Christian Bjørn Poulsen

Histone deacetylase 1, 2, 6 and acetylated histone H4 in B- and T-cell lymphomas.

Aims:  Histone deacetylase (HDAC) inhibitors are novel therapeutics in the treatment of peripheral T‐cell lymphoma, unspecified (PTCL) and diffuse large B‐cell lymphoma (DLBCL), where, for unknown reasons, T‐cell malignancies appear to be more sensitive than B‐cell malignancies. The aim was to determine HDAC expression in DLBCL and PTCL which has not previously been investigated.

Brain response to traumatic brain injury in wild-type and interleukin-6 knockout mice: a microarray analysis

Traumatic injury to the brain is one of the leading causes of injury‐related death or disability. Brain response to injury is orchestrated by cytokines, such as interleukin (IL)‐6, but the full repertoire of responses involved is not well known. We here report the results obtained with microarrays in wild‐type and IL‐6 knockout mice subjected to a cryolesion of the somatosensorial cortex and killed at 0, 1, 4, 8 and 16 days post‐lesion. Overall gene expression was analyzed by using Affymetrix genechips/oligonucleotide arrays with ∼12 400 probe sets corresponding to ∼10 000 different murine genes (MG_U74Av2). A robust, conventional statistical method (two‐way anova) was employed to select the genes significantly affected. An orderly pattern of gene responses was clearly detected, with genes being up‐ or down‐regulated at specific timings consistent with the processes involved in the initial tissue injury and later regeneration of the parenchyma. IL‐6 deficiency showed a dramatic effect in the expression of many genes, especially in the 1 day post‐lesion timing, which presumably underlies the poor capacity of IL‐6 knockout mice to cope with brain damage. The results highlight the importance of IL‐6 controlling the response of the brain to injury as well as the suitability of microarrays for identifying specific targets worthy of further study.

Microarray-based classification of diffuse large B-cell lymphoma

Abstract:  Objective: Hierarchical clusterings of diffuse large B‐cell lymphoma (DLBCL) based on gene expression signatures have previously been used to classify DLBCL into Germinal Center B‐cell (GCB) and Activated B‐cell (ABC) types. To examine if it was feasible to perform a cross‐platform validation on the Affymetrix HG‐U133A oligonucleotide arrays and improve the classification, we determined the expression profiles of pretreatment, diagnostic samples from 52 primary nodal DLBCL. Methods and results: First, three previously published gene lists were converted to the HG‐U133A probe sets and used for hierarchical clustering. In this way, three subtypes, including the GCB type (n = 20), the ABC type (n = 25) and an intermediate group, Type‐3 (n = 5), were distinguished. The CD10 and Bcl‐6 expression as well as t(14;18) translocation were prevalent, but not exclusive to the GCB type. By contrast, MUM1 was only expressed in the ABC and in Type‐3 samples. The 5‐year survival was similar between the groups, but GCB patients showed a better initial response to CHOP or CHOP‐like regimens than the remaining patients and tended to have less advanced disease and lower IPI scores. As a next step, an improved set of classifier genes was generated by analysis of 34 patients that were consistently classified as GCB or ABC in the above analyses. Seventy‐eight genes were selected and demonstrated on two previously published data sets (Shipp et al. Nat Med 2002;8:68–74 and Houldsworth et al. Blood 2004;103:1862–1868) to exhibit a higher specificity than the original gene lists. Conclusion: We conclude that gene expression profiling with Affymetrix Genechips is efficient to distinguish between GCB and ABC types of DLBCL and that these are likely to represent separate biological entities. The Genechip platform is highly standardised and therefore useful for future prospective investigations to establish the value of gene expression profiling in the clinical management of DLBCL.

