Quantification of circulating Mycobacterium tuberculosis antigen peptides allows rapid diagnosis of active disease and treatment monitoring

Proc Natl Acad Sci U S A. 2017 Apr 11;114(15):3969-3974. doi: 10.1073/pnas.1621360114. Epub 2017 Mar 27.

Abstract

Tuberculosis (TB) is a major global health threat, resulting in an urgent unmet need for a rapid, non-sputum-based quantitative test to detect active Mycobacterium tuberculosis (Mtb) infections in clinically diverse populations and quickly assess Mtb treatment responses for emerging drug-resistant strains. We have identified Mtb-specific peptide fragments and developed a method to rapidly quantify their serum concentrations, using antibody-labeled and energy-focusing porous discoidal silicon nanoparticles (nanodisks) and high-throughput mass spectrometry (MS) to enhance sensitivity and specificity. NanoDisk-MS diagnosed active Mtb cases with high sensitivity and specificity in a case-control study with cohorts reflecting the complexity of clinical practice. Similar robust sensitivities were obtained for cases of culture-positive pulmonary TB (PTB; 91.3%) and extrapulmonary TB (EPTB; 92.3%), and the sensitivities obtained for culture-negative PTB (82.4%) and EPTB (75.0%) in HIV-positive patients significantly outperformed those reported for other available assays. NanoDisk-MS also exhibited high specificity (87.1-100%) in both healthy and high-risk groups. Absolute quantification of serum Mtb antigen concentration was informative in assessing responses to antimycobacterial treatment. Thus, a NanoDisk-MS assay approach could significantly improve the diagnosis and management of active TB cases, and perhaps other infectious diseases as well.

Keywords: blood test; nanodisk; rapid diagnosis; treatment monitoring; tuberculosis.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antigens, Bacterial / blood*
  • Bacterial Proteins / blood
  • Case-Control Studies
  • Female
  • HIV Seropositivity
  • Humans
  • Male
  • Middle Aged
  • Mycobacterium tuberculosis / pathogenicity
  • Nanoparticles
  • Peptides / blood
  • Sensitivity and Specificity
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / instrumentation
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / methods
  • Tuberculosis / diagnosis*
  • Tuberculosis / drug therapy*
  • Tuberculosis / microbiology
  • Tuberculosis, Pulmonary / diagnosis
  • Tuberculosis, Pulmonary / drug therapy
  • Tuberculosis, Pulmonary / microbiology

Substances

  • Antigens, Bacterial
  • Bacterial Proteins
  • CFP-10 protein, Mycobacterium tuberculosis
  • ESAT-6 protein, Mycobacterium tuberculosis
  • Peptides
  • Mycobacterium tuberculosis antigens