Combining urine lipoarabinomannan with antibody detection as a simple non-sputum-based screening method for HIV-associated tuberculosis

• Published in: PloS one Vol. 14; no. 6; p. e0218606
• Main Authors: Younis, Hiba, Kerschbaumer, Isabell, Moon, Jee-Young, Kim, Ryung S, Blanc, Caroline J, Chen, Tingting, Wood, Robin, Lawn, Steven, Achkar, Jacqueline M
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 25.06.2019; Public Library of Science (PLoS)
• Subjects: Adult; Antibodies; Antibodies, Bacterial - blood; Antiretroviral agents; Antiretroviral drugs; Antiretroviral therapy; Arabinomannan; Biology and Life Sciences; Biomarkers; Care and treatment; Diagnosis; Diagnostic systems; Enzymes; Epidemiology; Female; Highly active antiretroviral therapy; HIV; HIV infections; HIV Infections - complications; HIV patients; HIV tests; Human immunodeficiency virus; Humans; Immunoglobulin G; Immunoglobulin M; Infectious diseases; Lipopolysaccharides - immunology; Lipopolysaccharides - urine; Male; Medical diagnosis; Medical research; Medical schools; Medical tests; Medicine; Medicine and Health Sciences; Microscopy; Patient outcomes; Proteins; Regression analysis; Regression models; Screening; Sensitivity; Sensitivity and Specificity; Serologic Tests - methods; South Africa; Sputum; Tuberculosis; Tuberculosis - blood; Tuberculosis - diagnosis; Tuberculosis - etiology; Tuberculosis - urine; Tutu, Desmond; Urine; South Africa; New York; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0218606

Simple methods for the accurate triaging and screening of HIV-associated tuberculosis (TB) are urgently needed. We hypothesized that combining serum antibody with urine lipoarabinomannan (U-LAM) detection can improve the detection of HIV-associated TB. We performed a case-control study with sampling from a prospective study of South African HIV-infected subjects who were screened for TB prior to initiating antiretroviral therapy. Sera from all available TB cases (n = 74) and randomly selected non-TB controls (n = 30), all tested for U-LAM, sputum microscopy, GeneXpert, and cultures, were evaluated for antibodies to LAM and arabinomannan (AM). Diagnostic logistic regression models for TB were developed based on the primary test results and the additive effect of antibodies with leave-one-out cross-validation. Antibody responses to LAM and AM correlated strongly (p<0.0001), and IgG and IgM reactivities were significantly higher in TB than non-TB patients (p<0.0001). At 80% specificity, the target specificity for a non-sputum-based simple triage/screening test determined by major TB stakeholders, combining U-LAM with IgG detection significantly increased the sensitivity for HIV-associated TB to 92% compared to 30% for U-LAM alone (p<0.001). Sputum microscopy combined with IgG detection increased sensitivity to 88% compared to 31% for microscopy alone, and Xpert with IgG increased sensitivity to 96% and 99% compared to 57% for testing one, and 70% for testing two sputa with Xpert alone, respectively. Combining U-LAM with serum antibody detection could provide a simple low-cost method that meets the requirements for a non-sputum-based test for the screening of HIV-associated TB.