Subclinical Sjögren's syndrome and anti-Ro/SSA-positive autoimmune fatigue syndrome in children

Abstract

Although Sjögren's syndrome (SS) is quite rare among children, subclinical conditions without any sicca symptoms have been reported. This condition is characterized by nonspecific rheumatic symptoms and histopathological findings in salivary glands which are equivalent to SS. Many children with subclinical SS are positive for anti-Ro/SSA. On the other hand, autoimmune fatigue syndrome (AIFS) is characterized by chronic nonspecific complaints and positive antinuclear antibodies, with or without fulfilling the criteria for chronic fatigue syndrome. Although a novel autoantibody against a 62 kD nuclear protein (anti-Sa) is detected in about 40% of AIFS patients, few marker antibodies for autoimmune diseases, such as anti-DNA, anti-Sm, anti-U1-ribonucleoprotein (RNP), or anticardiolipin, are found in AIFS patients. In this study, however, anti-Ro/SSA was detected in sera from 8 out of 122 AIFS patients. Seven of the 8 anti-Ro/SSA-positive patients were female. All 8 patients had fatigue and low-grade fever, but none complained of xerosis. Western immunoblot analysis revealed that 7 sera reacted with Ro52, and that none was positive for anti-La/SSB or anti-Sa. Two of the 8 patients had histories of recurrent parotitis. Lip biopsies showed mild chronic inflammation compatible with subclinical SS in these 2 patients, although the other 6 patients had no abnormal histopathology. Thus, at least some anti-Ro/SSA-positive patients could be diagnosed as having SS.