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The importance of salivary SARS-CoV-2 antibodies, following infection and vaccination, has not been fully established. 875 healthcare workers were sampled during the first wave in 2020 and 66 longitudinally in response to Pfizer BioNTech 162b2 vaccination. We measured SARS-CoV-2 total IgGAM and individual IgG, IgA and IgM antibodies. IgGAM seroprevalence was 39.9%; however, only 34.1% of seropositive individuals also had salivary antibodies. Infection generated serum IgG antibodies in 51.4% and IgA antibodies in 34.1% of individuals. In contrast, the salivary antibody responses were dominated by IgA (30.9% and 12% generating IgA and IgG antibodies, respectively). Post 2nd vaccination dose, in serum, 100% of infection naïve individuals had IgG and 82.8% had IgA responses; in saliva, 65.5% exhibited IgG and 55.2% IgA antibodies. Prior infection enhanced the vaccine antibody response in serum but no such difference was observed in saliva. Strong neutralisation responses were seen for serum 6 months post 2nd-vaccination dose (median 87.1%) compared to low neutralisation responses in saliva (median 1%). Intramuscular vaccination induces significant serum antibodies and to a lesser extent, salivary antibodies; however, salivary antibodies are typically non-neutralising. This study provides further evidence for the need of mucosal vaccines to elicit nasopharyngeal/oral protection. Although saliva is an attractive non-invasive sero-surveillance tool, due to distinct differences between systemic and oral antibody responses, it cannot be used as a proxy for serum antibody measurement. • Largest investigation of SARS-CoV-2 serum and salivary antibodies in 875 healthcare workers. • In-depth profiling of combined anti-Spike IgGAM and individual immunoglobulin classes. • Saliva is not equivalent to serum. [ABSTRACT FROM AUTHOR]

Background: Myeloma causes profound immunodeficiency and recurrent, serious infections. Around 5500 new cases of myeloma are diagnosed per year in the UK, and a quarter of patients will have a serious infection within 3 months of diagnosis. We aimed to assess whether patients newly diagnosed with myeloma benefit from antibiotic prophylaxis to prevent infection, and to investigate the effect on antibiotic-resistant organism carriage and health care-associated infections in patients with newly diagnosed myeloma.Methods: TEAMM was a prospective, multicentre, double-blind, placebo-controlled randomised trial in patients aged 21 years and older with newly diagnosed myeloma in 93 UK hospitals. All enrolled patients were within 14 days of starting active myeloma treatment. We randomly assigned patients (1:1) to levofloxacin or placebo with a computerised minimisation algorithm. Allocation was stratified by centre, estimated glomerular filtration rate, and intention to proceed to high-dose chemotherapy with autologous stem cell transplantation. All investigators, patients, laboratory, and trial co-ordination staff were masked to the treatment allocation. Patients were given 500 mg of levofloxacin (two 250 mg tablets), orally once daily for 12 weeks, or placebo tablets (two tablets, orally once daily for 12 weeks), with dose reduction according to estimated glomerular filtration rate every 4 weeks. Follow-up visits occurred every 4 weeks up to week 16, and at 1 year. The primary outcome was time to first febrile episode or death from all causes within the first 12 weeks of trial treatment. All randomised patients were included in an intention-to-treat analysis of the primary endpoint. This study is registered with the ISRCTN registry, number ISRCTN51731976, and the EU Clinical Trials Register, number 2011-000366-35.Findings: Between Aug 15, 2012, and April 29, 2016, we enrolled and randomly assigned 977 patients to receive levofloxacin prophylaxis (489 patients) or placebo (488 patients). Median follow-up was 12 months (IQR 8-13). 95 (19%) first febrile episodes or deaths occurred in 489 patients in the levofloxacin group versus 134 (27%) in 488 patients in the placebo group (hazard ratio 0·66, 95% CI 0·51-0·86; p=0·0018. 597 serious adverse events were reported up to 16 weeks from the start of trial treatment (308 [52%] of which were in the levofloxacin group and 289 [48%] of which were in the placebo group). Serious adverse events were similar between the two groups except for five episodes (1%) of mostly reversible tendonitis in the levofloxacin group.Interpretation: Addition of prophylactic levofloxacin to active myeloma treatment during the first 12 weeks of therapy significantly reduced febrile episodes and deaths compared with placebo without increasing health care-associated infections. These results suggest that prophylactic levofloxacin could be used for patients with newly diagnosed myeloma undergoing anti-myeloma therapy.Funding: UK National Institute for Health Research. [ABSTRACT FROM AUTHOR]

