Bloodwork showed + ana and anti-rnp of 6.7 ai. how does the 6.7 ai align to the elisa scale? that is, how serious is a 6.7? i dont know what the range is. what is the maximum?

That level is negligible if it's measured by ELISA method. Positive level is greater than 25 by ELISA method. Some lab reports equal or greater than 1 is positive (abnormal) but 6.7 is not a high titer. You should know the reference range for abnormal level by your lab report. Positive RNP Ab @ high titer is present in MCTD but low level is not that specific, presents in many autoimmune diseases.