Abstract
Serum free light chain (FLC) assay has been used to evaluate the prognosis of several hematologic malignancies. We evaluated the prognostic role of monoclonal gammopathy (MG) and polyclonal gammopathy (PG) measured by serum FLC and immunofixation (IF) in DLBCL.
We retrospectively reviewed 115 patients with DLBCL who treated with rituximab containing chemotherapy. MG was defined as elevated kappa (κ) or lambda (λ) FLC with abnormal κ to λ ratio or positive IF and PG was defined as elevated κ and/or λ FLC with normal κ to λ ratio and negative IF.
Fifty-six (48.7%) patients had an elevated FLC. Twenty (17.4%) patients had MG and 39 (33.9%) patients accompanied by a PG. Two-year overall survival (OS) was 89.2%, and 2-year event-free survival (EFS) was 88.4%. Elevated FLC was associated with inferior OS and EFS (p=0.013, p=0.012). Patients with MG had an inferior OS and EFS compared to patients with normal FLC (p=0.006, p=0.011). In multivariate analysis, both elevated FLC and MG showed the significance for OS (HR 4.57, 95% CI 1.43-14.60, p=0.001 and HR 5.63, 95% CI 1.50-21.09, p=0.010). Elevated FLC did not show the significantly shorter OS or EFS in non-germinal center B-cell (GCB) type according to the Han’s criteria. However, MG was a significant prognostic factor for OS and EFS in non-GCB type (HR 6.28, 95% CI 1.21-32.62, p=0.029, HR 6.38, 95% CI 1.58-25.74, p=0.009).
It important to evaluate the associated MG and PG using serum FLC and IF for predicting the prognosis of DLBCL, especially in non-GCB subtype.
Patients characteristics of monoclonal and polyclonal gammopathy compared to normal FLC
| . | MG . | PG . | Normal FLC . | . |
|---|---|---|---|---|
| . | n (%) . | n (%) . | n (%) . | p . |
| Age >60 years | 13 (11.3) | 25 (21.7) | 21 (18.3) | 0.016 |
| Male sex | 10 (8.7) | 21 (18.2) | 30 (26.1) | 0.956 |
| ECOG >1 | 4 (3.5) | 5 (4.3) | 5 (4.3) | 0.379 |
| Creatinine >UNL | 0 (0.0) | 4 (3.5) | 0 (0.0) | 0.028 |
| Stage III/IV | 16 (13.9) | 19 (16.5) | 21 (18.3) | 0.005 |
| Extranodal >1 | 10 (8.7) | 13 (11.3) | 17 (14.8) | 0.278 |
| LDH >UNL | 16 (13.9) | 21 (18.3) | 32 (27.8) | 0.126 |
| IPI HI/H | 12 (10.4) | 17 (14.8) | 19 (16.5) | 0.122 |
| B symptom | 9 (7.8) | 27 (23.5) | 48 (41.7) | 0.015 |
| Non-GCB | 11 (9.6) | 22 (19.1) | 25 (21.7) | 0.249 |
| ALC <1000 | 7 (6.1) | 11 (9.6) | 7 (6.1) | 0.046 |
| AMC ≥800 | 1 (0.9) | 2 (1.7) | 4 (3.5) | 0.999 |
| . | MG . | PG . | Normal FLC . | . |
|---|---|---|---|---|
| . | n (%) . | n (%) . | n (%) . | p . |
| Age >60 years | 13 (11.3) | 25 (21.7) | 21 (18.3) | 0.016 |
| Male sex | 10 (8.7) | 21 (18.2) | 30 (26.1) | 0.956 |
| ECOG >1 | 4 (3.5) | 5 (4.3) | 5 (4.3) | 0.379 |
| Creatinine >UNL | 0 (0.0) | 4 (3.5) | 0 (0.0) | 0.028 |
| Stage III/IV | 16 (13.9) | 19 (16.5) | 21 (18.3) | 0.005 |
| Extranodal >1 | 10 (8.7) | 13 (11.3) | 17 (14.8) | 0.278 |
| LDH >UNL | 16 (13.9) | 21 (18.3) | 32 (27.8) | 0.126 |
| IPI HI/H | 12 (10.4) | 17 (14.8) | 19 (16.5) | 0.122 |
| B symptom | 9 (7.8) | 27 (23.5) | 48 (41.7) | 0.015 |
| Non-GCB | 11 (9.6) | 22 (19.1) | 25 (21.7) | 0.249 |
| ALC <1000 | 7 (6.1) | 11 (9.6) | 7 (6.1) | 0.046 |
| AMC ≥800 | 1 (0.9) | 2 (1.7) | 4 (3.5) | 0.999 |
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
