Effects of aerobic and resistance exercise for 9 months on serum free light chains in type 2 diabetes.

Background and aims: Serum polyclonal free light chains (FLCs) levels are associated with overall survival in the general population, reflecting their utility as a biomarker of underlying immune activation and inflammation. Regular exercise is known to ameliorate low-grade inflammation in chronic diseases such as type 2 diabetes; however, the effects of different exercise training modalities on FLCs in adults with type 2 diabetes is unknown. This study investigated the effects of 9-month of aerobic, resistance or combined supervised exercise on serum FLCs in 164 patients with type 2 diabetes (age 58 ± 8 years; 63% female). Methods: 164 participants from the Health Benefits of Aerobic and Resistance Training in individuals with type 2 diabetes trial (HART-D) were randomly assigned to no exercise (n = 27), aerobic exercise alone (n = 41), resistance exercise alone (n = 49), or a combination of aerobic and resistance exercise (n = 47). Fasting serum samples were collected before and after completion of the intervention to quantify changes in kappa and lambda FLCs, and serum creatinine, using commercially-available ELISAs. Results: At baseline, combined kappa and lambda FLCs (FLC sum; calculated as kappa + lambda FLCs) were positively correlated with high-sensitive C-reactive protein (hs-CRP) (r = 0.237, p < 0.05) and fat mass (r = 0.162, p < 0.05), and negatively associated with aerobic fitness (r = -0.238, p < 0.05). While non-exercise controls exhibited an increase in FLCs over the 9-month study, exercise training blunted this increase (Δ FLC sum control arm: 3.25 ± 5.07 mg∙L-1 vs. all exercise arms: -0.252 ± 6.60 mg∙L-1, p < 0.05), regardless of exercise modality. Conclusion: Serum FLCs were associated with physical fitness and body composition in patients with type 2 diabetes. 9-month of exercise training prevented the accumulation of FLCs, regardless of exercise modality. Unlike hs-CRP-which did not change during the trial-serum FLCs may serve as a more sensitive biomarker of chronic low-grade inflammation in this population.

A single bout of vigorous intensity exercise enhances the efficacy of rituximab against human chronic lymphocytic leukaemia B-cells ex vivo.

Chronic lymphocytic leukaemia (CLL) is characterised by the clonal proliferation and accumulation of mature B-cells and is often treated with rituximab, an anti-CD20 monoclonal antibody immunotherapy. Rituximab often fails to induce stringent disease eradication, due in part to failure of antibody-dependent cellular cytotoxicity (ADCC) which relies on natural killer (NK)-cells binding to rituximab-bound CD20 on B-cells. CLL cells are diffusely spread across lymphoid and other bodily tissues, and ADCC resistance in survival niches may be due to several factors including low NK-cell frequency and a suppressive stromal environment that promotes CLL cell survival. It is well established that exercise bouts induce a transient relocation of NK-cells and B-cells into peripheral blood, which could be harnessed to enhance the efficacy of rituximab in CLL by relocating both target and effector cells together with rituximab in blood. In this pilot study, n = 20 patients with treatment-naïve CLL completed a bout of cycling 15 % above anaerobic threshold for âˆ¼ 30-minutes, with blood samples collected pre-, immediately post-, and 1-hour post-exercise. Flow cytometry revealed that exercise evoked a 254 % increase in effector (CD3-CD56+CD16+) NK-cells in blood, and a 67 % increase in CD5+CD19+CD20+ CLL cells in blood (all p < 0.005). NK-cells were isolated from blood samples pre-, and immediately post-exercise and incubated with primary isolated CLL cells with or without the presence of rituximab to determine specific lysis using a calcein-release assay. Rituximab-mediated cell lysis increased by 129 % following exercise (p < 0.001). Direct NK-cell lysis of CLL cells - independent of rituximab - was unchanged following exercise (p = 0.25). We conclude that exercise improved the efficacy of rituximab-mediated ADCC against autologous CLL cells ex vivo and propose that exercise should be explored as a means of enhancing clinical responses in patients receiving anti-CD20 immunotherapy.

Harnessing the immunomodulatory effects of exercise to enhance the efficacy of monoclonal antibody therapies against B-cell haematological cancers: a narrative review.

