SJOGREN’S SYNDROME: CLINICAL FEATURES, HISTOPATHOLOGY & DIAGNOSIS
Author: Sanketh DS, MDS
Sjogren’s syndrome (SS) is an autoimmune, chronic inflammatory disease characterized by dense infiltration of lymphocytes in the exocrine glands. Essentially, the body’s own immune cells, the lymphocytes, attack and infiltrate various exocrine glands and cause their functional impairment. The salivary and lacrimal glands are classically affected in SS, resulting in xerostomia (dry mouth) and keratoconjuctivitis sicca (dry eyes) respectively. Exocrine glands in the gastrointestinal system, respiratory system, skin and vagina may also be affected.
There are two types of presentations of SS. One where patients manifest with functional impairment of the exocrine glands especially with xerostomia and keratoconjuctivitis sicca and the other where patients apart from dry mouth and dry eyes also have other associated autoimmune diseases like rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) or scleroderma. The former is called Primary SS or Sicca syndrome and the latter is called Secondary SS.
SS is not an uncommon condition and affects middle aged to elderly adults usually in the age group of 40-50 years. The condition is predominantly seen in females with a female to male ratio of 9:1. Males and children could also be very rarely affected. At least 50% of patients may manifest with a bilateral parotid gland enlargement.
The main manifestations of SS are xerophthalmia (dry eyes) and xerostomia (dry mouth). The eyes are dry, itchy and painful. Apart from dry eyes, patients also have a scratchy sensation, like there is sand or gravel in the eyes. The chronic dryness and inflammation could cause keratosis of the ocular surface, hence called keratoconjunctivitis sicca. Ocular symptoms are least severe in the morning, with the symptoms worsening throughout the day.
Xerostomia or dry mouth could lead to a variety of secondary manifestations in the oral cavity. In general the oral mucosa is inflamed, erythematous and may be accompanied by a burning sensation. Patients may have an altered taste sensation, difficulty in eating and swallowing. The tongue appears to be fissured and also inflamed and erythematous due to the atrophy of the papillae. Saliva essentially has anti-bacterial properties, maintains pH of the oral cavity and has a self-cleansing action. Hence a lack of saliva would mean, these patients could be highly susceptible to dental caries and periodontal disease. Patients may also manifest with erythematous candidiasis and angular cheilitis secondary to xerostomia.
The most common auto-immune condition associated with SS is reported to be RA. Other diseases like SLE, scleroderma, vasculitis and polymyositis have also been reported.
Salivary glands of patients affected with this disorder show a pattern that is called “lymphoepithelial sialadenitis”. Under the microscope the affected tissue shows dense infiltration by lymphocytes. This infiltration could result in destruction of acinar units of the gland. Few residual ductal epithelial cells may however persist and rather proliferate in this chronically inflamed environment. They form round to irregular islands with lymphocytic infiltrates and may have residual ductal lumens. These islands are called “lymphoepithelial lesions” and were previously called epimyoepithelial islands.
Minor salivary glands from the lower lip of affected patients are usually biopsied checked for aggregates of lymphocytic infiltration. Now, a glandular area with 50 or more lymphocytes is considered to be a focus. The presence of more than one focus in an area of 4 mm2 of glandular area is considered to be supportive of a diagnosis of SS.
DIAGNOSIS (REFER VIDEO)
In order to aid the diagnosis of Sjogren’s syndrome, there have been criteria put across by various bodies like the American-European consensus group and the American college of Rheumatology. The most recent criteria for diagnosis have been proposed by the American-European consensus group in 2016. According to their criteria a diagnosis of Sjogren’s syndrome can be made if an individual:
1. Has an unstimulated salivary flow rate of <=0.1 mL/min (1 point) . This is an objective evidence for dry mouth.
2. Fails the Schrimer’s test (1 point) and has abnormal findings with fluorescein staining (1 point). These two examinations test the lacrimal function and is objective evidence for keratoconjunctivitis.
3. Is positive for anti SSA antibodies (3 points) and
4. Shows lymphoepithelial sialadenitis under the microscope and more than 1 focus of at least 50 lymphocytes in an area of 4 mm2 of glandular parenchyma (3 points).
Now the individual is given points according to the number of criteria he/she is positive for and a final score of 4 or more is considered to be SS positive. However, this is considered only after the patient has met the inclusion and exclusion criteria. A key requirement is the absence of other diseases that may cause SS like symptoms.
Diagnostic criteria referred from article: Stefanski AL, Tomiak C, Pleyer U, Dietrich T, Burmester GR, Dörner T: The diagnosis and treatment of Sjögren’s syndrome. Dtsch Arztebl Int 2017; 114: 354–61.
There is no effective treatment for SS. Treatment is usually symptomatic and systemic therapy should be considered according to the organ affected. As far as the oral symptoms are concerned, artificial saliva could be administered or the use of sugarless gum or candy could help in moistening the oral cavity. Patient should be motivated to maintain oral hygiene due to the increased risk of dental caries and periodontal disease. Sialogogues like pilocarpine could be administered to help in salivary secretion and artificial tears could help better the condition of dry eyes. Of significance is the fact that SS patients have an increased risk of developing low grade non-Hodgkin’s B-cell lymphoma.
Shiboski CH, Shiboski SC, Seror R, et al.: 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren’s syndrome: a consensus and datadriven methodology involving three international patient cohorts. Arthritis Rheumatol 2017; 69: 35–45.
Neville BW, Damm DD, Allen CM, Chi A. Oral and Maxillofacial Pathology. South Asian ed. Elsevier; 2016.
Sjogren’s syndrome (Medscape). Available at: https://emedicine.medscape.com/article/332125-overview
Sapp,Eversole,Wysoki. Contemporary Oral and Maxillofacial Pathology. 2nd ed.Mosby;2004.
Regezzi JA, Sciubba JJ, Jordan RCK. Oral Pathology: Clinicopathologic correlations.5th ed. Elsevier Saunders;2008.
Fletcher C. Diagnostic Histopathology of Tumors:Volume 1. 3rd ed.Elsevier;2007
1st Histology image (left)
2nd Histology image (right)
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