ABSTRACT
The fourth-generation QuantiFERON test for tuberculosis infection, QuantiFERON-TB Gold Plus (QFT-Plus) has replaced the earlier version, QuantiFERON-TB Gold In-Tube (QFT-GIT). A clinical need exists for information about agreement between QFT-Plus and other tests. We conducted this study to assess agreement of test results for QFT-Plus with those of QuantiFERON-TB Gold In-Tube (QFT-GIT), T-SPOT.TB (T-SPOT), and the tuberculin skin test (TST). Persons at high risk of latent tuberculosis infection (LTBI) and/or progression to tuberculosis (TB) disease were enrolled at the 10 sites of the Tuberculosis Epidemiologic Studies Consortium from October 2016 through May 2017; each participant received all four tests. Cohen's kappa (κ) and Wilcoxon signed-rank test compared qualitative and quantitative results of QFT-Plus with the other tests. Test results for 506 participants showed 94% agreement between QFT-Plus and QFT-GIT, with 19% positive and 75% negative results. When the tests disagreed, it was most often in the direction of QFT-GIT negative/QFT-Plus positive. QFT-Plus had similar concordance as QFT-GIT with TST (77% and 77%, respectively) and T-SPOT (92% and 91%, respectively). The study showed high agreement between QFT-GIT and QFT-Plus in a direct comparison. Both tests had similar agreement with TST and T-SPOT.
Subject(s)
Interferon-gamma Release Tests , Tuberculin Test , Tuberculosis/diagnosis , Adolescent , Adult , Aged , Child , Child, Preschool , Disease Progression , Female , Humans , Latent Tuberculosis/blood , Latent Tuberculosis/diagnosis , Latent Tuberculosis/microbiology , Male , Middle Aged , Predictive Value of Tests , Prospective Studies , Reagent Kits, Diagnostic , Tuberculosis/blood , Tuberculosis/microbiology , Young AdultABSTRACT
With the emergence of multi-drug resistant (MDR) and extensively drug resistant (XDR) Mycobacterium tuberculosis (Mtb), a new class of antimycobacterial agents with very different modes of action compared to classical antibiotics, are urgently needed. In this study, a series of 26-residue, amphipathic, α-helical antimicrobial peptides consisting of all D-amino acid residues and synthetic human L-LL37 (L-enantiomer) and D-LL37 (D-enantiomer) were investigated against M. tuberculosis susceptible strain (H37Rv) and a clinical multi-drug resistant strain (Vertulo). Minimal inhibitory concentrations (MICs) were determined through a peptide killing assay. D5, the most active analog against M. tuberculosis had a MIC value of 11.2 µM (35.2 µg/ml) against H37Rv strain and 15.6 µM (49 µg/ml) against the MDR strain. Peptide D1 had similar activity as D5 against the MDR strain (57 µg/mL), a 9-fold improvement in hemolytic activity and a 7.4-fold better therapeutic index compared to D5. Surprisingly, LL37 enantiomers showed little to no activity compared to the de-novo designed α-helical antimicrobial peptides.
Subject(s)
Antitubercular Agents/chemistry , Antitubercular Agents/pharmacology , Cathelicidins/chemistry , Cathelicidins/pharmacology , Drug Design , Amino Acid Sequence , Amino Acid Substitution , Antimicrobial Cationic Peptides , Antitubercular Agents/chemical synthesis , Cathelicidins/chemical synthesis , Cathelicidins/genetics , Drug Resistance, Multiple , Hemolysis/drug effects , Humans , Hydrophobic and Hydrophilic Interactions , Microbial Sensitivity Tests , Molecular Sequence Data , Mycobacterium tuberculosis/drug effects , Protein Structure, Secondary , Stereoisomerism , Structure-Activity RelationshipABSTRACT
A stable and high potency dry powder measles vaccine with a particle size distribution suitable for inhalation was manufactured by CO(2)-Assisted Nebulization with a Bubble Dryer(®) (CAN-BD) process from bulk liquid Edmonston-Zagreb live attenuated measles virus vaccine supplied by the Serum Institute of India. A novel dry powder inhaler, the PuffHaler(®) was adapted for use in evaluating the utility of cotton rats to study the vaccine deposition, vaccine virus replication, and immune response following inhalation of the dry powder measles vaccine. Vaccine deposition in the lungs of cotton rats and subsequent viral replication was detected by measles-specific RT-PCR, and viral replication was confined to the lungs. Inhalation delivery resulted in an immune response comparable to that following injection. The cotton rat model is useful for evaluating new measles vaccine formulations and delivery devices.