Clinical applications of genetic sequencing in lymphoma: A retrospective review

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Background: Personalized therapy through the identification of targetable mutations within individual tumors has increasingly become a focus in the management of patients (pts) with relapsed/refractory malignancy. To better understand how this is clinically applied, we reviewed 29 cases of B- and T-cell lymphomas that had genetic sequencing of their tumor. Methods: The electronic medical records of 29 pts who underwent Michigan Oncology Sequencing (MI-ONCOSEQ) testing at the University of Michigan from 2013-2016 were reviewed for disease and treatment history. Reports from whole-genome tumor sequencing were obtained for each patient to identify putative molecular targets. Results: Sixteen male and 13 female pts had a median age of 59 years (range 30-80 years) and median disease stage of IV at diagnosis. Five had CTCL, 5 PTCL, 11 follicular, 1 CLL/ mantle cell (MC), 1 MC, 1 marginal zone, 1 Waldenstrom’s (WM) and 4 DLBCL. Pts received a median of 2 therapies prior to MI-ONCOSEQ biopsy. Targetable mutations were identified in 15 pts and a total of 5 pts underwent MI-ONCOSEQ-based treatments. Bosutinib was given for FYB-FGR fusion, imatinib for FLI1-PDGFRB fusion, and everolimus for activating mTOR mutation with an avg. treatment duration of 3.6 weeks due to progressive disease. Bosutinib and imatinib were 3rd line therapies and everolimus was 5th. Another 2 pts were treated with ibrutinib for transformed WM with MYD88 mutation and bortezomib after classification of DLBCL as ABC-type based on MI-ONCOSEQ results, with CR in both. Other targetable mutations identified include BRAF, CDK, BCL2, EZH2 and NOTCH. Of the remaining 12 pts with targetable mutations, 8 pursued clinical trials, 2 responded to standard therapy, 1 died shortly after genetic analysis and 1 declined further therapy. About 50% of these pts remain alive. Conclusions: Our results demonstrate that targeted therapy is favored after standard therapy or clinical trial options are exhausted. Barriers to its use include the availability of clinical trials, off-label drug access and our incomplete knowledge of driver mutations. With further understanding of disease pathogenesis, we expect personalized therapy will be possible for all patients.

Challenges and opportunities for checkpoint blockade in T-cell lymphoproliferative disorders

The T-cell lymphoproliferative disorders are a heterogeneous group of non-Hodgkin’s lymphomas (NHL) for which current therapeutic strategies are inadequate, as most patients afflicted with these NHL will succumb to disease progression within 2 years of diagnosis. Appreciation of the genetic and immunologic landscape of these aggressive NHL, including PD-L1 (B7-H1, CD274) expression by malignant T cells and within the tumor microenvironment, provides a strong rationale for therapeutic targeting this immune checkpoint. While further studies are needed, the available data suggests that responses with PD-1 checkpoint blockade alone will unlikely approach those achieved in other lymphoproliferative disorders. Herein, we review the unique challenges posed by the T-cell lymphoproliferative disorders and discuss potential strategies to optimize checkpoint blockade in these T-cell derived malignancies.

A retrospective comparative outcome analysis following systemic therapy in Mycosis fungoides and Sezary syndrome

Cutaneous T-cell lymphomas (CTCL), with few exceptions, remain incurable and treatment is largely palliative. We performed a retrospective analysis of systemic treatment outcomes of patients diagnosed with MF/SS. We identified 223 patients with MF/SS evaluated at a single institution from 1997 to 2013. Disease stage at diagnosis, time of treatment, and treatments received were retrospectively analyzed using our CTCL database. The primary endpoint was time to next treatment (TTNT). Treatment outcomes were analyzed using Kaplan-Meier method and comparisons among groups were made using log-rank analysis. A superior TTNT was associated with retinoid or interferon therapies when compared with HDAC inhibitors or systemic chemotherapy. Retinoids and interferon were associated with superior TTNT in both limited-stage and advanced stage disease. Extracorporeal photophoresis (ECP) had a superior TTNT in Sezary Syndrome. HDAC inhibitors and chemotherapy were associated with inferior TTNT in both limited stage disease and advanced stage disease. With the exception of interferon, retinoids, or ECP, durable responses are rarely achieved with systemic therapies in MF/SS patients, particularly those with advanced-stage disease. Therefore, clinical trial participation with novel agents should be encouraged. Am. J. Hematol. 91:E491-E495, 2016. © 2016 Wiley Periodicals, Inc.

