RESUMO
Multiple myeloma (MM) and anti-MM therapy cause profound immunosuppression, leaving patients vulnerable to coronavirus disease 2019 (COVID-19) and other infections. We investigated anti-severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) antibodies longitudinally in ultra-high-risk patients with MM receiving risk-adapted, intensive anti-CD38 combined therapy in the Myeloma UK (MUK) nine trial. Despite continuous intensive therapy, seroconversion was achieved in all patients, but required a greater number of vaccinations compared to healthy individuals, highlighting the importance of booster vaccinations in this population. Reassuringly, high antibody cross-reactivity was found with current variants of concern, prior to Omicron subvariant adapted boostering. Multiple booster vaccine doses can provide effective protection from COVID-19, even with intensive anti-CD38 therapy for high-risk MM.
Assuntos
COVID-19 , Mieloma Múltiplo , Humanos , COVID-19/prevenção & controle , SARS-CoV-2 , Mieloma Múltiplo/terapia , Vacinação , Imunidade , Reino Unido/epidemiologia , Anticorpos AntiviraisRESUMO
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.
Assuntos
Mieloma Múltiplo , Proteínas do Mieloma , Humanos , Imunoglobulina A , Imunoglobulina G , Cadeias Leves de Imunoglobulina , Imunoglobulinas , Saliva/metabolismoRESUMO
Detecting antibody responses during and after SARS-CoV-2 infection is essential in determining the seroepidemiology of the virus and the potential role of antibody in disease. Scalable, sensitive and specific serological assays are essential to this process. The detection of antibody in hospitalized patients with severe disease has proven relatively straightforward; detecting responses in subjects with mild disease and asymptomatic infections has proven less reliable. We hypothesized that the suboptimal sensitivity of antibody assays and the compartmentalization of the antibody response may contribute to this effect. We systematically developed an ELISA, optimizing different antigens and amplification steps, in serum and saliva from non-hospitalized SARS-CoV-2-infected subjects. Using trimeric spike glycoprotein, rather than nucleocapsid, enabled detection of responses in individuals with low antibody responses. IgG1 and IgG3 predominate to both antigens, but more anti-spike IgG1 than IgG3 was detectable. All antigens were effective for detecting responses in hospitalized patients. Anti-spike IgG, IgA and IgM antibody responses were readily detectable in saliva from a minority of RT-PCR confirmed, non-hospitalized symptomatic individuals, and these were mostly subjects who had the highest levels of anti-spike serum antibodies. Therefore, detecting antibody responses in both saliva and serum can contribute to determining virus exposure and understanding immune responses after SARS-CoV-2 infection.
Assuntos
Anticorpos Antivirais/imunologia , COVID-19/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Antígenos Virais/imunologia , COVID-19/sangue , COVID-19/diagnóstico , Ensaio de Imunoadsorção Enzimática , Humanos , SalivaRESUMO
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, 0.5â¯h, 3â¯h, 6â¯h, 9â¯h and 14â¯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 3â¯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 0.5â¯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 variationâ¯≥â¯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.
Assuntos
Biomarcadores/metabolismo , Desidroepiandrosterona/metabolismo , Hidrocortisona/metabolismo , Imunoglobulina A/metabolismo , Saliva/imunologia , Saliva/metabolismo , Adulto , Ritmo Circadiano , Feminino , Humanos , Masculino , Adulto JovemRESUMO
CONTEXT: Salivary antibodies may act as non-invasive marker of systemic immunity enabling assessment of vaccination and protection against bacterial infections. OBJECTIVE: To assess if levels of anti-pneumococcal (Pn) antibodies in saliva reflect concentrations in serum and determine whether saliva can accurately identify protective concentrations in serum. METHODS: IgG, IgA and IgM antibody levels in paired saliva and serum samples were measured against 12 Pn polysaccharide antigens in 72 healthy adults. RESULTS: Antibody levels in saliva correlated positively with serum across immunoglobulin classes, most strongly for IgA. Individuals who had protective antibody levels in serum demonstrated significantly higher IgG and IgA salivary antibody concentrations/secretion rates. Salivary IgG and IgA Pn antibodies were able to distinguish between those with/without protective levels in serum for the majority of serotypes. Salivary IgM antibodies were not able to differentiate protective status. Median IgG and IgA Pn salivary parameters were able to identify individuals who had protective levels in serum on ≥8/12 serotypes with moderate accuracy: median IgA secretion rates provided the best sensitivity (73%) and specificity (71%). CONCLUSIONS: These findings suggest that IgG and IgA Pn specific antibodies in saliva may be useful surrogate markers of antibody status in serum.