Therapeutic monoclonal antibodies (mAbs) are standard care for many B-cell haematological cancers. The modes of action for these mAbs include: induction of cancer cell lysis by activating Fcγ-receptors on innate immune cells; opsonising target cells for antibody-dependent cellular cytotoxicity or phagocytosis, and/or triggering the classical complement pathway; the simultaneous binding of cancer cells with T-cells to create an immune synapse and activate perforin-mediated T-cell cytotoxicity against cancer cells; blockade of immune checkpoints to facilitate T-cell cytotoxicity against immunogenic cancer cell clones; and direct delivery of cytotoxic agents via internalisation of mAbs by target cells. While treatment regimens comprising mAb therapy can lead to durable anti-cancer responses, disease relapse is common due to failure of mAb therapy to eradicate minimal residual disease. Factors that limit mAb efficacy include: suboptimal effector cell frequencies, overt immune exhaustion and/or immune anergy, and survival of diffusely spread tumour cells in different stromal niches. In this review, we discuss how immunomodulatory changes arising from exposure to structured bouts of acute exercise might improve mAb treatment efficacy by augmenting (i) antibody-dependent cellular cytotoxicity, (ii) antibody-dependent cellular phagocytosis, (iii) complement-dependent cytotoxicity, (iv) T-cell cytotoxicity, and (v) direct delivery of cytotoxic agents.

Immune cell status, cardiorespiratory fitness and body composition among breast cancer survivors and healthy women: a cross sectional study.

Methods: We examined whether immune cell profiles differ between healthy women (n = 38) and breast cancer survivors (n = 27) within 2 years of treatment, and whether any group-differences were influenced by age, cytomegalovirus infection, cardiorespiratory fitness and body composition. Using flow cytometry, CD4+ and CD8+ T cell subsets, including naïve (NA), central memory (CM) and effector cells (EM and EMRA) were identified using CD27/CD45RA. Activation was measured by HLA-DR expression. Stem cell-like memory T cells (TSCMs) were identified using CD95/CD127. B cells, including plasmablasts, memory, immature and naïve cells were identified using CD19/CD27/CD38/CD10. Effector and regulatory Natural Killer cells were identified using CD56/CD16. Results: Compared to healthy women, CD4+ CM were +Δ21% higher among survivors (p = 0.028) and CD8+ NA were -Δ25% lower (p = 0.034). Across CD4+ and CD8+ subsets, the proportion of activated (HLA-DR+) cells was +Δ31% higher among survivors: CD4+ CM (+Δ25%), CD4+ EM (+Δ32%) and CD4+ EMRA (+Δ43%), total CD8+ (+Δ30%), CD8+ EM (+Δ30%) and CD8+ EMRA (+Δ25%) (p < 0.046). The counts of immature B cells, NK cells and CD16+ NK effector cells were higher among survivors (+Δ100%, +Δ108% and +Δ143% respectively, p < 0.04). Subsequent analyses examined whether statistically significant differences in participant characteristics, influenced immunological differences between groups. Compared to healthy women, survivors were older (56 ± 6 y vs. 45 ± 11 y), had lower cardiorespiratory fitness (V˙O2max mL kg-1 min-1: 28.8 ± 5.0 vs. 36.2 ± 8.5), lower lean mass (42.3 ± 5.0 kg vs. 48.4 ± 15.8 kg), higher body fat (36.3% ± 5.3% vs. 32.7% ± 6.4%) and higher fat mass index (FMI kg/m2: 9.5 ± 2.2 vs. 8.1 ± 2.7) (all p < 0.033). Analysis of covariance revealed divergent moderating effects of age, CMV serostatus, cardiorespiratory fitness and body composition on the differences in immune cell profiles between groups, depending on the cell type examined. Moreover, across all participants, fat mass index was positively associated with the proportion of HLA-DR+ CD4+ EMRA and CD8+ EM/EMRA T cells (Pearson correlation: r > 0.305, p < 0.019). The association between fat mass index and HLA-DR+ CD8+ EMRA T cells withstood statistical adjustment for all variables, including age, CMV serostatus, lean mass and cardiorespiratory fitness, potentially implicating these cells as contributors to inflammatory/immune-dysfunction in overweight/obesity.

Comments on the articles dealing with individual performance criteria that are included in this special issue of Military Psychology.

