Intestinal immunoglobulin A (IgA) is strongly involved in microbiota homeostasis, and microbiota disruption is a major risk factor of acute graft-versus-host disease (GvHD) after allogeneic stem cell transplantation (allo-SCT). Scheidler and colleagues analyzed intestinal IgA+ plasma cells in a series of 430 biopsies obtained from 115 patients after allo-SCT for different hematologic disorders. Results showed a prolonged suppression and deficiency of IgA+ plasma cells in patients with GvHD and revealed an association of increased IgA+ plasma cells with a highly increased relapse-related mortality, suggesting plasma cells are a sensitive target of alloreaction involved in graft-versus-leukemia even beyond overt GvHD.

A large number of patients with myelodysplastic syndrome (MDS) develop genuine chronic myelomonocytic leukemia (CMML), raising the question of a “pre-CMML” state. Tran Quang and colleagues performed a longitudinal study using a combination of phenotypic, genomic, and functional analyses with the aim of identifying robust predictors of MDS evolution to “overt” CMML. They identified a subset of MDS patients who may eventually develop CMML, revisiting the boundaries between MDS and MDS/MPN, and potentially defining a subgroup of patients with the poorest outcome.