Concurrent evaluation of cytokines improves the accuracy of antibodies against Mycobacterium tuberculosis antigens in the diagnosis of active tuberculosis

Data availability statement: All the important data relevant to this study was reported in the manuscript. Any additional data will be made available upon request from the corresponding author.Copyright © 2022 The Authors. Background: Antibodies against mycobacterial proteins are highly specific, but lack sensitivity, whereas cytokines have been shown to be sensitive but not very specific in the diagnosis of tuberculosis (TB). We assessed combinations between antibodies and cytokines for diagnosing TB. Methods: Immuoglubulin (Ig) A and IgM antibody titres against selected mycobacterial antigens including Apa, NarL, Rv3019c, PstS1, LAM, “Kit 1” (MTP64 and Tpx)”, and “Kit 2” (MPT64, Tpx and 19 kDa) were evaluated by ELISA in plasma samples obtained from individuals under clinical suspicion for TB. Combinations between the antibody titres and previously published cytokine responses in the same participants were assessed for diagnosing active TB. Results: Antibody responses were more promising when used in combination (AUC of 0.80), when all seven antibodies were combined. When anti-“Kit 1”-IgA levels were combined with five host cytokine biomarkers, the AUC increased to 97% (92–100%) with a sensitivity of 95% (95% CI, 73–100%), and specificity of 88.5% (95% CI, 68.7–97%) achieved after leave-one-out cross validation. Conclusion: When used in combination, IgA titres measured with ELISA against multiple Mycobacterium tuberculosis antigens may be useful in the diagnosis of TB. However, diagnostic accuracy may be improved if the antibodies are used in combination with cytokines.This work was part of the EDCTP1 programme supported by the European Union (grant number IP_2009_32040, AE-TBC; awarded to GW). The project was also supported by the South African Government through the National Research Foundation (NRF, awarded to NC) and the South African Medical Research Council (SAMRC, postgraduate scholarship to RJ)

Respostas fisiológicas de recém-nascidos pré-termo submetidos ao Metódo Mãe-Canguru e a posição prona Physical responses of pre-term newborn babies submitted to the Kangaroo-Mother Care Method in Prone position

O Ministério da Saúde recomenda e incentiva a Atenção Humanizada ao recém-nascido de baixo peso utilizando-se o Método Mãe-Canguru (MMC) nas unidades integrantes do Sistema Único de Saúde (SUS). O objetivo deste estudo foi avaliar e comparar as respostas fisiológicas entre o MMC e a posição prona (PP), em recém-nascidos pré-termo (RNPT). Foi feito um estudo de intervenção, realizado entre setembro e outubro de 2009, composto por 20 RNPT, de ambos os sexos, com idade gestacional entre 24 a 36 semanas, estáveis hemodinamicamente, sendo classificados como grupo I (MMC) e grupo II (PP). Foram consideradas as variáveis: frequência cardíaca (FC), frequência respiratória (FR), saturação periférica de oxigênio (SatO2) e temperatura corporal (T). As mensurações foram realizadas por três dias consecutivos, antes e 60 min após a aplicação das técnicas. No grupo PP, a FR aferida antes foi significativamente maior do que a aferida após a intervenção, nos 1º e 3º dias (p<0,0001; p<0,006); enquanto que, no MMC, a FR apresentou diferença significativa somente no 3º dia (p<0,006). A FC apresentou redução entre os momentos no 3º dia, nos grupos PP (p<0,02) e no MMC (p<0,04). No grupo PP, a variável SatO2 apresentou significativo aumento nos 1º (p<0,02) e 3º dias (p<0,02), entre os momentos de coleta, e no 3º dia do MMC (p<0,04). Não foram observadas alterações na FR, FC, T e SatO2 com a aplicação do MMC e PP, não havendo melhor desempenho em relação aos grupos. Observamos diminuição da FR após a aplicação do MMC e PP em momentos isolados e aumento da SatO2 no 3º dia após o MMC.<br>The Ministry of Health recommends and looks forward to the Humanized Attention of low weight newborn babies using the Kangaroo-Mother Care Method (MCM) in Unified Health System units. The aim of this work was to evaluate and compare the physiological responses between the MMC and the Prone Position (PP) in pre-term newborn babies (PNB). Intervention study, realized between September and October of 2009, was performed. It was formed by 20 PNB, both sexes, with gestational ages between 24 to 36 weeks, hemodynamic stable, classified as group I (MCM) and group II (PP). The following variables were considered: heart frequency (HF), breathing frequency (BF), periphery saturation of oxygen (SatO2), and body temperature (T). All measurements were realized for three consecutive days, before and 60 min after applying the procedures. On the PP group, the HF checked before was meaningfully higher than the one checked after the procedure, on the first and third days (p<0.0001; p<0.006). On the MCM, the HF presented meaningful difference only on the third day (p<0.006). The HF presented meaningful reduction between the moments of the third day, on the groups PP (p<0.02) and MCM (p<0.04). On the PP group, the variable SatO2 presented meaningful raise on the first (p<0.02) and third day (p<0.02) between the moments of the data collects, and on the third day of the MCM (p<0.04). No changes were observed on the BF, HF, T and SatO2with the application of the MCM and PP, and there were no different results between the groups. We noticed decreasing on the BF after application of the MMC and PP on occasional moments and increasing of SatO2on the third day after the MMC

