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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Investigation of choice for confirming Henoch Schonlein Purpura is
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The correct answer is  Biopsy of the kidney may be performed both to establish the diagnosis or to assess the severity of already suspected kidney disease. The main findings on kidney biopsy are increased cells and IgA deposition in the mesangium (pa of the glomerulus, where blood is filtered), white blood cells, and the development of crescents.(Refer: Nelson's Textbook of Pediatrics, SAE, 1st edition, pg no. 1217 - 1218)