Table 1.

Baseline characteristics

All patients (N = 34)MRD(n = 16)MRD+(n = 18)
Median age, y62.561.565
Female sex, n (%)13 (38.2)5 (31.3)9 (50)
Race/ethnicity, n
 White271215
 East Asian211
 African American321
 Unknown/not reported211
Mean BMI (range), kg/m226.5 (15.5-38.5)28.3 (20.7-38.5)24.9 (15.5-33.2)
Paraprotein isotype, n
 IgG κ1679
 IgG λ853
 IgA κ303
 IgA λ330
 Light chain κ303
 Nonsecretory110
Cytogenetic risk, n (%)
 High*10 (29)2 (12.5)8 (44.4)
 Standard24 (69)14 (87.5)10 (55.6)
ISS stage, n
 I251411
 II615
 III211
 Unknown101
Induction therapy regimen, n
 KRd + ASCT936
 KRd without ASCT16115
 Other induction + ASCT514
 Other without ASCT413
Prior ASCT, n (%)14 (41.2)4 (25)10 (55.6)
Antibiotics within 60 d of stool sample collection, n (%)8 (23.5)2 (12.5)6 (33.3)
Median serum immunoglobulin (IQR), mg/dL
 IgG584 (480-864)608 (480-1084)584 (488-834)
 IgA69.5 (30.2-109.2)74 (66.5-149)61.5 (26.5-87.5)
 IgM27.8 (14.8-31.5)22.5 (14.2-27.8)24 (17-32.5)
  • Patients with >1 line of therapy and patients on lenalidomide maintenance at time of MRD assessment were excluded.

  • ASCT, autologous stem cell transplantation; BMI, body mass index; Ig, immunoglobulin; ISS, International Staging System; KRd, carfilzomib, lenalidomide, and dexamethasone.

  • * High-risk cytogenetics defined as del(17/17p), t(4;14), t(14;16), t(14;20), gain 1q.

  • Seven patients exposed to trimethoprim/sulfamethoxazole (Bactrim); 1 patient in the MRD+ group exposed to levofloxacin (Levaquin).