T-cell Receptor Signaling Activates an ITK/NF-κB/GATA-3 axis in T-cell Lymphomas Facilitating Resistance to Chemotherapy

Purpose: T-cell lymphomas are a molecularly heterogeneous group of non-Hodgkin lymphomas (NHL) that account for a disproportionate number of NHL disease-related deaths due to their inherent and acquired resistance to standard multiagent chemotherapy regimens. Despite their molecular heterogeneity and frequent loss of various T cell-specific receptors, the T-cell antigen receptor is retained in the majority of these lymphomas. As T-cell receptor (TCR) engagement activates a number of signaling pathways and transcription factors that regulate T-cell growth and survival, we examined the TCR's role in mediating resistance to chemotherapy.Experimental Design: Genetic and pharmacologic strategies were utilized to determine the contribution of tyrosine kinases and transcription factors activated in conventional T cells following TCR engagement in acquired chemotherapy resistance in primary T-cell lymphoma cells and patient-derived cell lines.Results: Here, we report that TCR signaling activates a signaling axis that includes ITK, NF-κB, and GATA-3 and promotes chemotherapy resistance.Conclusions: These observations have significant therapeutic implications, as pharmacologic inhibition of ITK prevented the activation of this signaling axis and overcame chemotherapy resistance. Clin Cancer Res; 23(10); 2506-15. ©2016 AACR.

Cutaneous B-cell lymphomas: 2016 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).

DIAGNOSIS

Diagnosis and disease classification is based on histologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement.

RISK-STRATIFICATION

Disease histology remains the most important prognostic determinant. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

PCFCL and PCMZL patients with solitary or relatively few skin lesions may be affectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL. Am. J. Hematol. 91:1052-1055, 2016. © 2016 Wiley Periodicals, Inc.

Relationship of blood monocytes with chronic lymphocytic leukemia aggressiveness and outcomes: a multi-institutional study

Monocyte-derived cells, constituents of the cancer microenvironment, support chronic lymphocytic leukemia (CLL) cell survival in vitro via direct cell-cell interaction and secreted factors. We hypothesized that circulating absolute monocyte count (AMC) reflects the monocyte-derived cells in the microenvironment, and that higher AMC is associated with increased CLL cell survival in vivo and thus inferior CLL patient outcomes. We assessed the extent to which AMC at diagnosis of CLL is correlated with clinical outcomes, and whether this information adds to currently used prognostic markers. We evaluated AMC, clinically used prognostic markers, and time to event data from 1,168 CLL patients followed at the Mayo Clinic, the Duke University Medical Center, and the Durham VA Medical Center. Elevated AMC was significantly associated with inferior clinical outcomes, including time to first therapy (TTT) and overall survival (OS). AMC combined with established clinical and molecular prognostic markers significantly improved risk-stratification of CLL patients for TTT. As an elevated AMC at diagnosis is associated with accelerated disease progression, and monocyte-derived cells in the CLL microenvironment promote CLL cell survival and proliferation, these findings suggest that monocytes and monocyte-derived cells are rational therapeutic targets in CLL. Am. J. Hematol. 91:687-691, 2016. © 2016 Wiley Periodicals, Inc.

Colony-Stimulating Factor-1 Receptor Is Required for Nurse-like Cell Survival in Chronic Lymphocytic Leukemia

PURPOSE

Monocytes and their progeny are abundant constituents of the tumor microenvironment in lymphoproliferative disorders, including chronic lymphocytic leukemia (CLL). Monocyte-derived cells, including nurse-like cells (NLC) in CLL, promote lymphocyte proliferation and survival, confer resistance to chemotherapy, and are associated with more rapid disease progression. Colony-stimulating factor-1 receptor (CSF-1R) regulates the homeostatic survival of tissue-resident macrophages. Therefore, we sought to determine whether CSF-1R is similarly required for NLC survival.

EXPERIMENTAL DESIGN

CSF-1R expression by NLC was examined by flow cytometry and IHC. CSF-1R blocking studies were performed using an antagonistic mAb to examine its role in NLC generation and in CLL survival. A rational search strategy was performed to identify a novel tyrosine kinase inhibitor (TKI) targeting CSF-1R. The influence of TKI-mediated CSF-1R inhibition on NLC and CLL viability was examined.

RESULTS

We demonstrated that the generation and survival of NLC in CLL is dependent upon CSF-1R signaling. CSF-1R blockade is associated with significant depletion of NLC and consequently inhibits CLL B-cell survival. We found that the JAK2/FLT3 inhibitor pacritinib suppresses CSF-1R signaling, thereby preventing the generation and survival of NLC and impairs CLL B-cell viability.

CONCLUSIONS

CSF-1R is a novel therapeutic target that may be exploited in lymphoproliferative disorders, like CLL, that are dependent upon lymphoma-associated macrophages. Clin Cancer Res; 22(24); 6118-28. ©2016 AACR.

Cutaneous T-Cell Lymphoma: A Review with a Focus on Targeted Agents

Cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of extranodal lymphomas involving the skin. Diagnosis of the two main subtypes of CTCL-mycosis fungoides (MF) and Sézary syndrome (SS)-is based on the International Society for Cutaneous Lymphomas/European Organization for Research and Treatment of Cancer (ISCL/EORTC) classification system, which utilizes clinical, histopathological, molecular biologic, and immunopathologic features. Risk stratification, based on TNMB (tumor, node, metastasis, and blood) staging, provides prognostic information, with limited-stage disease conferring the longest median overall survival. Skin-directed therapies are preferred in the management of limited-stage disease, whereas advanced-stage disease requires systemic therapies. As the mechanisms of CTCL pathogenesis are increasingly understood, new monoclonal antibodies, checkpoint inhibitors, immunomodulatory agents, and small molecules are under investigation and may provide additional therapeutic options for those with advanced CTCL. This review examines the current landscape of targeted therapies in the treatment of CTCLs.

