My adult daughter is now in her 7th year of this harrowing illness; her compliment C4 level is very elevated, close to 5000. Does anyone know the significance of this? Also, her C3 is below the cut off number but the lab did not give a precise figure. Does anyone know a good lab. in the US that measures C3? Also, what is the significance of say an elevated C3? I tried to see if this subject has come up and when i punched it in the search, I did not come up with anything, but sometimes this is not accurate. Would be very grateful for any comments on these matters. Regards to all.