Diagnostic Accuracy of Recombinant Immunoglobulin-like Protein A-Based IgM ELISA for the Early Diagnosis of Leptospirosis in the Philippines

Background Leptospirosis is an important but largely under-recognized public health problem in the tropics. Establishment of highly sensitive and specific laboratory diagnosis is essential to reveal the magnitude of problem and to improve treatment. This study aimed to evaluate the diagnostic accuracy of a recombinant LigA protein based IgM ELISA during outbreaks in the clinical-setting of a highly endemic country. Methodology/Principal Findings A prospective study was conducted from October 2011 to September 2013 at a national referral hospital for infectious diseases in Manila, Philippines. Patients who were hospitalized with clinically suspected leptospirosis were enrolled. Plasma and urine were collected on admission and/or at discharge and tested using the LigA-IgM ELISA and a whole cellbased IgM ELISA. Sensitivity and specificity of these tests were evaluated with cases diagnosed by microscopic agglutination test (MAT), culture and LAMP as the composite reference standard and blood bank donors as healthy controls: the mean+3 standard deviation optical density value of healthy controls was used as the cut-off limit (0.062 for the LigA-IgM ELISA and 0.691 for the whole cell-based IgM ELISA). Of 304 patients enrolled in the study, 270 (89.1%) were male and the median age was 30.5 years; 167 (54.9%) were laboratory confirmed. The sensitivity and ROC curve AUC for the LigA-IgM ELISA was significantly greater than the whole cell-based IgM ELISA (69.5% vs. 54.3%, p<0.01; 0.90 vs. 0.82, p<0.01) on admission, but not at discharge. The specificity of LigA-IgM ELISA and whole cell-based IgM ELISA were not significantly different (98% vs. 97%). Among 158 MAT negative patients, 53 and 28 were positive by LigA- and whole cell-based IgM ELISA, respectively; if the laboratory confirmation was re-defined by LigA-IgM ELISA and LAMP, the clinical findings were more characteristic of leptospirosis than the diagnosis based on MAT/ culture/LAMP. Conclusions/Significance The newly developed LigA-IgM ELISA is more sensitive than the whole cell-based IgM based ELISA. Although the final diagnosis must be validated by more specific tests, LigAIgM ELISA could be a useful diagnostic test in a real clinical-setting, where diagnosis is needed in the early phase of infection

Adjustment of Pixel Intensity for Removal of Color Casts in Underwater Images

This article introduces a new color correction method based on the adjustment of pixel intensity to remove color casts in underwater images. As the underwater images are captured in non-homogeneous with nonuniform illumination, the Gray-World Assumption (GWA) causes red artefacts. The method mainly aims to overcome the drawback of GWA for white balancing the underwater images. Before employing GWA, the underwater image is preprocessed by adding a color inferiority-reducing factor to the inferior channels to increase the pixel intensity level. The GWA is applied to preserve the information for substantially removing color casts. The image is adjusted by saturating the 1&#x0025; top and bottom intensity levels pixels to remove the water haze. The color dominancy balanced image is finetuned by multi-scale image fusion technique with three derived inputs. The proposed method outperforms qualitatively and quantitatively based on the comparative analysis with four existing methods

A diecast mineralization process forms the tough mantis shrimp dactyl club

Biomineralization, the process by which mineralized tissues grow and harden via biogenic mineral deposition, is a relatively lengthy process in many mineral-producing organisms, resulting in challenges to study the growth and biomineralization of complex hard mineralized tissues. Arthropods are ideal model organisms to study biomineralization because they regularly molt their exoskeletons and grow new ones in a relatively fast timescale, providing opportunities to track mineralization of entire tissues. Here, we monitored the biomineralization of the mantis shrimp dactyl club—a model bioapatite-based mineralized structure with exceptional mechanical properties—immediately after ecdysis until the formation of the fully functional club and unveil an unusual development mechanism. A flexible membrane initially folded within the club cavity expands to form the new club’s envelope. Mineralization proceeds inwards by mineral deposition from this membrane, which contains proteins regulating mineralization. Building a transcriptome of the club tissue and probing it with proteomic data, we identified and sequenced Club Mineralization Protein 1 (CMP-1), an abundant mildly phosphorylated protein from the flexible membrane suggested to be involved in calcium phosphate mineralization of the club, as indicated by in vitro studies using recombinant CMP-1. This work provides a comprehensive picture of the development of a complex hard tissue, from the secretion of its organic macromolecular template to the formation of the fully functional club.Agency for Science, Technology and Research (A*STAR)National Research Foundation (NRF)This work was funded by the Singapore National Research Foundation (NRF) through an individual NRF Fellowship (to A.M.), and by the Strategic Initiative on Biomimetic and Sustainable Materials (IBSM, NTU). H.L.F. gratefully acknowledges the Swiss National Science Foundation for an individual postdoctoral scholarship (Grant_P2EZP2_172169). R.M.S. and L.C. were supported by A*Star core funding

Cellular and humoral immune response to SARS-CoV-2 vaccination and booster dose in immunosuppressed patients: An observational cohort study.

BackgroundHumoral and cellular immune responses to SARS-CoV-2 vaccination among immunosuppressed patients remain poorly defined, as well as variables associated with poor response.MethodsWe performed a retrospective observational cohort study at a large Northern California healthcare system of infection-naïve individuals fully vaccinated against SARS-CoV-2 (mRNA-1273, BNT162b2, or Ad26.COV2.S) with clinical SARS-CoV-2 interferon gamma release assay (IGRA) ordered between January through November 2021. Humoral and cellular immune responses were measured by anti-SARS-CoV-2 S1 IgG ELISA (anti-S1 IgG) and IGRA, respectively, following primary and/or booster vaccination.Results496 immunosuppressed patients (54% female; median age 50 years) were included. 62% (261/419) of patients had positive anti-S1 IgG and 71% (277/389) had positive IGRA after primary vaccination, with 20% of patients having a positive IGRA only. Following booster, 69% (81/118) had positive anti-S1 IgG and 73% (91/124) had positive IGRA. Factors associated with low humoral response rates after primary vaccination included anti-CD20 monoclonal antibodies (P&nbsp;&lt;&nbsp;0.001), sphingosine 1-phsophate (S1P) receptor modulators (P&nbsp;&lt;&nbsp;0.001), mycophenolate (P&nbsp;=&nbsp;0.002), and B cell lymphoma (P&nbsp;=&nbsp;0.004); those associated with low cellular response rates included S1P receptor modulators (P&nbsp;&lt;&nbsp;0.001) and mycophenolate (P&nbsp;&lt;&nbsp;0.001). Of patients who had poor humoral response to primary vaccination, 35% (18/52) developed a significantly higher response after the booster. Only 5% (2/42) of patients developed a significantly higher cellular response to the booster dose compared to primary vaccination.ConclusionsHumoral and cellular response rates to primary and booster SARS-CoV-2 vaccination differ among immunosuppressed patient groups. Clinical testing of cellular immunity is important in monitoring vaccine response in vulnerable populations