ABSTRACT
Clotting time under basal conditions and 30', 60' and 120' after 100 I.U. heparin/kg i.v. was determined in four groups:1) 15 healthy subjects aged less than 50 yr; 2) 27 "healthy" subjects over 65 yr; 3) 20 subjects with either myeloma (7 cases), benign monoclonal gammopathy (7) or rheumatoid arthritis (6); 4) 4 subjects with amyloidosis (2 primary, 1 secondary to rheumatoid arthritis, and 1 secondary to myeloma). Rectal biopsy and a histological search for amyloid substance were carried out in all subjects from the 3rd and 4th groups. Heparin tolerance was too widely scattered to enable statistically significantly means to be deduced. Comparison between the arithmetical means of the four groups, however, showed a greater resistance in aged opposed to young subjects, and in patients with amyloidosis as opposed to those in the other three groups. This was constant and marked after 60' and 120', suggesting that this test may offer indirect evidence in support of a diagnosis of amyloidosis.
