Research ArticleTuberculosis

Pharmacokinetics of rifapentine and rifampin in a rabbit model of tuberculosis and correlation with clinical trial data

See allHide authors and affiliations

Science Translational Medicine  04 Apr 2018:
Vol. 10, Issue 435, eaai7786
DOI: 10.1126/scitranslmed.aai7786
  • Fig. 1 Disease lesions in the rabbit model of pulmonary cavitary TB.

    (A) Diagram showing the method of bronchoscopic Mtb infection of the rabbit lung. Thick black lines show outline of lung lobes, thin black lines show the outline of bronchi, the gray line shows the bronchoscope probe, the blue line shows the inoculation tube, and the red oval shows the infection focus. Top image shows placement of the bronchoscope past the tertiary bronchial division. (B) Freshly resected rabbit lung showing gross pathology at the focus of Mtb infection. (C) Transverse section through the tubercolosis (TB) lesion in the rabbit lung in (B) confirming presence of a cavity. (D) Formalin-fixed cavity in the lower lung lobe of the rabbit model similar to the cavity in (C). (E) Hematoxylin and eosin (H&E) staining of a formalin-fixed representative cavity formed in rabbit lung after bronchoscopic infection with Mtb. The diameter of the cavity after fixation was 4.2 mm. (F) A modification of the same image in (E). The black sections identify areas of necrosis that were grossly identified as caseum (liquefied cell debris) in (D). (G) A fixed tissue section serial to the one in (E). The tissue section was formalin fixed and acid-fast stained; Mtb bacteria are stained red, other cells are blue. (G1A) to (G4A) show four fields of view taken at 50× corresponding to the box insets G1 to G4 in (F). (G1A) and (G4A) show regions of the cavity wall in (F) box insets G1 and G4 (black); (G2A) and (G3A) show regions of caseum/necrosis in (F) box insets G2 and G3 (yellow). (G1B) to (G4B) show four fields of view taken at 100× corresponding to the box insets G1 to G4 in (F). Scale bars, 10 mm (D), 3 mm (E and F), and 50 μm (G).

  • Fig. 2 Tissue-to-plasma drug concentration ratios after treatment of the rabbit TB model.

    Rabbits received either a single dose of rifampin or rifapentine antibiotic or the final dose of a multiple-dosing regimen. (A) Two hours after a single dose of rifampin or rifapentine, (B) 3 hours after a single dose of rifampin or rifapentine, (C) 6 hours after a single dose of rifampin or rifapentine, (D) 2 hours after the final dose of rifampin or rifapentine, and (E) 12 hours after the final dose of rifampin or rifapentine. For analysis of drug concentrations in lung tissue, three to six tissue replicates were collected from each compartment of the diseased rabbit lung after necropsy at different time points after intravenous injection of drug. The tissue-to-plasma ratios of drug concentration were calculated as follows: The drug concentration in tissue was divided by the drug concentration in plasma, which was collected before sacrifice of the rabbit. *P < 0.05, **P < 0.01, and ***P < 0.001, two-tailed t test. UI, uninvolved lung tissue; SL, tissue surrounding lesions; LE, cellular lesion; CAW, cavity wall; CAC/NC, cavity caseum/necrotic center.

  • Fig. 3 MALDI-MSI analysis and gross pathology of rabbit lung after a single dose of rifampin or rifapentine.

    Ion density maps of rifampin (A) or rifapentine (B) in rabbit lung biopsies taken at different time points (2, 3, and 6 hours) after a single drug dose are shown. The maps show the spatial distribution of rifampin and rifapentine across the tissue sections at 2, 3, and 6 hours after dosing. Rifampin and rifapentine were observed only at low signal intensities in the caseum. All matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) images are shown on fixed ion density scales. Images of H&E-stained lung tissue sections from the same biopsy are shown below each ion density map to confirm gross pathology and the type of lung lesion. Scale bar, 5 mm.

  • Fig. 4 MALDI-MSI analysis and gross pathology of rabbit lung after multiple doses of rifampin or rifapentine.

