Sensitive Detection of SARS-CoV-2-Specific Antibodies in Dried Blood Spot Samples.

Dried blood spot (DBS) samples can be used for the detection of severe acute respiratory syndrome coronavirus 2 spike antibodies. DBS sampling is comparable to matched serum samples with a relative 98.1% sensitivity and 100% specificity. Thus, DBS sampling offers an alternative for population-wide serologic testing in the coronavirus pandemic.

Prophylactic levofloxacin to prevent infections in newly diagnosed symptomatic myeloma: the TEAMM RCT.

BACKGROUND: Myeloma causes profound immunodeficiency and recurrent serious infections. There are approximately 5500 new UK cases of myeloma per annum, and one-quarter of patients will have a serious infection within 3 months of diagnosis. Newly diagnosed patients may benefit from antibiotic prophylaxis to prevent infection. However, the use of prophylaxis has not been established in myeloma and may be associated with health-care-associated infections (HCAIs), such as Clostridium difficile. There is a need to assess the benefits and cost-effectiveness of the use of antibacterial prophylaxis against any risks in a double-blind, placebo-controlled, randomised clinical trial. OBJECTIVES: To assess the risks, benefits and cost-effectiveness of prophylactic levofloxacin in newly diagnosed symptomatic myeloma patients. DESIGN: Multicentre, randomised, double-blind, placebo-controlled trial. A central telephone randomisation service used a minimisation computer algorithm to allocate treatments in a 1 : 1 ratio. SETTING: A total of 93 NHS hospitals throughout England, Northern Ireland and Wales. PARTICIPANTS: A total of 977 patients with newly diagnosed symptomatic myeloma. INTERVENTION: Patients were randomised to receive levofloxacin or placebo tablets for 12 weeks at the start of antimyeloma treatment. Treatment allocation was blinded and balanced by centre, estimated glomerular filtration rate and intention to give high-dose chemotherapy with autologous stem cell transplantation. Follow-up was at 4-week intervals up to 16 weeks, with a further follow-up at 1 year. MAIN OUTCOME MEASURES: The primary outcome was to assess the number of febrile episodes (or deaths) in the first 12 weeks from randomisation. Secondary outcomes included number of deaths and infection-related deaths, days in hospital, carriage and invasive infections, response to antimyeloma treatment and its relation to infection, quality of life and overall survival within the first 12 weeks and beyond. RESULTS: In total, 977 patients were randomised (levofloxacin, n = 489; placebo, n = 488). A total of 134 (27%) events (febrile episodes, n = 119; deaths, n = 15) occurred in the placebo arm and 95 (19%) events (febrile episodes, n = 91; deaths, n = 4) occurred in the levofloxacin arm; the hazard ratio for time to first event (febrile episode or death) within the first 12 weeks was 0.66 (95% confidence interval 0.51 to 0.86; p = 0.002). Levofloxacin also reduced other infections (144 infections from 116 patients) compared with placebo (179 infections from 133 patients; p-trend of 0.06). There was no difference in new acquisitions of C. difficile, methicillin-resistant Staphylococcus aureus and extended-spectrum beta-lactamase Gram-negative organisms when assessed up to 16 weeks. Levofloxacin produced slightly higher quality-adjusted life-year gains over 16 weeks, but had associated higher costs for health resource use. With a median follow-up of 52 weeks, there was no significant difference in overall survival (p = 0.94). LIMITATIONS: Short duration of prophylactic antibiotics and cost-effectiveness. CONCLUSIONS: During the 12 weeks from new diagnosis, the addition of prophylactic levofloxacin to active myeloma treatment significantly reduced febrile episodes and deaths without increasing HCAIs or carriage. Future work should aim to establish the optimal duration of antibiotic prophylaxis and should involve the laboratory investigation of immunity, inflammation and disease activity on stored samples funded by the TEAMM (Tackling Early Morbidity and Mortality in Myeloma) National Institute for Health Research Efficacy and Mechanism Evaluation grant (reference number 14/24/04). TRIAL REGISTRATION: Current Controlled Trials ISRCTN51731976. FUNDING DETAILS: This project was funded by the NIHR Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 23, No. 62. See the NIHR Journals Library website for further project information.