Individual performance criterion measurement is central to effective personnel management in the military services, and to all other organizations as well. The articles in this special issue summarize the state of the art in all major phases of performance criterion development and assessment. The overall record, while it varies in terms of current progress across the major parts, is admirable. What's next is an equally thorough examination of the utility of validity.

The effects of exercise training for eight weeks on immune cell characteristics among breast cancer survivors.

Methods: This study examined the effects of exercise training for 8 weeks on blood immune cell characteristics among 20 breast cancer survivors (age 56 ± 6 years, Body Mass Index 25.4 ± 3.0 kg m2) within two years of treatment. Participants were randomly allocated to a partly-supervised or a remotely-supported exercise group (n = 10 each). The partly supervised group undertook 2 supervised (laboratory-based treadmill walking and cycling) and 1 unsupervised session per week (outdoor walking) progressing from 35 to 50 min and 55% to 70% V˙O2max. The remotely-supported group received weekly exercise/outdoor walking targets (progressing from 105 to 150 min per week 55% to 70% V˙O2max) via weekly telephone calls discussing data from a fitness tracker. Immune cell counts were assessed using flow cytometry: CD4+ and CD8+ T cells (Naïve, NA; Central memory, CM; and Effector cells, EM and EMRA; using CD27/CD45RA), Stem cell-like memory T cells (TSCMs; using CD95/CD127), B cells (plasmablasts, memory, immature and naïve cells using CD19/CD27/CD38/CD10) and Natural Killer cells (effector and regulatory cells, using CD56/CD16). T cell function was assessed by unstimulated HLA-DR expression or interferon gamma (IFN-γ) production with Enzyme-linked ImmunoSpot assays following stimulation with virus or tumour-associated antigens. Results: Total leukocyte counts, lymphocytes, monocytes and neutrophils did not change with training (p > 0.425). Most CD4+ and CD8+ T cell subtypes, including TSCMs, and B cell and NK cell subtypes did not change (p > 0.127). However, across groups combined, the CD4+ EMRA T cell count was lower after training (cells/µl: 18 ± 33 vs. 12 ± 22, p = 0.028) and these cells were less activated on a per cell basis (HLA-DR median fluorescence intensity: 463 ± 138 vs. 420 ± 77, p = 0.018). Furthermore, the partly-supervised group showed a significant decrease in the CD4+/CD8+ ratio (3.90 ± 2.98 vs. 2.54 ± 1.29, p = 0.006) and a significant increase of regulatory NK cells (cells/µl: 16 ± 8 vs. 21 ± 10, p = 0.011). T cell IFN-γ production did not change with exercise training (p > 0.515). Discussion: In summary, most immune cell characteristics are relatively stable with 8 weeks of exercise training among breast cancer survivors. The lower counts and activation of CD4+ EMRA T cells, might reflect an anti-immunosenescence effect of exercise.

The effects of exercise on complement system proteins in humans: a systematic scoping review.

BACKGROUND: The complement system is comprised of the classical, lectin and alternative pathways that result in the formation of: pro-inflammatory anaphylatoxins; opsonins that label cells for phagocytic removal; and, a membrane attack complex that directly lyses target cells. Complement-dependent cytotoxicity (CDC) - cell lysis triggered by complement protein C1q binding to the Fc region of antibodies bound to target cells - is another effector function of complement and a key mechanism-of-action of several monoclonal antibody therapies. At present, it is not well established how exercise affects complement system proteins in humans. METHODS: A systematic search was conducted to identify studies that included original data and investigated the association between soluble complement proteins in the blood of healthy humans, and: 1) an acute bout of exercise; 2) exercise training interventions; or, 3) measurements of habitual physical activity and fitness. RESULTS: 77 studies were eligible for inclusion in this review, which included a total of 10,236 participants, and 40 complement proteins and constituent fragments. Higher levels of exercise training and cardiorespiratory fitness were commonly associated with reduced C3 in blood. Additionally, muscle strength was negatively associated with C1q. Elevated C3a-des-Arg, C4a-des-Arg and C5a, lower C1-inhibitor, and unchanged C3 and C4 were reported immediately post-laboratory based exercise, compared to baseline. Whereas, ultra-endurance running and resistance training increased markers of the alternative (factor B and H), classical (C1s), and leptin (mannose binding lectin) pathways, as well as C3 and C6 family proteins, up to 72-h following exercise. Heterogeneity among studies may be due to discrepancies in blood sampling/handling procedures, analytical techniques, exercise interventions/measurements and fitness of included populations. CONCLUSIONS: Increased anaphylatoxins were observed immediately following an acute bout of exercise in a laboratory setting, whereas field-based exercise interventions of a longer duration (e.g. ultra-endurance running) or designed to elicit muscle damage (e.g. resistance training) increased complement proteins for up to 72-h. C3 in blood was mostly reduced by exercise training and associated with increased cardiorespiratory fitness, whereas C1q appeared to be negatively associated to muscle strength. Thus, both acute bouts of exercise and exercise training appear to modulate complement system proteins. Future research is needed to assess the clinical implications of these changes, for example on the efficacy of monoclonal antibody therapies dependent on CDC.