A three-signal model of T-cell lymphoma pathogenesis

T-cell lymphoma pathogenesis and classification have, until recently, remained enigmatic. Recently performed whole-exome sequencing and gene-expression profiling studies have significant implications for their classification and treatment. Recurrent genetic modifications in antigen ("signal 1"), costimulatory ("signal 2"), or cytokine receptors ("signal 3"), and the tyrosine kinases and other signaling proteins they activate, have emerged as important therapeutic targets in these lymphomas. Many of these genetic modifications do not function in a cell-autonomous manner, but require the provision of ligand(s) by constituents of the tumor microenvironment, further supporting the long-appreciated view that these lymphomas are dependent upon and driven by their microenvironment. Therefore, the seemingly disparate fields of genomics and immunology are converging. A unifying "3 signal model" for T-cell lymphoma pathogenesis that integrates these findings will be presented, and its therapeutic implications briefly reviewed.

Cutaneous T-cell lymphoma: 2016 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell lymphoproliferative disorders involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral, or blood involvement are generally approached with biologic-response modifiers or histone deacetylase inhibitors before escalating therapy to include systemic, single-agent chemotherapy. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Cutaneous B-cell lymphomas: 2015 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL, LT).

DIAGNOSIS

DIAGNOSIS and disease classification is based on histologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement. Risk-stratification: Disease histology remains the most important prognostic determinant. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with 5-year survival rates that exceed 95%. In contrast, PCDLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

PCFCL and PCMZL patients with solitary or relatively few skin lesions may be affectively managed with local radiation therapy. While single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCDLBCL, LT is comparable to the management of patients with systemic DLBCL.

Survival in patients with limited-stage peripheral T-cell lymphomas

The natural history of limited-stage peripheral T-cell lymphoma (PTCL) remains poorly defined. Therefore, we examined outcomes in patients with the most common PTCL subtypes (PTCL, not otherwise specified [PTCL, NOS], angioimmunoblastic T-cell lymphoma [AITL], anaplastic large cell lymphoma [ALCL]) and limited-stage disease. In this retrospective, multicenter study, 75 patients with limited-stage disease were identified. The median event-free survival (EFS) and overall survival (OS) observed were 2.1 and 6.5 years, respectively. In a landmark analysis excluding patients with primary refractory disease, no significant benefit was observed for patients undergoing consolidative radiation therapy. With the exception of patients undergoing salvage hematopoietic stem cell transplant, survival following disease relapse or progression was poor, thus highlighting the need for improved therapeutic strategies.

Cutaneous T-cell lymphoma: 2014 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell lymphoproliferative disorders involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, and blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or blood involvement are generally approached with biologic-response modifiers or histone deacetylase inhibitors prior to escalating therapy to include systemic, single-agent chemotherapy. Multiagent chemotherapy (e.g., CHOP) may be employed for those patients with extensive visceral involvement requiring rapid disease control. In highly selected patients, allogeneic stem-cell transplantation may be considered.

Cutaneous B-cell lymphomas: 2013 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Approximately one-fourth of cutaneous lymphomas are B-cell derived and are generally classified into three distinct subgroups: primary cutaneous follicle-center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma (PCMZL), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCLBCL, LT).

DIAGNOSIS

Diagnosis and disease classification is based on histologic review and immunohistochemical staining of an appropriate skin biopsy. Pathologic review and an appropriate staging evaluation are necessary to distinguish primary cutaneous B-cell lymphomas from systemic B-cell lymphomas with secondary skin involvement. RISK-STRATIFICATION: Disease histology remains the most important prognostic determinant. Both PCFCL and PCMZL are indolent lymphomas that infrequently disseminate to extracutaneous sites and are associated with an excellent long-term prognosis. In contrast, PCLBCL, LT is an aggressive lymphoma with an inferior prognosis.

RISK-ADAPTED THERAPY

PCFCL and PCMZL patients with solitary or relatively few skin lesions may be affectively managed with local radiation therapy. Although single-agent rituximab may be employed for patients with more widespread skin involvement, multiagent chemotherapy is rarely appropriate. In contrast, management of patients with PCLBCL, LT is comparable to the management of patients with systemic DLBCL.

