Antinuclear antibodies in Nakajo-Nishimura syndrome. A bridge with research on refractory autoimmune diseases

Abstract

   Nakajo-Nishimura syndrome (NNS) is an autosomal, recessively inherited disorder, which has been reported by Japanese physicians. This disease is characterized by remittent fever, pernio-like skin rashes, nodular erythema-like skin eruptions and partial lipodystrophy. NNS is an immunoproteasome-associated autoinflammatory disorder caused by a mutation of the PSMB8 gene. In general, autoinflammatory diseases are not associated with autoantibody production because it is assumed that autoinflammatory disorders are caused by the dysfunction of innate immunity and/or the dysfunction of proteasomes that have been collectively designated as proteasome-associated autoinflammatory syndromes. Autoinflammatory diseases were originally defined as diseases in which autoantibodies and autoreactive T cells were not detected, without activation of antigen-specific adaptive immune system, unlike autoimmune diseases. However, in recent years, as we previously reported, cases with the appearance of autoantibodies have been reported, and the boundaries are becoming vague.   We herein discuss the relationship between ANA and autoinflammatory NNS. We collected 9 cases with NNS, in which 5 cases showed positive ANA or anti-dsDNA antibody during the course.   The autoantibodies in NNS is also expected due to abnormal production and response of IFNα, but detailed pathological conditions need to be elucidated by accumulation and examination of further cases in the future. In other words, NNS will become a bridge with research on refractory autoimmune diseases.