Any thoughts on Neopterin levels as possibly correlating with nagalase or as a hint to proceed with nagalase testing? I do have results and they are very high, indicating the following: Interpretation: Neopterin is a marker of inflammatory challenge such as that precipitated by interferon gamma in response to viral infection or intestinal bacterial overgrowth. http://www.betterhealthguy.com/joomla/blog/247-gcmaf : Neopterin is another test that is sometimes used as an indicator of immune suppression. As macrophages become activated, neopterin may rise and later fall. If one is in the normal range for neopterin and has an immune-related illness, this could be an indication that the immune system is suppressed and not responding appropriately. Thank you!