Light Chain Escape in 3 Cases: Evidence of Intraclonal Heterogeneity in Multiple Myeloma from a Single Institution in Poland

Table 1

Patient characteristics for three cases of progression to LCMM by light chain escape.

	Case  1	Case  2	Case  3
Age (years)	71	62	70
Gender	F	F	M
MGUS/MM type	IgGκ + λ FLC	IgGκ	IgAκ
M-protein by SPE at diagnosis (g/L)	3.9	7.4	16
HLC ratio at diagnosis	4.8	6.9	24.2
iFLC [ ratio] at diagnosis (mg/L)	316 [0.07]	47.3 [5.9]	3440 [558]
uBJP at diagnosis	+	−	+
ISS stage	N/A	I	II
Symptoms at relapse	Renal impairment	Renal impairment	Renal impairment
dFLC concentration at relapse (mg/L)	9726	2665	5404
Time prior to clinical relapse that increases in FLC detected (days)	114	187	0
Maximum response	N/A	PR	VGPR
Treatment	Methylprednisolone	CTD, PAD, and ASCT	VAD, CTD, CD, IR, and VCD
Follow-up (days)	1310	1019	1570

LCMM: light chain multiple myeloma, F: female, M: male, N/A not applicable, MGUS: monoclonal gammopathy of undetermined significance, MM: multiple myeloma, SPE: serum protein electrophoresis, HLC: heavy/light chain assay (Hevylite), iFLC: involved free light chain concentration (Freelite), uBJP: urinary Bence Jones protein, ISS: international staging system, dFLC: difference in concentration between involved and uninvolved free light chain measurement (Freelite), FLC: free light chains, PR: partial response, VGPR: very good partial response, ND: not determined, CTD: cyclophosphamide, thalidomide, and dexamethasone, PAD: bortezomib, doxorubicin, and dexamethasone, ASCT: autologous stem cell transplant, VAD: vincristine, doxorubicin, and dexamethasone, VCD: bortezomib, cyclophosphamide, and dexamethasone, CD: cyclophosphamide and dexamethasone, and IR: ionising radiation.