Absence of skin rash in Goodpasture's syndrome: the hyaluronan effect

Goodpasture's syndrome is a rare disease that involves rapidly progressive kidney failure as well as hemorrhagic lung disease. It is a form of autoimmune disorder with unusual features; marked male preponderance, in contrast with other autoimmune disease in which females are at far greater risk. The autoantibodies are directed again the carboxy-extension non-collagenous (NC1) portion of one of the basement membrane-specific collagen IV alpha 3 chains. Basal laminas throughout the body share this structure, including those in kidney, lung and skin. But curiously, skin is rarely involved in Goodpasture's syndrome. Hyaluronan is a large extracellular matrix carbohydrate polymer. Half of total body hyaluronan occurs in skin. High molecular weight hyaluronan, a potent immunosuppressive polymer, might be functioning as an immune shield for skin in Goodpasture's syndrome, and be the basis for the anomaly. A summary of this putative effect is described, including possible molecular mechanisms involved, and suggestions for testing this hypothesis.