High intratumoural galectin-1 expression predicts adverse outcome in ALK- ALCL and CD30+ PTCL-NOS.

Galectin-1 (Gal-1) has been associated with adverse prognosis in several cancers including lymphoma entities with CD30 expression. However, Gal-1 expression has not been systematically assessed in peripheral T-cell lymphomas (PTCL). Specimens from 169 nodal PTCL were assessed for intratumoural Gal-1 expression by immunohistochemistry. Overall survival (OS) in groups exhibiting high and low Gal-1 expression was compared in the cohort and in a subset analysis of CD30-positive PTCL only. Gal-1 expression was also correlated with biomarkers of the tumour microenvironment. No significant difference in OS based on Gal-1 expression was observed in the entire PTCL cohort. However, in the CD30-positive cohort, patients with high Gal-1 levels had significantly poorer outcome (5 years OS 10%, 95% confidence interval CI, 1-36) than their low Gal-1 counterparts (5 years OS 48%, 95% CI, 30-64, P = .021). In univariate analyses age 60 or younger, non-elevated lactate dehydrogenase (LDH), and performance score less than 2 correlated with superior survival but high Gal-1 expression significantly predicted adverse outcome at both univariate (HR 2.5, 95% CI, 1.1-5.7, P = .026) and multivariate levels (HR 3.2, 95% CI, 1.2-8.5, P = .017). Tumours with high Gal-1 had few cytotoxic T cells in the tumour microenvironment. High intratumoural Gal-1 expression before therapeutic intervention correlates with adverse outcome in nodal CD30+ , ALK- PTCL patients.

Genetic drivers of oncogenic pathways in molecular subgroups of peripheral T-cell lymphoma.

Peripheral T-cell lymphoma (PTCL) is a group of complex clinicopathological entities, often associated with an aggressive clinical course. Angioimmunoblastic T-cell lymphoma (AITL) and PTCL-not otherwise specified (PTCL-NOS) are the 2 most frequent categories, accounting for >50% of PTCLs. Gene expression profiling (GEP) defined molecular signatures for AITL and delineated biological and prognostic subgroups within PTCL-NOS (PTCL-GATA3 and PTCL-TBX21). Genomic copy number (CN) analysis and targeted sequencing of these molecular subgroups revealed unique CN abnormalities (CNAs) and oncogenic pathways, indicating distinct oncogenic evolution. PTCL-GATA3 exhibited greater genomic complexity that was characterized by frequent loss or mutation of tumor suppressor genes targeting the CDKN2A /B-TP53 axis and PTEN-PI3K pathways. Co-occurring gains/amplifications of STAT3 and MYC occurred in PTCL-GATA3. Several CNAs, in particular loss of CDKN2A, exhibited prognostic significance in PTCL-NOS as a single entity and in the PTCL-GATA3 subgroup. The PTCL-TBX21 subgroup had fewer CNAs, primarily targeting cytotoxic effector genes, and was enriched in mutations of genes regulating DNA methylation. CNAs affecting metabolic processes regulating RNA/protein degradation and T-cell receptor signaling were common in both subgroups. AITL showed lower genomic complexity compared with other PTCL entities, with frequent co-occurring gains of chromosome 5 (chr5) and chr21 that were significantly associated with IDH2 R172 mutation. CN losses were enriched in genes regulating PI3K-AKT-mTOR signaling in cases without IDH2 mutation. Overall, we demonstrated that novel GEP-defined PTCL subgroups likely evolve by distinct genetic pathways and provided biological rationale for therapies that may be investigated in future clinical trials.

Molecular profiling reveals immunogenic cues in anaplastic large cell lymphomas with DUSP22 rearrangements.

