The presence of two light chain bands on immunofixation is associated with poor outcomes in newly diagnosed multiple myeloma patients.

We aimed to describe the clinical and biological characteristics and the prognosis of patients presenting with an additional light chain (LC) band along with a complete monoclonal protein on immunofixation (IF).An 8-year descriptive study was conducted to assess all cases with confirmed monoclonal gammopathies (MG). We studied those with an entire M-protein with 2 bands of LC of the same isotype based on the results of IF. Data were collected from patients' files.Among 548 cases of MG, we found 32 cases (5.8%) with an additional LC band. We included 28 patients (5%) with a confirmed diagnosis of multiple myeloma (MM). The m/f ratio was 2.5 with a median age of 63 years [32-80 years]. All MM patients had anemia, 16 (57%) had renal failure, 14 (50%) had lytic lesions, 9 (32%) received hemodialysis, and 7 (25%) had hypercalcemia. The free-kappa-lambda ratio was abnormal in all cases: median = 0.07 [0.002-58.57]. The mean overall survival (OS) was 22 months ± 38.76.Fifteen MM patients (48%) received chemotherapy, and 7 (22%) autologous stem cell transplants (SCT). Patients who received SCT had an OS higher than those who received other treatments (p = 0.038). OS was low in patients with high β2microglobulin levels (rho = -0.791; p = 0.001), and abnormally low free-kappa-lambda ratio (rho = -0.852;p = 0.04).The presence of an additional LC band with a complete monoclonal protein seems to identify newly diagnosed MM patients with poor outcomes and frequent renal impairment.