Assuntos
Anticorpos Antibacterianos/imunologia , Biomarcadores/análise , Infecções Pneumocócicas/imunologia , Saliva/imunologia , Streptococcus pneumoniae/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Anticorpos Antibacterianos/sangue , Biomarcadores/sangue , Feminino , Humanos , Imunoglobulina A Secretora/sangue , Imunoglobulina A Secretora/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Imunoglobulina M/sangue , Imunoglobulina M/imunologia , Masculino , Pessoa de Meia-Idade , Infecções Pneumocócicas/sangue , Infecções Pneumocócicas/microbiologia , Saliva/microbiologia , Streptococcus pneumoniae/fisiologia , Adulto JovemRESUMO
BACKGROUND: Myeloma is consistently preceded by premalignant monoclonal gammopathy of undetermined significance (MGUS). In >5% of MGUS patients there is a second MGUS clone (biclonal gammopathy of undetermined significance; BGUS), yet, at myeloma diagnosis, presentation of biclonal gammopathy myeloma (BGMy) is considered less frequent, implying that myeloma eradicates coexisting MGUS. METHODS: In the largest study of its kind, we assessed BGMy frequency amongst 6399 newly diagnosed myeloma patients enrolled in recent UK clinical trials. RESULTS: Compared to expected prevalence (i.e., >5% of MGUS have BGUS), only 58 of 6399 (0.91%) newly diagnosed myeloma patients had BGMy, indicating myeloma typically eliminates coexistent MGUS. In these 58 BGMy cases, the MGUS plasma cell clone was greatly suppressed in size compared to typical levels observed in conventional MGUS; contrarily, the MGUS clone did not inhibit the myeloma plasma cell clone in BGMy. CONCLUSION: Myeloma eliminates the majority of competing MGUS, and when it does not, the MGUS clone is substantially reduced in size.
Assuntos
Anticorpos Monoclonais/sangue , Gamopatia Monoclonal de Significância Indeterminada/sangue , Gamopatia Monoclonal de Significância Indeterminada/patologia , Mieloma Múltiplo/patologia , Lesões Pré-Cancerosas/sangue , Lesões Pré-Cancerosas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise de Variância , Tamanho Celular , Progressão da Doença , Humanos , Imunoglobulina A/sangue , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/epidemiologia , Mieloma Múltiplo/sangue , Mieloma Múltiplo/epidemiologia , Lesões Pré-Cancerosas/epidemiologia , PrevalênciaRESUMO
This study aims to guide the integration of serum free light chain (sFLC) tests into clinical practice, including a new rapid test (Seralite® ). Blood and urine analysis from 5573 newly diagnosed myeloma patients identified 576 light chain only (LCO) and 60 non-secretory (NS) cases. Serum was tested by Freelite® and Seralite® at diagnosis, maximum response and relapse. 20% of LCO patients had urine FLC levels below that recommended for measuring response but >97% of these had adequate sFLC levels (oligosecretory). The recommended Freelite® sFLC ≥100 mg/l for measuring response was confirmed and the equivalent Seralite® FLC difference (dFLC) >20 mg/l identified. By both methods, ≥38% of NS patients had measurable disease (oligosecretory). Higher sFLC levels were observed on Freelite® at all time points. However, good clinical concordance was observed at diagnosis and in response to therapy. Achieving at least a very good partial response according to either sFLC method was associated with better patient survival. Relapse was identified using a Freelite® sFLC increase >200 mg/l and found 100% concordance with a corresponding Seralite® dFLC increase >30 mg/l. Both Freelite® and Seralite® sensitively diagnose and monitor LCO/oligosecretory myeloma. Rapid testing by Seralite® could fast-track FLC screening and monitoring. Response by sFLC assessment was prognostic for survival and demonstrates the clinical value of routine sFLC testing.