WHAT IS THE PROBLEM?: Myeloma is a type of cancer that develops from cells in the bone marrow, called plasma cells, which are part of the immune system. Because myeloma affects the immune system, people who have it are at greater risk of picking up infections. This risk is higher at the start of antimyeloma therapy when the myeloma is active. WHAT DID THE STUDY DO?: The trial looked to see if the risk of getting an infection can be reduced, rather than waiting to see if an infection developed and then treating it. An antibiotic already used all over the world, called levofloxacin was tested. Half of the patients (n = 489) took levofloxacin for 12 weeks and the other half (n = 488) were given a dummy tablet (placebo). The aim was to see if taking levofloxacin at the start of antimyeloma therapy reduced the risk of getting an infection. Alongside this, we evaluated three important groups of antibiotic-resistant bacteria to see whether or not the use of preventative levofloxacin increased the number of these resistant bacteria living in the body. In addition, the overall survival, economic impacts and the impact of using preventative antibiotics on patients' quality of life and response to antimyeloma treatment were evaluated. WHAT DID THE STUDY FIND?: During the 12 weeks from new diagnosis of myeloma, the addition of prophylactic levofloxacin to active myeloma treatment significantly reduced the number of febrile episodes and deaths [134 (febrile episodes alone, n = 112; febrile episodes plus death, n = 7; deaths alone, n = 15) out of 488 (27%) placebo patients vs. 95 (febrile episodes alone, n = 87; febrile episodes plus death, n = 4; deaths alone, n = 4) out of 489 (19%) levofloxacin patients; p = 0.002] without increasing antibiotic-resistant bacteria.

Unplanned admissions for patients with myeloma in the UK: Low frequency but high costs.

BACKGROUND: 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). METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

The utility of saliva for the assessment of anti-pneumococcal antibodies: investigation of saliva as a marker of antibody status in serum.

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.

Adjusting for patient crossover in clinical trials using external data: a case study of lenalidomide for advanced multiple myeloma.

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.

Assessment of oxidative stress in lymphocytes with exercise.

This study investigated whether changes in the cellular composition of blood during exercise could partly account for observations of exercise-induced changes in lymphocyte oxidative stress markers. Markers of oxidative stress were assessed before and after 60 min of intense treadmill running. Samples were collected from 16 men (means ± SD: age 33 ± 13 yr; body mass index 23.8 ± 2.5 kg/m(2); maximal oxygen uptake 59.7 ± 5.2 ml·kg(-1)·min(-1)). Peripheral blood lymphocytes were assayed for protein carbonyl concentration, and plasma was assessed for lipid peroxides and antioxidant capacity. In a separate study, intracellular thiol concentration was determined in lymphocyte subsets from eight characteristically similar men by flow cytometry, of which T-cell memory populations were further identified on the basis of CD27, CD28, and CD45RA expression. Total lymphocyte protein carbonyls were transiently increased with exercise and returned to baseline within 15 min (P < 0.001). This change was accompanied by an increase in plasma lipid peroxides (P < 0.05) and total antioxidant capacity (P < 0.001). Correlation analyses showed that lymphocyte protein carbonyl content was not related to changes in the cellular composition of peripheral blood during exercise. Natural killer cells (CD3(-)CD56(+)) and late-differentiated/effector memory cells (CD4(+)/CD8(+)CD27(-)CD28(-)/CD45RA(+)), which mobilized most with exercise, showed high intracellular thiol content (P < 0.001). High thiol content suggests a lower oxidative load carried by these lymphocytes. Thus vigorous exercise resulted in a transient increase in lymphocyte oxidative stress. Results suggest this was unrelated to the alterations in the cellular composition of peripheral blood.

Assessment of monoclonal gammopathies by nephelometric measurement of individual immunoglobulin kappa/lambda ratios.

