Serum alpha 2 globulin levels in granuloma annulare and necrobiosis lipoidica.

Alpha 2-macroglobulin, caeruloplasmin and haptoglobin were measured in the sera of patients with necrobiosis lipoidica, granuloma annulare and diabetes. Alpha 2 Macroglobulin and caeruloplasmin were significantly raised in diabetes, and caeruloplasmin was raised in necrobiosis lipoidica without diabetes. The ratio of alpha 2-globulin to serum albumin was significantly high for all three proteins in diabetes, and for haptoglobin and caeruloplasmin in necrobiosis lipoidica. None of these proteins was abnormally raised in non-diabetic patients with granuloma annulare. There is good evidence that the plasma protein changes in diabetes contribute to the development of microangiopathy by their influence on blood viscosity. The altered plasma protein profile in necrobiosis lipoidica may therefore be of relevance to the development of the vascular lesions in this disorder.