The B7 homologues and their receptors in hematologic malignancies

The B7 homologues and their receptors regulate both peripheral tolerance and adaptive immunity. This field is rapidly evolving as new ligands and receptors are being identified. Much of the work supporting their role in the regulation of host anti-tumor immunity has been derived from experimental models and clinical trials in solid malignancies. However, a growing body of evidence demonstrates that the B7-H family has important immunologic and non-immunologic functions in a variety of hematologic malignancies. Herein, we will review recent evidence that supports the therapeutic targeting of the B7 homologues in hematologic malignancies.

The absolute monocyte count is associated with overall survival in patients newly diagnosed with follicular lymphoma

Follicular lymphoma is characterized by a highly variable clinical course ranging from early transformation and disease-related mortality to prolonged periods of disease stability or even spontaneous remissions. This clinical heterogeneity is likely explained by differences in the tumor microenvironment, including variable infiltration by monocyte-derived cells. Therefore, we examined the absolute monocyte count obtained from a standard complete blood count with differential at the time of diagnosis as a prognostic factor in a cohort of patients with follicular lymphoma (n = 355) treated at a single institution between 1998 and 2007. We found that the absolute monocyte count at diagnosis is associated with overall survival, independent of the Follicular Lymphoma International Prognostic Index (FLIPI). Furthermore, the absolute monocyte count improved the ability to identify high-risk patients when used in conjunction with the FLIPI. These results further support the central role of non-neoplastic myeloid-lineage cells in follicular lymphoma biology.

Myeloid-derived suppressor cells: therapeutic modulation in cancer

Improved understanding of the cellular and molecular basis of adaptive immunity has been realized over the past few decades, leading to the development of novel immunotherapeutic strategies capable of promoting host anti-tumor immunity. In order to achieve clinically meaningful results, further understanding of the mechanisms by which tumors suppress host immunity, and the development of therapeutic strategies which overcome tumor-associated immune suppression, will be necessary. Myeloid-derived cells with potent immunosuppressive properties are ubiquitous in human cancers. Improved mechanistic understanding of factors promoting their development, activation and mechanisms of immune suppression are being translated into novel therapeutic approaches, and will be summarized herein.

Myeloid-derived suppressor cells: therapeutic modulation in cancer

Improved understanding of the cellular and molecular basis of adaptive immunity has been realized over the past few decades, leading to the development of novel immunotherapeutic strategies capable of promoting host anti-tumor immunity. In order to achieve clinically meaningful results, further understanding of the mechanisms by which tumors suppress host immunity, and the development of therapeutic strategies which overcome tumor-associated immune suppression, will be necessary. Myeloid-derived cells with potent immunosuppressive properties are ubiquitous in human cancers. Improved mechanistic understanding of factors promoting their development, activation and mechanisms of immune suppression are being translated into novel therapeutic approaches, and will be summarized herein.

Cutaneous T-cell lymphoma: 2011 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell lymphoproliferative disorders involving the skin, the majority of which may be classified as Mycosis fungoides (MF) or Sézary syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

Tumor, node, metastasis, and blood (TNMB) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral, or blood involvement are generally approached with biologic-response modifiers, denileukin diftitox, and histone deacetylase inhibitors before escalating therapy to include systemic, single-agent chemotherapy. Multiagent chemotherapy may be used for those patients with extensive visceral involvement requiring rapid disease control. In highly-selected patients with disease refractory to standard treatments, allogeneic stem-cell transplantation may be considered.

The absolute monocyte and lymphocyte prognostic score predicts survival and identifies high-risk patients in diffuse large-B-cell lymphoma

Despite the use of modern immunochemotherapy regimens, almost 50% of patients with diffuse large-B-cell lymphoma will relapse. Current prognostic models, including the International Prognostic Index, incorporate patient and tumor characteristics. In contrast, recent observations show that variables related to host adaptive immunity and the tumor microenvironment are significant prognostic variables in non-Hodgkin lymphoma. Therefore, we retrospectively examined the absolute monocyte and lymphocyte counts as prognostic variables in a cohort of 366 diffuse large-B-cell lymphoma patients who were treated between 1993 and 2007 and followed at a single institution. The absolute monocyte and lymphocyte counts in univariate analysis predicted progression-free and overall survival when analyzed as continuous and dichotomized variables. On multivariate analysis performed with factors included in the IPI, the absolute monocyte and lymphocyte counts remained independent predictors of progression-free and overall survival. Therefore, the absolute monocyte and lymphocyte counts were combined to generate a prognostic score that identified patients with an especially poor overall survival. This prognostic score was independent of the IPI and added to its ability to identify high-risk patients.