Reframing How Physical Activity Reduces The Incidence of Clinically-Diagnosed Cancers: Appraising Exercise-Induced Immuno-Modulation As An Integral Mechanism.

Undertaking a high volume of physical activity is associated with reduced risk of a broad range of clinically diagnosed cancers. These findings, which imply that physical activity induces physiological changes that avert or suppress neoplastic activity, are supported by preclinical intervention studies in rodents demonstrating that structured regular exercise commonly represses tumour growth. In Part 1 of this review, we summarise epidemiology and preclinical evidence linking physical activity or regular structured exercise with reduced cancer risk or tumour growth. Despite abundant evidence that physical activity commonly exerts anti-cancer effects, the mechanism(s)-of-action responsible for these beneficial outcomes is undefined and remains subject to ongoing speculation. In Part 2, we outline why altered immune regulation from physical activity - specifically to T cells - is likely an integral mechanism. We do this by first explaining how physical activity appears to modulate the cancer immunoediting process. In doing so, we highlight that augmented elimination of immunogenic cancer cells predominantly leads to the containment of cancers in a 'precancerous' or 'covert' equilibrium state, thus reducing the incidence of clinically diagnosed cancers among physically active individuals. In seeking to understand how physical activity might augment T cell function to avert cancer outgrowth, in Part 3 we appraise how physical activity affects the determinants of a successful T cell response against immunogenic cancer cells. Using the cancer immunogram as a basis for this evaluation, we assess the effects of physical activity on: (i) general T cell status in blood, (ii) T cell infiltration to tissues, (iii) presence of immune checkpoints associated with T cell exhaustion and anergy, (iv) presence of inflammatory inhibitors of T cells and (v) presence of metabolic inhibitors of T cells. The extent to which physical activity alters these determinants to reduce the risk of clinically diagnosed cancers - and whether physical activity changes these determinants in an interconnected or unrelated manner - is unresolved. Accordingly, we analyse how physical activity might alter each determinant, and we show how these changes may interconnect to explain how physical activity alters T cell regulation to prevent cancer outgrowth.

Investigating the utility of saliva immunoglobulins for the detection of myeloma and using myeloma proteins to clarify partition between oral and systemic immunity.

OBJECTIVES: Myeloma is characterised by the presence of monoclonal immunoglobulin (M-protein) and the free light chain (FLC) in blood. We investigated whether these M-proteins and FLC are detectable in myeloma patients' saliva to evaluate its utility for non-invasive screening and monitoring of haematological malignancies. METHODS: A total of 57 patients with monoclonal gammopathy and 26 age-matched healthy participants provided paired serum and saliva samples for immunoglobulin characterisation and quantification. RESULTS: Myeloma patients had IgG or IgA M-protein levels ranging up to five times and FLC levels up to a thousand times normal levels of polyclonal immunoglobulins. Despite these highly elevated levels, only two IgG and no IgA M-proteins or FLC could be detected in paired saliva samples. Most patients had reduced levels of serum polyclonal immunoglobulins, but all had normal levels of salivary IgA. CONCLUSIONS: Immunoglobulin transfer from blood is not determined by levels in the systemic circulation and more likely dictated by periodontal inflammation and the integrity of the oral epithelium. Immunoglobulins secreted by bone marrow plasma cells do not substantially enter saliva, which represents a poor medium for myeloma diagnosis. These findings, along with normal salivary IgA levels despite systemic immunoparesis, support a strong partitioning of oral from systemic humoral immunity.