Assuntos
Mieloma Múltiplo/diagnóstico , Assistência ao Convalescente , Intervalo Livre de Doença , Humanos , Imunoensaio/métodos , Cadeias Leves de Imunoglobulina/metabolismo , Imunoglobulinas/metabolismo , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/mortalidade , Recidiva Local de Neoplasia/diagnóstico , Recidiva Local de Neoplasia/imunologia , Recidiva Local de Neoplasia/mortalidade , Sistemas Automatizados de Assistência Junto ao Leito , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Serum free light chains (FLC) are sensitive biomarkers used for the diagnosis and management of plasma cell dyscrasias, such as multiple myeloma (MM), and are central to clinical screening algorithms and therapy response criteria. We have developed a portable, near-patient, lateral-flow test (Seralite®) that quantitates serum FLC in 10 min, and is designed to eliminate sample processing delays and accelerate decision-making in the clinic. METHODS: Assay interference, imprecision, lot-to-lot variability, linearity, and the utility of a competitive-inhibition design for the elimination of antigen-excess ('hook effect') were assessed. Reference ranges were calculated from 91 healthy donor sera. Preliminary clinical validation was conducted by retrospective analysis of sera from 329 patients. Quantitative and diagnostic results were compared to Freelite®. RESULTS: Seralite® gave a broad competitive-inhibition calibration curve from below 2.5 mg/L to above 200 mg/L, provided good assay linearity (between 1.6 and 208.7 mg/L for κ FLC and between 3.5 and 249.7 mg/L for λ FLC) and sensitivity (1.4 mg/L for κ FLC and 1.7 mg/L for λ FLC), and eliminated anomalous results from antigen-excess. Seralite® gave good diagnostic concordance with Freelite® (Roche Hitachi Cobas C501) identifying an abnormal FLC ratio and FLC difference in 209 patients with newly diagnosed MM and differentiating these patients from normal healthy donors with polyclonal FLC. CONCLUSIONS: Seralite® sensitively quantitates FLC and rapidly identifies clinical conditions where FLC are abnormal, including MM.
Assuntos
Biomarcadores Tumorais/sangue , Imunoensaio/métodos , Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Mieloma Múltiplo/sangue , Humanos , Cadeias Leves de Imunoglobulina/sangue , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos TestesRESUMO
BACKGROUND: Acute kidney injury (AKI) is common in patients with multiple myeloma (MM). Whether serum free light chain (sFLC) measurements can distinguish between myeloma and other causes of AKI requires confirmation to guide early treatment. A rapid and portable sFLC test (Seralite®) is newly available and could reduce delays in obtaining sFLC results and accelerate diagnosis in patients with unexplained AKI. This study evaluated the accuracy of Seralite® to identify MM as the cause of AKI. METHOD: sFLCs were retrospectively analysed in patients with AKI stage 3 as per KDIGO criteria (i.e. serum creatinine ≥354 µmol/L or those on dialysis treatment) (n = 99); 45/99 patients had a confirmed MM diagnosis. RESULTS: The Seralite® κ:λ FLC ratio accurately diagnosed all MM patients in the presence of AKI: a range of 0.14-2.02 returned 100% sensitivity and specificity for identifying all non-myeloma related AKI patients. The sFLC difference (dFLC) also demonstrated high sensitivity (91%) and specificity (100%): an optimal cut-off of 399 mg/L distinguished between myeloma and non-myeloma AKI patients. We propose a pathway of patient screening and stratification in unexplained AKI for use of Seralite® in clinical practice, with a κ:λ ratio range of 0.14-2.02 and dFLC 400 mg/L as decision points. CONCLUSIONS: Seralite® accurately differentiates between AKI due to MM and AKI due to other causes in patients considered at risk of myeloma. This rapid test can sensitively screen for MM in patients with AKI and help inform early treatment intervention.
