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Future lunar missions and beyond will require new and innovative approaches to radiation countermeasures. The Translational Research Institute for Space Health (TRISH) is focused on identifying and supporting unique approaches to reduce risks to human health and performance on future missions beyond low Earth orbit. This paper will describe three funded and complementary avenues for reducing the risk to humans from radiation exposure experienced in deep space. The first focus is on identifying new therapeutic targets to reduce the damaging effects of radiation by focusing on high throughput genetic screens in accessible, sometimes called lower, organism models. The second focus is to design innovative approaches for countermeasure development with special attention to nucleotide-based methodologies that may constitute a more agile way to design therapeutics. The final focus is to develop new and innovative ways to test radiation countermeasures in a human model system. While animal studies continue to be beneficial in the study of space radiation, they can have imperfect translation to humans. The use of three-dimensional (3D) complex in vitro models is a promising approach to aid the development of new countermeasures and personalized assessments of radiation risks. These three distinct and unique approaches complement traditional space radiation efforts and should provide future space explorers with more options to safeguard their short and long-term health.

The mechanisms responsible for determining neural stem cell fate are numerous and complex. To begin to identify the specific components involved in these processes, we generated several mouse neural stem cell (NSC) antibodies against cultured mouse embryonic neurospheres. Our immunohistochemical data showed that the NSC-6 antibody recognized NSCs in the developing and postnatal murine brains as well as in human brain organoids. Mass spectrometry revealed the identity of the NSC-6 epitope as brain abundant, membrane-attached signal protein 1 (BASP1), a signaling protein that plays a key role in neurite outgrowth and plasticity. Western blot analysis using the NSC-6 antibody demonstrated multiple BASP1 isoforms with varying degrees of expression and correlating with distinct developmental stages. Herein, we describe the expression of BASP1 in NSCs in the developing and postnatal mammalian brains and human brain organoids, and demonstrate that the NSC-6 antibody may be a useful marker of these cells. We are grateful to Grigori Enikolopov for critically reviewing the manuscript, Dwight Martin for expert technical assistance, and Huda Zoghbi for the use of flow cytometer. This work was supported by the NIGMS (5R01GM120033), U.S. Army Medical Research (DAMD170110754), Cynthia and Antony Petrello Endowment, and Mark A. Wallace Endowment (M.M.S.); the National Institute of Diabetes and Digestive and Kidney Diseases (T32DK07521-16) (L.N.M.); MINECO SAF-2015-70866R (J.M.E), FPI MICINN predoctoral Fellowship (I.D.); the Proteomics Center at Stony Brook University (NIH/NCRR 1S10 RR023680), and the BCM IDDRC Grant (P50HD10355) from the Eunice Kennedy Shriver National Institute of Child Health and Human Development for use of the Microscopy Core facilities, the RNA In Situ Hybridization Core facility, and the Human Neuronal Differentiation Core facility

Positive social experiences may induce oxytocin release. However, previous studies of moral elevation have generally utilized cross-sectional and simple modeling approaches to establish the relationship between oxytocin and emotional stimuli. Utilizing a cohort of 30 non-lactating women (aged 23.6±5.7 years), we tested whether exposure to a video identified as capable of eliciting moral elevation could change plasma oxytocin levels. Uniquely, we utilized a high-frequency longitudinal sampling approach and multilevel growth curve modeling with landmark registration to test physiological responses. The moral elevation stimulus, versus a control video, elicited significantly greater reports of being "touched/inspired" and "happy/joyful". However, the measured plasma oxytocin response was found to be markedly heterogeneous. While the moral elevation stimulus elicited increased plasma oxytocin as expected, this increase was only modestly larger than that seen following the control video. This increase was also only present in some individuals. We found no relationship between plasma oxytocin and self-report responses to the stimulus. From these data, we argue that future studies of the relationship between oxytocin and emotion need to anticipate heterogeneous responses and thus incorporate comprehensive individual psychological data; these should include evidence-based variables known to be associated with oxytocin such as a history of trauma, and the individual's psychological and emotional state at the time of testing. Given the complexity of physiological oxytocin release, such studies also need to incorporate frequent biological sampling to properly examine the dynamics of hormonal release and response.

