Urinary ferritin protein in subjects with prosthetic heart valves and other disorders.

Twenty-four-hour urine ferritin protein excretion (UFPE) was elevated in the great majority of patients with prosthetic cardiac valves. In this group, there was a positive correlation with the presence of haemosiderin in the urine and with another indirect measure of reduced red-cell survival, namely, serum lactic dehydrogenase. In a number of hospital patients with various disorders, UFPE was also increased. In this latter group, however, there was no constant accompanying haemosiderinuria or elevation of lactic dehydrogenase. The measurement of UFPE can be added to the list of screening tests for intravascular haemolysis, but analysis of the different isoferritins in urine is necessary to fully understand the mechanism of excretion in the different groups.