B cell-helper neutrophils stimulate the diversification and production of immunoglobulin in the marginal zone of the spleen.

Neutrophils use immunoglobulins to clear antigen, but their role in immunoglobulin production is unknown. Here we identified neutrophils around the marginal zone (MZ) of the spleen, a B cell area specialized in T cell-independent immunoglobulin responses to circulating antigen. Neutrophils colonized peri-MZ areas after postnatal mucosal colonization by microbes and enhanced their B cell-helper function after receiving reprogramming signals, including interleukin 10 (IL-10), from splenic sinusoidal endothelial cells. Splenic neutrophils induced immunoglobulin class switching, somatic hypermutation and antibody production by activating MZ B cells through a mechanism that involved the cytokines BAFF, APRIL and IL-21. Neutropenic patients had fewer and hypomutated MZ B cells and a lower abundance of preimmune immunoglobulins to T cell-independent antigens, which indicates that neutrophils generate an innate layer of antimicrobial immunoglobulin defense by interacting with MZ B cells.

The transmembrane activator TACI triggers immunoglobulin class switching by activating B cells through the adaptor MyD88.

BAFF and APRIL are innate immune mediators that trigger immunoglobulin G (IgG) and IgA class-switch recombination (CSR) in B cells by engaging the receptor TACI. The mechanism that underlies CSR signaling by TACI remains unknown. Here we found that the cytoplasmic domain of TACI encompasses a conserved motif that bound MyD88, an adaptor that activates transcription factor NF-kappaB signaling pathways via a Toll-interleukin 1 (IL-1) receptor (TIR) domain. TACI lacks a TIR domain, yet triggered CSR via the DNA-editing enzyme AID by activating NF-kappaB through a Toll-like receptor (TLR)-like MyD88-IRAK1-IRAK4-TRAF6-TAK1 pathway. TACI-induced CSR was impaired in mice and humans lacking MyD88 or the kinase IRAK4, which indicates that MyD88 controls a B cell-intrinsic, TIR-independent, TACI-dependent pathway for immunoglobulin diversification.

Identification of EWSR1 rearrangements in patients with immature hematopoietic neoplasms: A case series and review of literature.

Rearrangement of the EWSR1 gene (22q12.2) is a well-recognized genetic lesion in bone and soft tissue tumors. However, few reports have suggested that EWSR1 rearrangements may also occur in the setting of hematopoietic tumors. We herein describe two cases of immature hematopoietic neoplasms presenting with EWSR1 rearrangements. The first occurred in a 41-year-old female diagnosed with mixed-phenotype acute leukemia, B/T/myeloid, in which conventional chromosome analysis revealed a t(2;22)(q35;q12). Further analysis with whole genome sequencing revealed that this rearrangement led to an EWSR1::FEV gene fusion. The second case was identified in an 18-year-old male with a high-grade B-cell lineage malignant neoplasm with immature features in which conventional chromosome analysis revealed a t(17;22)(q25;q12). Mate-pair sequencing, a next generation sequencing-based assay, was performed and revealed three in-frame chimeric gene fusions involving the EWSR1, TEF and STRADA gene regions. This report further expands the repertoire of hematopoietic neoplasms with EWSR1 fusions and partner genes involved in these rearrangements.

Immunoglobulin D enhances immune surveillance by activating antimicrobial, proinflammatory and B cell-stimulating programs in basophils.

Immunoglobulin D (IgD) is an enigmatic antibody isotype that mature B cells express together with IgM through alternative RNA splicing. Here we report active T cell-dependent and T cell-independent IgM-to-IgD class switching in B cells of the human upper respiratory mucosa. This process required activation-induced cytidine deaminase (AID) and generated local and circulating IgD-producing plasmablasts reactive to respiratory bacteria. Circulating IgD bound to basophils through a calcium-mobilizing receptor that induced antimicrobial, opsonizing, inflammatory and B cell-stimulating factors, including cathelicidin, interleukin 1 (IL-1), IL-4 and B cell-activating factor (BAFF), after IgD crosslinking. By showing dysregulation of IgD class-switched B cells and 'IgD-armed' basophils in autoinflammatory syndromes with periodic fever, our data indicate that IgD orchestrates an ancestral surveillance system at the interface between immunity and inflammation.

HIV-1 evades virus-specific IgG2 and IgA responses by targeting systemic and intestinal B cells via long-range intercellular conduits.