    Ion density maps of rifampin (A) or rifapentine (B) after multiple dosing in rabbit lung biopsies taken 2 or 12 hours after the final dose are shown. At 12 hours after the final dose, the rifampin signal was higher in necrotic lesions than in surrounding infected lung tissue, whereas rifapentine did not concentrate in the necrotic lesions/caseum. All MALDI-MS images are shown on a fixed ion density scale. Images of H&E-stained lung tissue sections from the same biopsy are shown below each ion density map to confirm gross pathology and the type of lung lesion. Scale bar, 5 mm.

  • Fig. 5 11C-rifampin PET-CT imaging of an Mtb-infected rabbit with multiple cavitary lesions.

    (A) Three-dimensional CT reconstruction of the thoracic region of an Mtb-infected rabbit showing the bone (light brown), airways (cyan), and lung cavities (yellow). CT transverse views of the cavitary lesions are also shown. (B) Positron emission tomography (PET)–CT three-dimensional image of the same animal with the PET-CT signal localized in the liver (red) 55 min after intravenous injection of 11C-rifampin. (C) Dynamic PET standardized uptake values (SUV) representing concentrations of 11C-rifampin in rabbit blood. (D) Dynamic PET SUV values representing tissue concentrations of 11C-rifampin in liver measured at 22 time points over a 60-min period after intravenous injection of 11C-rifampin. (E) Mean activity of 11C-rifampin represented as SUV values in three different cavitary lung lesions (each with a minimum of 200 voxels) measured at 22 time points over a 60-min period after intravenous injection of 11C-rifampin. Cavity lesion tissue has a lower concentration of 11C-rifampin compared to the surrounding infected lung tissue (P < 0.0001, two-tailed t test).

  • Table 1 Appearance of disease after bronchoscopic instillation of Mtb into rabbits.

    Numbers in parentheses represent time (in weeks) after infection. The terms small, some, large, and huge represent the diameter of disease lesions, ≤0.5, 0.5 to 1.0, 1.0 to 2, and ≥2 cm, respectively. Mycobacterium tuberculosis, Mtb; CFU, colony-forming factor; CT, computed tomography.

    Concentration
    of Mtb H37Rv
    strain (CFU/ml)
    Volume (in
    milliliters) per
    instillation per
    rabbit
    First CT scan
    result
    (weeks after
    infection)
    Second CT
    scan or clinical
    result (weeks
    after infection)
    5 × 1041.2No sign of
    disease (3)
    No disease (8)
    1.2Small
    consolidation (3)
    Clear (8)
    1.2Small
    consolidation (3)
    Clear (8)
    5 × 1050.2Some
    consolidation (3)
    Clear (6)
    0.4Some
    consolidation (3)
    Clear (6)
    0.6Some
    consolidation (3)
    Clear (6)
    1.2Some
    consolidation (3)
    Clear (8)
    1.2Some
    consolidation (3)
    Two cavities (6)
    1.2Some
    consolidation (3)
    Two cities (7)
    5 × 1060.2Some
    consolidation (3)
    Two cavities (6)
    0.4Large
    consolidation (3)
    Some diffusion (8)
    0.6Large
    consolidation (3)
    One cavity (3)
    1.2Huge
    consolidation (3)
    Sacrificed (3)
    1.2Huge
    consolidation (3)
    Sacrificed (3)
    1.2Huge
    consolidation (3)
    Sacrificed (3)
    5 × 1070.15Large
    consolidation (1)
    Three cavities (4)
    0.30Large
    consolidation (1)
    One cavity (4)
    5 × 1080.15Large
    consolidation (1)
    Two cavities (4)
  • Table 2 Rifampin and rifapentine penetration into rabbit tubercular lesions and healthy lung tissue.

    n, number of samples; N, number of animals. FIX, parameter was fixed; 1/hour, per hour; CL, clearance; V, volume of distribution; CV, coefficient of variance.

