Bianka Karshikoff

University of Stavanger (UiS) · Department of Social Studies

Systemic inflammation can induce pain hypersensitivity in animal and human experimental models, and has been proposed to be central in clinical pain conditions. Women are overrepresented in many chronic pain conditions, but experimental studies on sex differences in pain regulation during systemic inflammation are still scarce. In two randomized an...

Low-grade systemic inflammation has been implicated in chronic pain, as well as in comorbid diseases like depression and fatigue. We have previously shown that women's pain perception and regulation is more affected by systemic inflammation than that of men. Here we investigated the neural substrates underlying these effects using an fMRI paradigm...

Human models demonstrate that experimental activation of the innate immune system has profound effects on brain activation and behavior, inducing fatigue, worsened mood and pain sensitivity. It has been proposed that inflammation is a mechanism involved in the etiology and maintenance of depression, chronic pain and long-term fatigue. These disease...

Today's treatment for chronic pain is inadequate, and novel targets need to be identified. This requires a better understanding of the mechanisms involved in pain sensitization and chronification. In this review, we discuss how peripheral inflammation, as occurs during an infection, modulates the central pain system. In rodents, neonatal inflammati...

The Sickness Questionnaire is a newly developed questionnaire for self-reported sickness behavior in humans. Here, we determined the time-course of sickness behavior and the association with changes in cytokine levels in an experimental study where 22 subjects received 2.0 ng/kg endotoxin or placebo in a crossover design, with a minimum of 20 days...

Introduction: In an attempt to avoid contact with infectious individuals, humans likely respond to generalised rather than specific markers of disease. Humans may thus perceive a non-infectious individual as socially less attractive if they look (e.g., have facial discoloration), move (e.g., have a slower walking pace), or sound (e.g., sneeze) sick...

Background: The immune system and the central nervous system exchange information continuously. This communication is a prerequisite for adaptive responses to physiological and psychological stressors. While the implicate relationship between inflammation and pain is increasingly recognized in clinical cohorts, the underlying mechanisms and the po...

Individuals may have a different body odor, when they are sick compared to healthy. In the non-human animal literature, olfactory cues have been shown to predict avoidance of sick individuals. We tested whether the mere experimental activation of the innate immune system in healthy human individuals can make an individuals’ body odor be perceived a...

Chronic pain is characterized by high psychological comorbidity, and diagnoses are symptom-based due to a lack of clear pathophysiological factors and valid biomarkers. We investigate if inflammatory blood biomarker signatures are associated with pain intensity and psychological comorbidity in a mixed chronic pain population. Eighty-one patients (7...

Background: The medical and scientific communities struggle to understand chronic pain and find effective treatments. Multimodal approaches are encouraging but show significant individual differences. Methods: Seventy-eight persons (56 women) with chronic pain received Acceptance and Commitment Therapy and provided blood samples before and after...

Objectives Low-grade inflammation is a possible contributing factor in the development and persistence of chronic primary pain syndromes. Related to inflammatory activity is sickness behavior, a set of behavioral responses including increased pain sensitivity, fatigue, malaise, fever, loss of appetite, as well as depressive behavior and anhedonia....

Introduction: The role of inflammation in common psychiatric diseases is now well acknowledged. However, the factors and mechanisms underlying inter-individual variability in the vulnerability to develop psychopathology-related symptoms in response to inflammation are not well characterized. Herein, we aimed at investigating morphological brain re...

Background: Low-grade inflammation has been implicated in the etiology of depression, long-term fatigue and chronic pain. TNFα and IL-6 are perhaps the most studied pro-inflammatory cytokines in the field of psychoneuroimmunology. The purpose of our study was to further investigate these relationships in patients with chronic pelvic pain specifical...

Introduction Disturbed sleep in inflammatory disorders such as allergy and rheumatoid arthritis (RA) is common and may be directly or indirectly related to disease processes, but has not been well characterized in these patient groups, especially not with objective methods. Aim The present study aimed to characterize objective and subjective sleep...

Increasing evidence from animal and human studies suggests that inflammation may be involved in mood disorders. Sickness behavior and emotional changes induced by experimental inflammatory stimuli have been extensively studied in humans and rodents to better understand the mechanisms underlying inflammation-driven mood alterations. However, researc...

Background Chronic sickness behavior is implicated in ME/CFS (Myalgic Encephalomyelitis/Chronic Fatigue Syndrome) and chronic pain but the level of subjective sickness behavior in these conditions has not been investigated or compared to other clinical and non-clinical samples, or to the level in experimental inflammation. Furthermore, the relation...

Inflammation is believed to be a central mechanism in the pathophysiology of fatigue. While it is likely that dynamic of the fatigue response after an immune challenge relate to the corresponding cytokine release, this lacks evidence. Although both fatigue and sleepiness are strong signals to rest, they constitute distinct symptoms which are not ne...

Background Patient-reported outcomes predict mortality and play increasingly important roles in care, but factors that modify central measures such as health ratings have been little investigated. Building on designated immune-to-brain pathways, we aimed to determine how a short-term induced inflammation response impacts self-reported health status...

Contagious disease is a major threat to survival, and the cost of relying on the immune system to defeat pathogens is high; therefore, behavioral avoidance of contagious individuals is arguably an adaptive strategy. Animal findings demonstrate the ability to detect and avoid sick individuals by the aid of olfactory cues, and a recent study indicate...

Seasonal allergy is associated with increased prevalence of psychiatric symptoms and disorders, as well as fatigue and cognitive difficulties that aggravate during pollen season. It is unclear if this results from the impact of peripheral allergic inflammation on the immune system in brain. We studied 15 allergic patients and 13 healthy controls in...

We have previously shown that acute inflammatory response causes robust alterations of state and trait dimensions of self-rated health. Here, we repeat the previous study using a higher dose of endotoxin and investigate consequences of inflammation that may mediate changes in health appraisal. 22 healthy subjects were injected twice, once with endo...

Allergy is associated with non-specific symptoms such as fatigue, sleep problems and impaired cognition. One explanation could be that the allergic inflammatory state includes activation of immune cells in the brain, but this hypothesis has not been tested in humans. The aim of the present study was therefore to investigate seasonal changes in the...

Chronic pain is a debilitating condition that still is challenging both clinicians and researchers. Despite intense research, it is still not clear why some individuals develop chronic pain while others do not or how to heal this disease. In this review, we argue for a multisystem approach to understand chronic pain. Pain is not only to be viewed s...

Fatigue is a highly disabling symptom in various medical conditions. While inflammation has been suggested as a potential contributor to the development of fatigue, underlying mechanisms remain poorly understood. In this review, we propose that a better assessment of central fatigue, taking into account its multidimensional features, could help elu...

Self-rated health (SRH) is a powerful and reliable predictor of future ill-health albeit many of its determinants, such as fatigue, pain and mood, are known to fluctuate over time. The aim of the present study was to study to if sickness behavior mediates the effect of inflammation on self-rated health. In two RTCs (n = 51 and n = 8) lipopolysaccha...

Severe health anxiety is characterized by a debilitating fear of somatic illness, and avoidance of disease-related stimuli plays a key role in the maintenance of the disorder. The aim of this study was to investigate severe health anxiety within an evolutionary disease-avoidance framework. We hypothesized that, compared to healthy controls, partici...

Inflammation-induced sickness is associated with a large set of behavioral alterations, but its motivational aspects remain poorly explored in humans. The present study assessed the effect of lipopolysaccharide (LPS) administration at a dose of 2 ng/kg of body weight on motivation in twenty-one healthy human subjects, in a double-blinded, placebo (...

Lipopolysaccharide (LPS) administration is a well-established model to assess afferent immune-to-brain communication and behavioral aspects of inflammation. Nevertheless, only few studies in comparatively small samples have assessed state anxiety as a psychological component of sickness behavior despite possible clinical implications for the pathop...