Assuntos
Injúria Renal Aguda/sangue , Injúria Renal Aguda/diagnóstico , Cadeias Leves de Imunoglobulina/sangue , Mieloma Múltiplo/sangue , Mieloma Múltiplo/diagnóstico , Injúria Renal Aguda/epidemiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/epidemiologia , Estudos Retrospectivos , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Free light chains (FLCs) have a range of biological functions and may act as a broad marker of immunesuppression and activation and inflammation. Measurement of salivary FLCs may provide practical advantages in a range of clinical populations. The aim of the present study was to develop normal reference ranges of FLCs in saliva and assess the effects of acute exercise on FLC levels in younger and older adults. METHODS: Saliva FLC concentrations and secretion rates were measuredin young (n = 88, aged 18-36) and older (n = 53, aged 60-80) adults. To assess FLC changes in response to acute exercise, young adults completed a constant work-rate cycling exercise trial at 60% VO2max (n = 18) or a 1 h cycling time trial (TT) (n = 10) and older adults completed an incremental submaximal treadmill walking exercise test to 75% HRmax (n = 53). Serum FLCs were measured at baseline and in response to exercise. RESULTS: Older adults demonstrated significantly higher levels of salivary FLC parameters compared with young adults. Median (5-95th percentile) concentrationswere 0.45 (0.004- 3.45) mg/L for kappa and 0.30 (0.08-1.54) mg/L for lambda in young adults; 3.91 (0.75-19.65) mg/L for kappa and 1.00 (0.02-4.50) mg/L for lambda in older ad ults. Overall median concentrations of salivary kappa and lambda FLCs were 10-fold and 20-fold lower than serum, respectively. Reductions in salivary FLC concentrations and secretion rates were observed immediately post- and at 1 h post exercise, but were only significant for the older cohort; FLCs began to recover between post and 1 h post-exercise. No changes in serum FLCs were observed in response to exercise.
Assuntos
Exercício Físico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Humanos , Cadeias Leves de Imunoglobulina , Cadeias lambda de Imunoglobulina , Pessoa de Meia-Idade , Valores de Referência , Adulto JovemRESUMO
The present study examined the relationship between habitual physical activity, life events stress, the diurnal rhythms of cortisol and DHEA, and the cortisol:dehydroepiandrosterone (DHEA) ratio in older adults. Thirty-six participants aged ≥ 65 reported their habitual physical activity, and indicated if a particular event happened to them in the past year (stress incidence) and how stressful they perceived the event to be (stress severity). Older adults with higher stress severity demonstrated a significantly higher cortisol:DHEA ratio. Individuals with higher stress incidence scores and who did not participate in aerobic exercise had a significantly higher cortisol:DHEA ratio and flatter DHEA diurnal rhythm compared with those who regularly participated in aerobic exercise. In conclusion, life events stress may have a negative impact on the cortisol:DHEA ratio in older adults. Under conditions of high stress exposure, exercise may protect older adults from an increased cortisol:DHEA ratio and flatter DHEA diurnal rhythm.
