Aminoterminal propeptides of type III procollagen in human cerebrospinal fluid

The concentrations of aminoterminal propeptides of procollagen type III were determined by radioimmunoassay in the cerebrospinal fluids of 64 patients with various neurological disorders, including 4 infant patients (less than 1 year). In cerebrospinal fluids of adult patients with normal composition (protein, glucose, cell count), adult patients with pathologic composition, and infant patients the peptide levels (mean value +/- S.D.) were 4.07 +/- 1.26 micrograms/l, 8.15 +/- 6.78 micrograms/l, and 56.9 +/- 31.0 micrograms/l, respectively. The concentrations ranged from 1.96 to 265 micrograms/l and were independent of the respective serum propeptide levels. No statistic correlation with other parameters was found. Gel chromatography revealed a high degree of molecular weight heterogeneity, a substantial portion of immunoreactive material was eluted even with the void volume of Sephacryl S 300. Different slopes of radioimmunoinhibition curves indicate heterogenous antigenicity among the propeptides from various patients. Interaction of the propeptides with fibronectin and/or heparin is probably not responsible for the heterogeneity. The diagnostic potential of cerebrospinal fluid propeptide levels for local connective tissue (collagen) turnover remains to be elucidated.