Immunodeficiency-associated primary central nervous system lymphoma (ID-PCNSL) represents a clinicopathologically distinct PCNSL subtype, for which large studies and prognostic models are lacking. To address this gap, the International PCNSL Collaborative Group conducted a retrospective multicenter study, integrating clinical, radiological, and pathological data from 308 ID-PCNSL cases, diagnosed at 23 participating sites in 7 countries. Preexisting immunodeficiency included administration of immunosuppressants for transplantation (41.2%) or autoimmunity (36.7%) and HIV infection (21.7%). All tumors were diffuse large B-cell lymphomas, with Epstein-Barr virus (EBV) detected in 79.2%. Immune reconstitution together with rituximab and methotrexate-based chemotherapy was associated with the highest response rates and prolonged progression-free survival, irrespective of immunodeficiency subtype and EBV status. Survival outcomes were highly variable, with a 54-month median overall survival. Multivariable Cox regression identified age (per year increment; hazard ratio [HR], 1.05 (95% confidence interval [CI], 1.02-1.07); P< .001), Karnofsky performance status (KPS) <70 (HR, 3.10; 95% CI, 1.67-5.87; P< .001), and EBV positivity (HR, 3.26; 95% CI, 1.47-7.33; P = .004) as prognostic factors for overall survival. A prognostic score was developed based on the sum of these adverse variables (age >60 years, KPS <70, EBV positivity). Stratification by this score yielded median survival times of 135, 29, and 3 months in patients with up to 1, 2, and 3 unfavorable markers (P< .0001). It allowed improved prognostic stratification of ID-PCNSL as compared with the Memorial Sloan Kettering Cancer Center and International Extranodal Lymphoma Study Group models developed for immunocompetent PCNSL. Collectively, this large international cohort defines clinicobiological features of ID-PCNSL and introduces a prognostic system with potential to guide future management.

Celiac disease (CeD) is an autoimmune disorder triggered by dietary gluten. While HLA-DQ2/8-mediated presentation of gliadin peptides is required for disease, the mechanisms that underlie the loss of oral tolerance to gluten remain incompletely understood. Long-noncoding RNAs (lncRNAs) have been increasingly recognized as regulators of immune function, yet their role in oral tolerance has not been previously explored. Here, using a screen designed to identify lncRNAs responsive to T cell activation and enriched for CeD-associated GWAS variants, we identified lnc13 as a top candidate. In HLA-DQ8 transgenic mice lacking lnc13, unmanipulated gluten ingestion led to molecular signatures resembling human CeD and hallmark features of loss of oral tolerance to gluten: increased IFN-γ lymphocytes, IL-12 myeloid cells, cytotoxic intraepithelial immune cells and crypt hyperplasia in the small intestine. Mechanistically, lnc13 binds specific DNA regulatory regions and limits immune cell responsiveness to proinflammatory signals. In particular, lnc13 restrains IL-15-driven differentiation of CD8 natural killer-like lymphokine-activated killer cells (an IL-15-dependent pathway strongly implicated in CeD). These findings establish lnc13 as a critical noncoding modulator of oral gluten tolerance.

Diffuse large B-cell lymphoma (DLBCL), the most common type of lymphoma, arises from various pathogenic mechanisms including gene translocations and fusions. Detection of gene rearrangements using fluorescence in situ hybridization (FISH) is a standard practice for DLBCL diagnosis and guides treatment decisions. High-throughput chromosome conformation capture (Hi-C) DNA sequencing is a next-generation sequencing-based technology to identify genome-wide rearrangements using a single assay. In this study, Hi-C sequencing was performed using FFPE tissues from 159 patients with DLBCL, and identified 746 cancer genes at or proximal to the rearrangement breakpoints with a total of 1903 occurrences. Focusing on clinically important rearrangements, Hi-C detected 102 rearrangements of MYC, BCL2, and/or BCL6 in 92 patients and revealed the fusion partners, including 25 rearrangements missed by FISH. Causes of FISH negative results included FISH-cryptic breakpoints, complex or faint FISH signals, low percentage of FISH positivity, and issues related to tissue fixation. Moreover, in 20 patients (12.6%), Hi-C sequencing detected 22 rearrangements characteristic of other lymphoma types, including CCND1 rearrangements that could lead to reclassification as mantle cell lymphoma. Survival analysis for genome-wide rearrangements using machine learning models identified MYC, PD-L1, CCND1, BCL2, NTRK1/PRCC, RRAS, and FANCE rearrangements with significant prognostic effects in the DLBCL cohort. In conclusion, Hi-C sequencing detects gene rearrangements crucial for diagnosis in an unbiased and molecular manner and showed high sensitivity and specificity in our study. These advantages of Hi-C sequencing offer help to improve the workflow of clinical pathology laboratories, diagnostic precision, and treatment of large B-cell lymphoma.

Lymph nodes (LN) are key secondary lymphoid organs (SLO) for a coordinated immune response. They have been extensively characterized by numerous investigative techniques chiefly as single cell suspensions because they are composed of vagile yet crowded hematolymphoid elements, unfriendly to spatial tissue organization-saving techniques. We comprehensively classify in situ all cells of 19 human LN free of pathology with a 78-marker antibody panel, an hyperplexed cyclic staining method, MILAN, and an analytical bioinformatic pipeline, BRAQUE. A total of 77 cell types were classified, encompassing T, B, innate immune and stromal cells. CD4 and CD8 T-cells were classified into 27 unique subsets by leveraging the expression profiles of TCF7, the presence of co-inhibitory receptors and the spatial distribution. CD5 and TCF7 expression defined novel B-cell types. CD27 + mature B-cells occupied previously unrecognized nodal spaces non-overlapping with the cortex and the plasma-cell rich medullary cords. Type 2 conventional dendritic cells were located in nodular paracortical aggregates. Statistically controlled pairwise neighborhood analysis showed sparse cell-cell interactions, known and new neighbors, established and novel LN landscape niches. A high-dimensional proteomic interrogation of the normal human LN provides spatial allocation of known cell types, novel interactions and the landscape organization.