Plasma volume, intravascular albumin and its transcapillary escape rate in patients with extensive skin disease.

Plasma volume and plasma concentration and transcapillary escape rate of albumin (TER alb), i.e. the fraction of intravascular mass of albumin that passes to the extravascular space per unit time, were determined using 125I-labelled human albumin in eight patients with extensive skin disease. Plasma volume and plasma albumin concentration were reduced (P less than 0-05). Thus the intravascular albumin mass was moderately decreased to an average of 0-55 +/- 0-06 (s.d.) g/cm height compared with a normal mean value of 0-77 +/- 0-07 (s.d.) g/cm. This 29% decrease is statistically significant (P less than 0-001). The transcapillary escape rate of albumin (TER alb) was significantly elevated, mean 8-6 +/- 1-1 (s.d.) % X h-1, as compared to normal subjects, mean 5-6 +/- 1-1 (s.d.) % X h-1, (+54%, P less than 0-001). The same patients were studied again after a 1-week treatment with prednisone, 25-60 mg per day. Plasma albumin concentration, plasma volume and intravascular mass of albumin were unchanged, while TER alb decreased significantly during treatment, mean 5-9 +/- 0-8 (s.d.) % X h-1, (P less than 0-01). It is suggested that displacement of albumin into the skin and loss of albumin from the skin are the dominating mechanisms of the reduction in the intravascular albumin mass in patients with extensive skin disease.