigation

Table 2 Summary of the investigations and demographic and clinical characteristics of patients

Case No	1	2	3
Gender	Female	Female	Female
Current age (age with latest reaction)	72 (63)	67 (60)	71 (67)
Cause of anaphylaxis	Wasp	Wasp	Wasp
Symptoms during manifestation(s) of anaphylaxis	Syncope, hypotension	Syncope, hypotension	Syncope, hypotension, dyspnea
Skin prick test	Vespula: Pos (2+)	Vespula: Pos (3+)	Vespula: Neg
Skin prick test	Honey bee: Neg	Honey bee: Neg	Honey bee: Neg
ImmunoCap (normal value <0.35 kU/L)	Vespula: 0.86 kE/L	Vespula: 0.76 kE/L	Vespula: <0.10 kE/L
ImmunoCap (normal value <0.35 kU/L)	Honey bee: <0.10 kE/L	Honey bee: <0.10 kE/L	Honey bee: <0.10 kE/L
Intracutaneous test	n/a	n/a	Vespula: Pos (at 10^-4 μg/ml concentration) Honey bee: Neg
Serum total IgE (kE/L)	14	89	35
sBT (normal value <11.4 μg/L)	12	14	23
UP-like skin lesions	None	None	None
Multifocal mast cell clusters	None	None	None
>25% mast cells spindle- shaped or with abnormal morphology	None	>25% spindle-shaped	None
Abberant immunophenotype (CD2/CD25 mast cells)	+/+	+/+	−/−
Kit mutation D816V	+	+	-
Venom immunotherapy	Yes, lifelong	Yes, lifelong	Planned for 5 years
Final diagnosis	MMAS^*	SM^#	Non-clonal HVA^¤

SM systemic mastocytosis, MMAS monoclonal mast cell activation syndrome, UP-like urticaria pigmentosa like, HVA hymenoptera venom allergy.
^*MMAS diagnosis was established by fulfillment of mast cells clonality (abberant immunophenotype and/or proven c-kit mutation D816V.
^#SM diagnosis was established by fulfillment of 3 minor criteria (presence of atypical mast cell morphology, abberant immunophenotype and Kit mutation D816V).
^¤Non-clonal HVA diagnosis was established after excluding mast cells clonality and other histopathological features of bone marrow mast cells.
n/a, not analyzed; sBT Baseline serum tryptase.

ISSN: 2045-7022