Contact-dependent communication between immune cells generates protection but also facilitates viral spread. Here we found that macrophages formed long-range actin-propelled conduits in response to negative factor (Nef), a human immunodeficiency virus type 1 (HIV-1) protein with immunosuppressive functions. Conduits attenuated immunoglobulin G2 (IgG2) and IgA class switching in systemic and intestinal lymphoid follicles by shuttling Nef from infected macrophages to B cells through a guanine-exchange factor-dependent pathway involving the amino-terminal anchor, central core and carboxy-terminal flexible loop of Nef. By showing stronger virus-specific IgG2 and IgA responses in patients with Nef-deficient virions, our data suggest that HIV-1 exploits intercellular 'highways' as a 'Trojan horse' to deliver Nef to B cells and evade humoral immunity systemically and at mucosal sites of entry.

Core Stability Exercises in Addition to Usual Care Physiotherapy Improve Stability and Balance After Stroke: A Systematic Review and Meta-analysis.

OBJECTIVE: To systematically review the effect of core stability exercises in addition to usual care physiotherapy on patient outcomes after stroke. DATA SOURCES: Cumulative Index to Nursing and Allied Health, MEDLINE, Physiotherapy Evidence Database (PEDro), PubMed, and EMBASE were searched to November 2018. STUDY SELECTION: Eleven randomized controlled trials that compared usual care physiotherapy with usual care physiotherapy with additional core stability exercises in people with stroke were included. The initial search yielded 1876 studies. DATA EXTRACTION: Two independent reviewers applied inclusion and exclusion criteria and extracted data on methodological quality using the PEDro scale, participant characteristics, intervention details, outcome measures, and results. DATA SYNTHESIS: Postintervention means and SDs were pooled to calculate either the standardized mean difference (SMD) or the mean difference (MD) and 95% CIs using a random-effects model and inverse variance methods. There was moderate quality evidence to suggest the addition of core stability exercises to usual care physiotherapy improved trunk control (SMD, 0.94; 95% CI, 0.44-1.44; I2=69%), functional dynamic balance (SMD, 1.23; 95% CI, 0.5-1.97; I2=71%), and walking speed (MD, 0.27m/s; 95% CI, 0.01-0.52; I2=40%) in people with acute and chronic stroke. No significant effect was found when assessing functional ambulation categories or the timed Up and Go test, and mixed results were found for global functioning. CONCLUSIONS: The addition of core stability exercises to usual care physiotherapy after stroke may lead to improved trunk control and dynamic balance. Therefore, core stability exercises should be included in rehabilitation if improvements in these domains will help clients achieve their goals. Future trials should consider incorporating outcomes of body kinematics during functional tasks to assess movement quality and assess participation outcomes.

De novo pure erythroid leukemia: refining the clinicopathologic and cytogenetic characteristics of a rare entity.

Per the revised fourth edition World Health Organization classification of acute myeloid leukemia, pure erythroid leukemia is now the sole type of acute erythroid leukemia. The diagnosis of this rare entity is often challenging and the cytologic overlap with non-neoplastic (eg, megaloblastic anemia) and neoplastic entities (eg, other types of acute leukemia and non-hematopoietic malignancies) warrants a significant degree of clinical, laboratory, immunophenotypic, and genetic investigation. Given the limited number of reports of this rare and diagnostically challenging entity, we report detailed clinicopathologic characteristics from 15 patients, the largest series thus far, of primary de novo pure erythroid leukemia to provide further diagnostic insights into this entity and reveal strategies for making the diagnosis. We found that de novo pure erythroid leukemia is a disease of adults (median age 68 years), exhibits a striking male predominance, is universally associated with an abnormal karyotype and has an exceedingly poor overall median survival of 1.4 months. Given the general inability of immunophenotypic markers to discriminate neoplastic from non-neoplastic erythroid proliferations, key features identified in this study to help establish the diagnosis of pure erythroid leukemia and exclude mimickers include circulating pronormoblasts, clear-cut dysplasia in erythroid, granulocytic, and/or megakaryocytic lineage, utilization of a broad immunophenotypic panel, TP53 immunohistochemical positivity, and identification of a complex, often highly complex, karyotype. Given the gravity of a diagnosis of de novo pure erythroid leukemia, it should be rendered with utmost confidence.

Brentuximab vedotin and AVD followed by involved-site radiotherapy in early stage, unfavorable risk Hodgkin lymphoma.

This multicenter pilot study assessed the safety and efficacy of brentuximab vedotin (BV) and AVD (adriamycin, vinblastine, and dacarbazine) followed by 30 Gy involved site radiation therapy (ISRT). Patients with newly diagnosed, early stage classical Hodgkin lymphoma (HL) with unfavorable-risk features were treated with 4 cycles of BV and AVD. Patients who achieved a negative positron emission tomography (PET) scan (Deauville score of 1-3) received 30 Gy ISRT. Thirty patients received treatment and were assessable for toxicity. Twenty-nine patients completed 4 cycles of BV + AVD, and 25 patients BV + AVD + 30 Gy ISRT. No clinically significant noninfectious pneumonitis was observed. Serious adverse events (≥grade 3) were reported in 4 patients, including febrile neutropenia, peripheral neuropathy, and hypertension. After 2 and 4 cycles of BV + AVD, 90% (26 of 29) and 93% (27 or 29) of patients achieved a negative PET scan, respectively. Two patients with biopsy-proven primary refractory HL were treated off-study. All 25 patients who completed BV + AVD + ISRT achieved a complete response. With a median follow-up of 18.8 months, by intent to treat, the 1-year progression-free survival is 93.3% (95% confidence interval, 84-102). Overall, the treatment was well-tolerated with no evidence of significant pulmonary toxicity. The majority of patients (≥90%) achieved negative interim PET scans after 2 and 4 cycles of BV + AVD. Excluding the 2 primary refractory patients, all patients are disease free, suggesting that this is a highly active treatment program even in patients with substantial disease bulk. This trial was registered at www.clinicaltrials.gov as #NCT01868451.

Assessment of CD37 B-cell antigen and cell of origin significantly improves risk prediction in diffuse large B-cell lymphoma.

CD37 (tetraspanin TSPAN26) is a B-cell surface antigen widely expressed on mature B cells. CD37 is involved in immune regulation and tumor suppression but its function has not been fully elucidated. We assessed CD37 expression in de novo diffuse large B-cell lymphoma (DLBCL), and investigated its clinical and biologic significance in 773 patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone (R-CHOP) and 231 patients treated with CHOP. We found that CD37 loss (CD37-) in ∼60% of DLBCL patients showed significantly decreased survival after R-CHOP treatment, independent of the International Prognostic Index (IPI), germinal center B-cell-like (GCB)/activated B-cell-like (ABC) cell of origin, nodal/extranodal primary origin, and the prognostic factors associated with CD37-, including TP53 mutation, NF-κBhigh, Mychigh, phosphorylated STAT3high, survivinhigh, p63-, and BCL6 translocation. CD37 positivity predicted superior survival, abolishing the prognostic impact of high IPI and above biomarkers in GCB-DLBCL but not in ABC-DLBCL. Combining risk scores for CD37- status and ABC cell of origin with the IPI, defined as molecularly adjusted IPI for R-CHOP (M-IPI-R), or IPI plus immunohistochemistry (IHC; IPI+IHC) for CD37, Myc, and Bcl-2, significantly improved risk prediction over IPI alone. Gene expression profiling suggested that decreased CD20 and increased PD-1 levels in CD37- DLBCL, ICOSLG upregulation in CD37+ GCB-DLBCL, and CD37 functions during R-CHOP treatment underlie the pivotal role of CD37 status in clinical outcomes. In conclusion, CD37 is a critical determinant of R-CHOP outcome in DLBCL especially in GCB-DLBCL, representing its importance for optimal rituximab action and sustained immune responses. The combined molecular and clinical prognostic indices, M-IPI-R and IPI+IHC, have remarkable predictive values in R-CHOP-treated DLBCL.

CD30 Expression Is Rare in Myeloid Leukemia Cutis: A Study of 55 Cases and Implications for Routine Diagnostic Algorithms.