Role of routine imaging in detecting recurrent lymphoma; a review of 258 patients with relapsed aggressive non-Hodgkin and Hodgkin lymphoma

After first‐line therapy, patients with Hodgkin lymphoma (HL) and aggressive non‐HL are followed up closely for early signs of relapse. The current follow‐up practice with frequent use of surveillance imaging is highly controversial and warrants a critical evaluation. Therefore, a retrospective multicenter study of relapsed HL and aggressive non‐HL (nodal T‐cell and diffuse large B‐cell lymphomas) was conducted. All included patients had been diagnosed during the period 2002–2011 and relapsed after achieving complete remission on first‐line therapy. Characteristics and outcome of imaging‐detected relapses were compared with other relapses. A total of 258 patients with recurrent lymphoma were included in the study. Relapse investigations were initiated outside preplanned visits in 52% of the patients. Relapse detection could be attributed to patient‐reported symptoms alone or in combination with abnormal blood tests or physical examination in 64% of the patients. Routine imaging prompted relapse investigations in 27% of the patients. The estimated number of routine scans per relapse was 91–255 depending on the lymphoma subtype. Patients with imaging‐detected relapse had lower disease burden (P = 0.045) and reduced risk of death following relapse (hazard ratio = 0.62, P = 0.02 in multivariate analysis). Patient‐reported symptoms are still the most common factor for detecting lymphoma relapse and the high number of scans per relapse calls for improved criteria for use of surveillance imaging. However, imaging‐detected relapse was associated with lower disease burden and a possible survival advantage. The future role of routine surveillance imaging should be defined in a randomized trial. Am. J. Hematol. 89:575–580, 2014.

Profiling of diffuse large B-cell lymphoma by immunohistochemistry: identification of prognostic subgroups.

Diffuse large B‐cell lymphoma (DLBCL) is a frequent lymphoma subtype with a heterogeneous behavior and a variable response to conventional chemotherapy. This clinical diversity is believed to reflect differences in the molecular pathways leading to lymphomagenesis. In this study, we have analyzed pretreatment, diagnostic samples from 108 DLBCL by immunohistology for expression of four markers linked to germinal center B‐cells (CD10, Bcl‐6), postgerminal center B‐cells (MUM1) and apoptosis (Bcl‐2). The results indicate that both CD10 and Bcl‐6 are favorable prognostic indicators, in contrast to Bcl‐2, which is an adverse parameter. Furthermore, using two algorithms for distinction between low‐ and high‐risk patients proposed by Hans et al. (Blood, 2004; 103:275) and Muris et al. (Journal of Pathology, 2006; 208:714), it is shown that both are useful for predicting outcome in DLBCL. However, in this report, the algorithm of Hans et al. was superior to that of Muris et al. These findings confirm and extend other studies and indicate that different prognostic subgroups of DLBCL can be distinguished by simple immunohistological investigations for a limited number of markers. Whether these groups are also relevant for individual treatment decisions will be important to investigate in prospective studies.

Novel roles for metallothionein‐I + II (MT‐I + II) in defense responses, neurogenesis, and tissue restoration after traumatic brain injury: Insights from global gene expression profiling in wild‐type and MT‐I + II knockout mice

Traumatic injury to the brain is one of the leading causes of injury‐related death or disability, especially among young people. Inflammatory processes and oxidative stress likely underlie much of the damage elicited by injury, but the full repertoire of responses involved is not well known. A genomic approach, such as the use of microarrays, provides much insight in this regard, especially if combined with the use of gene‐targeted animals. We report here the results of one of these studies comparing wild‐type and metallothionein‐I + II knockout mice subjected to a cryolesion of the somatosensorial cortex and killed at 0, 1, 4, 8, and 16 days postlesion (dpl) using Affymetrix genechips/oligonucleotide arrays interrogating ∼10,000 different murine genes (MG_U74Av2). Hierarchical clustering analysis of these genes readily shows an orderly pattern of gene responses at specific times consistent with the processes involved in the initial tissue injury and later regeneration of the parenchyma, as well as a prominent effect of MT‐I + II deficiency. The results thoroughly confirmed the importance of the antioxidant proteins MT‐I + II in the response of the brain to injury and opened new avenues that were confirmed by immunohistochemistry. Data in KO, MT‐I‐overexpressing, and MT‐II‐injected mice strongly suggest a role of these proteins in postlesional activation of neural stem cells.

