Inflammatory demyelinating polyneuropathy versus leptomeningeal disease following Ipilimumab

Background

Ipilimumab is an FDA-approved anti-CTLA-4 monoclonal antibody used in treatment of metastatic melanoma. We present an unusual neurological complication of Ipilimumab therapy and the diagnostic dilemma it caused.

Case presentation

A 42 year old male with Stage IV metastatic melanoma developed lower extremity weakness and sensory neuropathy following three doses of Ipilimumab. MRI of the lumbar spine was initially interpreted as diffuse leptomeningeal disease, and patient began Dexamethasone and radiation with improvement in symptoms. However, subsequent completion imaging revealed smooth nerve root involvement with sparing of the spinal cord, findings more compatible with inflammatory demyelinating polyneuropathy. The absence of malignant cells in the cerebrospinal fluid (CSF) and nerve conduction study (NCS) showing lumbar polyradiculoneuropathy with axonal involvement and demyelinating features supported the diagnosis of inflammatory demyelinating polyneuropathy. Later in the course of his disease, the patient developed frank leptomeningeal melanoma.

Conclusion

Ipilimumab immune-related toxicity presented as inflammatory demyelinating polyneuropathy, which was difficult to distinguish from leptomeningeal disease, a common complication of melanoma.

The Emergence of Stimulus Relations: Human and Computer Learning

Traditionally, investigations in the area of stimulus equivalence have employed humans as experimental participants. Recently, however, artificial neural network models (often referred to as connectionist models [CMs]) have been developed to simulate performances seen among human participants when training various types of stimulus relations. Two types of neural network models have shown particular promise in recent years. RELNET has demonstrated its capacity to approximate human acquisition of stimulus relations using simulated matching-to-sample (MTS) procedures (e.g., Lyddy & Barnes-Holmes Journal of Speech and Language Pathology and Applied Behavior Analysis, 2, 14-24, 2007). Other newly developed connectionist algorithms train stimulus relations by way of compound stimuli (e.g., Tovar & Chavez The Psychological Record, 62, 747-762, 2012; Vernucio & Debert The Psychological Record, 66, 439-449, 2016). What makes all of these CMs interesting to many behavioral researchers is their apparent ability to simulate the acquisition of diversified stimulus relations as an analogue to human learning; that is, neural networks learn over a series of training epochs such that these models become capable of deriving novel or untrained stimulus relations. With the goal of explaining these quickly evolving approaches to practical and experimental endeavors in behavior analysis, we offer an overview of existing CMs as they apply to behavior-analytic theory and practice. We provide a brief overview of derived stimulus relations as applied to human academic remediation, and we argue that human and simulated human investigations have symbiotic experimental potential. Additionally, we provide a working example of a neural network referred to as emergent virtual analytics (EVA). This model demonstrates a process by which artificial neural networks can be employed by behavior-analytic researchers to understand, simulate, and predict derived stimulus relations made by human participants.

Abstract 5001: High dose IL-2 (HDIL-2) results in increased PD-1 expression on CD45RA-CCR7-CD8+ and CD45RA-CCR7-CD4+ T cells in melanoma patients

Introduction: HDIL-2 is associated with long-term remissions in Stage IV melanoma in less than 10% of patients. We hypothesized that HDIL-2 alters the expression of PD-1 on T cell subsets in melanoma patients.

Methods: Samples were collected after written consent under an IRB approved protocol. Peripheral blood was collected at baseline and serially post-treatment at 24, 48, 72, and 96 hours from 6 patients with advanced stage melanoma undergoing HDIL-2. All patients were treatment naïve with regards to anti-PD-1 and anti-CTLA4 therapies. PBMCs were isolated and underwent intracellular cytokine and extracellular receptor staining. Co-signaling molecule expression was analyzed via flow cytometry. Statistical analysis was performed using paired t tests via Prism 6.0e software.

