What is Sjogren syndrome?

Sjögren's Syndrome

Sjögren's syndrome is a chronic systemic autoimmune disorder characterized by lymphocytic infiltration of the lacrimal and salivary glands, leading to dry eyes and dry mouth, with potential for multiple organ involvement and increased risk of lymphoma development. 1, 2

Definition and Pathophysiology

• Sjögren's syndrome is defined as dry eye and dry mouth associated with systemic immune dysfunction, affecting approximately 0.4% of the general population 1
• The condition is characterized by infiltration of the lacrimal and salivary glands with lymphocytes, resulting in secondary compromise of gland function 1
• The underlying mechanism involves destruction of the epithelium of exocrine glands due to abnormal B cell and T cell responses to autoantigens, particularly Ro/SSA and La/SSB 3

Epidemiology

• Women are much more commonly affected than men, with a female-to-male ratio of 20:1 1, 4
• Annual incidence is approximately 3.9-5.3 per 100,000 people, with a prevalence of 92.8 cases per 100,000 1
• About 10% of patients with clinically significant dry eye have an underlying Sjögren's syndrome 1

Classification

• Primary Sjögren's syndrome occurs alone as a distinct entity 1
• Secondary Sjögren's syndrome occurs in association with other autoimmune diseases such as rheumatoid arthritis, scleroderma, or systemic lupus erythematosus 1, 5

Clinical Manifestations

Glandular Symptoms

• Dry eyes (keratoconjunctivitis sicca) - sensation of dryness, irritation, foreign body sensation, and light sensitivity 6
• Dry mouth (xerostomia) - need for liquids to swallow dry foods, frequent sipping of water, burning sensation, and frequent dental cavities 6

Systemic Manifestations

• Arthralgia, myalgia, and fatigue are common systemic symptoms 1, 2
• Potential involvement of multiple organs beyond exocrine glands, including lungs, kidneys, liver, nervous system, and vasculature 4, 5
• Thyroid dysfunction or autoimmune thyroiditis may be associated with primary Sjögren's syndrome 4

Diagnostic Criteria

The latest classification criteria for Sjögren's syndrome are based on a weighted scoring system 1:

• Anti-SSA/Ro antibody positivity (3 points) 1, 6
• Focal lymphocytic sialadenitis with focus score ≥1 foci/4 mm² (3 points) 1
• Abnormal ocular staining score ≥5 or van Bijsterveld score ≥4 (1 point) 1
• Schirmer test result ≤5 mm/5 minutes without anesthesia (1 point) 1
• Unstimulated salivary flow rate ≤0.1 ml/minute (1 point) 1

A total score of ≥4 meets the criteria for primary Sjögren's syndrome in individuals with signs and/or symptoms suggestive of the condition 1, 6

Complications and Associated Risks

• Patients with Sjögren's syndrome have approximately a 5% risk of developing lymphoma 2, 4
• Decreased C4 levels at diagnosis are associated with a higher risk of developing lymphoma 1, 2, 4
• Other ocular manifestations of immune dysfunction may develop, including scleritis, sterile keratitis, and uveitis 1
• Potentially life-threatening vasculitic or lymphoproliferative disorders may occur 1

Management

Ocular Manifestations

• Evaluation should include symptoms of both discomfort and visual disturbance 1
• Assessment of relative contribution of aqueous production deficiency and evaporative loss of tear volume 1
• Tear substitutes are the mainstay of therapy for keratoconjunctivitis sicca 7

Oral Manifestations

• Intense oral hygiene, prevention and treatment of oral infections 7
• Use of saliva substitutes 7
• Local and systematic stimulation of salivary secretion 7

Systemic Therapy

• Cholinergic agents such as pilocarpine and cevimeline are the cornerstone of current therapy 7
• Corticosteroids, cyclophosphamide, and nucleoside analogues are reserved for severe extraglandular manifestations 7
• Anti-B-cell therapy shows promise for both glandular and extraglandular manifestations 7

Important Considerations

• Co-management with a rheumatologist is essential due to potential systemic complications 1, 4
• Regular monitoring for signs of lymphoma development is recommended 2, 4
• Screening for other autoimmune conditions may be warranted 4
• Patient education about the nature of the problem, aggravating factors, and goals of treatment is critical to successful management 1

Key Pitfalls to Avoid

• Overlooking the possibility of Sjögren's syndrome in patients with dry eye symptoms, especially in middle-aged women 1, 8
• Neglecting to screen for lymphoma in patients who develop unexplained hematologic abnormalities 2
• Failing to recognize medication-induced hematologic abnormalities in patients on immunosuppressive therapy 2