The mammalian hippocampus shows a remarkable capacity for continued neurogenesis throughout life. Newborn neurons, generated by the radial neural stem cells (NSCs), are important for learning and memory as well as mood control. During aging, the number and responses of NSCs to neurogenic stimuli diminish, leading to decreased neurogenesis and age-associated cognitive decline and psychiatric disorders. Thus, adult hippocampal neurogenesis has been the subject of intense investigation, generating both excitement and controversy. Identifying the core molecular machinery responsible for NSC preservation is of fundamental importance if we are to use neurogenesis to halt or reverse hippocampal age-related pathology. Here, we briefly overview the most frequently used mouse models to study hippocampal neurogenesis and then focus on a unique mouse model that allows NSC-specific studies based on their unique expression of lunatic fringe (Lfng). The Lfng-eGFP and Lfng(BAC)-CreERT2;RCL-tdT transgenic mice provide us with an excellent tool to resolve long-standing questions regarding the properties of NSCs, such as their specific molecular composition, potency, and plasticity, in isolation from any other cell in the hippocampal neurogenic niche.

Treatment-related sequelae following cranial irradiation have life changing impacts for patients and their caregivers. Characterization of the basic response of human brain tissue to irradiation has been difficult due to a lack of preclinical models. The direct study of human brain tissue in vitro is becoming possible due to advances in stem cell biology, neuroscience, and tissue engineering with the development of organoids as novel model systems which enable experimentation with human tissue models. We sought to establish a cerebral organoid (CO) model to study the radioresponse of normal human brain tissue. COs were grown using human induced pluripotent stem cells and a modified Lancaster protocol. Compositional analysis during development of the COs showed expected populations of neurons and glia. We confirmed a population of microglia-like cells within the model positive for the makers Iba1 and CD68. After 2-months of maturation, COs were irradiated to 0, 10, and 20 Gy using a Shepard Mark-II Cs-137 irradiator and returned to culture. Subsets of COs were prepared for immunostaining at 30- and 70-days post-irradiation. To examine the effect of irradiation on the neural stem cell (NSC) population, sections were stained for SOX2 and Ki-67 expression denoting NSCs and proliferation respectively. Slides were imaged and scored using the CellProfiler software package. The percentage of proliferating NSCs 30-days post-irradiation was found to be significantly reduced for irradiated COs (5.7% (P=0.007) and 3.4% (P=0.001) for 10 and 20 Gy respectively) compared to control (12.7%). The reduction in the proliferating NSC population subsequently translated to a reduced population of NeuN-labeled mature neurons 70 days post-irradiation. The loss of proliferating NSCs and subsequent reduction in mature neurons demonstrates the long-term effects of radiation. Our initial results indicate COs will be a valuable model to study the effects of radiation therapy on normal and diseased human tissue.

Dysregulation of the JAK/STAT signaling pathway is associated with Multiple Sclerosis (MS) and its mouse model, Experimental Autoimmune Encephalomyelitis (EAE). Suppressors Of Cytokine Signaling (SOCS) negatively regulate the JAK/STAT pathway. We previously reported a severe, brain-targeted, atypical form of EAE in mice lacking Socs3 in myeloid cells (Socs3ΔLysM), which is associated with cerebellar neutrophil infiltration. There is emerging evidence that neutrophils are detrimental in the pathology of MS/EAE, however, their exact function is unclear. Here we demonstrate that neutrophils from the cerebellum of Socs3ΔLysM mice show a hyper-activated phenotype with excessive production of reactive oxygen species (ROS) at the peak of EAE. Neutralization of ROS in vivo delayed the onset and reduced severity of atypical EAE. Mechanistically, Socs3-deficient neutrophils exhibit enhanced STAT3 activation, a hyper-activated phenotype in response to G-CSF, and upon G-CSF priming, increased ROS production. Neutralization of G-CSF in vivo significantly reduced the incidence and severity of the atypical EAE phenotype. Overall, our work elucidates that hypersensitivity of G-CSF/STAT3 signaling in Socs3ΔLysM mice leads to atypical EAE by enhanced neutrophil activation and increased oxidative stress, which may explain the detrimental role of G-CSF in MS patients.

