Sequence diversity of kappa light chains from patients with AL amyloidosis and multiple myeloma

Figures & data

Table 1. Characteristics of 41 AL amyloidosis and 83 multiple myeloma patients.

	AL_H (n = 8)	AL_K (n = 14)	AL_D (n = 19)	MM (n = 83)
Age [y], median (range)	62 (52-80)	61 (34-69)	63 (39-78)	61 (42-70)
Sex female/male [n]	4/4	4/10	6/13	30/53
Newly diagnosed [n]	6/8	14/14	16/19	83/83
Relapse/progress [n]	2/8	0/14	3/19	0/83
AL and concomitant MM	3/8	0/14	5/19
No. of organs involved, no. of patients
1	2	11	2
2	5	1	5
3	1	2	7
4	0	0	2
More than 4	0	0	3
different organs involved [n]
Heart	8/8	0/14	16/19
Kidney	0/8	14/14	5/19
Liver	0/8	2/14	9/19
ANS	1/8	0/14	5/19
PNS	0/8	0/14	4/19
GI	2/8	2/14	7/19
ST	4/8	1/14	9/19
dFLC [mg/L], median (range)	543 (207–1891)	97 (8–649)	472 (54–3784)	349 (0–30124)
FLC ratio >100	3/8	0/8	4/19
Cardiac stage^1
I	0/8	7/13	2/18
II	1/8	3/13	6/18
IIIa	3/8	2/13	7/18
IIIb	4/8	1/13	3/18
Renal stage
I	5/7	2/14	15/18
II	2/7	8/14	3/18
III	0/7	4/14	0/18
AP [U/L] median (range)	125 (52–199)	74 (41–240)	120 (45–2137)	70 (28–349)^2
M-Gradient [n]	5/8	8/14	8/19	74/83
Plasma cell infiltration [%] (range)	12 (8–43)	10 (5–20)	13 (2–67)	42 (2–100)
Monoclonal protein in the serum [n]	4/8	8/14	9/19	73/83
IgG	2/8	8/14	8/19	59/83
IgA	2/8	0/14	1/19	12/83
IgM	0/8	0/14	0/19	1/83
IgD	0/8	0/14	0/19	1/83
Light chain only	4/8	6/14	10/19	10/83
t(11;14) [n]	4/8	5/13	12/15	16/82
1q21 [n]	2/8	3/13	3/15	8/82
^1 EURO score^, 24 n/a

AL: AL amyloidosis; MM: multiple myeloma; AL_H: AL patients with dominant heart involvement; AL_K: AL patients with dominant kidney involvement; AL_D: AL patients with diverse organ involvement; ANS: autonomic nervous system; PNS: peripheral nervous system; GI: gastrointestinal tract; ST: soft tissue; iFISH: interphase fluorescence in situ hybridisation.

Figure 1. Variable region gene usage in AL amyloidosis and multiple myeloma patients. (A) IGKV-family usage in AL and MM. (B) IGKV-subgroups in AL (organ tropism) and MM. AL: AL amyloidosis; MM: multiple myeloma; AL, n = 41; MM, n = 83, AL_H: AL patients with dominant heart involvement; AL_K: AL patients with dominant kidney involvement; AL_D: AL patients with diverse organ involvement; AL_H, n = 8; AL_K, n = 14; AL_D, n = 19.

Figure 2. Influence of the presence of a heavy chain in serum on the most frequent IGKV-subgroups. (A) Comparison of the most abundant IGKV-subgroups with respect to a heavy chain in serum in AL and MM. (B) Influence of organ tropism on the expression of the most abundant IGKV-subgroups with respect to a heavy chain in serum. AL: AL amyloidosis; MM: multiple myeloma; AL, n = 41; MM, n = 83. HC: heavy chain in serum, no_HC: no heavy chain in serum; AL_HC n = 21; AL_no HC n = 20; MM_HC n = 73; MM_noHC n = 10. AL_H = AL patients with dominant heart involvement; AL_K = AL patients with dominant kidney involvement; AL_D = diverse AL patients; AL_H n = 8; AL_K n = 14; AL_D n = 19.

Figure 3. Comparison of the amino acid amount between AL amyloidosis and multiple myeloma sequences. (A) Comparison of AL and MM assigned to IGKV1/D-33, AL n = 13, MM n = 11. (B) Stratification in the presence or absence of a heavy chain in serum, AL_HC n = 7, AL_noHC = 6, MM_HC = 10, MM_noHC = 1. AL: AL amyloidosis; MM: multiple myeloma; HC: heavy chain in serum; noHC: no heavy chain in serum.

Table 2. Analysis of the IGKJ-usage in AL amyloidosis and multiple myeloma.

	IGKJ1	IGKJ2	IGKJ3	IGKJ4	IGKJ5	n/a
AL_H [%] (n = 8)	13	63	13	0	13	0
AL_K [%] (n = 14)	29	29	0	29	7	7
AL_D [%] (n = 19)	11	37	5	37	11	0
AL, whole cohort [%] (n = 41)	17	39	5	27	10	2
MM [%] (n = 83)	30	29	13	23	5	0

AL: AL amyloidosis; MM: multiple myeloma; AL_H: AL patients with dominant heart involvement; AL_K: AL patients with dominant kidney involvement; AL_D: diverse AL patients.

Table 3. Median mutation count and mutation frequency of IGKV1/D-33 sequences.

	n		IGKV 89 AA	FR1 18 AA	CDR1 11 AA	FR2 15 AA	CDR2 7 AA	FR3 32 AA	CDR3	IGKJ 12 AA
AL	13	[%]	100	69	77	85	77	92	77	77
		[n]	12.0	1.0	1.0	1.0	1.0	4.0	2.5	1.0
MM	11	[%]	100	36	73	82	64	91	100	64
		[n]	10.0	1.0	2.0	1.0	2.0	3.5	2.0	2.0
AL_HC	7	[%]	100	71	71	100	71	86	86	71
		[n]	12.0	1.0	1.0	1.0	1.0	4.0	2.5	1.0
AL_noHC	6	[%]	100	67	100	67	83	100	67	83
		[n]	10.5	1.0	1.5	1.0	1.0	3.5	2.0	1.0
MM_HC	10	[%]	100	30	70	80	60	90	100	60
		[n]	9.5	1.0	2.0	1.0	2.0	3.0	2.0	1.5
MM_noHC	1	[%]	–	–	–	–	–	–	–	–
		[n]

[%] = percentage of mutated segments, [n] = median mutation count. For the CDR3-region, the patient-specific linker and the first two AA of the J-segment were included and AA length was between 8 AA and 14 AA. AL: AL amyloidosis; MM: multiple myeloma; HC: heavy chain in serum; no_HC: no heavy chain in serum.

Figure 4. Extract of the IGKV1/D-33 and IGKJ2 alignment in AL amyloidosis and multiple myeloma patients. FORx = sequences from AL amyloidosis patients, MMx = sequences from multiple myeloma patients. H = dominant heart involvement, K = dominant kidney involvement, D = diverse organ involvement, red = nonsynonymous substitutions, green = linker-region, purple = insertions and deletions, highlighted in green = positive charged amino acids, highlighted in blue = negative charged amino acids. The first position of the IGKC-Ensembl reference was completed by the uni prot reference (P01834). The amino acids were numbered according to the Vbase2 reference. Complementary-determining regions (CDRs) were aligned according to Kabat using abYsis.

Data availability statement

The data that support the findings of this study are available from the corresponding author, SS and SoS, upon reasonable request. IGKV1/D-33 AL and MM sequence data were stored in the European Nucleotide Archive (accession: PRJEB65847).