Objectives Older adults are less able to produce a protective antibody response to vaccinations. One factor that contributes to this is immune ageing. Here we examined whether diurnal variations in immune responses might extend to the antibody response to vaccination. Design We utilised a cluster-randomised trial design. Setting 24 General Practices (GPs) across the West Midlands, UK who were assigned to morning (9–11 am; 15 surgeries) or afternoon (3–5 pm; 9 surgeries) vaccination times for the annual UK influenza vaccination programme. Participants 276 adults (aged 65+ years and without a current infection or immune disorder or taking immunosuppressant medication). Interventions Participants were vaccinated in the morning or afternoon between 2011 and 2013. Main outcome measures The primary outcome was the change in antibody titres to the three vaccine influenza strains from pre-vaccination to one month post-vaccination. Secondary outcomes of serum cytokines and steroid hormone concentrations were analysed at baseline to identify relationships with antibody responses. Results The increase in antibody levels due to vaccination differed between morning and afternoon administration; mean difference (95% CI) for H1N1 A-strain, 293.3 (30.97–555.66) p = .03, B-strain, 15.89 (3.42–28.36) p = .01, but not H3N2 A-strain, 47.0 (−52.43 to 146.46) p = .35; those vaccinated in the morning had a greater antibody response. Cytokines and steroid hormones were not related to antibody responses. No adverse events were reported. Conclusions This simple manipulation in the timing of vaccine administration to favour morning vaccination may be beneficial for the influenza antibody response in older adults, with potential implications for vaccination strategies generally. Trial registration This trial is registered with the ISRCTN (ISRCTN70898162). [ABSTRACT FROM AUTHOR]

Multiple myeloma (MM) is associated with high healthcare resource utilisation and increasing hospitalisation rates. The aim of this study was to characterise the hospital use by patients with MM in the English National Health Service (NHS). Routinely-collected aggregate data about all NHS-funded hospital admissions of patients with MM were analysed. Data were obtained from the English Hospital Episodes Statistics on admissions between 1 April 2014 and 31 March 2018. A total of 754,345 admissions were reported over four years, equivalent to a mean of 188,586 admissions per year. Of the 41,845 patients admitted during this period, 42% were women and 58% men. From the total admissions, 90% were elective and 10% unplanned. Mean annual estimated costs over the period were £46 million for elective and £56 million for unplanned admissions. The number of elective admissions increased by 4.5% with costs increasing 1.5% per year; for unplanned admissions, these figures were 4.1% and 9.0%, respectively. MM is associated with a significant number of hospital admissions and NHS costs. The majority of the hospital admissions are elective, but the highest burden in terms of costs relates to unplanned admissions, with numbers increasing over time. [ABSTRACT FROM AUTHOR]

