Autoimmunity in chronic fatigue syndrome in children

We have reported that about half of children with chronic non-specific complaints were positive for antinuclear antibodies (ANA) and that the commonest complaint was fatigue in ANA-positive patients. Therefore, we have proposed a novel disease entity of autoimmune fatigue syndrome (AIFS). In order to investigate the relationship between AIFS and chronic fatigue syndrome (CFS) in children, all CFS patients seen in our clinic were immunologically assessed. Immunological examinations including ANA, autoantibody analysis by Western immunoblotting, lymphocyte subsets and NK activities were performed on 14 CFS patients. Clinical courses of these patients were reviewed retrospectively. None of the patients had fulfilled the CDC criteria for CFS at their first visit. They fulfilled the criteria in a relatively short time, with a 6 months to 6 years smoldering period. All patients had been diagnosed as school refusal by physicians or school teachers. Thirteen patients were positive for ANA and the other one was positive for rheumatoid factor. Twelve patients were positive for antibodies to the 62 kDa protein (anti-Sa) which had been detected in about 40% of AIFS patients. NK activity was not as low as reported in adult patients with CFS. Most of the children with CFS were positive for ANA, suggesting an autoimmune mechanism may play an important role in the pathogenesis of childhood CFS. AIFS patients should be carefully followed because of the possibility of later development of CFS.