Table 3.

Patients’ characteristics

Patient number	Age (years)	Sex (m/f)	Diagnosis (SM variant)	Sample PB or BM	KIT D816V	Serum tryptase (ng/ml)	% MC in BM smearsa	% MC in BM histology	% MC in MNCb	TKI therapy before BMP	used in histamine release experimentsc
#1a	29	f	ISM	BM	+	50.2	2	10-15	0.02	no‡	no
#1b	29	f	ISM	PB	+	50.2	n.a.	n.a.	n.a.	no	yes
#2	39	f	ISM	PB	+	26.5	n.a.	n.a.	n.a.	n.a.	yes
#3	64	f	ISM	PB	+	39.8	n.a.	n.a.	n.a.	no	yes
#4	51	f	ISM	PB	n.a.	22.3	n.a.	n.a.	n.a.	no	yes
#5	41	f	ISM	PB	+	42.6	n.a.	n.a.	n.a.	no	yes
#6	70	f	ISM	BM	+	n.a.	5	30	1.41	no	yes
#7	60	f	ISM	PB	+	28.6	n.a.	n.a.	n.a.	no	yes
#8	59	m	ISM	BM	+	37.7	1	10	0.31	no	no
#9	54	m	SSM	BM	+	180	<5	70	0.30	no	no
#10	68	m	ASM	BM	+	650	3	50	1.72	no	no
#11	69	m	ASM	BM	+	119	4	3-5	0.11	no‡	no
#12	39	f	ISM-MPN	BM	+	44.1	1	15	0.11	no	no
#13	62	m	ASM-CMML	BM	+	200	<1	<1	<0.01	Midostaurin	no
#14a	71	m	ASM-CMML	BM	+	66.2	<1	<1	<0.01	Avapritinib	no
#14b	71	m	ASM-CMML	BM	+	62.4	<1	<1	0.02	Avapritinib	no
#15	65	m	ASM-AML	BM	-	n.a.	0.5-1	25	0.10	no†	no
#16	63	m	ASM-AML	BM	+	33.9	<1	15	0.22	no†	no
#17	58	m	MCL	BM	+	250	35	70	2.44	Midostaurin	no
#18	61	f	MCL	BM	-*	2146	93	90	60.50	no†	no
#19	49	f	MCL	BM	-*	533	73	70	9.20	no	no
#20	60	m	sMCL	BM	+	339	50	60	2.21	Midostaurin	no

Diagnoses were established according to WHO criteria. Patients were examined at diagnosis or during follow up. In patient #14, bone marrow (BM) was obtained at two time points (#14a and #14b). The percentage (%) of mast cells (MC) was determined in Wright-Giemsa-stained BM smears and in histologic studies by immunohistochemistry using antibodies against tryptase and/or KIT. Serum tryptase levels were routinely examined by fluoro-immuno-enzyme assay. Abbreviations: SM, Systemic Mastocytosis; M, male; F, female; MC, Mast Cells; BM, Bone Marrow; MNC, Mononuclear Cells; BMP, Bone Marrow Puncture; ASM, Aggressive SM; MCL, Mast Cell Leukemia; sMCL, Secondary MCL; MPN, Myeloproliferative Neoplasm; SSM, Smoldering SM; ISM, Indolent SM; CMML, Chronic Myelomonocytic Leukemia; PB, Peripheral Blood; n.a., not available; WHO, World Health Organization; BA, Basophils.

^aPercentage of MC was assessed in Wright-Giemsa-stained BM smears.

^bPercentage of MC in MNC was analyzed by flow cytometry using an antibody against KIT.

^cFrom patient #1 to #7 we were able to perform IgE-dependent histamine release with PB BA or BM MC (shown in Figure 8).

^*In patient #18 and #19 the D816H mutation of KIT was detected.

^‡Patient #1 progressed to ASM and patient #11 progressed to MCL.

^†Patients #15, #16, and #18 received cladribine or polychemotherapy.