Hey,

Pathogenesis of Tuberculosis that is TB can be explained as

Infections occurs when a droplet of the nuclei which contains the tubercle bacilli is inhaled by a person is infected. these are then ingested by alveolar macrophages and some of  these bacilli are destroyed in the inhibition period itself, but a few of them may multiply interacellularly and released with the death of the macrophages. These spread by lymphatic channel medium if they remain alive and then enter the blood stream which primes the immune system for systemic responses.

The bacilli multiply in the alveoli which is present in the host lung. A small number multiply, enter the blood stream and if the immune system cannot control the bacilli then they multiply rapidly in the host and thus causes the Tuberculosis disease. which can affect many major organs of the body including kidneys and brain.

I hope this helps.

All the best!