Traditionally, free light chains (FLCs) are used as key serum biomarkers in the diagnosis and monitoring of plasma cell malignancies, but polyclonal FLCs can also be used as an accurate real-time indicator of immune-activation and inflammation. The primary aim of the present study was to assess the effects of exercise training status on serum FLCs in older adults, and secondly, to examine if training status moderated serum FLC responses to acute exercise. Kappa and lambda serum FLC levels were measured in 45 healthy older adults (aged ≥ 60 years) who were either sedentary, physically active or endurance trained. FLCs were measured at baseline and in response to an acute bout of submaximal exercise. The endurance trained group had significantly lower levels of kappa and lambda serum FLCs compared with physically active or sedentary elderly adults; these effects were independent of age, BMI and renal function. There was no significant difference in whole immunoglobulins between groups. Exercise training status had no effect on serum FLC responses to acute exercise, which were marginal. In conclusion, endurance training was associated with lower FLC levels compared with less physically active individuals. These findings suggest that long-term endurance training may be beneficial in reducing basal inflammation in older adults as well as elevated FLCs present in inflammatory and autoimmune conditions, often associated with ageing. FLCs may serve as a useful biomarker for monitoring the efficacy of exercise intervention studies in healthy and clinical populations. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: In some trials, particularly in oncology, patients whose disease progresses under the comparator treatment are crossed over into the experimental arm. This unplanned crossover can introduce bias in analyses because patients who crossover likely have a different prognosis than those who do not cross over; for instance, sicker patients not responding to standard therapy or those expected to benefit the most may be selectively chosen to receive the experimental treatment. Standard statistical methods cannot adequately correct for this bias. We describe an approach designed to minimize the impact of crossover, and illustrate this by using data from two randomized trials in multiple myeloma (MM). Methods: The MM-009/010 trials compared lenalidomide and high-dose dexamethasone (Len+Dex) with dexamethasone alone (Dex). Nearly half (47%) of the patients randomized to Dex crossed over to Len with or without Dex (Len+/-Dex) at disease progression or study unblinding. Data from these trials was used to predict survival in an economic model evaluating the cost-effectiveness of lenalidomide. To adjust for crossover, the prediction equations were calibrated to match survival with Dex or Dex-equivalent therapies in trials conducted by the Medical Research Council (MRC) in the United Kingdom. To adjust for differences between the MM and MRC trial populations, a prediction equation was developed from the MRC data and used to predict survival by setting predictors to mean values for patients in the MM-009/010 trials. The expected survival with Dex without crossover was then predicted from the calibrated MM-009/010 equation (i.e., adjusted to match survival predicted from the MRC equation). Results: The adjusted median overall survival predicted by the MRC equation was 19.5 months (95%CI, 16.6–22.9) for patients with one prior therapy, and 11.6 months (95% CI, 9.5–14.2) for patients with >1 prior therapy. These estimates are considerably shorter than was observed in the clinical trials: 33.6 months (27.1-NE) and 27.3 months (95% CI, 23.3–33.3) as of December 2005. Conclusion: The calibration method described here is simple to implement, provided that suitable data are available; it can be implemented with other types of endpoints in any therapeutic area. [Copyright &y& Elsevier]

Background: Patients with multiple myeloma treated with lenalidomide maintenance therapy have improved progression-free survival, primarily following autologous stem-cell transplantation. A beneficial effect of lenalidomide maintenance therapy on overall survival in this setting has been inconsistent between individual studies. Minimal data are available on the effect of maintenance lenalidomide in more aggressive disease states, such as patients with cytogenetic high-risk disease or patients ineligible for transplantation. We aimed to assess lenalidomide maintenance versus observation in patients with newly diagnosed multiple myeloma, including cytogenetic risk and transplantation status subgroup analyses.Methods: The Myeloma XI trial was an open-label, randomised, phase 3, adaptive design trial with three randomisation stages done at 110 National Health Service hospitals in England, Wales, and Scotland. There were three potential randomisations in the study: induction treatment (allocation by transplantation eligibility status); intensification treatment (allocation by response to induction therapy); and maintenance treatment. Here, we report the results of the randomisation to maintenance treatment. Eligible patients for maintenance randomisation were aged 18 years or older and had symptomatic or non-secretory multiple myeloma, had completed their assigned induction therapy as per protocol and had achieved at least a minimal response to protocol treatment, including lenalidomide. Patients were randomly assigned (1:1 from Jan 13, 2011, to Jun 27, 2013, and 2:1 from Jun 28, 2013, to Aug 11, 2017) to lenalidomide maintenance (10 mg orally on days 1-21 of a 28-day cycle) or observation, and stratified by allocated induction and intensification treatment, and centre. The co-primary endpoints were progression-free survival and overall survival, analysed by intention to treat. Safety analysis was per protocol. This study is registered with the ISRCTN registry, number ISRCTN49407852, and clinicaltrialsregister.eu, number 2009-010956-93, and has completed recruitment.Findings: Between Jan 13, 2011, and Aug 11, 2017, 1917 patients were accrued to the maintenance treatment randomisation of the trial. 1137 patients were assigned to lenalidomide maintenance and 834 patients to observation. After a median follow-up of 31 months (IQR 18-50), median progression-free survival was 39 months (95% CI 36-42) with lenalidomide and 20 months (18-22) with observation (hazard ratio [HR] 0·46 [95% CI 0·41-0·53]; p<0·0001), and 3-year overall survival was 78·6% (95% Cl 75·6-81·6) in the lenalidomide group and 75·8% (72·4-79·2) in the observation group (HR 0·87 [95% CI 0·73-1·05]; p=0·15). Progression-free survival was improved with lenalidomide compared with observation across all prespecified subgroups. On prespecified subgroup analyses by transplantation status, 3-year overall survival in transplantation-eligible patients was 87·5% (95% Cl 84·3-90·7) in the lenalidomide group and 80·2% (76·0-84·4) in the observation group (HR 0·69 [95% CI 0·52-0·93]; p=0·014), and in transplantation-ineligible patients it was 66·8% (61·6-72·1) in the lenalidomide group and 69·8% (64·4-75·2) in the observation group (1·02 [0·80-1·29]; p=0·88). By cytogenetic risk group, in standard-risk patients, 3-year overall survival was 86·4% (95% CI 80·0-90·9) in the lenalidomide group compared with 81·3% (74·2-86·7) in the observation group, and in high-risk patients, it was 74.9% (65·8-81·9) in the lenalidomide group compared with 63·7% (52·8-72·7) in the observation group; and in ultra-high-risk patients it was 62·9% (46·0-75·8) compared with 43·5% (22·2-63·1). Since these subgroup analyses results were not powered they should be interpreted with caution. The most common grade 3 or 4 adverse events for patients taking lenalidomide were haematological, including neutropenia (362 [33%] patients), thrombocytopenia (72 [7%] patients), and anaemia (42 [4%] patients). Serious adverse events were reported in 494 (45%) of 1097 patients receiving lenalidomide compared with 150 (17%) of 874 patients on observation. The most common serious adverse events were infections in both the lenalidomide group and the observation group. 460 deaths occurred during maintenance treatment, 234 (21%) in the lenalidomide group and 226 (27%) in the observation group, and no deaths in the lenalidomide group were deemed treatment related.Interpretation: Maintenance therapy with lenalidomide significantly improved progression-free survival in patients with newly diagnosed multiple myeloma compared with observation, but did not improve overall survival in the intention-to-treat analysis of the whole trial population. The manageable safety profile of this drug and the encouraging results in subgroup analyses of patients across all cytogenetic risk groups support further investigation of maintenance lenalidomide in this setting.Funding: Cancer Research UK, Celgene, Amgen, Merck, and Myeloma UK. [ABSTRACT FROM AUTHOR]

