Infectious biomarkers in autoimmune diseases - importance in personalised medicine

Abstract

There is increasing evidence that bacteria may play important roles in the triggering of emerging diseases, including in autoimmune disease, attention deficit disorder (ADD), control of gut diseases, and depression. Bacterial presence in a susceptible host can be an important biomarker. In TB the presence of Mycobacterium tuberculosis is diagnostic of TB infection. With other members of the Mycobacterium species however, passive carriage or commensal colonisation may be ongoing and have no role in infection of the host. Atypical mycobacteria may be present in the normal individual and pose no risk, but the same organism may cause significant infections in the immune compromised host, in the elderly, and in children. Recent research into emerging infectious diseases suggests that over the last 40 years mycobacteria have evolved to exhibit novel biological mechanisms to avoid detection by the host and become “stealth pathogens”. The immune status of the host and the virulence of the infecting organism are therefore important considerations in diagnosing infectious diseases, and are challenges for the clinical laboratory. Close communication between the clinician and the medical laboratory staff are important requirements to ensure an optimal clinical response to complex interactions between bacteria and the host.