BACKGROUND: Currently, monoclonal immunoglobulins are identified and quantified from bands on electrophoretic gels. As an alternative, clonality might be determined by measuring the separate light chain types of each Ig class to allow numerical assessment of Ig'kappa/Ig'lambda ratios, analogous to free light chain kappa/lambda ratios. METHODS: Using immunization, tolerization, and adsorption procedures, we prepared sheep antibodies against each of the 6 separate molecules, IgGkappa, IgGlambda, IgAkappa, IgAlambda, IgMkappa, and IgMlambda. Antibody targets comprised the junctional epitopes between the heavy chain and light chain domains. After purification, we assessed the antisera on a Siemens Dade-Behring BN II nephelometer for analytical quality and clinical utility. RESULTS: High-avidity, specific antibodies allowed the production of automated nephelometric immunoassays for each Ig light chain type. Laboratory comparison with serum protein electrophoresis, using dilution experiments, showed lower analytical sensitivity for monoclonal IgG detection but similar or greater sensitivity for IgA and IgM, particularly when the monoclonal bands overlaid transferrin. Results obtained from typing of monoclonal proteins into IgG, A, or M types were comparable with results obtained by immunofixation-electrophoresis methods. Initial clinical studies, in multiple myeloma patients, indicated that Ig'kappa/Ig'lambda ratios were sometimes more sensitive than immunofixation electrophoresis, provided numerical results, and correlated with changes in disease. CONCLUSIONS: Immunoassays for intact Ig kappa/lambda pairs are possible and should assist in the management of patients with monoclonal gammopathies.

Diagnostic accuracy and clinical utility of a simplified low cost method of counting CD4 cells with flow cytometry in Malawi: diagnostic accuracy study.

OBJECTIVES: To assess the diagnostic accuracy and clinical utility of a simplified low cost method for measuring absolute and percentage CD4 counts with flow cytometry. DESIGN: A CD4 counting method (Blantyre count) using a CD4 and CD45 antibody combination with reduced blood and reagent volumes. Diagnostic accuracy was assessed by measuring agreement of the index test with two other assays (TruCount and FACSCount). Clinical utility was investigated by comparing CD4 counts with the new assay with WHO clinical staging in patients with HIV. SETTING: Research laboratories and antiretroviral therapy clinic at a medical school and large government hospital in southern Malawi. PARTICIPANTS: Assay comparisons were performed on consecutive blood samples sent for CD4 counting from 129 patients with HIV. Comparison of CD4 count with staging was conducted on 253 consecutive new patients attending the antiretroviral therapy clinic. MAIN OUTCOME MEASURES: Limits of agreement with 95% confidence intervals between index test and reference standards. RESULTS: The limits of agreement for Blantyre count and TruCount were excellent (cell count -48.9 to 27.0 x10(9)/l for absolute counts in the CD4 range <400x10(9)/l and -2.42% to 2.37% for CD4 percentage). The assay was affordable with reagent costs per test of $0.44 ( pound0.22, euro0.33) for both absolute count and CD4 percentage, and $0.11 for CD4 percentage alone. Of 193 patients with clinical stage I or II disease, who were ineligible for antiretroviral therapy by clinical staging criteria, 73 (38%) had CD4 counts <200x10(9)/l. By contrast, 12 (20%) of 60 patients with stage III or IV disease had CD4 counts >350x10(9)/l. CONCLUSIONS: This simplified method of counting CD4 cells with flow cytometry has good agreement with established commercial assays, is affordable for routine clinical use in Africa, and could improve clinical decision making in patients with HIV.

Serum test for assessment of patients with Bence Jones myeloma.

Bence Jones protein in urine (immunoglobulin free-light-chains) is characteristic of light-chain multiple myeloma. We aimed to compare a quantitative immunoassay for serum free-light-chains with urine tests. Of 224 patients with light-chain myeloma tested at entry to clinical trials, all were correctly identified from serum samples. During monitoring of 82 patients, changes in serum and urine free-light-chains corresponded, but urine became negative for free-light-chains in 26 patients, whereas it remained abnormal in serum in 73 patients. Serum assays could replace Bence Jones protein urine tests for patients with light-chain multiple myeloma.