Vitamin D2 und Lungentuberkulose. Wirkungsmechanismus und Behandlungsergebnisse

Vitamin D, vitamin D receptor, and cathelicidin in the treatment of tuberculosis

Vitamin D plays a major role in bone mineral density and calcium homeostasis. Apart from its classical action, the active form of vitamin D [1,25-dihydroxyvitamin D(3) (1,25(OH)(2)D(3))] influences the innate and adaptive immune functions through vitamin D receptor (VDR) that are present in various cells of the immune system. Vitamin D deficiencies have been associated with development of tuberculosis (TB) disease, caused by Mycobacterium tuberculosis. Vitamin D(3) is shown to enhance macrophage phagocytosis of M. tuberculosis and increases the production of antimicrobial peptide cathelicidin and killing of M. tuberculosis. During the preantibiotic era, exposure to sunlight and supplementation of vitamin D were the methods of choice for treatment of TB. Vitamin D supplementation showed sputum clearance and radiological improvement and reduction in mortality among human immunodeficiency virus (HIV)-infected patients with TB. VDR gene polymorphisms regulate the immunomodulatory effect of vitamin D(3) and are associated with faster sputum conversion during anti-TB treatment. The emerging evidences regarding immunomodulatory properties of vitamin D(3) have rekindled interest in vitamin D as an adjunct to anti-TB therapy. The current review explains the important potential application of vitamin D in enhancing the innate immunity to TB and the role of VDR gene variants on anti-TB treatment.

Vitamin D as supplementary treatment for tuberculosis: a double-blind, randomized, placebo-controlled trial

RATIONALE

Vitamin D has been shown to be involved in the host immune response toward Mycobacterium tuberculosis.

OBJECTIVES

To test whether vitamin D supplementation of patients with tuberculosis (TB) improved clinical outcome and reduced mortality.

METHODS

We conducted a randomized, double-blind, placebo-controlled trial in TB clinics at a demographic surveillance site in Guinea-Bissau. We included 365 adult patients with TB starting antituberculosis treatment; 281 completed the 12-month follow-up. The intervention was 100,000 IU of cholecalciferol or placebo at inclusion and again 5 and 8 months after the start of treatment.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was reduction in a clinical severity score (TBscore) for all patients with pulmonary TB. The secondary outcome was 12-month mortality. No serious adverse effects were reported; mild hypercalcemia was rare and present in both arms. Reduction in TBscore and sputum smear conversion rates did not differ among patients treated with vitamin D or placebo. Overall mortality was 15% (54 of 365) at 1 year of follow-up and similar in both arms (30 of 187 for vitamin D treated and 24 of 178 for placebo; relative risk, 1.19 [0.58-1.95]). HIV infection was seen in 36% (131 of 359): 21% (76 of 359) HIV-1, 10% (36 of 359) HIV-2, and 5% (19 of 357) HIV-1+2.

CONCLUSIONS

Vitamin D does not improve clinical outcome among patients with TB and the trial showed no overall effect on mortality in patients with TB; it is possible that the dose used was insufficient. Clinical trial registered with www.controlled-trials.com/isrctn (ISRCTN35212132).

Vitamin D in the treatment of pulmonary tuberculosis

Vitamin D was used to treat tuberculosis in the pre-antibiotic era. New insights into the immunomodulatory properties of 1alpha,25-dihydroxy-vitamin D have rekindled interest in vitamin D as an adjunct to antituberculous therapy. We describe the historical use of vitamin D in tuberculosis treatment; discuss the mechanisms by which it may modulate host response to infection with Mycobacterium tuberculosis; and review three clinical trials and ten case series in which vitamin D has been used in the treatment of pulmonary tuberculosis.