Table 1.
Pathologic characteristics and outcome of immune complex tubulointerstitial nephritides
| Disease | Light Microscopy | IF | Electron Microscopy | Glomerular Involvement | ABBA | Outcome |
|---|---|---|---|---|---|---|
| Lupus nephritis | Tubulitis and interstitial inflammation | Granular TBM for IgGs and complement | Electron-dense TBM deposits | Rarely with minimal glomerular involvement | − | Partial to complete response to high-dose corticosteroids1,2 |
| IgG4-related systemic disease | Storiform fibrosis with IgG4+plasma cell–rich infiltrate | Granular TBM for IgG and C3, commonly IgG4 subset | Electron-dense TBM deposits | With or without membranous glomerulopathy | − | General response to steroids; refractory cases may respond to rituximab3 |
| Idiopathic hypocomplementemic TIN | Tubulitis and interstitial inflammation | Granular TBM for IgG and C3 | Electron-dense TBM deposits | − | − | Partial to complete response to immunosuppression4 |
| Drug-induced TIN with TBM immune complex deposits | Tubulitis and interstitial inflammation with eosinophils with or without neutrophils | Granular TBM for IgG and C3 | Electron-dense TBM deposits | − | − | Responsive to steroids5 |
| Polyomavirus nephropathy | Viral cytopathic changes | Granular TBM staining for C4d, IgG, and C3 | Electron-dense TBM deposits | − | − | Responsive to decrease in immunosuppression plus cidofovir, leflunomide, or intravenous Ig8 |
| ABBA-TIN | Tubular injury and interstitial inflammation | Granular TBM staining for C4d, IgG, and C3 | Electron-dense TBM deposits | Minimal subepithelial deposits | + | Developed ESRD over years; recurred in transplant |