Results: HDIL-2 was associated with a preferential loss of effector memory (TEM; CD45RA-CCR7-) CD4+ and CD8+ T cells and a relative enrichment of naïve (CD45RA+CCR7+) CD4+ and CD8+ T cells in the blood during the first 3 days of treatment. On day 4, frequencies of CD4+ and CD8+ TEM had returned to baseline. Importantly, PD-1 expression was significantly increased on day 4 post-treatment on CD8+ TEM relative to baseline (22.1% +/- 13.2% on day 4 compared to 13.4% +/- 7.4% at baseline; p = 0.04). This finding was also true for CD4+ TEM (11.4% +/- 6.1% on day 4 compared to 6.1% +/- 3.7% at baseline, p = 0.04). PD-1 expression was not statistically different within the other CD4+ and CD8+ memory T cell subsets including: naïve, central memory (CD45RA-CCR7+), or TEMRA (CD45RA+CCR7-) lymphocytes.

Conclusion: These results demonstrate that HDIL-2 is associated with an increase in expression of PD-1 on TEM cells in patients with advanced melanoma suggesting a possible mechanism contributing to the limited efficacy of HDIL-2 in most patients. It is known that TEM cells function by migrating to peripheral tissues, and that CD8+ TEM cells are found specifically in metastatic melanoma lesions. Importantly, our findings illustrate a potential synergistic effect between HDIL-2 and PD-1 blockade. Upregulation of PD-1 and the chronologic pattern in which its expression changes under the effects of HDIL-2 provide a mechanistic rationale for testing the combination of HDIL-2 and anti-PD-1 therapy in patients with advanced melanoma.

Citation Format: Maggie L. Diller, Susan Maio, Cabell E. Eysmans, David Lawson, Keith A. Delman, Ragini R. Kudchadkar, Mandy L. Ford. High dose IL-2 (HDIL-2) results in increased PD-1 expression on CD45RA-CCR7-CD8+ and CD45RA-CCR7-CD4+ T cells in melanoma patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5001. doi:10.1158/1538-7445.AM2015-5001

Gene expression profiling for molecular staging of cutaneous melanoma in patients undergoing sentinel lymph node biopsy

BACKGROUND

A gene expression profile (GEP) test able to accurately identify risk of metastasis for patients with cutaneous melanoma has been clinically validated.

OBJECTIVE

We aimed for assessment of the prognostic accuracy of GEP and sentinel lymph node biopsy (SLNB) tests, independently and in combination, in a multicenter cohort of 217 patients.

METHODS

Reverse transcription polymerase chain reaction (RT-PCR) was performed to assess the expression of 31 genes from primary melanoma tumors, and SLNB outcome was determined from clinical data. Prognostic accuracy of each test was determined using Kaplan-Meier and Cox regression analysis of disease-free, distant metastasis-free, and overall survivals.

RESULTS

GEP outcome was a more significant and better predictor of each end point in univariate and multivariate regression analysis, compared with SLNB (P < .0001 for all). In combination with SLNB, GEP improved prognostication. For patients with a GEP high-risk outcome and a negative SLNB result, Kaplan-Meier 5-year disease-free, distant metastasis-free, and overall survivals were 35%, 49%, and 54%, respectively.

LIMITATIONS

Within the SLNB-negative cohort of patients, overall risk of metastatic events was higher (∼30%) than commonly found in the general population of patients with melanoma.

CONCLUSIONS

In this study cohort, GEP was an objective tool that accurately predicted metastatic risk in SLNB-eligible patients.

Ipilimumab administration for advanced melanoma in patients with pre-existing Hepatitis B or C infection: a multicenter, retrospective case series

Ipilimumab is a fully human, monoclonal antibody directed against Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) that has demonstrated a survival benefit and durable disease control in patients with advanced melanoma. Ipilimumab is associated with potentially serious immune-related adverse events, including autoimmune hepatitis. Because clinical trials of ipilimumab excluded patients with pre-existing hepatitis B or C infection, there is a paucity of data on the safety of ipilimumab administration to that patient population. Here, we report the largest case series to date of patients with hepatitis B or C who received ipilimumab for advanced melanoma. Two of the nine patients described in this case series experienced fluctuations in their liver function tests (LFTs) and were subsequently treated with corticosteroids. Although this is a small series, the rate of hepatotoxicity appears similar to what has been seen in the general population treated with ipilimumab, and the ability to administer ipilimumab did not appear to be affected by concomitant hepatitis B or C infection. The use of ipilimumab in patients with metastatic melanoma who have pre-existing hepatitis can be considered among other therapeutic options.