Anaplastic large cell lymphomas (ALCLs) are CD30-positive T-cell non-Hodgkin lymphomas broadly segregated into ALK-positive and ALK-negative types. Although ALK-positive ALCLs consistently bear rearrangements of the ALK tyrosine kinase gene, ALK-negative ALCLs are clinically and genetically heterogeneous. About 30% of ALK-negative ALCLs have rearrangements of DUSP22 and have excellent long-term outcomes with standard therapy. To better understand this group of tumors, we evaluated their molecular signature using gene expression profiling. DUSP22-rearranged ALCLs belonged to a distinct subset of ALCLs that lacked expression of genes associated with JAK-STAT3 signaling, a pathway contributing to growth in the majority of ALCLs. Reverse-phase protein array and immunohistochemical studies confirmed the lack of activated STAT3 in DUSP22-rearranged ALCLs. DUSP22-rearranged ALCLs also overexpressed immunogenic cancer-testis antigen (CTA) genes and showed marked DNA hypomethylation by reduced representation bisulfate sequencing and DNA methylation arrays. Pharmacologic DNA demethylation in ALCL cells recapitulated the overexpression of CTAs and other DUSP22 signature genes. In addition, DUSP22-rearranged ALCLs minimally expressed PD-L1 compared with other ALCLs, but showed high expression of the costimulatory gene CD58 and HLA class II. Taken together, these findings indicate that DUSP22 rearrangements define a molecularly distinct subgroup of ALCLs, and that immunogenic cues related to antigenicity, costimulatory molecule expression, and inactivity of the PD-1/PD-L1 immune checkpoint likely contribute to their favorable prognosis. More aggressive ALCLs might be pharmacologically reprogrammed to a DUSP22-like immunogenic molecular signature through the use of demethylating agents and/or immune checkpoint inhibitors.

Utility of interim and end-of-treatment PET/CT in peripheral T-cell lymphomas: A review of 124 patients.

According to the updated guidelines for imaging in lymphoma, 18F-FDG positron emission tomography/computed tomography (PET/CT) is recommended for staging and evaluation of treatment response in FDG-avid lymphomas. The purpose of the study was to evaluate the utility of PET/CT in nodal peripheral T-cell lymphomas (PTCL). Patients with newly diagnosed nodal PTCL (peripheral T-cell lymphoma NOS, anaplastic large-cell lymphoma, or angioimmunoblastic T-cell lymphoma) seen at five Danish hematology centers during the period 2006 to 2012 were included, if they had been pretherapeutically staged with PET/CT. Medical records were reviewed for baseline clinical and follow-up information. Staging, interim (I-PET), and end-of-treatment PET/CT (E-PET) studies were centrally reviewed, and reported using the Deauville 5-point score (DS). A total of 124 patients fulfilled the inclusion criteria. The median age was 58 years, and 88% received CHOP/CHOP-like therapy. Five years PFS and OS of the study population was 36.8% (95% CI 27.3-46.4) and 49.7% (95% CI 38.9-59.6), respectively. The presence of PET/CT-ascertained lung and/or liver involvement was associated with a worse outcome. The sensitivity of PET/CT for detecting biopsy-defined bone marrow involvement was only 18% (95% CI 4-43). An interim DS >3 was not prognostic for worse OS and PFS among CHOP/CHOP-like treated patients in uni- or multivariate analyses. A DS >3 after treatment predicted a worse prognosis. In conclusion, I-PET was not predictive of outcome in CHOP/CHOP-like treated PTCL patients when using the DS. Prospective studies are needed to determine the optimal use of PET/CT in PTCL including the role of quantitative PET/CT analysis.

Curvature of synthetic and natural surfaces is an important target feature in classical pathway complement activation.

The binding of Abs to microbial surfaces followed by complement activation constitutes an important line of defense against infections. In this study, we have investigated the relationship between complement activation and the binding of human IgM Abs to surfaces with different curvatures. IgM Abs to dextran were shown to activate complement potently on dextran-coated particles having a diameter around 250 nm, whereas larger (600 nm) particles were less potent activators. This selectivity regarding particle dimension was also found for complement activation by colloidal substances of microbial origin. Peptidoglycan (PGN) is the major chemical component in the cell wall of Gram-positive bacteria. Fragments of purified PGN with sizes of approximately 100 nm promoted complement activation effectively through the classical pathway. By contrast, larger or smaller fragments of PGN did not activate complement strongly. A careful analysis of PGN fragments released during planctonic growth of Staphylococcus aureus showed that these include curvatures that would permit strong IgM-mediated complement activation, whereas the curvature of intact cells would be less effective for such activation. Consistently, we found that the suspended PGN fragments were strong activators of complement through the classical pathway. We suggest that these fragments act as decoy targets for complement activation, providing protection for S. aureus against the host immune response to infection.