Thomas Addis, MD (1881-1949): Scottish-American clinical laboratory researcher, social activist and pioneer of renal medicine.

Addis was born and educated in Edinburgh, from the University of which he graduated MB in 1905, and MD in 1908, in which year he also gained membership of Edinburgh's Royal College of Physicians. After researching disordered haemostasis associated with various clinical conditions, he spent over a year in Germany: in Berlin with Dr. E.

Genotype at the secretor blood group locus is a determinant of plasma von Willebrand factor level.

Previous reports on the effect of Secretor and Lewis blood groups on plasma factor VIII-von Willebrand factor (FVIII-VWF) levels have produced conflicting findings. To determine whether either or both loci can influence plasma FVIII-VWF complex levels, we studied the relationship between Secretor and Lewis genotypes, determined definitively using polymerase chain reaction-restriction fragment length polymorphism analysis, and plasma FVIII coagulant activity (FVIII:C) and VWF antigen (VWF:Ag) levels in 136 healthy volunteers. Overall, significantly higher VWF:Ag levels were found in those individuals homozygous for the Se allele (genotype SeSe) than in those heterozygous for the Se allele (P < 0.

Amount of H antigen expressed on circulating von Willebrand factor is modified by ABO blood group genotype and is a major determinant of plasma von Willebrand factor antigen levels.

To investigate whether the effect of ABO blood group on plasma von Willebrand factor (vWF) levels is mediated by the ABH antigenic determinants carried on N-linked glycans of vWF, we studied 158 group A and group O healthy volunteers. vWF antigen (vWF:Ag) and factor VIII antigen (FVIII:Ag) levels were highest in A(1)A(1) individuals and higher in A(1)O(1) than in A(2)O(1) or O(1)O(1) individuals. Plasma A transferase activity and the amount of A antigen expressed per unit vWF (AvWF) were significantly higher in A(1)A(1) than in A(1)O(1) individuals and higher in A(1)O(1) than in A(2)O(1) individuals.