Engineered fusokine GIFT4 licenses the ability of B cells to trigger a tumoricidal T-cell response

Engineered chimeric cytokines can generate gain-of-function activity in immune cells. Here, we report potent antitumor activity for a novel fusion cytokine generated by N-terminal coupling of GM-CSF to IL4, generating a fusokine termed GIFT4. B cells treated with GIFT4 clustered GM-CSF and IL4 receptors on the cell surface and displayed a pan-STAT hyperphosphorylation associated with acquisition of a distinct phenotype and function described to date. In C57BL/6J mice, administration of GIFT4 expanded endogenous B cells and suppressed the growth of B16F0 melanoma cells. Furthermore, B16F0 melanoma cells engineered to secrete GIFT4 were rejected immunologically in a B-cell-dependent manner. This effect was abolished when GIFT4-expressing B16F0 cells were implanted in B-cell-deficient mice, confirming a B-cell-dependent antitumor effect. Human GIFT4-licensed B cells primed cytotoxic T cells and specifically killed melanoma cells in vitro and in vivo. Taken together, our results demonstrated that GIFT4 could mediate expansion of B cells with potent antigen-specific effector function. GIFT4 may offer a novel immunotherapeutic tool and define a previously unrecognized potential for B cells in melanoma immunotherapy.

Effects of a complex housing environment on heart rate and blood pressure of rats at rest and after stressful challenges

Housing enrichment for rodents continues to be a discussion topic within the animal care community. The objective of this study was to determine the extent to which a complex housing environment affects heart rate, blood pressure, and activity of rats when undisturbed and after exposure to stressful challenges and whether autonomic controls of heart rate would be affected. Male and female Sprague-Dawley and Wistar rats with radiotelemetry transmitters were evaluated under nonenriched single-housing conditions and after acclimation to a complex environment of dim light and cohabitation with 3 conspecifics in large cages with hiding, food foraging, and nesting items. Telemetry data were collected when rats were undisturbed, after acute challenges (cage change, intraperitoneal injections, restraint), during a forced running protocol, and after cholinergic or adrenergic blockade. The complex environment reduced heart rate and increased activity in undisturbed rats but did not affect blood pressure. Heart rate responses to challenges were unaffected, decreased, or increased by complex housing, depending on the stock and sex of rats. Forced running was either unaffected or decreased, depending on the stock and sex of rats. Heart rate responses to cholinergic or β1-adrenergic blockade were not affected. We conclude that the complex housing did not reduce indices of stress (for example, heart rate) as compared with simpler housing. However, the possibility that some environmental elements interact negatively with each other must be considered in future studies.

The Society for Immunotherapy of Cancer consensus statement on tumour immunotherapy for the treatment of cutaneous melanoma

Immunotherapy is associated with durable clinical benefit in patients with melanoma. The goal of this article is to provide evidence-based consensus recommendations for the use of immunotherapy in the clinical management of patients with high-risk and advanced-stage melanoma in the USA. To achieve this goal, the Society for Immunotherapy of Cancer sponsored a panel of melanoma experts--including physicians, nurses, and patient advocates--to develop a consensus for the clinical application of tumour immunotherapy for patients with melanoma. The Institute of Medicine clinical practice guidelines were used as a basis for this consensus development. A systematic literature search was performed for high-impact studies in English between 1992 and 2012 and was supplemented as appropriate by the panel. This consensus report focuses on issues related to patient selection, toxicity management, clinical end points and sequencing or combination of therapy. The literature review and consensus panel voting and discussion were used to generate recommendations for the use of immunotherapy in patients with melanoma, and to assess and rate the strength of the supporting evidence. From the peer-reviewed literature the consensus panel identified a role for interferon-α2b, pegylated-interferon-α2b, interleukin-2 (IL-2) and ipilimumab in the clinical management of melanoma. Expert recommendations for how to incorporate these agents into the therapeutic approach to melanoma are provided in this consensus statement. Tumour immunotherapy is a useful therapeutic strategy in the management of patients with melanoma and evidence-based consensus recommendations for clinical integration are provided and will be updated as warranted.

