Treatment failure of tuberculosis due to concomitant pathology.

Introduction Tuberculosis is a worldwide problem. Nearly 3 million cases of tuberculosis occur per year in Southeast Asia alone.1 Several factors contribute to treatment failure and significant morbidity and mortality. While the most common causes in the "Third World" include poor compliance, late presentation, improper therapy, and the development of drug resistance2, underdiagnosis of this disease is an important reason in the West.3 We present two cases that demonstrate the importance of another factor, the impairment of the body's innate defense mechanism due to concomitant pathology, as a cause of treatment failure.