The purpose of this study is to determine whether adjunctive L-arginine and vitamin D can improve response to standard short course TB therapy in people with newly diagnosed pulmonary TB.
The two major pathways proposed to mediate macrophage mycobacterial killing in humans are the arginine-nitric oxide and Vitamin D-1,25 dihydroxyvitamin D pathways. Our aim is to determine if the key immunomodulatory agents L-arginine and vitamin D can improve the rapidity and magnitude of the microbiological and clinical response in pulmonary TB. We will test the following hypotheses in newly-diagnosed TB patients in Timika, Papua, Indonesia: Our specific aims are to: 1. Determine whether supplementation with L-arginine and/or vitamin D is safe, and results in more rapid improvement in clinical, mycobacterial, immunological, radiological, physiological and functional measures of treatment outcome. We will randomise patients with pulmonary TB to receive, in addition to standard TB therapy, adjunctive arginine, vitamin D and / or placebo in a randomised, double-blind factorial 2x2 design. We will relate serial measurements of plasma concentrations of L-arginine and vitamin D, and immunological responses (pulmonary NO production, T cell function and phenotype) to measures of treatment outcome \[mycobacterial (sputum smear clearance and culture conversion), physiological (spirometry), clinical (symptoms and weight), radiological (chest Xray) and functional (six-minute walk test, modified St George Respiratory Questionnaire)\]. 2. Determine whether pulmonary production of NO is inversely related to disease severity at presentation. Baseline and serial measures of NO production will be related to disease severity and the magnitude and rapidity of clinical response
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
200
L-arginine 6g orally daily
Cholecalciferol 50000 IU once monthly orally
placebo L-arginine once daily
Timika Tuberculosis Clinic and Community Hospital
Timika, Papua Province, Indonesia
Proportion of pulmonary TB patients who are culture negative at 1 month
Time frame: 1 month
Difference in improvement in composite clinical endpoint comprising weight, cough clearance and FEV1 at 2 months.
Time frame: 2 months
Change in plasma L-arginine concentration
Time frame: week 0, 2, 4, 8, 24
Change in plasma 25(OH)D3 concentration
Time frame: week 0, 2, 4, 8, 24
Death, clinical failure and default independently, and 'death or clinical failure or default'.
Time frame: week 24
Hypercalcaemia
Time frame: week 0, 2, 4, 8, 24
Gastrointestinal side effects
Time frame: weekly to week 8 then at week 24
Sputum smear conversion time
Time frame: weekly to week 8 then at week 24
Radiological improvement (percentage lung involvement on CXR at 2 months).
Time frame: week 0, 2, 4, 8, 24
Cough clearance
Time frame: weekly to week 8 then at week 24
Difference in improvement in percent predicted FEV1 at 2 and 6 months.
Time frame: weeks 0, 4, 8, 24
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placebo vitamin D orally once monthly
Weight gain
Time frame: weekly to week 8 then at week 24
Immunological improvement (exhaled NO)
Time frame: week 0, 2, 4, 8, 24
Immunological improvement (T cell CD3ζ expression and T cell function)
Time frame: week 0, 2, 4, 24
Functional improvement measured using six minute walk test
Time frame: week 0, 4, 8, 24
Quality of life assessment using modified St George Respiratory Questionnaire.
Time frame: weeks 0, 4, 8, 24
Primary end points stratified by HIV status.
Time frame: weekly to week 8 then at week 24
Primary end points stratified by baseline vitamin D and L-arginine status.
Time frame: weekly to week 8 then week 24
Primary end points stratified by ethnicity (Papuan and non-Papuan patients).
Time frame: weekly to week 8 then week 24