Diagnostic immunology

The frequency of invasive fungal infections has risen dramatically in recent decades, mostly because of a larger population of at-risk patients who are immunocompromised, neutropenic, or critically ill. For clinicians evaluating these patients, it has become increasingly important to make the diagnosis early so that timely antifungal therapy can be instituted. While histopathology and culture for the causative fungus are required for a definitive diagnosis, adequate tissue samples from protected anatomical sites are not always available and culture may lack sensitivity and require several weeks for results to become available. Thus, immunodiagnosis has become an important adjunctive strategy to diagnose most of the clinically relevant fungi. Many immunodiagnostic methods have been developed and generally target three important aspects of the infection: host antibody, fungal antigen, and fungal metabolites.