Assuntos
Envelhecimento , Ritmo Circadiano/fisiologia , Desidroepiandrosterona/metabolismo , Exercício Físico , Hidrocortisona/metabolismo , Atividade Motora/fisiologia , Estresse Psicológico , Idoso , Envelhecimento/metabolismo , Envelhecimento/psicologia , Exercício Físico/fisiologia , Exercício Físico/psicologia , Feminino , Humanos , Acontecimentos que Mudam a Vida , Masculino , Fatores de Proteção , Saliva/metabolismo , Estatística como Assunto , Estresse Psicológico/etiologia , Estresse Psicológico/metabolismo , Estresse Psicológico/prevenção & controle , Estresse Psicológico/psicologiaRESUMO
UNLABELLED: BACKGROUND/STUDY CONTEXT: The cortisol diurnal rhythm has previously been examined in relation to age and health behaviors. However, less is known about the relationship between multiple health behaviors and diurnal cortisol in the context of aging, where it is possible that the impact of health behaviors on cortisol varies as a function of age. This study compared the awakening response and diurnal rhythm of cortisol in young versus older adults in relation to health behaviors. METHODS: Twenty-four young students (aged 18-22) and 48 community-dwelling older adults (aged 65-88) completed an assessment of health behaviors (exercise, smoking, sleep, diet, alcohol) over the past year. Salivary cortisol was measured over the course of 1 day: immediately upon awakening, 30 min later, and then 3, 6, 9, and 12 h post awakening. Repeated measures/univariate analysis of variance (ANOVA) was used to test main effects of age and health behaviors, and any interaction effects in relation to diurnal cortisol. RESULTS: Older adults displayed significantly reduced cortisol upon awakening, a lower cortisol awakening response, and a flatter diurnal profile represented by a reduced area under the curve and cortisol slope. There was also a significant interaction of age, cortisol, and diet; younger adults with a higher fat and lower fruit and vegetable intake exhibited the flattened diurnal cortisol phenotype of the older adults. CONCLUSION: These findings suggest that the diurnal rhythm and awakening response of salivary cortisol is significantly reduced in older adults and that variations in the cortisol diurnal rhythm of younger adults are associated with dietary factors. Younger adults with a poor quality of food intake may be vulnerable to a reduction in the amplitude of the cortisol diurnal profile and this may have implications for other aspects of health.
Assuntos
Envelhecimento/fisiologia , Ritmo Circadiano/fisiologia , Comportamentos Relacionados com a Saúde , Hidrocortisona/fisiologia , Saliva/química , Adolescente , Idoso , Idoso de 80 Anos ou mais , Área Sob a Curva , Dieta , Feminino , Humanos , Hidrocortisona/análise , Masculino , Adulto JovemRESUMO
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.
Assuntos
Cadeias Leves de Imunoglobulina/análise , Estresse Psicológico/metabolismo , Adulto , Biomarcadores , Desidroepiandrosterona/análise , Feminino , Humanos , Hidrocortisona/análise , Cadeias Leves de Imunoglobulina/fisiologia , Imunoglobulinas/análise , Masculino , Saliva/química , Estresse Psicológico/fisiopatologia , Estudantes/psicologia , Universidades , Adulto JovemRESUMO
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.
