A high reading in the Immune Function Index indicates that there is dysfunction within your immune system and further assessment is needed to pinpoint exactly what that dysfunction is.
Some of the factors to consider include immune insufficiency, bacterial or viral infections or GI dysfunction associated with immune function: abnormal mucosal barrier function, secretory IgA dysfunction or dysbiosis.
A useful test would be the GI effects from Genova which will assess your gut function. We know that the origin of the majority of health issues comes from the gut, so this is a good starting point.