Nephrotic Syndrome
Proteinuria > 3.5 g/24hr, hypoalbuminemia, severe peripheral/orbital edema, hyperlipidemia, fatty casts ('Maltese cross').
Nephritic Syndrome
Hematuria, dysmorphic RBCs, RBC casts, hypertension, oliguria, mild-to-moderate proteinuria (< 3.5 g/day).
IgA Nephropathy
Young male with gross hematuria 1-2 days post-URI ('synpharyngitic'); normal complement levels; mesangial IgA deposits.
Post-Strep GN (PSGN)
Gross hematuria 1-3 weeks post-strep pharyngitis or impetigo; low serum C3; subepithelial 'humps' on electron microscopy.
Nephrotic vs. Nephritic Syndromes: Core Diagnostic Divergence
Glomerular diseases divide fundamentally into podocyte injury (nephrotic) vs. inflammatory endocapillary proliferation and crescent formation (nephritic):
| Category | Hallmark Urinalysis | Classic Diseases | Key Mechanism |
|---|---|---|---|
| Nephrotic | Heavy proteinuria (> 3.5 g/day), oval fat bodies ('Maltese cross' under polarized light) | Minimal Change Disease, Focal Segmental Glomerulosclerosis (FSGS), Membranous Nephropathy, Diabetic Nephropathy, Amyloidosis | Podocyte effacement, loss of glomerular charge and size barrier permeability |
| Nephritic | Dysmorphic red blood cells, red blood cell (RBC) casts, acanthocytes | IgA Nephropathy, Post-Streptococcal GN (PSGN), Lupus Nephritis, Granulomatosis with Polyangiitis (GPA), Goodpasture Disease | Immune complex deposition, leukocyte influx, GBM breaks, endocapillary proliferation |
Serum Complement (C3/C4) Diagnostic Sorter
Testing serum C3 and C4 provides immediate diagnostic differentiation in glomerulonephritis:
- Low C3 / Hypocomplementemic GN: Post-streptococcal GN (low C3, normal C4), Lupus nephritis (low C3 and C4), Membranoproliferative GN (MPGN), Cryoglobulinemia (very low C4).
- Normal Complement GN: IgA Nephropathy (Berger disease), Granulomatosis with Polyangiitis (ANCA+), Microscopic Polyangiitis, Anti-GBM (Goodpasture) disease.
OMM Board Correlate: Renal Viscerosomatics & Thoracolumbar Junction
- Renal Sympathetic Innervation: T10-T11 via the lesser splanchnic nerve and aorticorenal ganglion. Paraspinal hypertonicity and tissue texture changes are prominently felt at T10-T11.
- Renal Chapman Reflex: Anterior point: 1 inch superior and 1 inch lateral to the umbilicus. Posterior point: intertransverse space between T12 and L1.
- Diaphragmatic Crura: The medial and lateral arcuate ligaments cross the psoas and quadratus lumborum adjacent to the kidneys. Treating diaphragmatic somatic dysfunctions optimizes renal venous outflow.
Board Traps & Common Distractors
- Nephrotic syndrome generates a hypercoagulable state due to urinary loss of antithrombin III, protein C, and protein S; acute flank pain, hematuria, and sudden worsening of proteinuria indicate Renal Vein Thrombosis.
- In patients presenting with nephritic syndrome and hemoptysis (pulmonary-renal syndrome), immediately test for Anti-GBM and ANCA antibodies; rapid initiation of plasmapheresis and pulse steroids preserves renal function.
- Minimal change disease in elderly adults warrants evaluation for occult Hodgkin lymphoma; membranous nephropathy warrants evaluation for occult solid tumors (colon, lung, prostate).