Assuntos
Doenças do Sistema Imunitário/diagnóstico , Cadeias kappa de Imunoglobulina/isolamento & purificação , Cadeias lambda de Imunoglobulina/isolamento & purificação , Kit de Reagentes para Diagnóstico , Biomarcadores/sangue , Conjuntos de Dados como Assunto , Ensaio de Imunoadsorção Enzimática/instrumentação , Ensaio de Imunoadsorção Enzimática/métodos , Voluntários Saudáveis , Humanos , Doenças do Sistema Imunitário/sangue , Doenças do Sistema Imunitário/imunologia , Cadeias kappa de Imunoglobulina/sangue , Cadeias kappa de Imunoglobulina/imunologia , Cadeias lambda de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/imunologia , Valores de Referência , Reprodutibilidade dos Testes , Estudos RetrospectivosRESUMO
BACKGROUND: Serum free light chain (sFLC) quantitation is central for plasma cell dyscrasias. Several assays are available and switching sFLC methods may be advantageous in certain laboratories. This study performed Freelite and Seralite simultaneously for samples received by the clinical laboratory over a 10 month period and compared quantitation and its impact on interpretation of patient results. METHODS: Patients (N = 189) included multiple myeloma (MM) and related plasma cell cancers, monoclonal gammopathy of unknown significance (MGUS), AL amyloidosis and renal impairment. sFLC quantitation and clinical agreement was assessed between methods. RESULTS: Clinical agreement was substantial at diagnosis (κ = 0.647, p < .01) and moderate for monitoring (κ = 0.591, p < .01). Good concordance was seen for MM and related plasma disorders and MGUS, with poorer agreement seen for AL amyloidosis. Case studies illustrated agreement in pattern of myeloma disease activity. Bland-Atman plots showed small mean bias but increasing variation between methods with increasing FLC concentrations. Passing-Bablok analysis confirmed systematic differences in quantitation between methods. CONCLUSIONS: Despite differences in quantitation, overall, agreement was seen between the different sFLC platforms in relation to the clinical interpretation. As a rapid test without the need for large and expensive analysers, Seralite may be highly applicable in certain laboratories to enable in-house testing.
Assuntos
Mieloma Múltiplo , Paraproteinemias , Humanos , Imunoensaio , Cadeias Leves de Imunoglobulina , Laboratórios , Mieloma Múltiplo/diagnóstico , Paraproteinemias/diagnósticoRESUMO
Multiple myeloma (MM) is associated with increased risk of infection, but little is known regarding antibody levels against specific bacteria. We assessed levels of polyclonal immunoglobulin and antibacterial antibodies in patients recruited to the TEAMM trial, a randomised trial of antibiotic prophylaxis at the start of anti-myeloma treatment. Polyclonal IgG, IgA and IgM levels were below the reference range in 71%, 83% and 90% of 838 MM patients at diagnosis. Anti-vaccine targeted tetanus toxoid antibodies were protective in 95% of 193 healthy controls but only 41% of myeloma patients. In healthy controls, protective antibodies against 6/12 pneumococcal serotypes, haemophilus and meningococcus A were present in 67%, 41% and 56% compared to just 15%, 21% and 17% of myeloma patients. By 1 year, myeloma patients IgG levels had recovered for 57% of patients whilst the proportion with protective levels of IgG against thymus-dependent protein antigen tetanus toxoid had changed little. In contrast the proportions of patients with protective levels against thymus independent polysaccharide antigens pneumococcus, haemophilus and meningococcus had fallen from 15 to 7%, 21 to 0% and 17 to 11%. Findings highlight the need for strategies to protect patients against bacterial infections during therapy and vaccination programmes during remission.
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Antibacterianos/administração & dosagem , Anticorpos Antibacterianos/administração & dosagem , Infecções Bacterianas/tratamento farmacológico , Mieloma Múltiplo/tratamento farmacológico , Idoso , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Detecting antibody responses during and after SARS-CoV-2 infection is essential in determining the seroepidemiology of the virus and the potential role of antibody in disease. Scalable, sensitive and specific serological assays are essential to this process. The detection of antibody in hospitalized patients with severe disease has proven straightforward; detecting responses in subjects with mild disease and asymptomatic infections has proven less reliable. We hypothesized that the suboptimal sensitivity of antibody assays and the compartmentalization of the antibody response may contribute to this effect. METHODS: We systemically developed an ELISA assay, optimising different antigens and amplification steps, in serum and saliva from symptomatic and asymptomatic SARS-CoV-2-infected subjects. RESULTS: Using trimeric spike glycoprotein, rather than nucleocapsid enabled detection of responses in individuals with low antibody responses. IgG1 and IgG3 predominate to both antigens, but more anti-spike IgG1 than IgG3 was detectable. All antigens were effective for detecting responses in hospitalized patients. Anti-spike, but not nucleocapsid, IgG, IgA and IgM antibody responses were readily detectable in saliva from non-hospitalized symptomatic and asymptomatic individuals. Antibody responses in saliva and serum were largely independent of each other and symptom reporting. CONCLUSIONS: Detecting antibody responses in both saliva and serum is optimal for determining virus exposure and understanding immune responses after SARS-CoV-2 infection. FUNDING: This work was funded by the University of Birmingham, the National Institute for Health Research (UK), the NIH National Institute for Allergy and Infectious Diseases, the Bill and Melinda Gates Foundation and the University of Southampton.