Does exercise attenuate age- and disease-associated dysfunction in unconventional T cells? Shining a light on overlooked cells in exercise immunology.

Unconventional T Cells (UTCs) are a unique population of immune cells that links innate and adaptive immunity. Following activation, UTCs contribute to a host of immunological activities, rapidly responding to microbial and viral infections and playing key roles in tumor suppression. Aging and chronic disease both have been shown to adversely affect UTC numbers and function, with increased inflammation, change in body composition, and physical inactivity potentially contributing to the decline. One possibility to augment circulating UTCs is through increased physical activity. Acute exercise is a potent stimulus leading to the mobilization of immune cells while the benefits of exercise training may include anti-inflammatory effects, reductions in fat mass, and improved fitness. We provide an overview of age-related changes in UTCs, along with chronic diseases that are associated with altered UTC number and function. We summarize how UTCs respond to acute exercise and exercise training and discuss potential mechanisms that may lead to improved frequency and function.

Automated detection of early-stage ROP using a deep convolutional neural network.

BACKGROUND/AIM: To automatically detect and classify the early stages of retinopathy of prematurity (ROP) using a deep convolutional neural network (CNN). METHODS: This retrospective cross-sectional study was conducted in a referral medical centre in Taiwan. Only premature infants with no ROP, stage 1 ROP or stage 2 ROP were enrolled. Overall, 11 372 retinal fundus images were compiled and split into 10 235 images (90%) for training, 1137 (10%) for validation and 244 for testing. A deep CNN was implemented to classify images according to the ROP stage. Data were collected from December 17, 2013 to May 24, 2019 and analysed from December 2018 to January 2020. The metrics of sensitivity, specificity and area under the receiver operating characteristic curve were adopted to evaluate the performance of the algorithm relative to the reference standard diagnosis. RESULTS: The model was trained using fivefold cross-validation, yielding an average accuracy of 99.93%±0.03 during training and 92.23%±1.39 during testing. The sensitivity and specificity scores of the model were 96.14%±0.87 and 95.95%±0.48, 91.82%±2.03 and 94.50%±0.71, and 89.81%±1.82 and 98.99%±0.40 when predicting no ROP versus ROP, stage 1 ROP versus no ROP and stage 2 ROP, and stage 2 ROP versus no ROP and stage 1 ROP, respectively. CONCLUSIONS: The proposed system can accurately differentiate among ROP early stages and has the potential to help ophthalmologists classify ROP at an early stage.

Salivary free light chains as a new biomarker to measure psychological stress: the impact of a university exam period on salivary immunoglobulins, cortisol, DHEA and symptoms of infection.

INTRODUCTION: Measurement of immunoglobulin free light chains (FLCs) in saliva can serve as a non-invasive biomarker in health and behavioural research. FLCs have been explored in relation to physiological stress but FLC responses to psychological stress and their relationship with infections remain unknown. This study aimed to investigate the impact of exam period stress on salivary FLCs alongside other established biomarkers of stress and whether FLCs relate to symptoms of infection. METHODS: 58 healthy adults studying at university completed saliva samples and questionnaires in a period without exams (baseline), and again prior to the start of an exam period. Saliva samples were assessed for FLCs, IgA, cortisol and dehydroepiandrosterone (DHEA). Measures of life events stress, perceived stress, anxiety and depression were completed. Students also reported incidence and severity of symptoms of infection and rated general well-being at baseline, prior to, during and after the exam period. Exercise, sleep and alcohol consumption were also assessed at both timepoints. RESULTS: FLCs secretion rates were significantly lower at the exam period compared to baseline (p < .01), with reductions of 26% and 25% for κ FLC and λ FLC, respectively. In agreement, salivary IgA secretion rate was lower at exams (non-significant trend, p = .07). Cortisol concentration significantly increased at exams (p < .05) while DHEA did not change, leading to an increase in the cortisol:DHEA ratio (p = .06). Depression (p < .05) and anxiety increased from baseline to exams and life stress reported in the build up to the exam period was higher compared with baseline (p < .001). Well-being significantly decreased from baseline to exams (p < .01). The proportion of participants reporting infection symptoms (70%) was unchanged between baseline and prior to exams. No significant relationships were found between FLCs or other saliva parameters and infection symptoms, well-being or stress/psychological measures. Changes in saliva parameters between timepoints were independent of health behaviours. CONCLUSIONS: Salivary FLCs are responsive to life events stress and corroborate with IgA. This preliminary study highlights the potential utility of FLCs as a new salivary biomarker in stress research.