Dysregulation of the JAK/STAT signaling pathway is associated with multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Suppressors of cytokine signaling (SOCS) negatively regulate the JAK/STAT pathway. We previously reported a severe, brain-targeted, atypical form of EAE in mice lacking Socs3 in myeloid cells (Socs3(ΔLysM)), and that this atypical EAE is associated with cerebellar neutrophil infiltration. There is emerging evidence that neutrophils are detrimental in the pathology of MS/EAE; however, their exact function is unclear. Here we demonstrate that neutrophils from the cerebellum of Socs3(ΔLysM) mice show a hyperactivated phenotype with excessive production of reactive oxygen species (ROS) at the peak of EAE. Neutralization of ROS in vivo delayed the onset and reduced severity of atypical EAE. Mechanistically, Socs3-deficient neutrophils exhibited enhanced signal transducer and activator of transcription 3 (STAT3) activation, a hyperactivated phenotype in response to granulocyte colony–stimulating factor (G-CSF), and upon G-CSF priming, increased ROS production. Neutralization of G-CSF in vivo significantly reduced the incidence and severity of the atypical EAE phenotype. Overall, our work elucidates that hypersensitivity of G-CSF/STAT3 signaling in Socs3(ΔLysM) mice leads to atypical EAE by enhanced neutrophil activation and increased oxidative stress, which may explain the detrimental role of G-CSF in MS patients.

Worldwide, the incidence of wrist fracture is increasing. There are currently no externally validated prognostic models to inform early decision making for these patients.To develop and validate a prognostic model from a comprehensive range of candidate prognostic factors that can identify patients who are at risk of developing persistent pain following wrist or hand fracture.We developed and validated a prognostic model using secondary data derived from a prospective cohort study (n = 715), with recruitment sites in 3 metropolitan hospitals in Sydney, Australia. The primary outcome was persistent pain 4 months following the injury. The current study used a backward stepwise regression analysis to develop the model in 2 hospitals (n = 408) and externally validate it in a third hospital (n = 307). To determine the accuracy of the model, we assessed calibration and discrimination in accordance with the PROGnosis RESearch Strategy framework.Complete data were available for 95% of the cohort. Of 14 candidate variables, the final model contained 2 prognostic factors: patient age and pain intensity reported at initial presentation. The area under the receiver operating characteristic curve was 0.63 (95% confidence interval: 0.56, 0.69) in the development sample and 0.61 (95% confidence interval: 0.51, 0.70) in the validation sample. The model systematically overestimated risk (intercept, -1.13; slope, 0.73).We developed and externally validated a prognostic model to predict persistent pain 4 months after a wrist or hand fracture. Future studies are needed to assess whether the accuracy of this model can be improved by updating and validating it in local settings.Prognosis, level 1b. J Orthop Sports Phys Ther 2019;49(1):28-35. Epub 12 Sep 2018. doi:10.2519/jospt.2019.8342.

The purpose of this longitudinal blood sampling study was to examine relationships between sex hormones and fibromyalgia pain. Eight women meeting case definition criteria for fibromyalgia provided venous blood samples and reported their fibromyalgia pain severity over 25 consecutive days. All women exhibited normal menstrual cycles and were not taking oral contraceptives. Cortisol, and the sex hormones estradiol, progesterone, and testosterone, were assayed from serum. A linear mixed model was used to determine if fluctuations of sex hormones were associated with changes in pain severity. In the entire sample, day to day changes in progesterone (P = .002) as well as testosterone (P = .015) were significantly and inversely correlated with pain severity. There was no relationship between estradiol and pain (P = .551) or cortisol and pain (P = .633). These results suggest that progesterone and testosterone play a protective role in fibromyalgia pain severity. Sex and other hormones may serve to increase as well as decrease fibromyalgia pain severity. Perspective Sex hormones fluctuate normally in women with fibromyalgia, but may still contribute to pain severity.

Low-dose naltrexone (LDN) has been demonstrated to reduce symptom severity in conditions such as fibromyalgia, Crohn’s disease, multiple sclerosis, and complex regional pain syndrome. We review the evidence that LDN may operate as a novel anti-inflammatory agent in the central nervous system, via action on microglial cells. These effects may be unique to low dosages of naltrexone and appear to be entirely independent from naltrexone’s better-known activity on opioid receptors. As a daily oral therapy, LDN is inexpensive and well-tolerated. Despite initial promise of efficacy, the use of LDN for chronic disorders is still highly experimental. Published trials have low sample sizes, and few replications have been performed. We cover the typical usage of LDN in clinical trials, caveats to using the medication, and recommendations for future research and clinical work. LDN may represent one of the first glial cell modulators to be used for the management of chronic pain disorders.

