ABSTRACT
Calprotectin, a metal ion-binding protein complex, plays a crucial role in the innate immune system and has gained prominence as a biomarker for various intestinal and systemic inflammatory and infectious diseases, including inflammatory bowel disease (IBD) and tuberculosis (TB). Current clinical testing methods rely on enzyme-linked immunosorbent assays (ELISAs), limiting accessibility and convenience. In this study, we introduce the Fab-Enabled Split-luciferase Calprotectin Assay (FESCA), a novel quantitative method for calprotectin measurement. FESCA utilizes two new fragment antigen binding proteins (Fabs), CP16 and CP17, that bind to different epitopes of the calprotectin complex. These Fabs are fused with split NanoLuc luciferase fragments, enabling the reconstitution of active luciferase upon binding to calprotectin either in solution or in varied immobilized assay formats. FESCA's output luminescence can be measured with standard laboratory equipment as well as consumer-grade cell phone cameras. FESCA can detect physiologically relevant calprotectin levels across various sample types, including serum, plasma, and whole blood. Notably, FESCA can detect abnormally elevated native calprotectin from TB patients. In summary, FESCA presents a convenient, low-cost, and quantitative method for assessing calprotectin levels in various biological samples, with the potential to improve the diagnosis and monitoring of inflammatory diseases, especially in at-home or point-of-care settings.
Subject(s)
Biosensing Techniques , Leukocyte L1 Antigen Complex , Luminescent Measurements , Leukocyte L1 Antigen Complex/analysis , Humans , Biosensing Techniques/methods , Luminescent Measurements/methods , Luciferases/metabolism , Luciferases/chemistry , Biomarkers/analysis , Biomarkers/blood , Inflammatory Bowel Diseases/diagnosis , Inflammatory Bowel Diseases/metabolism , Tuberculosis/diagnosis , Tuberculosis/blood , LuminescenceABSTRACT
BACKGROUND: Severe hypoxemic respiratory failure (SHRF) due to Pneumocystis jiroveci pneumonia (PJP) in AIDS patients represents the main cause of admission and mortality in respiratory intensive care units (RICUs) in low- and middle-income countries. OBJECTIVE: The objective of this study was to develop a predictive scoring system to estimate the risk of mortality in HIV/AIDS patients with PJP and SHRF. METHODS: We analyzed data of patients admitted to the RICU between January 2013 and January 2018 with a diagnosis of HIV infection and PJP. Multivariate logistic regression and Kaplan-Meier method were used in data analysis. The RICU and inhospital mortality were 25% and 26%, respectively. Multivariate analysis identified four independent predictors: body mass index, albumin, time to ICU admission, and days of vasopressor support. A predictive scoring system was derived and validated internally. The discrimination was 0.869 (95% confidence interval: 0.821-0.917) and calibration intercept (α) and slope (ß) were 0.03 and 0.99, respectively. The sensitivity was 47.2%, specificity was 84.6%, positive predictive value was 89.2%, and negative predictive value was 82.6%. CONCLUSIONS: This scoring system is a potentially useful tool to assist clinicians, in low- and medium-income countries, in estimating the RICU and inhospital mortality risk in patients with HIV/AIDS and SHRF caused by PJP.
Subject(s)
Acquired Immunodeficiency Syndrome/mortality , HIV Infections/mortality , Pneumonia, Pneumocystis/mortality , Respiratory Insufficiency/mortality , Acquired Immunodeficiency Syndrome/complications , Adult , Cohort Studies , Female , HIV Infections/complications , Hospital Mortality , Humans , Hypoxia/etiology , Hypoxia/mortality , Intensive Care Units , Male , Pneumonia, Pneumocystis/etiology , Predictive Value of Tests , Prognosis , Prospective Studies , Respiratory Insufficiency/etiology , Sensitivity and SpecificityABSTRACT
Background Severe hypoxemic respiratory failure (SHRF) due to Pneumocystis jiroveci pneumonia (PJP) in AIDS patients represents the main cause of admission and mortality in respiratory intensive care units (RICUs) in low- and middle-income countries. Objective The objective of this study was to develop a predictive scoring system to estimate the risk of mortality in HIV/AIDS patients with PJP and SHRF. Methods We analyzed data of patients admitted to the RICU between January 2013 and January 2018 with a diagnosis of HIV infection and PJP. Multivariate logistic regression and KaplanMeier method were used in data analysis. The RICU and inhospital mortality were 25% and 26%, respectively. Multivariate analysis identified four independent predictors: body mass index, albumin, time to ICU admission, and days of vasopressor support. A predictive scoring system was derived and validated internally. The discrimination was 0.869 (95% confidence interval: 0.821-0.917) and calibration intercept (α) and slope (β) were 0.03 and 0.99, respectively. The sensitivity was 47.2%, specificity was 84.6%, positive predictive value was 89.2%, and negative predictive value was 82.6%. Conclusions This scoring system is a potentially useful tool to assist clinicians, in low- and medium-income countries, in estimating the RICU and inhospital mortality risk in patients with HIV/AIDS and SHRF caused by PJP.
