Sjögren Syndrome: Pathological Essentials
Sjögren syndrome is a chronic autoimmune disease characterized by the lymphocytic infiltration and destruction of exocrine glands, most notably the lacrimal and salivary glands. It can present as a primary condition or secondary to other autoimmune diseases like Rheumatoid Arthritis.
1. Pathophysiological Markers
| Marker/Feature | Clinical/Pathological Significance |
|---|---|
| Autoantibodies | Anti-Ro (SSA) and Anti-La (SSB). (Positive in roughly 70-90% of cases). |
| HLA Association | Associated with HLA-DR3. |
| Diagnosis | Labial salivary gland biopsy showing **focal lymphocytic sialadenitis**. |
2. Clinical Manifestations
- Sicca Symptoms: Keratoconjunctivitis sicca (dry eyes) causing blurred vision and burning; Xerostomia (dry mouth) leading to dysphagia and increased dental caries.
- Parotid Enlargement: Symmetric swelling of the parotid glands, which may be tender.
- Extraglandular involvement: Arthralgias, cutaneous vasculitis, and interstitial lung disease.
3. High-Yield Clinical Pearls
Malignancy Risk: Patients with Sjögren syndrome have a 40-fold increased risk of developing B-cell Non-Hodgkin Lymphoma (specifically MALT lymphoma of the parotid gland). Watch for sudden, asymmetric enlargement of the parotid gland in these patients.
- Neonatal Lupus: Mothers with Anti-Ro (SSA) antibodies who become pregnant have a higher risk of giving birth to children with neonatal lupus and congenital heart block.
- Schirmer Test: A simple bedside test used to quantify decreased tear production (< 5mm wetting of the filter paper in 5 minutes is diagnostic).