Fig. 3.

BMP7- and BMP2-aAB measurements in fracture patients. Analysis of 530 samples from 265 fracture patients treated or not with rhBMP7. (A) Of all the measured samples, 5% show signals above the cut point (dashed line) indicating positivity for BMP7-aAB. Some of the BMP7-aAB signals are up to 10 times above the median. (B) The respective number of samples positive for BMP2-aAB is considerably smaller. (C) The prevalence of BMP7-aAB is higher in the BMP7 treated group with 6% positive patients at surgery and 18% four weeks after surgery compared to the untreated group with 1–2% BMP7-aAB positive sera at these time points. Dotted lines connect the samples for a given patient from time point surgery to 4 weeks after surgery. (D) BMP2-aAB detection divided by treatment groups showed 2% of aAB positive samples in the BMP7-naïve group both before and after surgery. Four weeks after BMP7 treatment, the number increased to 6% BMP2-aAB positive patients, albeit without strongly positive reactions.