Immunoparesis Recovery As Predictor Marker of Progression after Autologous Stem Cell Transplantation in Multiple Myeloma

BACKGROUND

High dose therapy followed by autologous stem cell transplantation (ASCT) remains the standard of care, especially in Europe, for young and eligible multiple myeloma patients (usually younger than 65 years old).

Immunoparesis is defined as a reduction (below the lower normal limit) in the levels of 1 or 2 uninvolved immunoglobulins (Ig) and it is related to a reversible suppression of B lymphocytes that correlates inversely with disease stage. B Lymphocyte reconstitution begins at 3 months after ASCT, with maximum B lymphocyte levels at 1 year after ASCT.

AIMS

The goal of the present study was to investigate the role of the immunoparesis recovery after ASCT as predictor of relapse or progression in multiple myeloma (MM).

METHODS

We reviewed medical records of MM patients who underwent to ASCT at University Hospital of Salamanca between 1992 and 2013. The primary endpoint was time to relapse or progression from ASCT. Ig (Ig G, Ig A e Ig M) were collected at the time of diagnosis, before ASCT, every 3 months during the first year after ASCT, and every year up to 5 years after ASCT among eligible patients until the relapse or disease progression.

RESULTS

106 multiple myeloma patients who underwent ASCT were included in the analysis. Conventional chemotherapy was administered as induction regimen in 69 patients (65%), whereas novel agents were used in 37 patients (35%).

Most patients had immunoparesis at diagnosis (91%) and at the moment of ASCT as well (94%). After a median follow-up of 62 months, median time to progression or relapse (TTP) from ASCT was 31 months (95 % CI: 24.1 - 37.1 months). MM patients with immunoparesis 1 year after ASCT had a significantly shorter median TTP as compared with patients without immunoparesis (33.5 months vs 94.2 months; HR: 2.14, 95% CI: 1.13-4.05; p=0.019). In the group of patients with reduction of both Igs, median TTP was slightly inferior than in the group with reduction of only one of them(33.5 vs 36.4 months, p=0.03).

Presence of ISS 3, high-risk cytogenetics at diagnosis, less than partial response achieved before and three months after ASCT were also identified as predictors of progression. Multivariate analysis selected immunoparesis 1 year after ASCT as an independent variable for relapse or progression (HR: 5.97, 95% CI: 1.63-21.88; P=0.007).

CONCLUSIONS

The lack of immunoparesis recovery at 1 year after ASCT in MM patients is associated with significantly higher risk of relapse or progression and this group of patients could potentially benefit of continuous treatment after ASCT to enhance the immune recovery.