Dysfunction in the central nervous systemis thought to underlie themovement disorders that commonly occur in complex regional pain syndrome (CRPS), with much of the literature focusing on reorganization of the primary motor cortex (M1). Presumed changes in the M1 representation of the CRPS-affected body part have contributed to new CRPS treatments, which are increasingly being integrated in the clinic. We systematically investigated the evidence for altered M1 function in CRPS. We adhered to rigorous systematic review procedure in our search strategy, risk-of-bias appraisal, and data extraction. Eighteen studies comprising 14 unique data sets were included. The included studies used several neuroimaging techniques, whose outcomeswe grouped intoM1 cortical excitability, spatial representation, reactivity, and glucose metabolism, and conducted meta-analyses where possible. Risk of bias across studies was high, mainly due tomissing data and unblinded assessment of outcomes. No definitive conclusions can be drawn regarding M1 spatial representation, reactivity, or glucose metabolism in CRPS. There is limited evidence for bilateralM1 disinhibition in CRPS of the upper limb. Perspective: Despite widely held assumptions of primary motor cortex dysfunction in complex regional pain syndrome, there is only evidence to support bilateral disinhibition, and there is high risk of bias across the literature. Refereed/Peer-reviewed

That complex regional pain syndrome (CRPS) is associated with functional reorganization in the primary somatosensory cortex (S1) is widely accepted and seldom questioned. Despite more than a decade of research, there has been no systematic review of the CRPS literature concerning the changes in S1 function, and therefore the extent of these changes is unclear. Here we conduct a systematic review and meta-analysis to quantify the spatial and temporal aspects of S1 function in CRPS. A comprehensive search strategy identified functional neuroimaging studies of S1 in CRPS. We adhered to a rigorous systematic review protocol when extracting data and appraising risk of bias. Outcomes were grouped into spatial representation; activation levels, including disinhibition; peak latency of activation; and glucose metabolism. Meta-analysis was conducted where possible. Fifteen studies were included, all investigating upper-extremity CRPS. In patients with CRPS, the S1 spatial representation of the affected hand is smaller than that of the unaffected hand and that of non-CRPS controls; however, this evidence comes from only a few studies. There is no difference in activation, disinhibition, or latency of peripherally evoked S1 responses in CRPS. The risk of bias was high across studies, mainly from unclear sampling methods and unblinded analysis of outcomes. Perspective: The evidence for a difference in function of the primary somatosensory cortex in CRPS compared with controls is clouded by high risk of bias and conflicting results, but reduced representation size seems consistent. Refereed/Peer-reviewed

Objective: Chronic pain is a common problem that is associated with mood disorders such as depression. The Depression, Anxiety, and Stress Scales (DASS-21) questionnaire is commonly used to help measure disordered mood. In this study, we used Rasch analysis to analyze the clinimetric properties of the DASS-21 in a chronic low back pain sample. Study Design and Setting: A Rasch analysis was conducted on data collected as a part of a randomized hospital-based placebo controlled trial. DASS-21 questionnaires were completed by the 154 enrolled participants. Results: The DASS-21 subscales fit the Rasch model. No differential item functioning was detected for age, gender, pain severity, or disability. Reliability for individual use was supported for the depression subscale (Person Separation Index [PSI]50.86) but group use only for the anxiety (PSI50.74) and stress (PSI50.82) subscales. A DASS-21 aggregate score of ‘‘negative affect’’ lacked fit to the Rasch model (c25191.48, P!0.001). Conclusion: This is the first study that used Rasch analysis to demonstrate that the DASS-21 subscales demonstrate adequate measurement properties for research involving groups with chronic pain. Only the DASS-21 depression subscale demonstrated adequate reliability for use with individuals with chronic pain. The use of a single DASS-21 aggregate score as a measure of ‘‘negative affect’’ was not supported. Refereed/Peer-reviewed

Background and Purpose Orofacial pain disorders are relatively uncommon and pose a substantial diagnostic challenge. This case report documents the diagnosis and management of hemifacial pain in a patient who was referred to an interdisciplinary pain medicine unit. The purpose of this case report is twofold. First, it presents complex regional pain syndrome (CRPS) as a potential differential diagnosis in cases of facial pain. Second, it describes the successful adaption of contemporary management approaches for distal-extremity CRPS to treat people with CRPS of the facial region. Case Description The patient had hemifacial pain and concomitant motor and autonomic symptoms after a small laceration of the eyelid. Extensive specialist medical evaluations were undertaken to exclude an underlying structural pathology. After detailed clinical assessments by a physical therapist, pain physician, and clinical psychologist, a diagnosis of CRPS involving the face was made. Outcomes The patient's pain was largely unresponsive to pharmacological agents. A modified graded motor imagery program, together with desensitization and discrimination training, was commenced by the physical therapist and clinical psychologist. A positive clinical response was indicated by a decrease in allodynia, normalization of motor control, and regained function in activities of daily living. Discussion Complex regional pain syndrome is an infrequently reported differential diagnosis that can be considered in patients with persistent facial pain. This case report highlights how careful examination and clinical decision making led to the use of an innovative therapeutic strategy to manage a challenging condition.