Cancer-associated myeloproliferation: old association, new therapeutic target

The association between malignancy and development of a paraneoplastic leukocytosis, the so-called leukemoid reaction, has long been appreciated. Although a leukemoid reaction has conventionally been defined as a peripheral blood leukocytosis composed of both mature and immature granulocytes that exceeds 50,000/microL, a less profound leukocytosis may be appreciated in many patients harboring a malignant disease. More recent insights have shed new light on this long-recognized association, because research performed in both murine models and cancer patients has uncovered multiple mechanisms by which tumors both drive myelopoiesis, sometimes leading to a clinically apparent leukocytosis, and inhibit the differentiation of myeloid cells, resulting in a qualitative change in myelopoiesis. This qualitative change leads to the accumulation of immature myeloid cells, which due to their immune suppressive effects have been collectively called myeloid-derived suppressor cells. More recently, myeloid cells have been shown to promote tumor angiogenesis. Cancer-associated myeloproliferation is not merely a paraneoplastic phenomenon of questionable importance but leads to the suppression of host immunity and promotion of tumor angiogenesis, both of which play an integral part in tumorigenesis and metastasis. Therefore, cancer-associated myeloproliferation represents a novel therapeutic target in cancer that, decades after its recognition, is only now being translated into clinical practice.

Paucity of intraepidermal FoxP3-positive T cells in cutaneous T-cell lymphoma in contrast with spongiotic and lichenoid dermatitis

BACKGROUND

FoxP3 is the most specific available marker for regulatory T cells (Tregs). Tumor-associated FoxP3-positive Tregs have been identified in various neoplasms, including cutaneous T-cell lymphoma (CTCL). FoxP3 expression in CTCL varies across groups; few studies have compared CTCL with inflammatory conditions.

METHODS

Lesional skin biopsies from 20 patients with CTCL [13 mycosis fungoides (MF); 7 Sézary syndrome (SS)] and 22 with inflammatory dermatoses (11 spongiotic; 11 lichenoid or interface) were examined for FoxP3 expression by immunohistochemistry. Epidermal FoxP3-positive lymphocytes were counted as a percentage of the total epidermal CD3-positive T-cell population.

RESULTS

FoxP3-positive T cells composed the minority of infiltrate in all major categories. Lower numbers of epidermal FoxP3-positive T cells were observed in CTCL, particularly MF, than in inflammatory dermatoses (P < .001). CTCL neoplastic T cells did not express FoxP3.

CONCLUSION

FoxP3-positive T cells are less frequently encountered in MF than in inflammatory dermatoses. FoxP3-positive T cells occur in higher proportions in the dermis than in the epidermis and probably correlate with coexisting inflammatory components. CTCL neoplastic cells do not typically express a Treg phenotype and are associated with low numbers of FoxP3-positive Tregs in the infiltrate. FoxP3 expression by immunohistochemistry may aid histologic evaluation of these conditions.

Two cases of Cryptococcus meningitis presenting as leukoencephalopathy prior to amphotericin therapy

We report two patients with cryptococcal meningitis and combined immunodeficiency with unusual magnetic resonance imaging findings of gadolinium-enhancing white matter lesions, quite different from cryptococcomas and seen prior to anti-fungal treatment. The lesions resembled demyelinating plaques and resolved. In one patient, biopsy of the lesion revealed cryptococci, non-specific inflammatory changes and occasional small perivascular lymphocyte collections, but not demyelination. Leukoencephalopathy, previously rarely observed in Cryptococcal meningitis, was thought to be the sequelae of amphotericin toxicity. Our cases demonstrate cryptococcal meningitis may present with leukoencephalopathy, possibly as an immune response to the organism.

Childhood obesity among Head Start enrollees in southeastern Minnesota: prevalence and risk factors

BACKGROUND

Up to 32% of US Head Start enrollees in inner-city settings have been reported to be obese. However, little is known about the prevalence of overweight and associated risk factors in Head Start enrollees in non-inner-city settings.

OBJECTIVES

To determine the prevalence of childhood obesity from 1998 to 2001 and associated risk factors for overweight among Head Start enrollees in southeast Minnesota.

METHODS

The study was designed as a cross-sectional study. Subjects were 788 children ages three to five years who were enrolled in Head Start of Olmsted and Freeborn Counties, Minnesota, between 1998 and 2001. Anthropometric data and other sociodemographic variables were collected. The Centers for Disease Control and Prevention (CDC) classification for body mass index (BMI) was used (ie, overweight is > 95th percentile BMI for age). Data were fit to a logistic regression model to identify risk factors associated with overweight.

RESULTS

From 1998 to 2001, the overall prevalence of overweight and at risk for overweight was 12.9% and 12.2%, respectively. The prevalence of overweight from 1998 to 2001 remained steady, but the prevalence of at risk doubled from 8.2% in 1998 to 16.1% in 2001. On the basis of BMI at the time of enrollment in Head Start, Mexican origin (OR = 2.76; P = .002) and speaking English as a second language (ESL) at home (OR = 1.75; P = .026) were independent predictors for overweight.

CONCLUSIONS

The Head Start setting in a nonurban area does not confer any more or less risk for overweight for enrollees, compared to those in urban settings. Children within a certain ethnic group (eg, Mexican) and those who speak English as a second language at home have a higher risk of being overweight. Specific early interventions for these children in a Head Start setting are warranted.