RESUMO
Periods of short-term intensified training (IT) are often used by athletes during training cycles over the season and undergoing phases of increased physical stress may impact upon the immune system. This study investigated the effects of a period of IT on free light chains (FLCs) in saliva - an emerging immune biomarker of oral inflammation - and matched serum samples in well-trained athletes. It also examined if IT influences basal FLC levels and FLC flux during acute exercise. Highly trained male cyclists (nâ¯=â¯10) underwent a 9-day period of IT; before and after IT participants performed a 1â¯h time trial (TT) on a cycle ergometer, with blood and saliva samples collected pre- and post-exercise. FLCs were assessed in serum and saliva, and IgG, IgA, IgM and creatinine were also measured in serum. Weekly training volume increased by 143% (95% CI 114-172%), pâ¯<â¯0.001, during IT compared with pre-trial baseline training. Following IT, the cyclists demonstrated higher salivary FLC levels. Both salivary lambda FLC concentrations (pâ¯<â¯0.05, η2â¯=â¯0.384) and secretion rates, and kappa FLC concentrations and secretion rates increased after IT. Salivary FLCs concentration and secretion rates decreased in response to the TT following IT (pâ¯<â¯0.05, η2â¯=â¯0.387-0.428), but not in response to the TT prior to IT. No significant effects of IT on serum FLCs were observed. There were no significant changes in serum FLCs in response to the TT, before or after the IT period, nor did IT impact upon other serological responses to the TT. In conclusion, IT increased basal salivary FLC parameters and amplified decreases in salivary FLCs in response to acute exercise. Increases in salivary FLC concentration likely reflects alterations to oral inflammation during times of heavy training, and we show for the first time that FLCs may have utility as a marker of exercise stress and oral health status.
Assuntos
Ciclismo/fisiologia , Treino Aeróbico/efeitos adversos , Cadeias Leves de Imunoglobulina/metabolismo , Saliva/química , Estomatite/etiologia , Ensino , Adulto , Análise de Variância , Sangue/metabolismo , Creatinina/sangue , Creatinina/metabolismo , Feminino , Humanos , Masculino , Saliva/imunologia , Fatores de Tempo , Adulto JovemRESUMO
We measured immunosuppression at myeloma diagnosis and assessed the impact on survival in 5826 UK myeloma trial patients. Polyclonal immunoglobulin levels were below normal in 85% of patients and above normal in only 0.4% of cases for IgA, 0.2% for IgM and no cases for IgG. Immunoparesis had a greater impact in recent trials: median overall survival (OS) was up to 3 years longer for patients without immunoparesis compared to the old trials, less than 1 year longer. Median progression-free survival (PFS) was 39%, 36% and 57% longer for patients with normal IgG, IgA and IgM levels, respectively. The depth of IgM suppression, but not the depth of IgG or IgA suppression, was prognostic for survival: the most severely suppressed IgM tertile of patients OS was 0.9 years shorter than those in the top tertile, and 2.6 years shorter than OS of those with normal IgM levels (p = .007). The degree of suppression of polyclonal IgM levels below normal was associated with worse PFS (p = .0002). Infection does not appear to be the main mechanism through which immunoparesis affects survival. We hypothesise that IgM immunoparesis impacts through a combination of being associated with more aggressive disease and reduced immune surveillance against relapse.