Artificial intelligence for retinopathy of prematurity.

PURPOSE OF REVIEW: In this article, we review the current state of artificial intelligence applications in retinopathy of prematurity (ROP) and provide insight on challenges as well as strategies for bringing these algorithms to the bedside. RECENT FINDINGS: In the past few years, there has been a dramatic shift from machine learning approaches based on feature extraction to 'deep' convolutional neural networks for artificial intelligence applications. Several artificial intelligence for ROP approaches have demonstrated adequate proof-of-concept performance in research studies. The next steps are to determine whether these algorithms are robust to variable clinical and technical parameters in practice. Integration of artificial intelligence into ROP screening and treatment is limited by generalizability of the algorithms to maintain performance on unseen data and integration of artificial intelligence technology into new or existing clinical workflows. SUMMARY: Real-world implementation of artificial intelligence for ROP diagnosis will require massive efforts targeted at developing standards for data acquisition, true external validation, and demonstration of feasibility. We must now focus on ethical, technical, clinical, regulatory, and financial considerations to bring this technology to the infant bedside to realize the promise offered by this technology to reduce preventable blindness from ROP.

Can exercise affect immune function to increase susceptibility to infection?

Multiple studies in humans and animals have demonstrated the profound impact that exercise can have on the immune system. There is a general consensus that regular bouts of short-lasting (i.e. up to 45 minutes) moderate intensity exercise is beneficial for host immune defense, particularly in older adults and people with chronic diseases. In contrast, infection burden is reported to be high among high performance athletes and second only to injury for the number of training days lost during preparation for major sporting events. This has shaped the common view that arduous exercise (i.e. those activities practiced by high performance athletes/ military personnel that greatly exceed recommended physical activity guidelines) can suppress immunity and increase infection risk. However, the idea that exercise per se can suppress immunity and increase infection risk independently of the many other factors (e.g. anxiety, sleep disruption, travel, exposure, nutritional deficits, environmental extremes, etc.) experienced by these populations has recently been challenged. The purpose of this debate article was to solicit opposing arguments centered around this fundamental question in the exercise immunology field: can exercise affect immune function to increase susceptibility to infection. Issues that were contested between the debating groups include: (i) whether or not athletes are more susceptible to infection (mainly of the upper respiratory tract) than the general population; (ii) whether exercise per se is capable of altering immunity to increase infection risk independently of the multiple factors that activate shared immune pathways and are unique to the study populations involved; (iii) the usefulness of certain biomarkers and the interpretation of in vitro and in vivo data to monitor immune health in those who perform arduous exercise; and (iv) the quality of scientific evidence that has been used to substantiate claims for and against the potential negative effects of arduous exercise on immunity and infection risk. A key point of agreement between the groups is that infection susceptibility has a multifactorial underpinning. An issue that remains to be resolved is whether exercise per se is a causative factor of increased infection risk in athletes. This article should provide impetus for more empirical research to unravel the complex questions that surround this contentious issue in the field of exercise immunology.

A Phenomic Perspective on Factors Influencing Breast Cancer Treatment: Integrating Aging and Lifestyle in Blood and Tissue Biomarker Profiling.

Breast cancer is the most common malignancy among women worldwide. Over the last four decades, diagnostic and therapeutic procedures have improved substantially, giving patients with localized disease a better chance of cure, and those with more advanced cancer, longer periods of disease control and survival. However, understanding and managing heterogeneity in the clinical response exhibited by patients remains a challenge. For some treatments, biomarkers are available to inform therapeutic options, assess pathological response and predict clinical outcomes. Nevertheless, some measurements are not employed universally and lack sensitivity and specificity, which might be influenced by tissue-specific alterations associated with aging and lifestyle. The first part of this article summarizes available and emerging biomarkers for clinical use, such as measurements that can be made in tumor biopsies or blood samples, including so-called liquid biopsies. The second part of this article outlines underappreciated factors that could influence the interpretation of these clinical measurements and affect treatment outcomes. For example, it has been shown that both adiposity and physical activity can modify the characteristics of tumors and surrounding tissues. In addition, evidence shows that inflammaging and immunosenescence interact with treatment and clinical outcomes and could be considered prognostic and predictive factors independently. In summary, changes to blood and tissues that reflect aging and patient characteristics, including lifestyle, are not commonly considered clinically or in research, either for practical reasons or because the supporting evidence base is developing. Thus, an aim of this article is to encourage an integrative phenomic approach in oncology research and clinical management.

