Sjogren's Syndrome Flashcards
Define Sjogren’s syndrome.
Sjogren syndrome is a systemic auto-immune disorder characterised by the presence of dry eyes (keratoconjunctivitis sicca) and dry mouth (xerostomia) as a consequence of lymphocytic infiltration into the lacrimal and salivary glands.
Sjogren syndrome can occur alone (primary Sjogren syndrome) or along with another auto-immune disease (secondary Sjogren syndrome) such as lupus, rheumatoid arthritis, and systemic sclerosis.
What is the aetiology of Sjogren’s syndrome?
Unknown - linked to HLA-A1, B8, DR3
Associated with RA, scleroderma, SLE, polymyositis and organ specific AI diseases (e.g. PBC, AI hepatitis, AI thyroid disease, myasthenia gravis)
What is the pathophysiology of Sjogren’s syndrome?
- Salivary gland damage involves immunological, genetic, hormonal and viral components.
- Polyclonal B lymphocytes produce auto-antibodies.
- Antibodies to the binding components of Ro/La ribonucleoprotein complex are very common. Biopsies show anti-Ro- and anti-La-producing B-cells are present in the infiltrates.
- Antinuclear antibodies, rheumatoid factor, anti-thyroglobulin and antibodies to the lacrimal and salivary glands are also seen.
- T cell mechanisms may further the auto-immune cascade
Most common in women - oestrogen strongly affects course of auto-immune diseases and is crucial for initiation of AI. Women have more Ig at baseline and produce more Ig in response to infection/immunisation compared to males. Androgens protect from AI so perhaps women with Sjogren’s are androgen deficient. There may also be association with extra X chromosome e.g. SLE is more common in trisomy X
What is the age of onset for Sjogren’s? Is there gender predominance?
Onset usually between 15-65yrs
Male:female 1:9 ratio
What are the risk factors for Sjogren’s? (3)
- Female
- SLE
- RA
- Systemic sclerosis
- HLA class II markers - A1, B8, DR3/DQ2, anti-Ro/L-positive
- age 20-30 and after menopause
What are the symptoms of Sjogren’s syndrome?
- General: Fatigue, fever, weight loss, depression.
- Dry eyes (keratoconjunctivitis sicca): Gritty, sore eyes.
- Dry mouth (xerostomia): Dysphagia may result secondarily.
- Dry upper airways: Dry cough, recurrent sinusitis.
- Dry skin or hair (uncommon).
- Dry vagina (uncommon): May cause dyspareunia.
- Less GI mucus secretion causing symptoms of reflux oesophagitis, gastritis,
- constipation.
- Arthralgia
- Raynaud’s phenomenon
- Organ specific disease e.g. PBC, MG, thyroid disease, AI hepatitis and pancreatitis.
- Renal - nephrogenic diabetes insipidus and renal tubular necrosis
- Pulomnary diffusion defects/fibrosis
- Vasculitis
- Increased incidence of non-Hodgkin’s B-cell lymphoma.
What are the signs of Sjogren’s on examination?
- Parotid or salivary gland enlargement.
- Dry eyes.
- Dry mouth or tongue.
- Vasculitis - most common beyond exocrine galnd manifestations. Manifests as skin rash.
- Dental caries - may lead to loss of all teeth
- Signs of the associated conditions.
What investigations would you do for Sjogren’s syndrome?
Bloods:
- ESR - raised
- Amylase - raised if salivary glands involved
-
Auto-antibodies - RF, ANA (60%), Anti-ENA (anti-Ro, anti-La)
- anti-60 kD (SS-A) Ro and anti-La (SS-B) - found in up to 90% of Sjogren’s cases. Vasculitis is associated with their presence.
Other:
- Schirmer’s test - positive
- Fluorescein corneal staining test - Cornea is stained and this elucidates corneal changes associated with insufficient tear flow/excessive dryness. Inspected under microscope.
- Sialometry - parotid salivary flow rate reduced,
- Isotope scan - reduced uptake or secretion
- Biopsy - salivary or labial glands (lower lip), focus score of 1 or more supports diagnosis (at least 50 inflammatory cells in a 4 mm^2 glandular section)
What is Schirmer’s test?
Quantitatively measures tears. A filter paper is placed in the lower conjunctival sac. The test is positive if less than 5 mm of paper is wetted after 5 minutes
What is Sjogren’s affecting the eyes called?
keratoconjunctivitis sicca
What is Sjogren’s causing a dry mouth called?
Xerostomia
