Nephritic Syndrome

Features

  • Rapid onset
  • Hypertension
  • Mild proteinuria (2+ on dipstick, <3.5 g/day)
  • Hematuria
  • RBC casts on UA

Approach

  • UA with microscopy to evaluate for hematuria and RBC casts
    • Erythrocyte casts: Specific for hematuria of glomerular origin
      • Cylindrical/tubular with inclusion of small, agranular spherocytes
  • C3/C4 levels within normal limits
    • pANCA positive (Anti-myeloperoxidase, perinuclear, or Anti-MPO Antibody)
      • Eosinophilic granulomatosis with polyangiitis (EGPA, formerly Churg-Strauss)
        • Associated with asthma, chronic rhinosinusitis
        • Peripheral eosinophilia
      • Microscopic polyangiitis (MPA)
        • May have associated sinusitis or other ENT symptoms
    • c-ANCA positive (Anti-proteinase 3, or Anti-PR3 Antibody)
      • Granulomatosis with polyangiitis (GPA, formerly Wegener’s)
        • Inflammation of upper and lower airway, may have associated cough, sinusitis, or shortness of breath
    • ANCA-negative
      • IgA Nephropathy
        • Classically presents after a viral upper respiratory infection or physical exertion
      • IgA Vasculitis (Henoch-Schonlein Purpura)
        • Classically presents in children and includes abdominal pain, leukocytoclastic vasculitis, and arthralgias. May also present after an acute viral upper respiratory infection
  • C3/C4 levels below normal limits
    • Post-streptococcal glomerulonephritis
      • Low C3, normal C4
      • ~1-3 weeks after Group A streptococcal illness (skin or pharynx)
      • Diagnosis (1):
        • Anti-Streptolysin O (ASO) serology
        • Streptozyme: includes anti-nicotinamide-adenine dinucleotidase (anti-NAD), anti-DNAse B, and anti-hyaluronidase (AHase). Most sensitive.
      • Treatment is supportive
    • Staphylococcal glomerulonephritis
      • Concurrent infection
      • Diagnostic evaluation includes clinical evidence of very recent or current staphylococcal infection and ruling out other etiologies
      • Treatment: Treat underlying infection
    • Membranoproliferative Glomerulonephritis (MPGN)
      • Associated with HBV, HCV, autoimmune diseases, and multiple myeloma/amyloidosis
      • HBV serologies, HCV antibody, ANA, anti-dsDNA antibody, SPEP/UPEP, serum free light chains, serum immunofixation
      • Treat underlying etiology
    • Cryoglobulinemia
      • Cryoglobulins are immunoglobulins that precipitate at temperatures <37 degrees Celsius (2)
      • Associated with infections (most commonly HCV), malignancy, autoimmune disorders (3)
      • Associated symptoms include purpura and arthralgias
      • Diagnose with serum cryoglobulins
    • Endocarditis
      • Diagnose with blood cultures, transesophageal echocardiogram (TEE)
      • Treatment: IV Antibiotics
    • Hereditary Nephritis (Alport Syndrome)
      • Autosomal recessive
      • Associated with deafness
      • Anti-glomerular basement membrane (GBM) antibodies

References

  1. Rawla, P. (2020, August 08). Poststreptococcal Glomerulonephritis. Retrieved January 02, 2021, from https://www.ncbi.nlm.nih.gov/books/NBK538255/
  2. Chen, Y., Cheng, H., Rui, H., & Dong, H. (2019, July 20). Cryoglobulinemic vasculitis and glomerulonephritis: Concerns in clinical practice. Retrieved January 02, 2021, from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6759094/
  3. Ramos-Casals, M., Stone, J. H., Cid, M. C., & Bosch, X. (2012). The cryoglobulinaemias. The Lancet, 379(9813), 348-360. doi:https://doi.org/10.1016/S0140-6736(11)60242-0

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: