Doxycycline in Human Pulmonary Tuberculosis

Study Overview
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Brief Summary
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Pulmonary cavitation, a hallmark of tuberculosis (TB), is the site of high mycobacterial burden leading to disease transmission. The cause of tissue destruction leading to cavitation in TB is primarily due to the host inflammatory response. A matrix degrading phenotype develops in TB, in which the activity of host proteolytic enzymes, specifically matrix metalloproteinases (MMPs) is unopposed by their specific Tissue Inhibitors of Metalloproteinases (TIMPs), thus driving tissue destruction and cavitation in TB. This tissue destruction causes morbidity and mortality. MMP inhibition with doxycycline has shown to improve lung function in patients with chronic lung diseases but its use in TB is unclear. We hypothesise that the MMP inhibitor doxycycline will reduce tissue destruction in human pulmonary tuberculosis. Specific aims: To investigate the MMP and TIMP secretion and gene expression in M. tuberculosis (M.tb) - infected primary neutrophils and monocytes from healthy volunteers taking doxycycline. To investigate the intracellular signaling pathways modulated by doxycycline To investigate the effects doxycycline has on biological markers of tissue destruction in TB patients To assess the tolerability and side effects of doxycycline with concurrent standard TB therapy

Detailed Description
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All TB patients are to keep to their standard anti-tuberculous treatment. A standardized questionnaire of symptoms, side-effects and weight shall be recorded. Induced sputum and plasma samples from all TB patients shall be analysed for MMPs and TIMPs before and after the administration of doxycycline for two weeks. In addition, neutrophils and mononuclear cells from TB patients and these shall be stimulated with live, virulent M. tuberculosis in a Biosafety Level 3 laboratory. The supernatants from these cells shall be analysed for MMPs and TIMPs. Healthy volunteers shall be recruited and administered doxycycline for 2 weeks. Neutrophils and mononuclear cells will be isolated from blood prior to treatment, at weeks 2 and 8 and infected with M.tb. Cell culture supernatants and nucleic acids will be harvested. MMP and TIMP expression will be analysed using luminex array and real-time polymerase chain reaction. Intracellular signaling pathways will be examined with a human phospho-kinase array. Matrix destruction will be assessed using collagen quantitative fluorescent assays.

Official Title
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Doxycycline and the Modulation of Host Immunopathology in Human Pulmonary Tuberculosis: A Pilot Study

Conditions
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Tuberculosis

Intervention / Treatment
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* Drug: Doxycycline
* Drug: placebo


Participation Criteria
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Eligibility Criteria
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Healthy Volunteers 10 volunteers will be recruited comprising 5 females and 5 males. Inclusion criteria: No known medical conditions Aged 21 years to less than 70. Exclusion criteria: Unable to give informed consent Prisoners Pregnancy or nursing On medication or oral contraceptives Any concurrent illness, such as influenza TB patients Inclusion criteria: Patients should meet all criteria Patients receiving ≤ 7 days of TB treatment or about to start standard combination TB treatment Confirmed pulmonary TB with positive acid-fast bacilli smear and/or positive TB GeneXpert test and/or culture results Chest radiograph demonstrating pulmonary involvement Aged 21 years to less than 70 Exclusion criteria: HIV co-infection Previous pulmonary TB Severe, pre-existing lung disease such as pulmonary fibrosis, bronchiectasis, Chronic obstructive pulmonary disease and lung cancer Pregnant or breast feeding Allergies to tetracyclines Patients on retinoic acid, neuromuscular blocking agents and pimozide which may increase risk of drug toxicity Autoimmune disease and/or on systemic immunosuppressants Unable to provide informed consent Haemoglobin < 8 g/dl Creatinine 2 times upper limit of normal (ULN) Alanine transaminase >3 times ULN Use of any investigational or non-registered drug, vaccine or medical device other than the study drug within 182 days preceding dosing of study drug, or planned use during the study period Enrolment in any other clinical trial involving a systemic drug or intervention involving the lung Evidence of severe depression, schizophrenia or mania Principal investigator assessment of lack of willingness to participate and comply with all requirements of the protocol, or identification of any factor felt to significantly increase the participant's risk of suffering an adverse outcome

Ages Eligible for Study
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Minimum Age: 21 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Doxycycline<br>Doxycycline 100 mg twice daily with once daily anti-tuberculous treatment comprising of rifampicin 10 mg/kg, isoniazid 5 mg/kg, ethambutol 20 mg/kg, pyrazinamide 25 mg/kg and pyridoxine 10-50 mg per day according to managing physicians' discretion. These will be given daily for 14 days. Subsequently doxycycline will be ceased and patients are to continue with their standard anti-tuberculous treatment and duration according to their managing physician | Drug: Doxycycline<br> <br> |
| Placebo Comparator: Placebo<br>Placebo twice daily with once daily anti-tuberculous treatment comprising of rifampicin 10 mg/kg, isoniazid 5 mg/kg, ethambutol 20 mg/kg, pyrazinamide 25 mg/kg and pyridoxine 10-50 mg per day according to managing physicians' discretion. These will be given daily for 14 days. Subsequently placebo will be ceased and patients are to continue with their standard anti-tuberculous treatment and duration according to their managing physician | Drug: placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of serum marker Procollagen III N-terminal peptide (PIIINP) from day 0 to day 14 in TB patients |  | Day 0 and Day 14 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Number of participants with treatment-related adverse events |  | day 0 to day 56 |