Are diabetics prone to tuberculosis

Diabetes drug could also help against tuberculosis

15.12.2014

A well-known drug used to treat diabetes can also be used to fight tuberculosis. With the active ingredient, the immune defense becomes immune defense
The body's defense system consists of three functional circles:
(1) Bone marrow as a place where immune cells form.
(2) Various central immune organs such as thymus (imprinting T lymphocytes) and lymphatic organs near the gut (for imprinting B lymphocytes).
(3) Secondary lymphatic organs such as the spleen, lymph nodes and tonsils (tonsils).
A distinction is made between the so-called humoral defense (via the body fluids containing antibodies and factors from the so-called complement system) and the cell-mediated defense (with B and T cells, macrophages, antigen-presenting cells, granulocytes, etc.).
significantly improved after infection by mycobacteria, report researchers from the University of Basel and colleagues. A solution to the increasing spread of resistant strains of the bacterium would thus be in sight.

Tuberculosis is a global bacterial infectious disease caused by mycobacteria and most commonly affects the lungs in humans. With 9 million new infections and 1.5 million deaths every year (WHO, 2014), especially in southern and eastern countries, it leads the global statistics of fatal infectious diseases.

Because the triggering bacterium Mycobacterium tuberculosis grows only very slowly, treatment with antibiotics increasingly poses the problem of the development of resistance. Instead of targeting the bacterium directly, researchers in their search for new active ingredients have increasingly concentrated in recent years on strengthening the patient's immune response.

Now researchers at the Department of Biomedicine at the University and University Hospital Basel, together with colleagues in Singapore, have come across the long-approved drug metformin. It is used in the treatment of type 2 diabetes and improves the immune response even after a tuberculosis infection, the scientists found (see Science Translational Medicine 2014, Volume 6/263, page: 263ra159). In cell cultures, but also in living mice infected with tuberculosis, metformin was able to slow the growth of bacteria by increasing the specific immune response.

Metformin is able to prevent the tuberculosis bacterium from growing by increasing the production of so-called reactive oxygen compounds (ROS) in the infected organism. This in turn acts to contain the inflammation. ROS are formed as natural by-products of normal oxygen metabolism and play an important role in signal transmission and the antimicrobial defense against pathogens: the bacteria that have penetrated the cells are killed. People with disorders in ROS production are susceptible to various infectious diseases.

The researchers also found that metformin treatment could control and alleviate the disease in diabetic patients infected with tuberculosis. The treated tuberculosis patients had fewer cavities in the lungs, which meant that fewer mycobacteria could settle there. The active ingredient can be taken by diabetics for years and does not cause any side effects. “Our data suggest that metformin could be used as an adjuvant therapy against tuberculosis,” the scientists said. The effectiveness of the drug should therefore be tested in prospective clinical studies.

Source: University of Basel