IgA vasculitis with nephritis: an overview of the pathogenesis and clinical characteristics

IgA vasculitis with nephritis (IgAVN) is closely related to IgA nephritis (IgAN) and IgA vasculitis (IgAV), but the clinical characteristics and exact pathogenesis of IgAVN remain unclear. In the present study, we have reviewed 8 clinical trials with different treatments and found that most IgAVN patients had partial recovery after treatments while few patients (26.5%) recovered completely within 6 months. Adding cyclophosphamide to mycophenolate mofetil was beneficial in children with severe kidney damage but was not effective in adults with serious organ damage (p=0.847). Tonsillectomy reduced the recurrence rate (p=0.03). In 18 reported cases we summarised, intravenous methylprednisolone pulse (MEP) combined with immunosuppressants (66.7%) and MEP combined with oral prednisolone (27.8%) were the two most commonly utilised treatments, and rituximab (40%) was the most frequently used monoclonal antibody. Mechanistically, activated cytotoxic T lymphocytes, natural killer cells, macrophage and completements contributed to the inflammation and endothelial cell apoptosis in IgAVN patients. Galactose-deficient IgA1 may be a threshold for IgAVN. The bulk formation of immune complexes and the decreased clearance rate led to the deposition of immune complexes. In severe cases, coagulation cascade would be triggered and thus caused renal fibrosis.