Strict vegan diet leading to malnutrition and active tuberculosis (TB)

Introduction:

Cell mediated immunity is the basis of the body's defense mechanisms against mycobacterium tuberculosis. Effective cell mediated immunity requires effective adequate phagocytosis and T-cell function. Vitamin B12 and Vitamin D deficiency has been linked to impaired oxygen burst reaction, which is needed for effective phagocytosis. Experimental data has shown protein energy malnutrition to impair T-cell mediated immune pathways. Strict vegan and vegetarian diets are known to be lacking in cobalamin, protein and vitamin D.

Case Summary:

We present the case of an immunocompetent 40-year-old female who presented to pulmonary clinic with a chronic intractable cough. Social history revealed that she adhered to a strict vegan diet for many years. After initial work up was inconclusive, bronchoalveolar lavage revealed AFB positive smears leading to the diagnosis of acute mycobacterial tuberculosis infection. Albumin levels were noted to be 2.8 g/dl during her admission, and Vitamin D was noted to be 29ng/ml. Molecular testing revealed an INH resistant strain of mycobacterium TB.

Conclusion:

Certain studies have found a correlation between vegetarian diets and increased incidence of active TB. Additionally, vegetarian and vegan diets have been shown to alter our microbiome, an intrinsic part of our innate immunity. The long-term effects of these changes on the respiratory tract are yet to be elucidated. Further research is needed into the effects of vegetarian and vegan diets on the immune system.