Glomerulonephritis and Complement Levels Explained
Glomerulonephritis (GN) involves inflammation of the kidney's glomeruli. The complement system is part of the immune response. In certain types of GN, immune complexes activate the complement cascade, leading to its consumption and thus, low levels (hypocomplementemia), particularly C3 and C4.
Conditions Associated with Low Complement GN
Several conditions commonly present with glomerulonephritis and low complement levels due to immune complex deposition:
- Subacute bacterial endocarditis (SBE): Immune complexes formed against bacterial antigens can deposit in glomeruli, activating complement.
- Systemic lupus erythematosus (SLE): Lupus nephritis is often driven by autoantibodies forming immune complexes that deposit in glomeruli, consuming complement.
- Cryoglobulinaemia: Immune complexes involving cryoglobulins can deposit in glomeruli, leading to complement activation and low levels.
Identifying the Exception: IgA Nephropathy
IgA nephropathy is characterized by deposits of Immunoglobulin A (IgA) in the glomeruli. While it is an immune-mediated glomerular disease, it is typically associated with normal or sometimes elevated complement levels. Unlike SBE, SLE, and cryoglobulinemia, significant complement consumption is not a hallmark feature of IgA nephropathy.
Conclusion on Low Complement GN
Therefore, IgA nephropathy is the condition listed that is NOT consistently associated with glomerulonephritis presenting with low complement levels.
Important Questions from Nephrotic Syndrome
A 40-year-old female with nephritic range proteinuria is found to have low serum complement levels. Which of the following can be the likely etiology?
1. Systemic lupus erythematosus
2. Post-infectious glomerulonephritis
3. Infective endocarditis
4. Mesangio-capillary glomerulonephritis
Select the correct answer using the code given below:
- Which of the following are the indications of Renal biopsy?
1. Chronic Kidney disease with normal sized kidney
2. Nephrotic syndrome in adults
3. Nephrotic syndrome in children with atypical features
Select the correct answer using the code given below: - Presence of Dysmorphic Erythrocytes in urine analysis is suggestive of:
- Of all the types of lupus nephritis, the worst outcome is seen in:
Match list I with list II and select the correct answer using the code given below the lists:
List I (Urine exam) List II (Disease) A. Red cell casts 1. Nephrotic syndrome B. Microscopic haematuria 2. Chronic renal failure C. Proteinuria 3. Polycystic kidney disease D. Broad cell casts 4. Glomerulonephritis
