Challenges in interpreting cytokine biomarkers in biobehavioral research: a breast cancer exemplar

An Aptamer Linked Immobilized Sorbent Assay (ALISA) to Detect Circulatory IFN-α, an Inflammatory Protein among Tuberculosis Patients

Dysregulation of IFN-α is the basis for pathogenesis of autoimmune as well as infectious diseases. Identifying inflammatory signatures in peripheral blood of patients is an approach for monitoring active infection. Hence, estimation of type I IFNs as an inflammatory biomarker to scrutinize disease status after treatment is useful. Accordingly, an Aptamer Linked Immobilized Sorbent Assay (ALISA) for the detection of IFN-α in serum samples was developed. Sixteen aptamers were screened for their ability to bind IFN-α. Aptamer IFNα-3 exhibited specificity for IFN-α with no cross-reactivity with interferons β and γ and human serum albumin. The disassociation constant (K_d) was determined to be 3.96 ± 0.36 nM, and the limit of detection was ∼2 ng. The characterized IFNα-3 aptamer was used in ALISA to screen tuberculosis (TB) patients' sera. An elevated IFN-α level in sera derived from untreated TB patients (median = 0.31), compared to nontuberculous household contacts (median = 0.13) and healthy volunteers (median = 0.12), and further a decline in IFN-α level among treated patients (median = 0.13) were seen. The ALISA assay facilitates direct estimation of inflammatory protein(s) in circulation unlike mRNA estimation by real time PCR. Designing of aptamers similar to the IFNα-3 aptamer provides a novel approach to assess other inflammatory protein(s) in patients before, during, and after completion of treatment and would denote clinical improvement in successfully treated patients.

Multiple analyte profiling (MAP) index as a powerful diagnostic and therapeutic monitoring tool

A robust data mining algorithm is presented as a critical solution to the challenge of managing intensive data generated from the recently developed multiplexing techniques, which allow simultaneous detection of up to 500 biomarkers in a few microliters of a single sample. Furthermore, detailed methodology is provided for exploiting the new algorithm along with examples for description of the first application as a powerful diagnostic and therapeutic monitoring tool in the management of breast cancer, as a disease model.

The Role of Inflammation in the Pain, Fatigue, and Sleep Disturbance Symptom Cluster in Advanced Cancer

CONTEXT

Symptom researchers have proposed a model of inflammatory cytokine activity and dysregulation in cancer to explain co-occurring symptoms including pain, fatigue, and sleep disturbance.

OBJECTIVES

We tested the hypothesis that psychological stress accentuates inflammation and that stress and inflammation contribute to one's experience of the pain, fatigue, and sleep disturbance symptom cluster (symptom cluster severity, symptom cluster distress) and its impact (symptom cluster interference with daily life, quality of life).

METHODS

We used baseline data from a symptom cluster management trial. Adult participants (N = 158) receiving chemotherapy for advanced cancer reported pain, fatigue, and sleep disturbance on enrollment. Before intervention, participants completed measures of demographics, perceived stress, symptom cluster severity, symptom cluster distress, symptom cluster interference with daily life, and quality of life and provided a blood sample for four inflammatory biomarkers (interleukin-1β, interleukin-6, tumor necrosis factor-α, and C-reactive protein).

RESULTS

Stress was not directly related to any inflammatory biomarker. Stress and tumor necrosis factor-α were positively related to symptom cluster distress, although not symptom cluster severity. Tumor necrosis factor-α was indirectly related to symptom cluster interference with daily life, through its effect on symptom cluster distress. Stress was positively associated with symptom cluster interference with daily life and inversely with quality of life. Stress also had indirect effects on symptom cluster interference with daily life, through its effect on symptom cluster distress.

CONCLUSION

The proposed inflammatory model of symptoms was partially supported. Investigators should test interventions that target stress as a contributing factor in co-occurring pain, fatigue, and sleep disturbance and explore other factors that may influence inflammatory biomarker levels within the context of an advanced cancer diagnosis and treatment.

Multiplexing and Beyond in Biobehavioral Research

In contrast to traditional singleplex assays that provide values for only a single analyte in a single biological sample, multiplex assays are a time- and resource-efficient high-throughput approach that provides the opportunity to determine numerous analytes within a single- and small-sample volume. In this editorial on an article by Dorn et al. in this issue of Psychosomatic Medicine, we provide a brief description of the advantages and challenges related to multiplex assays. Although the use of multiplexing as a tool has been relatively limited in biobehavioral research, more recent studies are taking advantage of this technology to obtain deeper insight into regulatory patterns in health and disease states. Multiplex approaches range from several targets to global target profiling that importantly enable unbiased biomarker and pathway discovery.

Association of symptoms and cytokines in prostate cancer patients receiving radiation treatment

INTRODUCTION

Men with prostate cancer undergoing radiation treatment frequently report fatigue, insomnia, depression, anxiety and urinary, bowel, sexual, and hormonal symptoms. Plasma concentrations of cytokines may be related to these symptoms, but few studies have examined these relationships. The study purpose was to explore the association between prostate cancer symptoms and cytokine levels at pretreatment and posttreatment.

METHOD

In this longitudinal, correlational study, 29 men with nonmetastatic prostate cancer completed symptom questionnaires at preradiation and postradiation treatment. Blood drawn at these same time points was used to determine levels of tumor necrosis factor-alpha (TNF-α) and interleukins-1β, 6, 10, and 4 (IL-1β, IL-6, IL-10, and IL-4).

RESULTS

Men reported symptom severity at pretreatment and posttreatment as low to moderate. There were significant differences from pretreatment to posttreatment in fatigue, insomnia, urinary irritative and incontinence, bowel, sexual, and hormonal problems. There were no significant differences in TNF-α, IL-6, IL-10, or IL-4. At pretreatment, TNF-α was associated with depression, anxiety, urinary irritative, and bowel problems, and IL-4 was related to urinary irritative symptoms. At posttreatment, IL-4 was associated with urinary irritative symptoms. Findings suggest that, in men with prostate cancer, there is no strong association between symptom reporting and cytokine levels. Ongoing research focused on neuroendocrine and genetic markers and their associations with symptoms is promising and may result in the provision of better markers for quantifying the symptom experience in patients with cancer.