Background: Relapsed multiple myeloma has no standard treatment, and the role of autologous stem-cell transplantation (ASCT) has not been fully defined. We aimed to compare high-dose melphalan plus salvage ASCT with cyclophosphamide in patients with relapsed multiple myeloma who had previously undergone ASCT. Methods: This multicentre, randomised, open-label, phase 3 study recruited patients aged at least 18 years with multiple myeloma who needed treatment for first progressive or relapsed disease at least 18 months after a previous ASCT from 51 centres across the UK. Before randomisation, eligible patients received bortezomib, doxorubicin, and dexamethasone (PAD) induction therapy and then underwent peripheral blood stem-cell mobilisation and harvesting if applicable. Eligible patients (with adequate stem-cell harvest) were randomly assigned (1:1), using an automated telephone randomisation line, to either high-dose melphalan 200 mg/m² plus salvage ASCT or oral cyclophosphamide (400mg/m² per week for 12 weeks). Randomisation was stratified by length of first remission or plateau and response to PAD re-induction therapy. The primary endpoint was time to disease progression, analysed by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT00747877, and EudraCT, number 2006-005890-24. Findings: Between April 16, 2008, and Nov 19, 2012, 297 patients were registered, of whom 293 received PAD re-induction therapy. Between Aug 26, 2008, and Nov 16, 2012, 174 patients with sufficient PBSCs were randomised to salvage ASCT (n=89) or cyclophosphamide (n=85). After a median follow-up of 31 months (IQR 19-42), median time to progression was significantly longer in the salvage ASCT than in the cyclophosphamide group (19 months [95% CI 16-25] vs 11 months [9-12]; hazard ratio 0·36 [95% CI 0·25-0·53]; p<0·0001). Frequently reported (in >10% of patients) grade 3-4 adverse events with PAD induction, salvage ASCT, and cyclophosphamide were: neutropenia (125 [43%] of 293 patients after PAD, and 63 [76%] of 83 patients in the salvage ASCT group vs 11 [13%] of 84 patients in the cyclophosphamide group), thrombocytopenia (150 [51%] after PAD, and 60 [72%] vs four [5%], respectively), and peripheral neuropathy (35 [12%] after PAD, and none vs none, respectively). Interpretation: This study provides evidence for the improved efficacy of high-dose melphalan plus salvage ASCT when compared with cyclophosphamide in patients with relapsed multiple myeloma eligible for intensive therapy, which might help to guide clinical decisions regarding the management of such patients. Funding: Cancer Research UK. [ABSTRACT FROM AUTHOR]

Abstract: Monoclonal κ and λ immunoglobulin free light chain (FLC) paraproteins in serum and urine are important markers in the diagnosis and monitoring of B cell dyscrasias. Current nephelometric and turbidimetric methods that use sheep polyclonal antisera to quantify serum FLC have a number of well-observed limitations. In this report, we describe an improved method using specific mouse anti-human FLC monoclonal antibodies (mAbs). Anti-κ and anti-λ FLC mAbs were, separately, covalently coupled to polystyrene Xmap® beads and assayed, simultaneously, in a multi-plex format by Luminex® (mAb assay). The mAbs displayed no cross-reactivity to bound LC, the alternate LC type, or other human proteins and had improved sensitivity and specificity over immunofixation electrophoresis (IFE) and Freelite™. The assay gives good linearity and sensitivity (<1mg/L), and the competitive inhibition format gave a broad calibration curve up to 437.5mg/L and prevented anomalous results for samples in antigen excess i.e. high FLC levels. The mAbs displayed good concordance with Freelite™ for the quantitation of normal polyclonal FLC in plasma from healthy donors (n=249). The mAb assay identified all monoclonal FLC in serum from consecutive patient samples (n=1000; 50.1% with monoclonal paraprotein by serum IFE), and all FLC in a large cohort of urine samples tested for Bence Jones proteins (n=13090; 22.8% with monoclonal κ, 9.0% with monoclonal λ, and 0.8% with poly LC detected by urine IFE). Importantly this shows that the mAbs are at least close to the ideal of detecting FLC from all patients and neoplastic plasma cell clones. Given the overall effectiveness of the anti-FLC mAbs, further clinical validation is now warranted on serial samples from a range of patients with B cell disorders. Use of these mAbs on other assay platforms should also be investigated. [Copyright &y& Elsevier]

Abstract: Acute exercise at the time of vaccination can enhance subsequent immune responses. However, the potential benefit of this effect will be its efficacy in boosting poor responses, and thus protection in at-risk populations. The current study tested the effect of exercise on the response to either a full- or half-dose Pneumococcal (Pn) vaccination to elicit stronger and weaker responses. Subjects were 133 young healthy adults, randomised to one of four groups: exercise or control task, receiving a full- or half-dose Pn vaccination. Prior to vaccination, exercise groups completed a 15min arm and shoulder exercise task, control groups rested quietly. Antibody levels to 11 Pn strains were evaluated at baseline and 1-month. Across all participants, exercise groups showed significantly greater increase in antibody levels than control groups. When doses were compared, it emerged that those who exercised had significantly larger responses than those who rested in the half-dose group, but in the full-dose groups responses were similar. This data indicates the effectiveness of exercise as a vaccine adjuvant, particularly in weaker responses. Thus, given the potential public health benefits of no-cost behavioural intervention to enhance response to vaccination, testing in at-risk populations should be pursued. [Copyright &y& Elsevier]

Abstract: The measurement of antibody responses to vaccination is useful in the assessment of immune status in suspected immune deficiency. Previous reliance on enzyme-linked immunoabsorbent assays (ELISA) has been cumbersome, time-consuming and expensive. The availability of flow cytometry systems has led to the development of multiplexed assays enabling simultaneous measurement of antibodies to several antigens. We optimized a flow cytometric bead-based assay to measure IgG and IgM concentrations in serum to 19 antigens contained in groups of bacterial subunit vaccines: pneumococcal vaccines, meningococcal vaccines, Haemophilus influenzae b (Hib), and tetanus and diphtheria toxoid vaccines. 89-SF was employed as the standard serum. The assay was used to determine specific antibody levels in serum from 193 healthy adult donors. IgG and pneumococcal IgM antibody concentrations were measurable across 3 log10 ranges encompassing the threshold protective IgG antibody levels for each antigen. There was little interference between antibody measurements by the 19-plexed assay compared with monoplexed assays, and a lack of cross-reactive IgG antibody, but evidence for cross-reacting IgM antibody for 3/19 pneumococcal antigens. 90th centile values for 15/19 IgG concentrations and 12/12 IgM concentrations of the 193 adult sera were within these ranges and percentages of sera containing protective IgG antibody levels varied from 4% to 95% depending on antigen. This multiplexed assay can simultaneously measure antibody levels to 19 bacterial vaccine antigens. It is suitable for use in standard clinical practice to assess the in vivo immune response to test vaccinations and measure absolute antibody levels to these antigens. [Copyright &y& Elsevier]

