MMP9 and Menkes disease: The valves with myxomatous degeneration exhibited significant correlations between the quantity of bacterial antigens, inflammatory cells and MMP9: Borrelia burgdorferi was positively correlated with the MD percentage (r = 0.52 and p = 0.018), and Mycoplasma pneumoniae was positively correlated with CD45 (r = 0.51 and p = 0.02) and MMP9 (r = 0.45 and p = 0.04).