Reduction of medical error at the point-of-care using electronic clinical information delivery

There is accumulating evidence that point-of-care delivery of clinical information such as evidence-based medicine, practice guidelines and drug information can streamline clinical practice and reduce preventable errors. In Australia, hospital-based physicians have -generally been slow to fully use these resources to enhance their clinical practice. Here we provide an introduction to the practical application of several hand-held and electronic information systems available to Australian physicians.

Ligation of CD137 receptor prevents and reverses established anergy of CD8+ cytolytic T lymphocytes in vivo

T-cell anergy is a tolerance mechanism defined as a hyporesponsive status of antigen-specific T cells upon prior antigen encounter and is believed to play a critical role in the evasion of tumor immunity and the amelioration of allogeneic transplant rejection. Molecular mechanisms in controlling T-cell anergy are less known. We show here that administration of an agonistic monoclonal antibody (mAb) to CD137, a member of the tumor necrosis factor receptor superfamily, prevents the induction of CD8+ cytolytic T-lymphocyte (CTL) anergy by soluble antigens. More importantly, CD137 mAb restores the functions of established anergic CTLs upon reencountering their cognate antigen. As a result, infusion of CD137 mAb inhibits progressive tumor growth that is caused by soluble tumor antigen-induced tolerance in a P815R model. CD137 mAb also restores proliferation and effector functions of anergic alloreactive 2C T cells in a bone marrow transplantation model. Our results indicate that ligation of CD137 receptor delivers a regulatory signal for T-cell anergy and implicate manipulation of the CD137 pathway as a new approach to break T-cell tolerance.

Persistent abnormality detected in the non-ictal electroencephalogram in primary generalised epilepsy

OBJECTIVES

Gamma oscillations (30-100 Hz gamma electroencephalographic (EEG) activity) correlate with high frequency synchronous rhythmic bursting in assemblies of cerebral neurons participating in aspects of consciousness. Previous studies in a kainic acid animal model of epilepsy revealed increased intensity of gamma rhythms in background EEG preceding epileptiform discharges, leading the authors to test for intensified gamma EEG in humans with epilepsy.

METHODS

64 channel cortical EEG were recorded from 10 people with primary generalised epilepsy, 11 with partial epilepsy, and 20 controls during a quiescent mental state. Using standard methods of EEG analysis the strength of EEG rhythms (fast Fourier transformation) was quantified and the strengths of rhythms in the patient groups compared with with controls by unpaired t test at 1 Hz intervals from 1 Hz to 100 Hz.

RESULTS

In patients with generalised epilepsy, there was a threefold to sevenfold increase in power of gamma EEG between 30 Hz and 100 Hz (p<0.01). Analysis of three unmedicated patients with primary generalised epilepsies revealed an additional 10-fold narrow band increase of power around 35 Hz-40 Hz (p<0.0001). There were no corresponding changes in patients with partial epilepsy.

CONCLUSIONS

Increased gamma EEG is probably a marker of the underlying ion channel or neurotransmitter receptor dysfunction in primary generalised epilepsies and may also be a pathophysiological prerequisite for the development of seizures. The finding provides a new diagnostic approach and also links the pathophysiology of generalised epilepsies to emerging concepts of neuronal correlates of consciousness.

Signaling through NK cell-associated CD137 promotes both helper function for CD8+ cytolytic T cells and responsiveness to IL-2 but not cytolytic activity

NK cells possess both effector and regulatory activities that may be important during the antitumor immune response. In fact, the generation of antitumor immunity by the administration of an agonistic mAb against CD137 is NK cell-dependent. In this study, we report that NK cells could be induced by IL-2 and IL-15 to express CD137 and ligation of CD137-stimulated NK cell proliferation and IFN-gamma secretion, but not their cytolytic activity. Importantly, CD137-stimulated NK cells promoted the expansion of activated T cells in vitro, demonstrating immunoregulatory or "helper" activity for CD8(+)CTL. Furthermore, tumor-specific CTL activity against P815 tumor Ags was abrogated following anti-CD137 treatment in NK-depleted mice. We further demonstrate that CD137-stimulated helper NK cells expressed the high-affinity IL-2R and were hyperresponsive to IL-2. Taken together with previous findings that CD137 is a critical receptor for costimulation of T cells, our findings suggest that CD137 is a stimulatory receptor for NK cells involved in the crosstalk between innate and adaptive immunity.

Impaired infiltration of tumor-specific cytolytic T cells in the absence of interferon-gamma despite their normal maturation in lymphoid organs during CD137 monoclonal antibody therapy

Engagement of CD137 receptor by agonistic monoclonal antibodies (mAb) stimulates IFN-gamma production and eradicates established tumors in syngeneic mouse models. Using IFN-gamma-deficient mice or neutralizing mAb, we demonstrate that IFN-gamma is an absolute requirement for the antitumor effect of CD137 mAb. Despite progressive tumor growth in IFN-gamma-depleted mice, a fully competent CD8(+) cytolytic T cell (CTL) response developed in the lymph nodes. In addition, tumor cell sensitivity to IFN-gamma was not required because expression of a dominant-negative IFN-gamma receptor on the tumor did not affect the therapeutic effect of CD137 mAb. However, in the absence of IFN-gamma, the number of tumor-infiltrating CD8(+) CTLs was drastically decreased. Our results demonstrate that IFN-gamma is a critical factor regulating the infiltration of antigen-specific CTL into the tumor.

