Differential Diagnosis for Low C3 and C8 Cells and High IgG
- Single most likely diagnosis:
- Systemic Lupus Erythematosus (SLE): This condition is characterized by low complement levels (C3 and C8) due to consumption during immune complex formation and high IgG levels due to chronic inflammation and immune activation.
- Other Likely diagnoses:
- Membranoproliferative Glomerulonephritis (MPGN): A type of kidney disease that can cause low C3 levels due to alternative pathway activation and high IgG levels due to immune complex deposition.
- Post-Streptococcal Glomerulonephritis (PSGN): An immune complex-mediated disease that can cause low C3 levels and high IgG levels due to the immune response to streptococcal infection.
- Chronic Hepatitis: Certain types of chronic hepatitis, such as hepatitis C, can cause low C3 levels due to consumption and high IgG levels due to chronic inflammation.
- Do Not Miss (ddxs that may not be likely, but would be deadly if missed.):
- Hemolytic Uremic Syndrome (HUS): A condition characterized by low C3 levels due to alternative pathway activation and high IgG levels due to immune complex formation, which can lead to renal failure and death if not promptly treated.
- Atypical Hemolytic Uremic Syndrome (aHUS): A rare but life-threatening condition that can cause low C3 levels and high IgG levels due to uncontrolled complement activation.
- Rare diagnoses:
- C3 Glomerulopathy: A rare group of disorders characterized by low C3 levels due to dysregulation of the alternative complement pathway and high IgG levels due to immune complex formation.
- Hyper-IgG Syndrome (Job Syndrome): A rare condition characterized by high IgG levels due to impaired neutrophil function and low C3 levels due to consumption during chronic inflammation.