Fatty aldehydes in cyanobacteria are a metabolically flexible precursor for a diversity of biofuel products

We describe how pathway engineering can be used to convert a single intermediate derived from lipid biosynthesis, fatty aldehydes, into a variety of biofuel precursors including alkanes, free fatty acids and wax esters. In cyanobacteria, long-chain acyl-ACPs can be reduced to fatty aldehydes, and then decarbonylated to alkanes. We discovered a cyanobacteria class-3 aldehyde-dehydrogenase, AldE, that was necessary and sufficient to instead oxidize fatty aldehyde precursors into fatty acids. Overexpression of enzymes in this pathway resulted in production of 50 to 100 fold more fatty acids than alkanes, and the fatty acids were secreted from the cell. Co-expression of acyl-ACP reductase, an alcohol-dehydrogenase and a wax-ester-synthase resulted in a third fate for fatty aldehydes: conversion to wax esters, which accumulated as intracellular lipid bodies. Conversion of acyl-ACP to fatty acids using endogenous cyanobacterial enzymes may allow biofuel production without transgenesis.

Spontaneous extradural aerocele following cardiopulmonary resuscitation - an unrecognised complication

We present a case report of a 61-year-old gentleman who had a cardiac arrest and was delivered cardiopulmonary resuscitation (CPR) by a bystander. After resuscitation, he regained cardiac output and was breathing spontaneously. CT scan of the head showed spontaneous right frontal extradural aerocele with fracture of the posterior wall of the frontal sinus with no sign of head injury. We discuss the pathophysiology of this unrecognised complication due to CPR.

Laboratory based experiments to assess the use of green and food based compost to improve water quality in a Sustainable Drainage (SUDS) device such as a swale

Many tonnes of compost are generated per year due to door step composting of both garden and kitchen waste. Whilst there are commercial outlets for the finer grade of compost (<10mm) in plant nurseries, there is little demand for the coarser material (>25 mm). This paper reports part of a WRAP-sponsored (Waste Resources Action Programme) study which investigated the potential for green (GC) and mixed green and food (MC) composts to be incorporated into Sustainable Drainage (SUDS) devices such as swales, and replace the topsoil (TS) onto which turf is laid or grass seed distributed. However, it is not known whether compost can replace TS in terms of pollutant remediation, both the trapping of polluted particulates and in dealing with hydrocarbons such as oil, but also from a biofilm development and activity perspective. Using laboratory based experiments utilising leaching columns and an investigation of microbiological development in the composts studied, it was found that many of the differences in performance between MC and GC were insignificant, whilst both composts performed better in terms of pollutant retention than TS. Mixed compost in particular could be used in devices where there may be oil spillages, such as the lorry park of a Motorway Service Area due to its efficiency in degrading oil. Samples of GC and MC were found to contain many of the bacteria and fungi necessary for an active and efficient biofilm which would be an argument in their favour for replacement of TS and incorporation in swales.

The Use of Preventive Strategies for Bone Loss

Osteoporosis is a worldwide problem that is increasing significantly as the global population both increases and ages. While osteoporosis has been extensively studied in recent years, the utilization of traditional Chinese medicine (TCM) for the diagnosis, prevention and treatment of this condition has seldom been examined. This paper examines the theories and the literature that relate to diagnosis, prevention and treatment of bone loss at the time of menopause according to the principles of TCM. It also considers practical developments in these areas as illustrated by the authors' research findings in recent studies. TCM diagnosis attributes a number of different underlying patterns to menopausal bone loss. A very common pattern in this situation is a Kidney qi and yin deficiency pattern. TCM analysis can be used as an early determinant of those persons who are potentially at risk of bone loss. Acupuncture, herbal medicine and Tai Ji exercise can then be applied to prevent and treat osteoporosis. These treatments can be effective, if they are applied correctly. The therapies may also be used in the treatment and prevention of osteoporosis, as well as the general maintenance of women's health during menopause.