Expression of CD30 in blastoid cutaneous infiltrates typically signifies a CD30 lymphoproliferative disorder, often requiring minimal immunohistochemical workup, if clinically consonant. However, myeloid and other hematologic malignancies often express CD30. We retrospectively examined the prevalence of CD30 expression in 41 patients (median age 59) and 55 biopsies with the diagnosis of leukemia cutis (LC) to determine whether an extensive immunohistochemical workup is warranted in all large, round cell CD30 cutaneous infiltrates. Each patient had refractory or recurrent disease, the histologic presence of a large mononuclear cell infiltrate, and varied cytogenetics. CD30 mononuclear cells within the infiltrate ranged from rare to many in 22 biopsies (22/55). In 18 biopsies, CD30 cells were interpreted as lymphocytic based on morphology, strong cytoplasmic and Golgi staining for CD30, and negative CD34 and CD117 staining. One case showing 3+ staining of lymphocytes was identified as a posttransplant lymphoproliferative disorder. The second 3+ case was favored to represent a subset of CD30-positive acute myeloid leukemia. Three other cases with 1+ membranous and cytoplasmic staining were interpreted as myeloid leukemia. In conclusion, CD30 positivity in myeloid leukemia in the skin is rare and does not often exhibit the strong membranous (2+ or 3+) and/or Golgi staining seen in reactive lymphocytes. Acute myeloid leukemia or myeloid LC may occasionally show 1+ (and rarely 2-3+) cytoplasmic/membranous or nonspecific blush nuclear CD30 labeling. Strong diffuse staining for CD30 should prompt consideration of a reactive lymphoid/lymphoproliferative process, and, when the clinical likelihood of CD30 LC is low, may obviate the need for further immunohistochemistry.

Clinical features, tumor biology, and prognosis associated with MYC rearrangement and Myc overexpression in diffuse large B-cell lymphoma patients treated with rituximab-CHOP.

MYC dysregulation, including MYC gene rearrangement and Myc protein overexpression, is of increasing clinical importance in diffuse large B-cell lymphoma (DLBCL). However, the roles of MYC and the relative importance of rearrangement vs overexpression remain to be refined. Gaining knowledge about the tumor biology associated with MYC dysregulation is important to understand the roles of MYC and MYC-associated biology in lymphomagenesis. In this study, we determined MYC rearrangement status (n=344) and Myc expression (n=535) in a well-characterized DLBCL cohort, individually assessed the clinical and pathobiological features of patients with MYC rearrangement and Myc protein overexpression, and analyzed the prognosis and gene expression profiling signatures associated with these MYC abnormalities in germinal center B-cell-like and activated B-cell-like DLBCL. Our results showed that the prognostic importance of MYC rearrangement vs Myc overexpression is significantly different in germinal center B-cell-like vs activated B-cell-like DLBCL. In germinal center B-cell-like DLBCL, MYC-rearranged germinal center B-cell-like DLBCL patients with Myc overexpression significantly contributed to the clinical, biological, and prognostic characteristics of the overall Myc-overexpressing germinal center B-cell-like DLBCL group. In contrast, in activated B-cell-like DLBCL, the occurrence, clinical and biological features, and prognosis of Myc overexpression were independent of MYC rearrangement. High Myc levels and Myc-independent mechanisms, either tumor cell intrinsic or related to tumor microenvironment, conferred significantly worse survival to MYC-rearranged germinal center B-cell-like DLBCL patients, even among Myc(high)Bcl-2(high) DLBCL patients. This study provides new insight into the tumor biology and prognostic effects associated with MYC dysregulation and suggest that detection of both MYC translocations and evaluation of Myc and Bcl-2 expression is necessary to predict the prognosis of DLBCL patients.

Prognostic and biological significance of survivin expression in patients with diffuse large B-cell lymphoma treated with rituximab-CHOP therapy.

Survivin, a member of the inhibitor of apoptosis protein family, is overexpressed in a variety of human neoplasms. The prognostic significance of survivin expression in diffuse large B-cell lymphoma patients treated with rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) is unclear. We used standard immunohistochemistry methods to quantify survivin expression in 463 patients with de novo diffuse large B-cell lymphoma who received the R-CHOP. Of the 463 patients, 269 (58%) had survivin overexpression with a cutoff of >25%, associated with an International Prognostic Index score of >2 (P=0.015), disease in ≥2 extranodal sites (P=0.011), and a high Ki-67 index (P<0.0001). Among patients with activated B cell-like disease, the overall survival rate of survivin-positive patients was significantly lower than that of survivin-negative patients (P=0.033); multivariate analysis confirmed that in these patients, survivin overexpression was an independent prognostic factor for survival. Among patients with wild-type p53 overexpression, the overall survival and progression-free survival rates of the survivin-positive group were significantly lower than those of the survivin-negative group (P=0.035 and P=0.04 respectively). In STAT3-positive patients, survivin overexpression was associated with significantly better survival. Among patients with activated B cell-like disease, survivin-positive compared with survivin-negative groups had significantly different gene expression signatures, including genes involved in mitosis or tumor cell proliferation. Our results indicate that survivin is an independent prognostic factor for poor outcome in patients with activated B cell-like disease treated with the R-CHOP regimen, and patients with survivin-positive activated B cell-like diffuse large B-cell lymphoma seem to benefit less from this treatment and may require additional novel agents.

