Autoimmunity in Satoyoshi Disease: a Systematic Review

BackgroundSatoyoshi syndrome (SS) is a rare multisystem disease. Although its cause is unknown, an autoimmune etiology has been postulated. In this paper we carried out a systematic review of all published cases of SS to evaluate the available evidence to support that autoimmune hypothesis. MethodsWe carried out a systematic review of the published cases of SS following the recommendations of the PRISMA statement for systematic reviews. We searched for SS cases in PubMed, the Web of Knowledge (WOS) 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. Results77 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. Other frequent manifestations included: diarrhea, malabsorption, growth retardation, amenorrhea and bone deformity. SS was associated with other autoimmune diseases: myasthenia gravis (2 patients), autoimmune thyroiditis (one patient), idiopathic thrombocytopenic purpura (one patient), atopic dermatitis (one patient), bronchial asthma (one patient) and lupus erythematosus (one patient). Autoantibody determinations were performed in 39 patients, of which 27 had positive results. The most frequently detected autoantibodies were antinuclear antibodies (21 patients). Other less frequently found auto-antibodies were: anti-acetylcholine receptor antibodies (7 patients), anti-DNA antibodies (5 patients), antithyroid antibodies (3 patients), anti-GAD (2 patients) and anti-gliadin antibodies (2 patients). Pharmacological treatment was reported in 50 patients. Most of them improved with corticosteroids (33 patients), immunosuppressants (9 patients) and immunoglobulins (10 patients), or a combination of these medications. ConclusionsSS is associated with other autoimmune diseases and a variety of autoantibodies. Improvement after corticosteroid or other immunosupressant treatment was observed in 90% of cases. These data support an autoimmune etiology for SS. More studies are necessary, including the systematic determination of autoantibodies in all patients with SS to help us advance in our understanding of this disease.