Novel primary immunodeficiencies relevant to internal medicine: novel phenotypes

Area of Science:

• Immunology
• Internal Medicine
• Genetics

Background:

• Primary immunodeficiencies (PIDs) are increasingly recognized in adult patients, including those with delayed diagnoses and adult-onset forms.
• A growing number of children diagnosed with PIDs are surviving into adulthood, requiring ongoing care.
• PIDs affect multiple organ systems, necessitating multidisciplinary management by various internal medicine specialists.

Purpose of the Study:

• To highlight the evolving landscape of primary immunodeficiencies in adults.
• To emphasize the diverse clinical manifestations of PIDs beyond common infectious, allergic, autoimmune, and oncologic presentations.
• To introduce the concept of novel PIDs presenting with seemingly unrelated conditions.

Main Methods:

• Review of current literature on adult primary immunodeficiencies.
• Analysis of recent case reports and cohort studies identifying novel PID phenotypes.
• Synthesis of evidence linking inborn errors of immunity to atypical clinical presentations.

Main Results:

• PIDs are frequently diagnosed in adults, often presenting with complex, multi-organ involvement.
• Established PIDs can manifest with infectious diseases, allergies, autoimmunity, and cancers.
• Emerging evidence suggests that conditions like atypical haemolytic uraemic syndrome, Crohn's disease, and alveolar proteinosis may represent novel PIDs.

Conclusions:

• The recognition and diagnosis of primary immunodeficiencies in adults are expanding.
• The clinical spectrum of PIDs is broader than previously understood, encompassing a wider range of internal medicine conditions.
• Identifying novel PIDs is crucial for accurate diagnosis and effective management of patients with atypical presentations.