68: Sjögren Syndrome Flashcards
What is the primary characteristic of Sjögren syndrome?
Sjögren syndrome is characterized by chronic lymphocytic infiltration and destruction of exocrine glands and epithelia, leading to dry mouth and dry eyes.
What are the common systemic manifestations associated with primary Sjögren syndrome (pSS)?
Common systemic manifestations of pSS include:
- Mild sicca symptoms
- Fatigue
- Arthralgias
- Severe systemic symptoms involving multiple organ systems.
What is the estimated annual incidence rate of primary Sjögren syndrome (pSS)?
The estimated annual incidence rate of pSS is 3.9 to 5.3 per 100,000 individuals.
What role does the Type 1 interferon (IFN) signaling pathway play in Sjögren syndrome?
The Type 1 interferon (IFN) signaling pathway plays a central role in Sjögren syndrome by contributing to apoptosis in epithelial cells of damaged salivary glands and activating autoreactive lymphocytes and autoantibodies, perpetuating chronic inflammation.
What are some environmental factors implicated in the pathogenesis of Sjögren syndrome?
Environmental factors implicated in the pathogenesis of Sjögren syndrome include:
- Viruses: especially Epstein–Barr virus (EBV), Hepatitis C virus, and HIV.
- Chronic inflammation in salivary glands.
- Other viruses: cytomegalovirus, coxsackie A virus, and endogenous retroviruses.
What is the gender distribution of Sjögren syndrome?
Sjögren syndrome has a strong predominance in females, with a female to male ratio of 9:1.
What are some genetic factors associated with primary Sjögren syndrome (pSS)?
Genetic factors associated with pSS include:
- HLA DQA1*0501
- HLA DQB1*0201
- Susceptibility genes such as IRF5, STAT4, IL12A, BLK, and CXCR5.
What role does the Type 1 interferon (IFN) signaling pathway play in the pathogenesis of primary Sjögren syndrome (pSS)?
The Type 1 IFN signaling pathway is central to the pathogenesis of pSS, contributing to increased apoptosis in epithelial cells of damaged salivary glands, activation of plasmacytoid dendritic cells (pDCs), autoreactive lymphocytes, and the production of autoantibodies, which perpetuate chronic inflammatory processes.
How do genetic factors contribute to the susceptibility of primary Sjögren syndrome (pSS)?
Genetic factors such as specific HLA class genes (e.g., HLA DQA10501, HLA DQB10201) and susceptibility genes identified in genomewide association studies (GWAS) like IRF5, STAT4, and IL12A are associated with pSS. These genes are involved in immune regulation and the Type I IFN pathway, influencing the disease’s development.
What environmental factors are implicated in the development of primary Sjögren syndrome (pSS)?
Environmental factors include viral infections, particularly Epstein–Barr virus (EBV), which replicates in salivary glands, and other viruses like Hepatitis C and HIV. These factors contribute to chronic inflammation in the salivary glands, which is associated with the disease’s pathogenesis.
What is the significance of the ‘IFN signature’ in patients with primary Sjögren syndrome (pSS)?
The ‘IFN signature’ refers to the overexpression of IFN-stimulated genes and proteins in approximately 50% of pSS patients. This signature is confirmed in peripheral blood and/or salivary glands and indicates heightened Type I IFN activity, which is a key feature of the disease.
How does the presence of anti-Ro/SSA and anti-La/SSB antibodies correlate with the risk of lymphoma in primary Sjögren syndrome (pSS)?
The presence of anti-Ro/SSA and anti-La/SSB antibodies in pSS patients correlates with an increased risk of developing lymphoma, with studies indicating that about 1 in 5 pSS patients may develop lymphoma, particularly in the context of B-cell activation and proliferation.
What is the role of CD4+ T lymphocytes in the pathogenesis of primary Sjögren’s syndrome (pSS)?
CD4+ T lymphocytes are involved in the immune response by interacting with antigen-presenting cells, leading to the recruitment of inflammatory cells and contributing to the autoimmune process in pSS.
What are the characteristic features of xerostomia in primary Sjögren’s syndrome?
Xerostomia, or dry mouth, is characterized by:
- Decreased saliva secretion
- Persistent dryness throughout the day and night
- Difficulty in chewing and swallowing dry foods
- Altered sense of taste and burning discomfort
- Physical examination may reveal a red and fissured tongue with atrophy of the filiform papillae.
What are the common extraglandular manifestations associated with primary Sjögren’s syndrome?
Common extraglandular manifestations include:
- Vasculitis
- Peripheral neuropathy
- Hematologic abnormalities
- Lymphoma
- Cryoglobulinemia
- Primary biliary cirrhosis
- Raynaud phenomenon
- Fatigue and myalgia.
What is the significance of anti-Ro/SSA and anti-La/SSB antibodies in primary Sjögren’s syndrome?
Anti-Ro/SSA and anti-La/SSB antibodies are hallmark autoantibodies in systemic autoimmune diseases, particularly in pSS. They are associated with:
- Targeting ribonucleoprotein antigens
- High prevalence in patients with pSS
- Potential to cause fetal heart block in newborns of affected women.
What are the clinical findings associated with keratoconjunctivitis sicca in primary Sjögren’s syndrome?
Keratoconjunctivitis sicca is characterized by:
- Ocular dryness
- Burning and itching sensation in the eyes
- Lack of tear production
- Intolerance to contact lenses
- Corneal injection and mucous discharge in the lower fornix
- Enlarged lacrimal glands.
What is the significance of rheumatoid factor positivity in a patient with pSS?
Rheumatoid factor positivity is a marker of systemic autoimmune response in pSS.
What is the significance of ANA positivity in a patient with pSS?
ANA positivity is a marker of systemic autoimmune response in pSS.
What is the significance of anti-Ro/SSA antibody positivity in a patient with pSS?
Anti-Ro/SSA antibody positivity is associated with extraglandular manifestations, vasculitis, and hematologic abnormalities in pSS.
What is the significance of anti-La/SSB antibody positivity in a patient with pSS?
Anti-La/SSB antibody positivity is associated with systemic and hematologic alterations in pSS.
What is the significance of anticentromere autoantibody positivity in a patient with pSS?
Anticentromere autoantibody positivity is associated with increased risk of Raynaud phenomenon, thyroid dysfunction, vasculitis, and peripheral neuropathy in pSS.
What should be your primary concern with a patient with pSS who develops unilateral parotid gland enlargement?
Persistent unilateral parotid gland enlargement in pSS raises suspicion for lymphoma.
What serological findings might you expect in a patient with pSS who has a history of peripheral neuropathy?
Serological findings may include anti-Ro/SSA and anti-La/SSB antibodies, rheumatoid factor, and ANA positivity.