Plasma and urine concentrations of
factor XIII and its circulating substrates (
fibronectin,
fibrinogen, and
alpha 2-antiplasmin) were measured in a group of 36 patients with
nephrotic syndrome. The results were compared with those obtained in a group of 32 normal volunteers (control group) and 12 patients with
end-stage renal disease (
ESRD). A mild but significant reduction in plasma level and an abnormal urinary excretion of alpha 2-antiplasmin was found in the nephrotic group. Plasma concentrations of
factor XIII,
fibronectin, and
fibrinogen were significantly elevated in patients with
nephrosis. In contrast, patients with
ESRD showed no significant difference in the plasma concentrations of either
factor XIII,
fibronectin, or alpha 2-antiplasmin and only a modest elevation of
fibrinogen when compared with normal controls. No significant correlation was found between serum
creatinine concentration and plasma levels of
factor XIII and its circulating substrates in the nephrotic group. No measurable quantities of
factor XIII and only small quantities of
fibronectin were found in the urine of patients with
nephrosis. Elevation of plasma
factor XIII,
fibronectin, and
fibrinogen concentrations in the nephrotic group is considered to be the result of a combination of increased synthesis and possibly contracted intravascular distribution of these macromolecular
proteins in the face of their negligible urinary losses. The presence of the observed abnormalities in the nephrotic group and their absence in the non-nephrotic
ESRD group tends to exclude
renal failure as a cause of these abnormalities. Although the clinical significance of these abnormalities is uncertain, they can potentially contribute to the thrombophilic
diathesis and platelet hyperaggregability in
nephrotic syndrome.