Polyclonal immunoglobulin recovery 1 year after autologous stem cell transplantation (ASCT) in multiple myeloma patients may help to predict progression-free and overall survival, according to research published online Jan. 25 in Haematologica.
“Most multiple myeloma patients (85%-90%) exhibit immunoparesis at the time of diagnosis,” wrote Verónica González-Calle, MD, of the Instituto de Investigación Biomédica de Salamanca (Spain) and her coauthors. While the recovery of polyclonal immunoglobulins is expected after high doses of akylating agents like melphalan and the infusion of stem cells in the setting of ASCT, but whether the “persistence of immunoparesis after ASCT may predict worse progression or survival in patients with multiple myeloma” has not been studied.
In a retrospective cohort study, Dr. González-Calle and her colleagues evaluated 295 patients with symptomatic multiple myeloma who underwent ASCT at two referral centers in Spain.
One year after the transfer, 52% of the surviving 169 patients had experienced immunoglobulin recovery – defined as normalization of polyclonal immunoglobulin levels – and 48% had not (Haematologica. 2017 Jan 25. doi: 10.3324/haematol.2016.158345). Of the 88 patients who experienced immunoglobulin recovery, 36% had recovered by 100 days, 18% by 6 months, 17% by 9 months, and 26% by 1 year after stem cell transfer.
Immunoglobulin recovery significantly affected both progression-free survival (PFS) and overall survival. Median PFS was significantly longer in the 88 patients who experienced immunoglobulin recovery than in those who did not (60.4 vs. 27.9 months; hazard ratio, 0.45; 95% CI, 0.31-0.66; P less than .001). Similarly, median overall survival was 11.3 years in the group who experienced immunoglobulin recovery and 7.3 years in those with persistent immunoparesis from 1 year (P = .002).
There was also a significant interaction between the time to immunoglobulin recovery and the duration of PFS, with a shorter recovery time being associated with a significantly lower PFS.
“One possible explanation is that the prognostic significance of the polyclonal Ig recovery could be established only in those patients who lived enough to have experienced complete and uneventful B-cell reconstitution 1 year after ASCT,” the authors wrote. “Thus, if the polyclonal Igs have recovered by this time, our results would lead us to expect a positive outcome. By contrast, persistence of immunoparesis at this time was independently associated with shorter [progression-free survival] and worse [overall survival].”
The authors said polyclonal immunoglobulin recovery after 1 year could be considered an independent long-term marker for predicting PFS and overall survival. It is also a marker that could be easily assessed in clinical practice.
One author was supported by the Fundación AMIR and another was supported by the Fundación Española de Hematología y Hemoterapia and Janssen. No conflicts of interest were declared.