Increased collagen IV layer in the basal membrane area of the capillaries in severe chronic venous insufficiency.
Lipodermatosclerosis is a sign of severe chronic venous insufficiency. In this stage of CVI one can find capillary leakage of water and plasmaproteins which results in a higher capillary filtration rate. In skin biopsies the result of this process can be seen as a pericapillary halo. The group of Burnand recently described fibrinogen deposits in this area. We studied the capillaries and their surrounding tissue to determine the thickness of the collagen IV deposits. In severe CVI with lipodermatosclerosis a significant increase of the collagen IV layer was observed. Collagen IV thickness was measured by an index method. The collagen IV thickness for this purpose refers to the capillary diameter. It can be suggested that the increase of the venous pressure in the capillaries leads to leakage of several proteins and namely fibrinogen. As a result of the increase of fibrinogen the collagen IV layer becomes thicker which leads to a decreasing function of the capillaries. In this way an auto-amplification mechanism maintains CVI. An other explanation can be induction of collagen IV due to the high capillary pressure in CVI.
Neumann
H A
HA
Department of Dermatology, Elkerliekziekenhuis Helmond-Deurne.
Van den Broek
M J
MJ
D000328:Adult; D000368:Aged; D001485:Basement Membrane / Q000473:pathology; D002196:Capillaries / Q000473:pathology; D003094:Collagen / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D008875:Middle Aged; D009131:Muscle, Smooth, Vascular / Q000473:pathology; D012594:Scleroderma, Localized / Q000473:pathology; D014689:Venous Insufficiency / Q000473:pathology*
D003094:Collagen