Upper limb fracture is a common musculoskeletal injury and can lead to marked pain-related disability. Unlike other common painful musculoskeletal conditions, such as low back pain, little consideration has been given to the role that psychological variables may play in explaining the relationship between pain and disability during early fracture recovery. This cross-sectional study aimed to determine if psychological distress (symptoms of depression, anxiety, and/or stress) mediate the relationship between pain and disability in acute hand/wrist fractures. Self-reported data from a consecutive sample of 594 patients with acute hand/wrist fracture were used. Mediation analyses were conducted to determine the role of depression, anxiety, and stress in the relationship between pain and disability, controlling for relevant demographic and fracture-related variables. Depression and stress, but not anxiety, significantly mediated the relationship between pain and disability. That is, although each psychological distress variable was associated with pain (P.001), only depression (b1 = 0.27, P = .03) and stress (b3 = .23, P = .02) were significantly associated with disability and fulfilled recommended criteria for establishing a mediating variable. Increased depression and stress, but not anxiety, explain the relationship between pain and disability and may be novel targets for interventions designed to reduce pain-related disability after upper limb fracture. Perspective: This study presents the mediating effect of psychological distress on the relationship between pain and disability in acute upper limb fracture. These factors may be novel targets for interventions designed to reduce pain-related disability after acute fracture.

Editors' Note: Parkitny and O'Connell point out the divergence in the initial hypothesis and final article on repetitive transcranial magnetic stimulation for fibromyalgia and critique how the authors interpreted the study results. Guedj and Boyer, authors of the study, respond. Freeman makes interesting observations and raises questions regarding the higher rate of intensive care unit admission and mortality in patients with multiple sclerosis. Marrie and Garland offer additional clarification. —Chafic Karam, MD, and Robert C. Griggs, MD Boyer et al.1 diverge—without disclosure—from the registered protocol for this trial. The authors stated that …

Background The Pain Self-Efficacy Questionnaire (PSEQ) is used by physical therapists in clinical practice and in research. However, current understanding of the PSEQ's measurement properties is incomplete, and investigators cannot be confident that it provides unbiased information on patient self-efficacy. Objective The aims of this study were: (1) to investigate the scale properties of the PSEQ using Rasch analysis and (2) to determine whether age, sex, pain intensity, pain duration, and pain-related disability bias function of the PSEQ. Design This was a retrospective study; data were obtained from 3 existing studies. Methods Data were combined from more than 600 patients with low back pain of varying duration. Rasch analysis was used to evaluate targeting, category ordering, unidimensionality, person fit, internal consistency, and item bias. Results There was evidence of adequate category ordering, unidimensionality, and internal consistency of the PSEQ. Importantly, there was no evidence of item bias. Limitations The PSEQ did not adequately target the sample; instead, it targeted people with lower self-efficacy than this population. Item 7 was hardest for participants to endorse, showing excessive positive misfit to the Rasch model. Response strings of misfitting persons revealed older participants and those reporting high levels of disability. Conclusions The individual items of the PSEQ can be validly summed to provide a score of self-efficacy that is robust to age, sex, pain intensity, pain duration, and disability. Although item 7 is the most problematic, it may provide important clinical information and requires further investigation before its exclusion. Although the PSEQ is commonly used with people with low back pain, of whom the sample in this study was representative, the results suggest it targets patients with lower self-efficacy than that observed in the current sample.

Cytokine concentrations are thought to be affected by methods of sampling and processing and by storage conditions. In this study we compared 17 cytokine concentrations obtained from plasma and serum at baseline and after a controlled thaw condition. We found that absolute agreement was poor between concentrations of cytokines in plasma and serum, except for MIP1β. A thaw condition significantly changed the concentrations of most cytokines, but serum appeared less affected by this than plasma was. Closer examination using Bland-Altman analyses revealed that for each comparison, agreement was moderately good for many cytokine concentrations. This is important because measures of agreement must be interpreted based on the required precision, which may differ between clinical and research demands. We also identified that for some cytokines, the relationship between serum and plasma is affected by concentration, thus advocating for the use of appropriate methods when performing such comparisons in studies such as systematic reviews and meta-analyses.

