Pauci-immune crescentic XXXX associated with ANCA of IgA class.

@entity1 @entity5727 @entity8 @entity1333 @entity288 @entity1985 @entity811 @entity631 @entity28295 @entity19417
Pauci-immune @entity8 is associated strongly with antineutrophil cytoplasmic antibodies (ANCAs) of the immunoglobulin G (IgG) class, which are detected in 80% to 90% of affected @entity1 . IgA ANCAs have been reported in association with various conditions, but never in the setting of @entity19417 . A 28-year-old @entity1 with unexplained polyclonal hyper- @entity5727 diagnosed in childhood presented with decreased kidney function, @entity1985 , and microscopic @entity811 . Kidney biopsy showed pauci-immune crescentic @entity631 . Serum test results were negative for IgG ANCA by means of both indirect immunofluorescence and enzyme-linked immunosorbent assay techniques. Conversely, indirect immunofluorescence performed using anti-IgA antibody was strongly positive with a cytoplasmic ANCA pattern, and an enzyme-linked immunosorbent assay test had positive results for both antimyeloperoxidase and anti-proteinase 3 IgA. IgA ANCAs were not detected in 2 control serum samples from 1 patient with @entity28295 patient with monoclonal hyper-IgA. The @entity1 received @entity288 and 4 weekly perfusions of rituximab (375 mg/m2). After a 6-month follow-up, decreased kidney function and @entity1985 persisted and IgA ANCA titers were unchanged. However, a control kidney biopsy showed a decrease in @entity1333 activity. This first case of @entity19417 associated with ANCA of the IgA class suggests the potential pathogenetic role of these peculiar antibodies. Additional studies are needed to determine whether IgA ANCAs, which are not routinely screened for, can be detected in @entity1 with @entity19417 either alone or in association with IgG ANCA.
