Stable isotope variation in pathological bone

Bone samples taken at autopsy from seven individuals from western Canada are studied histologically and the bone protein is analysed for stable isotopes of carbon and nitrogen. The objective of the study is to determine if pathological conditions result in variations in bone protein stable isotope ratios. Of the seven individuals sampled, three are normal and four are pathological. The latter include post-paralytic atrophy, healing fracture, active periostitis and healing osteomyelitis. The normal samples are included in order to determine how much variation to expect in different segments of a bone. In the three samples analysed, the variation is ±0.3 for δ13C and ±0.2 for δ15N. Three of the four pathological specimens exceed normal variation. The greatest variation occurs in the bone with osteomyelitis from an individual who had AIDS (the diseased segment was approximately 2‰ greater for δ15N than the two normal segments from the same individual). The higher nitrogen isotope ratio in the bone segment with osteomyelitis is most likely a result of the fact that the collagen was formed from the catabolism of existing proteins in the body. This finding has implications for the interpretation of nitrogen isotope ratios in individuals who may have died from wasting diseases. Copyright © 1999 John Wiley & Sons, Ltd.