Task-based fMRI has been used to study the effects of experimental inflammation on the human brain, but it remains unknown whether intrinsic connectivity in the brain at rest changes during a sickness response. Here, we investigated the effect of experimental inflammation on connectivity between areas relevant for monitoring of bodily states, motiv...

Experimental endotoxin administration is a well-established model to analyze the effect of inflammation on the development of mood impairments. However, it remains unknown from previous studies in comparatively small samples whether pre-existing inter-individual differences modulate the behavioral response during endotoxemia. We addressed this ques...

Health anxiety is characterized by a persistent and debilitating worry of somatic illness, as well as of avoidance behaviours. However, little is known of the cognitive mechanisms involved. We hypothesized that a higher degree of health anxiety would relate to an altered interpretation of other people’s health status and that this would be driven b...

An ability to detect subtle signs of sickness in others would be highly beneficial, as it would allow for behaviors that help us avoid contagious pathogens. Recent findings suggest that both animals and humans are able to detect distinctive odor signals of individuals with activated innate immune responses. This study tested whether an innate immun...

Observational studies have suggested that with time, some diseases result in a characteristic odor emanating from different sources on the body of a sick individual. Evolutionarily, however, it would be more advantageous if the innate immune response were detectable by healthy individuals as a first line of defense against infection by various path...

Observational studies have suggested that with time, some diseases result in a characteristic odor emanating from different sources on the body of a sick individual. Evolutionarily, however, it would be more advantageous if the innate immune response were detectable by healthy individuals as a first line of defense against infection by various path...

Animal research suggests that systemic inflammation may induce pain hypersensitivity through central mechanisms such as glia cell activation, a mechanism that has also been proposed to be central in several clinical pain conditions. In two placebo controlled studies we used two low doses of lipopolysaccharide (LPS) injections (0.6 ng/kg and 0.8 ng/...

Factors that influence subjective health ratings (e.g. pain, tiredness, lack of energy) resemble immune activated sickness behavior. Accordingly, previous research has shown a relation between inflammatory cytokines and poor self-rated health. However, neither the causality of the association, nor what mediates it, is clear. In this study we invest...

The lack of questionnaires to measure subjective feelings of being sick made us develope the Sickness Questionnaire (SicknessQ) for assessment of sickness behavior in people. The objective of the present investigation was to test its internal consistency, criteria validity, and sensitivity to capture the sickness response in an experimental setting...

The sickness response consists of a set of evolutionary stable behaviors facilitating recovery. Animals increase their pain sensitivity during sickness, but this has not been shown in humans. The present study investigated how an experimentally induced sickness response affected pain sensitivity in humans. Fifty healthy subjects (half women) were i...

Self-rated health is often viewed as a relatively stable construct and few studies have investigated short-term variations or used experimental approaches to manipulate subjective health perception. We have previously showed that higher levels of inflammatory cytokines are generally connected with less favorable self-rated health. Therefore, we exp...

Rodents avoid body odors of infected individuals, which suggest that an ability to detect disease in our peers would be of an evolutionary advantage. To investigate whether humans can detect if a person is sick we let naïve panelists judge photographs, films and body odors from individuals with a mild systemic inflammation. Eight individuals were i...

Serotonin (5-HT) is highly involved in pain regulation and serotonin-1A (5-HT1A) receptors are important in determining central 5-HT tone. Accordingly, variation in the 5-HT1A receptor gene (HTR1A) may contribute to inter-individual differences in human pain sensitivity. The minor G-allele of the HTR1A single nucleotide polymorphism (SNP) rs6295 at...

Despite the existing knowledge regarding the neuropathology of Alzheimer's disease (AD), the cause of sporadic forms of the disease is unknown. It has been suggested that systemic inflammation may have a role, but the exact mechanisms through which inflammatory processes influence the pathogenesis and progress of AD are not obvious. Allergy is a ch...