Free light chains as an emerging biomarker in saliva: Biological variability and comparisons with salivary IgA and steroid hormones.

BACKGROUND: Salivary free light chains (FLCs) are an emerging biomarker in health and behavioural research. However, little is known regarding biological variability of salivary FLCs and how they relate to other established salivary biomarkers. This study aimed to investigate the diurnal and day-to-day variation of salivary FLCs and their relationship with salivary IgA and steroid hormones. METHODS: A total of 46 healthy adults participated in studies exploring the biological variability of FLCs. Diurnal variation was investigated by collecting saliva samples immediately upon waking, 0.5 h, 3 h, 6 h, 9 h and 14 h post-waking. Saliva samples were assessed for FLCs, IgA, cortisol and dehydroepiandrosterone (DHEA). Between-day variation in FLCs and IgA was assessed by collecting saliva samples immediately upon waking for seven consecutive days. Participants underwent a dental examination to exclude oral health as a potential confounding variable. Within and between-person day-to day variation was explored in relation to a range of different factors: awakening time, sleep, exercise, well-being and alcohol consumption. RESULTS: Salivary secretion rates of FLCs decreased following waking and up to 3 h post-waking and then plateaued. This same pattern was observed for IgA. DHEA was stable upon waking and higher levels were seen in the morning with significantly lower levels thereafter. Cortisol levels significantly increased 0.5 h post-waking then continued to decline across the day. FLCs were significantly correlated with IgA but not cortisol or DHEA. Both FLCs and IgA parameters showed day-to-day variability, with coefficients of variation ≥ 40%. Earlier waking time was significantly correlated with higher FLC and IgA secretion rates. Inter-person differences in saliva parameter variability were observed but the degree of variation in FLCs and IgA was related within person. Inter-person day-to-day variation appeared to be uninfluenced by lifestyle or behavioural factors. CONCLUSIONS: Saliva FLCs secretion exhibits diurnal fluctuation that mirrors IgA fluctuation. Findings strongly indicate salivary FLC secretion is orchestrated by local plasma cells. FLCs and IgA both showed notable variability day-to-day, which was similar within person and influenced by awakening time. FLCs offer a promising adjunct to IgA in the measurement of oral immune activation.

Analytical validation of new ELISAs for the quantitation of polyclonal free light chains and comparison to existing assays for healthy and patient samples.

BACKGROUND: Polyclonal FLCs can be used as a biomarker of inflammation and immune activation in a range of diseases. This study evaluated the performance of new FLC ELISAs (Seralite FLC ELISA) for the quantitation of polyclonal κ and λ FLC, including comparisons to existing assays. METHODS: Technical performance was assessed for the ELISA and reference ranges were generated using healthy donor serum (N = 91). Patients with a range of conditions associated with polyclonal FLC dysregulation (N = 164) were measured across platforms. RESULTS: The ELISAs generated references ranges of: 8.72-23.0 mg/L κ FLC, and 8.52-25.24 mg/L for λ FLC. ELISAs demonstrated linearity across the calibration range and intra-assay (≤ 8.7%) and inter-assay (≤ 12.3%) imprecision was low. The limit of detection was 0.63 mg/L for κ and 0.57 mg/L for λ FLC. Minimal cross-reactivity was observed for interference agents, alternate FLC and whole immunoglobulin (median change ≤3.6 mg/L). Assays showed good batch-to-batch consistency. For patient samples, methods generated different κ and λ FLC concentrations and differences were seen between methods for the number of patients classified as below, with and above references ranges for κ and λ FLC. There was no significant difference in the FLC sum between the different techniques. CONCLUSIONS: The ELISAs displayed good analytical and technical performance. The quantification of individual κ and λ FLC appears inherently different between platforms. These differences are attenuated if using the FLC sum, which was similar between methods and provided agreement in relation to patients having normal or elevated FLCs.