Cutting edge: Expression of functional CD137 receptor by dendritic cells

Interaction between dendritic cells (DCs) and T cells is a prerequisite for the initiation of a T cell response. The molecular nature of this interaction remains to be fully characterized. We report in this work that freshly isolated mouse splenic DCs and bone marrow-derived DCs express CD137 on the cell surface and in soluble form. Triggering CD137 increased the secretion of IL-6 and IL-12 from DCs. More importantly, infusion of an agonistic mAb to CD137 into naive mice enhanced the ability of DCs to stimulate T cell proliferation in response to both alloantigens and a nominal Ag in vitro. This enhancement of DC function is not mediated through activation of T cells, because the effect was also observed in RAG-1 knockout mice that lack T cells. Our findings implicate CD137 as an important receptor involved in the modulation of DC function.

Provision of antigen and CD137 signaling breaks immunological ignorance, promoting regression of poorly immunogenic tumors

Treatment of advanced, poorly immunogenic tumors in animal models, considered the closest simulation available thus far for conditions observed in cancer patients, remains a major challenge for cancer immunotherapy. We reported previously that established tumors in mice receiving an agonistic mAb to the T cell costimulatory molecule 4-1BB (CD137) regress due to enhanced tumor antigen-specific cytotoxic T lymphocyte responses. In this study, we demonstrate that several poorly immunogenic tumors, including C3 tumor, TC-1 lung carcinoma, and B16-F10 melanoma, once established as solid tumors or metastases, are refractory to treatment by anti-4-1BB mAb. We provide evidence that immunological ignorance, rather than anergy or deletion, of tumor antigen--specific CTLs during the progressive growth of tumors prevents costimulation by anti-4-1BB mAb. Breaking CTL ignorance by immunization with a tumor antigen-derived peptide, although insufficient to stimulate a curative CTL response, is necessary for anti--4-1BB mAb to induce a CTL response leading to the regression of established tumors. Our results suggest a new approach for immunotherapy of human cancers.

Immunotherapy of human papillomavirus-associated malignancies and the challenges posed by T-cell tolerance

Human papillomaviruses are associated with a broad range of carcinomas, including cervical cancer. Although the delivery of immunogenic tumor-associated antigens represents a promising approach in the treatment of these malignancies, the imposition of T cell tolerance poses a significant challenge in this endeavor. The purpose of this review is to discuss T cell tolerance and the role of T cell costimulation in the immunotherapy of HPV-associated malignancies.

Provision of antigen and CD137 signaling breaks immunological ignorance, promoting regression of poorly immunogenic tumors

Treatment of advanced, poorly immunogenic tumors in animal models, considered the closest simulation available thus far for conditions observed in cancer patients, remains a major challenge for cancer immunotherapy. We reported previously that established tumors in mice receiving an agonistic mAb to the T cell costimulatory molecule 4-1BB (CD137) regress due to enhanced tumor antigen-specific cytotoxic T lymphocyte responses. In this study, we demonstrate that several poorly immunogenic tumors, including C3 tumor, TC-1 lung carcinoma, and B16-F10 melanoma, once established as solid tumors or metastases, are refractory to treatment by anti-4-1BB mAb. We provide evidence that immunological ignorance, rather than anergy or deletion, of tumor antigen--specific CTLs during the progressive growth of tumors prevents costimulation by anti-4-1BB mAb. Breaking CTL ignorance by immunization with a tumor antigen-derived peptide, although insufficient to stimulate a curative CTL response, is necessary for anti--4-1BB mAb to induce a CTL response leading to the regression of established tumors. Our results suggest a new approach for immunotherapy of human cancers.

The personal digital assistant, a new medical instrument for the exchange of clinical information at the point of care

Personal digital assistants can provide a portable, integrated platform for point-of-care clinical reference, patient management and data communication. Clinical reference programs allow the user to access information from the Internet and guidelines. Patient management programs allow doctors to access and store clinical information. Wireless technologies have potential for rapid exchange of clinical laboratory results and efficient "electronic patient handovers". Thus, these devices provide the potential for true continuity of care across the healthcare system.

Perceived barriers to rural nurse practitioner practice

Studies of barriers to nurse practitioner (NP) practice show similar results for more than 20 years. Comparisons of barriers to rural NP practice have not been performed. Descriptive data about perceived barriers to practice were collected from 292 NPs in one midwestern state (urban, 229; rural, 63; response rate, 60%). A primary barrier was a lack of understanding by the general public about the NP role, which respondents found was detrimental to practice success. Physicians also lacked knowledge about the NP role. Rural practice barriers also included lack of peer support, suggesting that isolation from other NPs detracted from practice success. Educating the public and health professionals about NP education, scope of practice, and roles continues to be necessary. Media campaigns can increase understanding of NP practice. Rural NPs can use electronic means to communicate with each other to decrease practice isolation. Removing barriers to practice remains an ongoing task to enhance rural nursing practice.

