Primary immunodeficiency diseases in adulthood.

Occasionally, patients present with clinical episodes of infectious disease that seem to fall beyond the scope of normal immunocompetence. Examples include infections that are unusually persistent, recurrent or resistant to treatment, or those involving unexpected dissemination of disease or atypical pathogens. Recent cellular and molecular advances in immunology help to inform the investigation and management of these cases and provide opportunities for family surveillance and disease prevention. More than 100 separate primary (inherited) immunodeficiency disease (PID) states have now been defined, each with a range of syndromic manifestations. Many of these are rare diseases of childhood, but some, either in atypical or attenuated forms, emerge for the first time in adulthood. We outline a diagnostic approach to five groups of PID presenting in adulthood and describe the recently launched web-based PID Register of Australia and New Zealand--a new mechanism for improving knowledge and service delivery to Australasian patients and their clinical carers.