New insight into the pathogenesis of minimal change nephrotic syndrome: Role of the persistence of respiratory tract virus in immune disorders.

The pathogenesis of minimal change nephrotic syndrome (MCNS) is a complex clinical problem which, unfortunately, has been in need of significant breakthroughs for decades. Improved understanding of the mechanisms is important to develop effective treatment strategies. To our knowledge, the pathogenesis of MCNS is multifactorial, involving both intrinsic and extrinsic factors, reasonable to be regarded as a "long chain" cascade reaction. Current studies implicating that the disease could probably be caused by immune disorders, however, have focused merely on the middle or terminal of this "long chain". It remains unclear what really triggers the immune disorders. It is noteworthy that the close association of respiratory tract infection with the occurrence, relapse and aggravation of nephrotic syndrome has been confirmed for over two decades. Derived from what we demonstrated in earlier studies, that the persistence of respiratory tract virus may contribute to the onset and development of MCNS, this review summarizes current evidence investigating the possible mechanisms of viral persistence, and discusses the role of viral persistence in the pathogenesis of MCNS. The key point is: whether the persistence of respiratory tract virus results in immune disorders. The available evidence under review also highlight the fact that the background of genetic susceptibility to the disease was found in many patients, which could be triggered by extrinsic factors, e.g. by the infection of respiratory tract virus.