Page 170 - Haematologica Vol. 107 - September 2022

ARTICLE - Immune deficiency during RM after transplantation L. Bouard et al. AB
CD
Figure 3. Progression-free survival from randomization according to occurrence of hypogammaglobulinemia <6 g/L and hypo- gammaglobulinemia <4 g/L. Representation of progression-free survival (PFS) in (A) the whole cohort and in (B) the rituximab maintenance (RM) arm according to γ globulin status <6 g/L and PFS in (C ) the whole cohort and in (D) the RM arm according to occurrence of hypogammaglobulinemia <4 g/L. GAMMAG: γ globulin rate.
globulinemia was statistically more frequent in RM. This highlights the side effect of RM on humoral immunity. Multivariate analysis shows that patients who received at least nine rituximab injections, which amounts to half the maintenance program, are more exposed to infec- tious events and hypogammaglobulinemia. Our work cor- roborates previously reported findings on the cumulative effect of RM on infectious risk.10
Although data were collected and monitored prospec- tively, our study has its limits: microbiological documen- tations are frequently missing mainly because the vast majority of infections were of low grade in upper and lower respiratory tracts which are not routinely explored by physicians in practice. In addition, the LyMa trial elec- tronic case report form (e-CRF) did not report treatment prophylaxis and use of granulocyte colony-stimulating factor (G-CSF) support but we can presume that, ac- cording to international guidelines16 in this post-ASCT
setting, the patients did receive at least P.jiroveci and herpes simplex virus prophylaxis and probably G-CSF support when needed. Thus, we can not conclude about these associated measures and treatments. Unfor- tunately, LyMa e-CRF did not report the vaccination strategy used for patients and thus patients were vacci- nated according to local vaccination strategy in each center. We believe that European Society for Blood and Marrow Transplantation recommendations17 were ap- plied. We also did not investigate the impact of recurring low grade infection consequences on quality of life. However, the higher incidence of infections in the RM arm is offset by its benefits in terms of EFS, PFS and OS. This higher incidence could be explained, to a large ex- tent, by the occurrence of hypogammaglobulinemia after 1 year post transplant, and not by neutropenia or T CD4 depletion. Ig substitution was not recommended in the LyMa trial and was left to the choice of investigator in
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