Pseudotemporal ordering of spatial lymphoid tissue microenvironment profiles trails Unclassified DLBCL at the periphery of the follicle.

We have established a pseudotemporal ordering for the transcriptional signatures of distinct microregions within reactive lymphoid tissues, namely germinal center dark zones (DZ), germinal center light zones (LZ), and peri-follicular areas (Peri). By utilizing this pseudotime trajectory derived from the functional microenvironments of DZ, LZ, and Peri, we have ordered the transcriptomes of Diffuse Large B-cell Lymphoma cases. The apex of the resulting pseudotemporal trajectory, which is characterized by enrichment of molecular programs fronted by TNFR signaling and inhibitory immune checkpoint overexpression, intercepts a discrete peri-follicular biology. This observation is associated with DLBCL cases that are enriched in the Unclassified/type-3 COO category, raising questions about the potential extra-GC microenvironment imprint of this peculiar group of cases. This report offers a thought-provoking perspective on the relationship between transcriptional profiling of functional lymphoid tissue microenvironments and the evolving concept of the cell of origin in Diffuse Large B-cell Lymphomas.

Rituximab with cyclophosphamide, vincristine, non-pegylated liposomal doxorubicin and prednisone as first-line treatment for splenic marginal zone lymphoma: a Fondazione Italiana Linfomi phase II study.

Rituximab® provides high response rates and effective disease palliation in patients with splenic marginal zone lymphoma (SMZL). We conducted a phase II trial in patients with SMZL who were either untreated or were splenectomized but had shown disease progression within 1 year after splenectomy. Treatment consisted of six courses of Rituximab with cyclophosphamide, vincristine, non-pegylated liposomal doxorubicin and prednisone (R-COMP). Fifty-one patients were eligible for the analysis. The overall response rate was 84%. The 6-year progression-free survival and overall survival were 54% and 72%, respectively. Toxicity was substantial (grade≥3 neutropenia: 26%; grade≥3 infections: 8%). Of the 15 deaths, two occurred on treatment (one sepsis and one pneumonia). Six deaths were due to lymphoma progression, four to secondary neoplasia, one to sepsis, one to pneumonia and one to splenectomy complications. R-COMP should be restricted to patients with bulky disease associated with symptoms or to patients with possible histological transformation.