B7-H3: a costimulatory molecule for T cell activation and IFN-gamma production

We describe here a newly identified member of the human B7 family, designated B7 homolog 3 (B7-H3), that shares 20-27% amino acid identity with other B7 family members. B7-H3 mRNA is not detectable in peripheral blood mononuclear cells, although it is found in various normal tissues and in several tumor cell lines. Expression of B7-H3 protein, however, can be induced on dendritic cells (DCs) and monocytes by inflammatory cytokines and a combination of phorbol myristate acetate (PMA) + ionomycin. Soluble B7-H3 protein binds a putative counter-receptor on activated T cells that is distinct from CD28, cytotoxic T lymphocyte antigen 4 (CTLA-4), inducible costimulator (ICOS) and PD-1. B7-H3 costimulates proliferation of both CD4+ and CD8+ T cells, enhances the induction of cytotoxic T cells and selectively stimulates interferon gamma (IFN-gamma) production in the presence of T cell receptor signaling. In contrast, inclusion of antisense B7-H3 oligonucleotides decreases the expression of B7-H3 on DCs and inhibits IFN-gamma production by DC-stimulated allogeneic T cells.Thus, we describe a newly identified costimulatory pathway that may participate in the regulation of cell-mediated immune responses.

Variable cytochrome P450 2D6 expression and metabolism of codeine and other opioid prodrugs: implications for the Australian anaesthetist

Codeine is a popular opioid prodrug dependent on the activity of the specific cytochrome P450 enzyme 2D6 (CYP2D6). This enzyme catalyses the production of the potent analgesic metabolite morphine, but genetic studies have demonstrated that individuals from different ethnic groups exhibit considerable variability in the functional capacities of their expressed CYP2D6 enzymes, and pharmacological studies have shown many commonly prescribed drugs can reduce the action of CYP2D6 enzymes. These findings have significant clinical implications for the rational prescription of effective analgesia, especially in a multicultural country like Australia.

Evidence for the involvement of a small subregion of the endoplasmic reticulum in the inositol trisphosphate receptor-induced activation of Ca2+ inflow in rat hepatocytes

The roles of a subregion of the endoplasmic reticulum (ER) and the cortical actin cytoskeleton in the mechanisms by which Ins(1,4,5)P3 induces the activation of store-operated Ca2+ channels (SOCs) in isolated rat hepatocytes were investigated. Adenophostin A, a potent agonist at Ins(1,4,5)P3 receptors, induced ER Ca2+ release and the activation of Ca2+ inflow. The concentration of adenophostin A that gave half-maximal stimulation of Ca2+ inflow (10 nM) was substantially lower than that (20 nM) which gave half-maximal ER Ca2+ release. A low concentration of adenophostin A (approx. 13 nM) caused near-maximal stimulation of Ca2+ inflow but only 20% of maximal ER Ca2+ release. Similar results were obtained using another Ins(1,4,5)P3-receptor agonist, 2-hydroxyethyl-alpha-d-glucopyranoside 2,3',4'-trisphosphate. Anti-type-1 Ins(1,4,5)P3-receptor monoclonal antibody 18A10 inhibited vasopressin-stimulated Ca2+ inflow but had no observable effect on vasopressin-induced ER Ca2+ release. Treatment with cytochalasin B at a concentration that partially disrupted the cortical actin cytoskeleton inhibited Ca2+ inflow and ER Ca2+ release induced by vasopressin by 73 and 45%, respectively. However, it did not substantially affect Ca2+ inflow and ER Ca2+ release induced by thapsigargin or 13 nM adenophostin A, intracellular Ca2+ release induced by ionomycin or Ins(1,4, 5)P3P4(5)-1-(2-nitrophenyl)ethyl ester ['caged' Ins(1,4,5)P3] or basal Ca2+ inflow. 1-(5-Chloronaphthalene-1-sulphonyl)homopiperazine, HCl (ML-9), an inhibitor of myosin light-chain kinase, also inhibited vasopressin-induced Ca2+ inflow and ER Ca2+ release by 53 and 44%, respectively, but had little effect on thapsigargin-induced Ca2+ inflow and ER Ca2+ release. Neither cytochalasin B nor ML-9 inhibited vasopressin-induced Ins(1,4,5)P3 formation. It is concluded that the activation of SOCs in rat hepatocytes induced by Ins(1,4,5)P3 requires the participation of a small region of the ER, which is distinguished from other regions of the ER by a different apparent affinity for Ins(1,4,5)P3 analogues and is associated with the plasma membrane through the actin skeleton. This conclusion is discussed briefly in relation to current hypotheses for the activation of SOCs.