Summary: Background: Bisphosphonates are the standard of care for reducing the risk of skeletal-related events in patients with bone lesions from multiple myeloma. The MRC Myeloma IX study was designed to compare the effects of zoledronic acid versus clodronic acid in newly diagnosed patients with multiple myeloma. Here, we report the secondary outcomes relating to skeletal events. Methods: Patients (≥18 years) with newly diagnosed multiple myeloma were enrolled from 120 centres in the UK and received intensive or non-intensive antimyeloma treatment. A computer-generated randomisation sequence was used to allocate patients in a 1:1 ratio, through an automated telephone service to intravenous zoledronic acid (4 mg every 21–28 days) or oral clodronic acid (1600 mg/day), and the drugs were continued at least until disease progression. No investigators, staff, or patients were masked to treatment allocation. The primary endpoints—overall survival, progression-free survival, and overall response rate—and adverse events have been reported previously. We assessed between-group differences with Cox proportional hazards models for time to first skeletal-related event and incidence of skeletal-related events. These were defined as fractures, spinal cord compression, radiation or surgery to bone, and new osteolytic lesions. Data were analysed until disease progression. Analyses were by intention to treat. This trial is registered, number ISRCTN68454111. Findings: 1960 patients were randomly assigned and analysed—981 in the zoledronic acid group and 979 in the clodronic acid group. This trial is fully enrolled, and follow-up continues. At a median follow-up of 3·7 years (IQR 2·9–4·7), patients in the zoledronic acid group had a lower incidence of skeletal-related events than did those in the clodronic acid group (265 [27%] vs 346 [35%], respectively; hazard ratio 0·74, 95% CI 0·62–0·87; p=0·0004). Zoledronic acid was also associated with a lower risk of any skeletal-related event in the subsets of patients with (233 [35%] of 668 vs 292 [43%] of 682 with clodronic acid; 0·77, 0·65–0·92; p=0·0038) and without bone lesions at baseline (29 [10%] of 302 vs 48 [17%] of 276 with clodronic acid; 0·53, 0·33–0·84; p=0·0068). Fewer patients in the zoledronic acid group had vertebral fractures than did those in the clodronic acid group (50 [5%] in the zoledronic acid group vs 88 [9%] in the clodronic acid group; p=0·0008), other fractures (45 [5%] vs 66 [7%]; p=0·04), and new osteolytic lesions (46 [5%] vs 95 [10%]; p<0·0001). Interpretation: The results of this study support the early use of zoledronic acid rather than clodronic acid in patients with newly diagnosed multiple myeloma for the prevention of skeletal-related events, irrespective of bone disease status at baseline. Funding: Medical Research Council (London, UK), Novartis, Schering Health Care, Chugai, Pharmion, Celgene, and Ortho Biotech. [Copyright &y& Elsevier]

Abstract: B-cell lines of diverse neoplastic origin express the serotonin transporter (SERT/SLC6A4) and growth arrest in response to SERT-ligands, including the antidepressants chlomipramine and fluoxetine. Here we detail SLC6A4 transcript (Q-PCR) and protein (FACS) expression in primary cells from patients with: chronic lymphocytic leukaemia; mantle cell lymphoma; follicular lymphoma; Burkitt''s lymphoma; and diffuse large B-cell lymphoma. The ability of the SERT-binding antidepressants to impact the growth of these cells when sustained on CD154-transfected fibroblasts was also determined. The results reveal a broad spectrum of primary B-cell malignancies expressing SLC6A4 with a proportion additionally displaying growth arrest on SERT-ligand exposure. [Copyright &y& Elsevier]

• Salivary FLC were significantly decreased in relation to an exam period. • Salivary IgA also decreased while cortisol increased. • Depression and anxiety increased and well-being decreased at exams. • Salivary FLCs are responsive to life events stress and corroborate with IgA. • FLCs may serve as a new salivary biomarker in stress research. 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. 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. 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. 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. [ABSTRACT FROM AUTHOR]

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. 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. 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. 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. • Polyclonal FLCs are a biomarker of inflammation/immune dysregulation. • Seralite ELISAs showed good performance for the quantitation of polyclonal κ and λ FLCs. • Differences were seen between the ELISAs and existing assays. • Choice in FLC platforms may help improve access to FLC testing. [ABSTRACT FROM AUTHOR]