MONOCLONAL-ANTIBODIES TO TYPE-VI COLLAGEN DEMONSTRATE NEW TISSUE AUGMENTATION OF A COLLAGEN-BASED BIOMATERIAL IMPLANT

We developed a panel of highly specific monoclonal antibodies (MAb) to either human or dog collagen Type VI. Various degrees of species cros sreactivities were found with ELISA and immunohistology. Because of th ese differentiating species specificities, which allowed distinction b etween the original donor collagen and newly formed host collagen, the MAb proved to be valuable tools in examination of explanted samples o f an ovine composite vascular prosthesis retrieved from a canine model . With an MAb that reacts with dog but not sheep collagen Type VI, new ly synthesized pockets of collagen Type VI could readily be detected w ithin the prosthesis as early as 3 months after implantation. These ar eas were associated with regions of cell infiltration, presumably deri ved from the host. This association was also apparent in the newly for med intimal region of the prosthesis where only host cells were found. Another of the MAb, which was positive against human but not sheep co llagen, was also used to demonstrate marked deposition of host collage n Type VI in a retrieved human sample of the prosthesis. In this case the antibody was able to detect collagen on a formalin-fixed tissue, w hich would broaden the scope of its use in clinical and pathological s ituations. Use of these novel antibody probes provides a rapid marker for new tissue augmentation of implanted biological devices which woul d be an indicator of the long-term performance of a prosthesis.