Diagnostic performance of a seven-marker serum protein biosignature for the diagnosis of active TB disease in African primary healthcare clinic attendees with signs and symptoms suggestive of TB.

: User-friendly, rapid, inexpensive yet accurate TB diagnostic tools are urgently needed at points of care in resource-limited settings. We investigated host biomarkers detected in serum samples obtained from adults with signs and symptoms suggestive of TB at primary healthcare clinics in five African countries (Malawi, Namibia, South Africa, The Gambia and Uganda), for the diagnosis of TB disease. : We prospectively enrolled individuals presenting with symptoms warranting investigation for pulmonary TB, prior to assessment for TB disease. We evaluated 22 host protein biomarkers in stored serum samples using a multiplex cytokine platform. Using a pre-established diagnostic algorithm comprising of laboratory, clinical and radiological findings, participants were classified as either definite TB, probable TB, questionable TB status or non-pulmonary TB. : Of the 716 participants enrolled, 185 were definite and 29 were probable TB cases, 6 had questionable TB disease status, whereas 487 had no evidence of TB. A seven-marker biosignature of C reactive protein, transthyretin, IFN-γ, complement factor H, apolipoprotein-A1, inducible protein 10 and serum amyloid A identified on a training sample set (n=491), diagnosed TB disease in the test set (n=210) with sensitivity of 93.8% (95% CI 84.0% to 98.0%), specificity of 73.3% (95% CI 65.2% to 80.1%), and positive and negative predictive values of 60.6% (95% CI 50.3% to 70.1%) and 96.4% (95% CI 90.5% to 98.8%), respectively, regardless of HIV infection status or study site. : We have identified a seven-marker host serum protein biosignature for the diagnosis of TB disease irrespective of HIV infection status or ethnicity in Africa. These results hold promise for the development of a field-friendly point-of-care screening test for pulmonary TB.<br/

Evaluation of cytokine responses against novel Mtb antigens as diagnostic markers for TB disease.

: We investigated the accuracy of host markers detected in Mtb antigen-stimulated whole blood culture supernatant in the diagnosis of TB. : Prospectively, blood from 322 individuals with presumed TB disease from six African sites was stimulated with four different Mtb antigens (Rv0081, Rv1284, ESAT-6/CFP-10, and Rv2034) in a 24 h whole blood stimulation assay (WBA). The concentrations of 42 host markers in the supernatants were measured using the Luminex multiplex platform. Diagnostic biosignatures were investigated through the use of multivariate analysis techniques. : 17% of the participants were HIV infected, 106 had active TB disease and in 216 TB was excluded. Unstimulated concentrations of CRP, SAA, ferritin and IP-10 had better discriminating ability than markers from stimulated samples. Accuracy of marker combinations by general discriminant analysis (GDA) identified a six analyte model with 77% accuracy for TB cases and 84% for non TB cases, with a better performance in HIV uninfected patients. : A biosignature of 6 cytokines obtained after stimulation with four Mtb antigens has moderate potential as a diagnostic tool for pulmonary TB disease individuals and stimulated marker expression had no added value to unstimulated marker performance.<br/