Clinical and Histologic Characteristics of Dysproteinemias
MYELOMA | AMYLOIDOSIS (AL/AA/AH) | LCDD | FIBRILLARY GLOMERULONEPHRITIS | IMMUNOTACTOID GLOMERULONEPHRITIS | WALDENSTRĂ–M MACROGLOBULINEMIA | |
|---|---|---|---|---|---|---|
| Clinical presentation | Acute kidney injury | Nephrotic syndrome | Nephritic syndrome | Nephritic syndrome | Nephritic syndrome | Nephritic or nephrotic hyperviscosity |
| Urinalysis | Bland or proteinuria (no or minimal albumin) | Bland predominant albuminuria | Hematuria Proteinuria casts | Hematuria Proteinuria casts | Hematuria Proteinuria casts | Hematuria Proteinuria casts |
| Serum paraprotein class | IgD/IgA/IgG | None | None | Uncommon | IgG | IgM |
| Serum free light chains | κ and λ | λ > κ (primary) None (secondary/hereditary) | κ > λ (LCDD) | Unknown | Unknown | λ |
| Histology | ||||||
| Light microscopy | Interstitial fibrosis, edema, inflammation, and giant cells with distal casts | All show similar features with acidophilic deposits in the mesangium, peripheral capillaries, and blood vessels | Heterogeneous most severe pattern is membranoproliferative (mesangiocapillary) with nodularity | Heterogeneous mesangial to membrano-proliferative pattern | Heterogeneous proliferative to membrano-proliferative pattern | Subendothelial deposits and thrombi |
| Congo red stain | Negative | All positive | Negative | Negative | Negative | Negative |
| Immunofluorescence | κ or λ only | λ > κ | κ > λ | Polyclonal IgG κ and λ | Monoclonal IgGκ or IgGλ ± IgM | IgM ± IgG |
| Complement C3 | Negative | All negative | Negative | Positive | Positive | Positive |
| Electron microscopy | Tubular crystals | All show similar random fibrils 8–12 nm | Amorphous dense deposits | Random fibrils 15–30 nm | Parallel microtubules 10–90 nm | Dense deposits ± cryoglobulin microtubules |
Nephrotic syndrome = edema, hypoalbuminemia, and heavy albuminuria.Nephritic syndrome = hematuria and proteinuria, hypertension, kidney impairment.LCDD , Light chain deposition disease.
