Is Satoyoshi syndrome an autoimmune disease? A systematic review.

OBJECTIVES: Satoyoshi syndrome (SS) is a rare multisystem disease of presumed autoimmunea aetiology. We carried out a systematic review to evaluate the available evidence to support that autoimmune hypothesis.

METHODS: We searched for SS cases in PubMed, the Web of Knowledge and Scopus up to January 2022, using keywords "Satoyoshi syndrome" or "Komuragaeri disease". Data on symptoms, associated autoimmune diseases, presence of autoantibodies and response to treatment were collected.

RESULTS: 77 patients from 57 articles published between 1967 and 2021 were included. 59 patients were women. The mean age at diagnosis was 21.2 years. All cases had painful muscular spasms and alopecia. Frequent manifestations included: diarrhoea, malabsorption, growth retardation, amenorrhea and bone deformity. SS was associated with other autoimmune diseases: myasthenia gravis, autoimmune thyroiditis, idiopathic thrombocytopenic purpura, atopic dermatitis, bronchial and lupus erythematosus. Autoantibody determinations were performed in 39 patients, of which 27 had positive results. The most frequently detected autoantibodies were antinuclear antibodies. Other less frequently found auto-antibodies were: anti-acetylcholine receptor antibodies, anti-DNA antibodies, antithyroid antibodies, anti-GAD and anti-gliadin antibodies. Pharmacological treatment was reported in 50 patients. Most of them improved with corticosteroids, immunosuppressants and immunoglobulins, or a combination of these medications.

CONCLUSION: SS is associated with other autoimmune diseases and a variety of autoantibodies. Improvement after corticosteroid or other immunosuppressant treatment was observed in 90% of cases. These data support an autoimmune aetiology for SS. More studies including systematic determination of autoantibodies in all patients with SS will help us advance in our understanding of this disease.