Quantitative assessment of multiple pathogen exposure and immune dynamics at scale.

IMPORTANCE: Serology reveals exposure to pathogens, as well as the state of autoimmune and other clinical conditions. It is used to evaluate individuals and their histories and as a public health tool to track epidemics. Employing a variety of formats, studies nearly always perform serology by testing response to only one or a few antigens. However, clinical outcomes of new infections also depend on which previous infections may have occurred. We developed a high-throughput serology method that evaluates responses to hundreds of antigens simultaneously. It can be used to evaluate thousands of samples at a time and provide a quantitative readout. This tool will enable doctors to monitor which pathogens an individual has been exposed to and how that changes in the future. Moreover, public health officials could track populations and look for infectious trends among large populations. Testing many potential antigens at a time may also aid in vaccine development.

Luminex screening first vs. direct single antigen bead assays: Different strategies for HLA antibody monitoring after kidney transplantation.

MAIN PROBLEM: Luminex panel and single antigen beads (SAB) are used for screening and DSA specificity determination respectively. The cost of SAB may limit its general use, so some labs perform SAB tests only after positive screening. METHODS: We compared both strategies: 1) SAB only if positive screening with kits from manufacturer A, and 2) direct SAB from manufacturer B, and correlate their sensitivity with histological findings. RESULTS: We selected 118 kidney transplant recipients with a normal biopsy (n = 19), histological antibody-mediated damage (ABMR, n = 52) or interstitial fibrosis/tubular atrophy (IFTA, n = 47) following Banff 2015 and 2017 classification. Direct SAB detected DSA in 13 patients missed by screening. Strategy 1 detected DSA in 0% normal, 61.5% ABMR and 8.5% IFTA patients; percentages with strategy 2 were 5.2%, 78.8% and 14.8% (p=0.004). Strategy 2 identified DSA allowing full ABMR diagnosis in 17% cases missed by strategy 1. Thereafter, direct SAB from manufacturer A confirmed DSA in 46% DSA-positive cases with strategy 2 (55.5% ABMR cases). CONCLUSIONS: Luminex screening failed to identify clinically relevant HLA antibodies, hampering DSA detection in patients with possible ABMR. Direct SAB testing should be the chosen strategy for post-transplantation monitoring, albeit direct SAB from the two existing manufacturers may diverge in as much as 50% of cases.

Cost effectiveness of routine duodenal biopsies in iron deficiency anemia.

AIM: To investigate the cost effectiveness of routine small bowel biopsies (SBBs) in patients with iron deficiency anemia (IDA) independent of their celiac disease (CD) serology test results. METHODS: We used a state transition Markov model. Two strategies were compared: routine SBBs during esophagogastroduodenoscopy (EGD) in all patients with IDA regardless their celiac serology status (strategy A) vs SBBs only in IDA patients with positive serology (strategy B). The main outcomes were quality adjusted life years (QALY), average cost and the incremental cost effectiveness ratio (ICER). One way sensitivity analysis was performed on all variables and two way sensitivity analysis on selected variables were done. In order to validate the results, a Monte Carlo simulation of 100 sample trials with 10, and an acceptability curve were performed. RESULTS: Strategy A of routine SBBs yielded 19.888 QALYs with a cost of $218.10 compared to 19.887 QALYs and $234.17 in strategy B. In terms of cost-effectiveness, strategy A was the dominant strategy, as long as the cost of SBBs stayed less than $67. In addition, the ICER of strategy A was preferable, providing the cost of biopsy stays under $77. Monte Carlo simulation demonstrated that strategy A yielded the same QALY but with lower costs than strategy B. CONCLUSION: Our model suggests that EGD with routine SBBs is a cost-effective approach with improved QALYs in patients with IDA when the prevalence of CD is 5% or greater. SBBs should be a routine screening tool for CD among patients with IDA, regardless of their celiac antibody status.

Aspecto clínico-epidemiológicos e imunológicos da hanseníase em área heperendêmica do estado do Maranhão / epidemiological and immunological aspect of leprosy in hyperendemic area of the state of Maranhão

A hanseníase ou mal de Hansen (MH), causada pelo patógeno Mycobacterium leprae, ainda constitui um problema de saúde pública no Brasil, e em especial no Maranhão. A doença é hiperendêmica em 77 municípios do Estado. A resposta imune ao patógeno de indivíduos dessas regiões permanece obscuro podendo contribuir na manutenção da hiperendemia. Por isso, este estudo teve por objetivo caracterizar o perfil clínico-epidemiológico e imunológico de pacientes infectados por M. leprae, e de seus contatos, procedentes de área hiperendêmica. Para o desenvolvimento deste trabalho foi realizado um estudo transversal foi realizado nos municípios de Açailândia, Imperatriz e São Luís, no período 2009 a 2012. Pacientes e contatos foram clinicamente avaliados e tiveram os dados epidemiológicos coletados. Uma amostra de sangue foi obtida para realização das sorologias para detecção de anticorpos IgM anti-PGL1 pelos testes de ELISA e ML-Flow, e dosagem de citocinas e quimiocinas. A análise descritiva demonstrou que a maioria dos pacientes eram adultos, do gênero masculino, diagnosticados principalmente com as formas intermediárias da doença (60%)...

Leprosy, caused by the pathogen Mycobacterium leprae, it is a public health problem in Brazil yet, especially in Maranhão. The disease is hyperendemic in 77 counties of the State. Immune response to the pathogen of individuals in these regions remains unclear and may be contributing to maintenance of high endemicity. Therefore, this study aimed to characterize epidemiological and immunological profile of patients infected with M. leprae, and their contacts, from hyperendemic regions. Cross-sectional study was accomplished in Açailândia, Imperatriz and São Luís counties, 2009-2012. Patients and contacts were clinically evaluated and had their epidemiological data collected. A blood sample was obtained for performing serological tests IgM anti-PGL1 detection by ELISA and ML-Flow and measurement of cytokines and chemokines. Descriptive analysis showed that most patients were adults, male, diagnosed with intermediate forms mainly (60%)...

Selected serology: pregnancy testing, hepatitis A and B, and infectious mononucleosis.

The basic principles of serologic testing are discussed in this article. Specific emphasis is placed on pregnancy tests, hepatitis serology, and infectious mononucleosis testing. Indications for emergency department use are elucidated.

[Approximate assessment of the successfulness of bacteriological and serological methods of studying rodents in natural plague foci]. / Primernaia otsenka rezul'tativnosti bakteriologicheskogo i serologicheskogo metodov issledovaniia gryzunov v prirodynkh ochagakh chumy

On the basis of the study of two mathematical models of the epizootics the authors suggest a criterion for the determination of the correlation of the value of the results of bacteriological and serological examination of rodents in the natural foci of plague. In accordance with the criteria obtained an evaluation was made of this correlation for Pallasiomys meridianus of the left and right banks of the Volga. It appeared that the calculated assessment of the value of the results of the two methods under study correlated satisfactorily with the data obtained in practice during the epizootologic examination of the Volgo-Urals natural focus of infection.