Table 1. Immunopathologic and clinical characteristics of fibrillary and immunotactoid glomerulopathies
| Characteristics | Amyloidosis (AL-type) |
Fibrillary GN |
Immunotactoid glomerulopathy |
Congo red staining |
Yes |
No |
No |
Composition |
Fibrils |
Fibrils |
microfibrils |
Fibril/microfibril size (nm) |
8-15 |
12-22 |
>30 |
Organization in tissues |
Random (s-plated sheet) |
Random |
Parallel arrays |
Immunoglobulin deposition |
Monoclonal light chain (mostly £f) |
Usually polyclonal (mostly IgG4), occasionally monoclonal IgG£e) |
Usually monoclonal (IgG£e or IgG£f) |
Glomerular lesions |
Deposits spreading from the mesangium |
Mesangial proliferation, membranoproliferative glomerulonephritis, crescentic glomerulonephritis |
Atypical membranous nephropathy, membranoproliferative glomerulonephritis |
Extrarenal manifestations (fibrillar deposits) |
Systemic deposition disease |
Pulmonary hemorrhage |
Microtubular inclusions in leukemic lymphocytes |
Association with lymphoproliferative disorder |
Yes (myeloma) |
Uncommon |
Common (chronic lymphocytic leukemia, nonHodgkin lymphoma) but debated |
Renal presentation |
Severe nephrotic syndrome, absence of hypertension and hematuria |
Nephrotic syndrome with hematuria, hypertension; rapidly progressive glomerulonephritis |
Nephrotic syndrome with microhematuria and hypertension |