Evaluation of NF-κB subunit expression and signaling pathway activation demonstrates that p52 expression confers better outcome in germinal center B-cell-like diffuse large B-cell lymphoma in association with CD30 and BCL2 functions.

Nuclear factor-κB (NF-κB) is a transcription factor with a well-described oncogenic role. Study for each of five NF-κB pathway subunits was only reported on small cohorts in diffuse large B-cell lymphoma (DLBCL). In this large cohort (n=533) of patients with de novo DLBCL, we evaluated the protein expression frequency, gene expression signature, and clinical implication for each of these five NF-κB subunits. Expression of p50, p52, p65, RELB, and c-Rel was 34%, 12%, 20%, 14%, and 23%, whereas p50/p65, p50/c-Rel, and p52/RELB expression was 11%, 11%, and 3%, respectively. NF-κB subunits were expressed in both germinal center B-cell-like (GCB) and activated B-cell-like (ABC) DLBCL, but p50 and p50/c-Rel were associated with ABC-DLBCL. p52, RELB, and p52/RELB expressions were associated with CD30 expression. p52 expression was negatively associated with BCL2 (B-cell lymphoma 2) expression and BCL2 rearrangement. Although p52 expression was associated with better progression-free survival (PFS) (P=0.0170), singular expression of the remaining NF-κB subunits alone did not show significant prognostic impact in the overall DLBCL cohort. Expression of p52/RELB was associated with better overall survival (OS) and PFS (P=0.0307 and P=0.0247). When cases were stratified into GCB- and ABC-DLBCL, p52 or p52/RELB dimer expression status was associated with better OS and PFS (P=0.0134 and P=0.0124) only within the GCB subtype. However, multivariate analysis did not show p52 expression to be an independent prognostic factor. Beneficial effect of p52 in GCB-DLBC appears to be its positive correlation with CD30 and negative correlation with BCL2 expression. Gene expression profiling (GEP) showed that p52(+) GCB-DLBCL was distinct from p52(-) GCB-DLBCL. Collectively, our data suggest that DLBCL patients with p52 expression might not benefit from therapy targeting the NF-κB pathway.

MYC/BCL2 protein coexpression contributes to the inferior survival of activated B-cell subtype of diffuse large B-cell lymphoma and demonstrates high-risk gene expression signatures: a report from The International DLBCL Rituximab-CHOP Consortium Program.

Diffuse large B-cell lymphoma (DLBCL) is stratified into prognostically favorable germinal center B-cell (GCB)-like and unfavorable activated B-cell (ABC)-like subtypes based on gene expression signatures. In this study, we analyzed 893 de novo DLBCL patients treated with R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone). We show that MYC/BCL2 protein coexpression occurred significantly more commonly in the ABC subtype. Patients with the ABC or GCB subtype of DLBCL had similar prognoses with MYC/BCL2 coexpression and without MYC/BCL2 coexpression. Consistent with the notion that the prognostic difference between the 2 subtypes is attributable to MYC/BCL2 coexpression, there is no difference in gene expression signatures between the 2 subtypes in the absence of MYC/BCL2 coexpression. DLBCL with MYC/BCL2 coexpression demonstrated a signature of marked downregulation of genes encoding extracellular matrix proteins, those involving matrix deposition/remodeling and cell adhesion, and upregulation of proliferation-associated genes. We conclude that MYC/BCL2 coexpression in DLBCL is associated with an aggressive clinical course, is more common in the ABC subtype, and contributes to the overall inferior prognosis of patients with ABC-DLBCL. In conclusion, the data suggest that MYC/BCL2 coexpression, rather than cell-of-origin classification, is a better predictor of prognosis in patients with DLBCL treated with R-CHOP.

CD30 expression defines a novel subgroup of diffuse large B-cell lymphoma with favorable prognosis and distinct gene expression signature: a report from the International DLBCL Rituximab-CHOP Consortium Program Study.