There is increasing evidence that chronic pain problems are characterised by alterations in brain structure and function. Chronic back pain is no exception. There is a growing sentiment, with accompanying theory, that these brain changes contribute to chronic back pain, although empirical support is lacking. This paper reviews the structural and functional changes of the brain that have been observed in people with chronic back pain. We cast light on the clinical implications of these changes and the possibilities for new treatments but we also advise caution against concluding their efficacy in the absence of solid evidence to this effect. National Health & Medical Research Council of Australia.

Objective. To assess the effects of preclinic group education sessions and system redesign on tertiary pain medicine units and patient outcomes. Design. Prospective cohort study. Setting. Two public hospital multidisciplinary pain medicine units. Patients. People with persistent pain. Interventions. A system redesign from a “traditional” model (initial individual medical appointments) to a model that delivers group education sessions prior to individual appointments. Based on Patient Triage Questionnaires patients were scheduled to attend Self-Training Educative Pain Sessions (STEPS), a two day eight hour group education program, followed by optional patient-initiated clinic appointments. Outcome Measures. Number of patients completing STEPS who subsequently requested individual outpatient clinic appointment(s); wait-times; unit cost per new patient referred; recurrent health care utilization; patient satisfaction; Global Perceived Impression of Change (GPIC); and utilized pain management strategies. Results. Following STEPS 48% of attendees requested individual outpatient appointments. Wait times reduced from 105.6 to 16.1 weeks at one pain unit and 37.3 to 15.2 weeks at the second. Unit cost per new patient appointed reduced from $1,805 Australian Dollars (AUD) to AUD$541 (for STEPS). At 3 months, patients scored their satisfaction with “the treatment received for their pain” more positively than at baseline (change score = 0.88; P = 0.0003), GPIC improved (change score = 0.46; P < 0.0001) and mean number of active strategies utilized increased by 4.12 per patient ( P = 0.0004). Conclusions. The introduction of STEPS was associated with reduced wait-times and costs at public pain medicine units and increased both the use of active pain management strategies and patient satisfaction.

Many chronic pain and psychiatric conditions are associated with changes in the concentrations of cytokines. Cytokine concentrations may also be associated with pain and mood during early recovery after injury. We aimed to investigate this in people after acute orthopaedic trauma. We tested 240 randomly selected serum samples obtained from a cohort of patients enrolled in a larger project investigating recovery following wrist fractures. Patients (18–75 years old) were prospectively recruited from three tertiary hospital outpatient clinics in Sydney, Australia. All participants were interviewed and completed validated questionnaires; 78% of participants also consented to a blood test. Serum cytokine concentrations were measured using a human 25-plex panel and luminex technology. In the primary analysis, regression models investigated the relationship between a priori -nominated cytokines and pain, depression, anxiety, stress, and quality of sleep. Pain was positively associated with increased systemic concentrations of CCL5 ( r = 0.25 p r = 0.25 p r = 0.22 p r = 0.22 p r = 0.19 p

Background Gulf War Illness (GWI) is a clinically heterogeneous chronic condition that affects many veterans of the 1990–1991 Persian Gulf War. One of the most prevalent and debilitating symptoms of GWI is abnormal fatigue. The mechanisms underlying GWI generally, and fatigue symptoms specifically, have yet to be conclusively identified, although immune system abnormalities are suspected to be involved. The first goal of this immune monitoring study was to determine if GWI is associated with higher absolute levels and daily variability of pro-inflammatory immune factors. The second goal was to explore the relationship between day-to-day immune marker fluctuations and daily self-reported fatigue severity. Methods We recruited veterans with GWI and healthy veteran control (HV) participants to provide self-reported fatigue severity data and blood samples, over 25 consecutive days. We profiled inflammatory processes by using a longitudinal, daily immune-monitoring approach. For each day, serum cytokine and chemokine concentrations were determined using multiplex assays. Results Seven veterans with GWI and eight healthy veteran control (HV) participants completed the study protocol. We found that GWI was associated with higher variability in the expression of eotaxin-1 (p