Hi Haider, It all depends on the context. In Behcet's disease IgG, IgM, IgA are very low (Rheum Int 25:33-36). OK these are immune responses but illustrative of divergent responses in particular individuals. In other studies the capsular material alone initiates immune disturbance. CMV is a master of subterfuge. Try reading http://www.omicsonline.org/widespread-outbreaks-of-a-subtle-condition-leading-to-hospitalisation-and-death-2161-1165.1000137.php?aid=20306 Cheers Rod