Marker for the renal vasculitis in children is
High-Yield Explanation
Answer is A (Increased IgA levels): The most common systemic vasculitis in children is Henoch Schonlein Purpura, and the most common primary of glomerular disease is IgA Nephropathy. H.S purpura and IgA nephropathy may actually represent spectra of same disease and both are associated with elevated levels of IgA which is the single best answer of choice.