Final answer:
C3/C4 levels are part of the complement system and vary in diseases like PIGN, MPGN, Lupus, and IgA Nephropathy. They help in diagnosing, determining disease activity, and informing prognosis. PIGN often shows low C3, MPGN may have low C3/C4, Lupus often exhibits both low, while IgA Nephropathy typically has normal levels.
Step-by-step explanation:
The C3/C4 levels refer to the complement system, which is part of the immune system that enhances the ability of antibodies and phagocytic cells to clear microbes and damaged cells, promote inflammation, and attack pathogen's cell membrane. In medical conditions such as Post-Infectious Glomerulonephritis (PIGN), Membranoproliferative Glomerulonephritis (MPGN), Systemic Lupus Erythematosus (Lupus), and IgA Nephropathy, C3 and C4 levels can be insightful.
Each illness can affect complement levels in different ways. In PIGN, C3 levels are often low, typically normalizing within several weeks to months. In MPGN, low C3 levels can be seen and may be accompanied by low C4 levels in some types. Lupus is characterized by low complement levels, especially during active disease periods, which may include both low C3 and C4. Finally, in IgA Nephropathy, C3 and C4 levels are usually normal as the complement system is not typically activated. Monitoring these levels can guide diagnosis, indicate disease activity, and inform prognosis.