The "endothelium/platelet unit" in hypertrophic osteoarthropathy

Various pathogenetic theories of hypertrophic osteoarthropathy (HOA) have been proposed (neurogenic, hormonal, artero-venous shunts, genetic theory), but none of them is able to satisfactorily explain the genesis of HOA. The hypothesis of a central role of the "endothelium/platelet unit" was recently discussed. Above all, the release of the platelet derived growth-factor (PDGF) contained in platelet granules is particularly interesting. In order to assess the microvascular involvement in HOA we set up a research project whose aims were to evaluate the morphology of the capillary network at the nailfold, the dynamic aspects of microcirculation and in vivo platelet function. Since this study is still in progress, for the time being we present only a few preliminary results.