Autoimmune Conditions Among the Listed Disorders
Systemic lupus erythematosus and Sjögren's syndrome are definitive autoimmune conditions, while sarcoidosis, chronic mucocutaneous candidiasis, and selective IgA deficiency have varying relationships with autoimmunity but are not primarily classified as autoimmune disorders.
Autoimmune Conditions
Systemic lupus erythematosus (SLE) is a classic autoimmune disease characterized by production of multiple autoantibodies and multi-organ involvement. It is often associated with other autoimmune conditions and presents with manifestations including arthralgia, skin rashes, and internal organ involvement 1, 2.
Sjögren's syndrome is a definitive autoimmune disorder characterized by lymphocytic infiltration of the lacrimal and salivary glands with secondary compromise of gland function, leading to dry eyes and dry mouth. It can occur as primary Sjögren's syndrome or secondary to other autoimmune diseases like SLE 1.
Non-Autoimmune Conditions
Sarcoidosis is a multisystem granulomatous disease of unknown etiology. While it can coexist with autoimmune diseases and shares some immunological features with them (including autoantibody production), it is not primarily classified as an autoimmune disease but rather as a granulomatous disorder 3.
Chronic mucocutaneous candidiasis (CMC) is characterized by susceptibility to Candida infections of skin, nails, and mucous membranes. It can be associated with autoimmune endocrinopathies in conditions like autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED), but CMC itself is an infectious manifestation of immune dysfunction rather than an autoimmune disease 1, 4, 5.
Selective IgA deficiency is a primary immunodeficiency characterized by decreased or absent IgA with normal levels of other immunoglobulins. While it can be associated with autoimmune conditions, it is classified as a primary immunodeficiency rather than an autoimmune disease 1.
Key Distinctions and Relationships
SLE and Sjögren's syndrome frequently coexist, with systematic reviews showing a secondary Sjögren's syndrome prevalence in SLE patients of about 14%-17.8% 2.
Complement deficiencies (which can be seen in selective IgA deficiency) can present with systemic autoimmune disease resembling lupus erythematosus, highlighting the complex relationship between immunodeficiency and autoimmunity 1.
Chronic mucocutaneous candidiasis can occur in patients with autoimmune polyendocrinopathy syndrome type-1 (APS-1), which is caused by mutations in the autoimmune regulator (AIRE) gene 1, 6.
While sarcoidosis is not primarily an autoimmune disease, it can coexist with autoimmune disorders including SLE and Sjögren's syndrome, suggesting potential shared immunopathogenic mechanisms 3.
Clinical Implications
Patients with one autoimmune condition (like SLE or Sjögren's syndrome) should be monitored for the development of additional autoimmune disorders 1.
Patients with primary immunodeficiencies like selective IgA deficiency may have an increased risk of developing autoimmune conditions, requiring appropriate screening and monitoring 1.
The presence of chronic mucocutaneous candidiasis should prompt investigation for underlying immune dysregulation, including possible autoimmune endocrinopathies in the context of APS-1 1, 6.
By understanding the distinctions between these conditions, clinicians can better approach diagnosis, monitoring, and management of patients with these disorders.