Clinical significance of plasma factor VIII levels in renal disease.

The plasma levels of factor VIII related antigen (FVIIIRA), factor VIII coagulant activity (FVIIIC) and the ratio between them were evaluated in 57 patients with kidney disease of diverse etiology, and with either normal (49) or impaired (8) renal function. Renal biopsy specimens were obtained from 47 patients with normal renal function. No correlation was observed between the increased plasma values of FVIIIRA and FVIIIC and renal function, histologic findings, and the pattern of deposition of immunoglobulin and complement. In contrast, plasma levels of both components of factor VIII were positively correlated with the magnitude of proteinuria. In the authors' opinion, the determination of factor VIII components is of no value in establishing the diagnosis and prognosis of patients with kidney disease. The finding on immunofluorescence of simultaneous deposition of factor VIII and C3 in the arteriolar walls might suggest incipient atherosclerotic damage. The FVIIIRA/FVIIIC ratio was increased in 87% of the patients and particularly in those with membrano-proliferative glomerulonephritis and chronic renal failure; however, the clinical relevance of this finding remains to be elucidated. The significant correlation between the two components suggests that in renal disease a simultaneous aggregation of the two proteins in factor VIII takes place.