RETRACTED: M-CSF Deficiency Leads to Reduced Metallothioneins I and II Expression and Increased Tissue Damage in the Brain Stem after 6-Aminonicotinamide Treatment

6-Aminonicotinamide (6-AN) is a niacin antagonist, which leads to degeneration of gray-matter astrocytes followed by a vigorous inflammatory response. Macrophage colony stimulating factor (M-CSF) is important during inflammation, and in order to further clarify the roles for M-CSF in neurodegeneration and brain cell death, we have examined the effect of 6-AN on osteopetrotic mice with genetic M-CSF deficiency (op/op mice). The 6-AN-induced degeneration of gray-matter areas was comparable in control and op/op mice, but the numbers of reactive astrocytes, macrophages, and lymphocytes in the damaged areas were significantly decreased in op/op mice relative to controls. The levels of oxidative stress (as determined by using immunoreactivity for inducible nitric oxide synthase, nitrotyrosine, and malondialdehyde) and apoptotic cell death (as determined by using TUNEL and immunoreactivity for caspases and cytochrome c) were significantly increased in 6-AN-injected op/op mice relative to controls. From a number of antioxidant factors assayed, only metallothioneins I and II (MT-I+II) were decreased in op/op mice in comparison to controls. Thus, the present results indicate that M-CSF is an important growth factor for coping with 6-AN-induced central nervous system damage and suggest that MT-I+II are likely to have a significant role.

Danish National Lymphoma Registry.

Aim of database The Danish National Lymphoma Registry (LYFO) was established in order to monitor and improve the diagnostic evaluation and the quality of treatment of all lymphoma patients in Denmark. Study population The LYFO database was established in 1982 as a seminational database including all lymphoma patients referred to the departments of hematology. The database became nationwide on January 1, 2000. Main variables The main variables include both clinical and paraclinical variables as well as details of treatment and treatment evaluation. Up to four forms are completed for each patient: a primary registration form, a treatment form, a relapse form, and a follow-up form. Variables are used to calculate six result quality indicators (mortality 30 and 180 days after diagnosis, response to first-line treatment, and survival estimates 1, 3, and 5 years after the time of diagnosis), and three process quality indicators (time from diagnosis until the start of treatment, the presence of relevant diagnostic markers, and inclusion rate in clinical protocols). Descriptive data Approximately 23,000 patients were registered in the period 1982–2014 with a median age of 65 years (range: 16–100 years) and a male/female ratio of 1.23:1. Patients can be registered with any of 42 different subtypes according to the World Health Organization classifications. Conclusion LYFO is a nationwide database for all lymphoma patients in Denmark and includes detailed information. This information is used for both epidemiological research and clinical follow-up as well as for administrative purposes.

The Danish National Chronic Lymphocytic Leukemia Registry

Aim In 2008, the Danish National Chronic Lymphocytic Leukemia Registry was founded within the Danish National Hematology Database. The primary aim of the registry is to assure quality of diagnosis and care of patients with chronic lymphocytic leukemia (CLL) in Denmark. Secondarily, to evaluate adherence to national guidelines and to provide source data for research purposes. Study population All patients diagnosed with CLL in Denmark from 2008 onward are included in the registry. Patients are followed in one of nine hematology centers. All centers participate in the registry and are all obliged to collect data. Main variables Predefined data are collected at the time of diagnosis, and follow-up at the time of significant events: treatment, progression, transplantation, and death. Parameters included in the International Workshop on Chronic Lymphocytic Leukaemia criteria for diagnosis, and for decision on treatment initiation as well as characteristics included in the CLL International Prognostic Index are collected. Descriptive data To ensure full coverage of Danish CLL patients in the registry, both continuous queries in case of missing data, and cross-referencing with the Danish National Patient Registry are performed. Data from the registry are published in an annual report summarizing the collected data, the overall survival for yearly cohorts, and the degree of data coverage. Per year approximately 450 new patients with CLL are registered in the registry, cumulative as of July 1, 2015, 3,082 patients have been registered. Conclusion The Danish National CLL Registry is based within the Danish National Hematology Database. The registry covers a cohort of all patients diagnosed with CLL in Denmark since 2008. It forms the basis for quality assessment of CLL treatment in Denmark and offers a unique opportunity for population-based research.

Rituximab Maintenance after First Line Immunochemotherapy Improves Overall Survival in Patients with Follicular Lymphoma

In this issue of Blood , [Khandelwal et al][1] show that B cells bind platelet factor 4 (PF4)/heparin complexes in a non–antigen-specific fashion, mediated by complement activation and resulting complex binding via B-cell complement receptors (CD21).[1][2] ![Figure][3] Activation of