Chronic bilateral dacryo-adenitis in identical twins: a possible incomplete form of Sjögren syndrome

Abstract

We report an unusual case of chronic bilateral dacryo-adenitis in 10-year-old identical twin sisters. Both girls presented with bilateral lacrimal gland enlargement and developed moderate xerophthalmia and keratitis. Both the lacrimal and minor salivary gland biopsies showed a non-granulomatous inflammatory infiltration of mono-nuclear cells. All granulomatous diseases and neoplasms could therefore be ruled out and only Sjögren syndrome and very few other forms of chronic dacryo-adenitis remained as possible diagnoses. Both patients and their parents were evaluated for auto-antibodies. Very low titres of smooth muscle antibodies were found in one, antinuclear antibodies in two and anti-dsDNA antibodies in all four members of the family. Even though the titres of antinuclear and anti-dsDNA antibodies increased in one of the sisters, both patients did not develop any sign or symptom of a systemic connective tissue disease. During the 6 years' follow up, both patients showed persistent tarsal gland enlargement but no other symptoms apart from a moderate xerophthalmia and occasional mild keratitis.

Familial Risk of Sjögren's Syndrome and Co‐aggregation of Autoimmune Diseases in Affected Families: A Nationwide Population Study

“…Formal evidence for familial aggregation and the magnitude of any familial or genetic contribution are rarely reported. Concordance of SS in several twin pairs has been reported previously , generally with very similar phenotypes (e.g., pathologic findings and serologic and clinical presentations). For example, a pair of monozygotic twins with SS exhibited nearly identical and clonally restricted anti‐Ro/SSA autoantibodies .…”

Primary Sjögren's syndrome in monozygotic twins

“…The HLA type of both twins was the B*08‐DRB1*03‐DQB1*02 haplotype, but the healthy sister lacked this haplotype . Other cases of monozygotic twins with primary SS have also demonstrated very similar phenotypes, clinical symptoms and serologic data between the siblings . In the present case, twin A complained of clinical symptoms (dry eyes and mouth), but twin B did not have classic sicca symptoms and his laboratory findings were also different, including the ANA, anti‐Ro, anti‐La and rheumatoid factor results.…”

Genes and Sjögren's Syndrome

“…Evidence for a genetic component often is derived from studies demonstrating increased concordance rates among monozygotic twins and familial aggregation. Several case reports of twins who had SS have been published, but reliable twin concordance rates have not been estimated 7–10. Scofield and colleagues10 reported a case of monozygotic twins who had SS and who had anti-60 kD Ro/SSA autoantibodies in their sera.…”