CD30, originally identified as a cell-surface marker of Reed-Sternberg and Hodgkin cells of classical Hodgkin lymphoma, is also expressed by several types of non-Hodgkin lymphoma, including a subset of diffuse large B-cell lymphoma (DLBCL). However, the prognostic and biological importance of CD30 expression in DLBCL is unknown. Here we report that CD30 expression is a favorable prognostic factor in a cohort of 903 de novo DLBCL patients. CD30 was expressed in ∼14% of DLBCL patients. Patients with CD30(+) DLBCL had superior 5-year overall survival (CD30(+), 79% vs CD30(-), 59%; P = .001) and progression-free survival (P = .003). The favorable outcome of CD30 expression was maintained in both the germinal center B-cell and activated B-cell subtypes. Gene expression profiling revealed the upregulation of genes encoding negative regulators of nuclear factor κB activation and lymphocyte survival, and downregulation of genes encoding B-cell receptor signaling and proliferation, as well as prominent cytokine and stromal signatures in CD30(+) DLBCL patients, suggesting a distinct molecular basis for its favorable outcome. Given the superior prognostic value, unique gene expression signature, and significant value of CD30 as a therapeutic target for brentuximab vedotin in ongoing successful clinical trials, it seems appropriate to consider CD30(+) DLBCL as a distinct subgroup of DLBCL.

MDM2 phenotypic and genotypic profiling, respective to TP53 genetic status, in diffuse large B-cell lymphoma patients treated with rituximab-CHOP immunochemotherapy: a report from the International DLBCL Rituximab-CHOP Consortium Program.

MDM2 is a key negative regulator of the tumor suppressor p53, however, the prognostic significance of MDM2 overexpression in diffuse large B-cell lymphoma (DLBCL) has not been defined convincingly. In a p53 genetically-defined large cohort of de novo DLBCL patients treated with rituximab, cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (R-CHOP) chemotherapy, we assessed MDM2 and p53 expression by immunohistochemistry (n = 478), MDM2 gene amplification by fluorescence in situ hybridization (n = 364), and a single nucleotide polymorphism in the MDM2 promoter, SNP309, by SNP genotyping assay (n = 108). Our results show that MDM2 overexpression, unlike p53 overexpression, is not a significant prognostic factor in overall DLBCL. Both MDM2 and p53 overexpression do not predict for an adverse clinical outcome in patients with wild-type p53 but predicts for significantly poorer survival in patients with mutated p53. Variable p53 activities may ultimately determine the survival differences, as suggested by the gene expression profiling analysis. MDM2 amplification was observed in 3 of 364 (0.8%) patients with high MDM2 expression. The presence of SNP309 did not correlate with MDM2 expression and survival. This study indicates that evaluation of MDM2 and p53 expression correlating with TP53 genetic status is essential to assess their prognostic significance and is important for designing therapeutic strategies that target the MDM2-p53 interaction.

Mutational profile and prognostic significance of TP53 in diffuse large B-cell lymphoma patients treated with R-CHOP: report from an International DLBCL Rituximab-CHOP Consortium Program Study.

TP53 mutation is an independent marker of poor prognosis in patients with diffuse large B-cell lymphoma (DLBCL) treated with cyclophosphamide, hydroxydaunorubicin, vincristine, and prednisone (CHOP) therapy. However, its prognostic value in the rituximab immunochemotherapy era remains undefined. In the present study of a large cohort of DLBCL patients treated with rituximab plus CHOP (R-CHOP), we show that those with TP53 mutations had worse overall and progression-free survival compared with those without. Unlike earlier studies of patients treated with CHOP, TP53 mutation has predictive value for R-CHOP-treated patients with either the germinal center B-cell or activated B-cell DLBCL subtypes. Furthermore, we identified the loop-sheet-helix and L3 motifs in the DNA-binding domain to be the most critical structures for maintaining p53 function. In contrast, TP53 deletion and loss of heterozygosity did not confer worse survival. If gene mutation data are not available, immunohistochemical analysis showing > 50% cells expressing p53 protein is a useful surrogate and was able to stratify patients with significantly different prognoses. We conclude that assessment of TP53 mutation status is important for stratifying R-CHOP-treated patients into distinct prognostic subsets and has significant value in the design of future therapeutic strategies.