ATIN was the most common pathologic finding on biopsy (14 of 16) and presented in almost all cases as either the major microscopic finding or as a mild form of interstitial inflammation in association with other glomerular pathologies (pauci-immune glomerulonephritis, membranous glomerulonephritis, C3 glomerulonephritis, immunoglobulin A (IgA) nephropathy, or amyloid A (AA) amyloidosis).
While there is no established association between immunoglobulin A (IgA) nephropathy and secondary amyloidosis, which is typically found in chronic inflammatory conditions, it is hypothesized that IgA nephropathy may be a systemic condition with inflammatory mediators.