    Rifampin (sample size)n/NRifapentine (sample size)n/N
    Plasma38/849/11
    CL (liter/hour per kg)0.175 (3)0.087 (26)
    V (liter/kg)0.54 (5)0.67 (11)
    Residual error of plasma, CV %34 (5)23 (15)
    IIV (CL), CV %42 (17)65 (30)
    IIV (V), CV %30 (42)
    Correlation CL-V0.59 (27)
    Uninvolved lung15/542/11
    Ratio of uninvolved lung/plasma 0.78 (12)0.71 (12)
    Rate constant of plasma to
    uninvolved lung (1/hour)
    1.29 (27)10 FIX
    Residual variability of
    uninvolved lung, CV %
    22 (41)33 (38)
    Cellular lesion20/519/6
    Ratio of cellular lesion/plasma1.12 (5)1.1 (14)
    Rate constant of plasma to
    cellular lesion (1/hour)
    0.59 (19)1.86 (33)
    Residual variability of cellular
    lesion, CV %
    19 (30)27 (25)
    Tissue surrounding lesion12/515/6
    Ratio of tissue surrounding
    lesion/plasma
    1.01 (16)1.05
    Rate constant of plasma to
    tissue surrounding lesion
    (1/hour)
    0.74 (138)0.83
    Residual variability of tissue
    surrounding lesion, CV %
    22 (55)29
    Cavity caseum9/313/4
    Ratio of cavity caseum/plasma1.11 (21)0.25 (21)
    Rate constant of plasma to
    cavity caseum (1/hour)
    0.086 (40)234 (40)
    Residual variability of cavity
    caseum, CV %
    57 (5)60 (31)
    Cavity wall7/216/4
    Ratio of cavity wall/plasma0.98 (8)1.01 (8)
    Rate constant of plasma to
    cavity wall (1/hour)
    0.37 (13)0.63 (4)
    Residual variability of cavity
    wall, CV %
    26 (42)15 (5)

Supplementary Materials

  • www.sciencetranslationalmedicine.org/cgi/content/full/10/435/eaai7786/DC1

    Materials and Methods

    Fig. S1. Concentration-time curve in plasma and lung tissue after a single dose of 30 mg/kg rifapentine administered to healthy rabbits.

    Fig. S2. Concentration-time curve for rifampin and rifapentine in plasma and lung lesions after a single drug dose in rabbits with pulmonary cavitary TB.

    Fig. S3. Concentration-time curve for rifampin or rifapentine in plasma after multiple doses in rabbits with cavitary TB sacrificed 2 or 12 hours after the final drug dose.

    Fig. S4. Absolute drug concentrations of rifampin or rifapentine in different compartments of lung lesions after single or multiple doses in rabbits with pulmonary cavitary TB.

    Fig. S5. PK model describing tissue penetration of rifampin and rifapentine.

    Table S1. PK parameters of rifampin and rifapentine in plasma and in lung lesions after a single drug dose.

  • Supplementary Material for:

    Pharmacokinetics of rifapentine and rifampin in a rabbit model of tuberculosis and correlation with clinical trial data

    Dalin Rifat, Brendan Prideaux, Radojka M. Savic, Michael E. Urbanowski, Teresa L. Parsons, Brian Luna, Mark A. Marzinke, Alvaro A. Ordonez, Vincent P. DeMarco, Sanjay K. Jain, Veronique Dartois, William R. Bishai, Kelly E. Dooley*

    *Corresponding author. Email: kdooley1{at}jhmi.edu

    Published 4 April 2018, Sci. Transl. Med. 10, eaai7786 (2018)
    DOI: 10.1126/scitranslmed.aai7786

    This PDF file includes:

    • Materials and Methods
    • Fig. S1. Concentration-time curve in plasma and lung tissue after a single dose of 30 mg/kg rifapentine administered to healthy rabbits.
    • Fig. S2. Concentration-time curve for rifampin and rifapentine in plasma and lung lesions after a single drug dose in rabbits with pulmonary cavitary TB.
    • Fig. S3. Concentration-time curve for rifampin or rifapentine in plasma after multiple doses in rabbits with cavitary TB sacrificed 2 or 12 hours after the final drug dose.
    • Fig. S4. Absolute drug concentrations of rifampin or rifapentine in different compartments of lung lesions after single or multiple doses in rabbits with pulmonary cavitary TB.
    • Fig. S5. PK model describing tissue penetration of rifampin and rifapentine.
    • Table S1. PK parameters of rifampin and rifapentine in plasma and in lung lesions after a single drug dose.

    [Download PDF]

Navigate This Article