Activity Staining in Congenital Factor XIII Deficiency

Recently, Stenberg and Stenflo [Analytical Biochemistry in press 1979) introduced an activity staining procedure for transamidating enzymes (transglutaminases; endo-γ-glutamine: ε-lysine transferases! e.g. Factor XIII). This specific technique combines agarose gel electrophoresis with activity staining based on the enzyme catalyzed incorporation of mono-dansylthiacadaverine into casein. The method permits detection of plasma Factor XIII activity down to 1% of the normal adult standard. The procedure was applied to plasma and red blood cell lysate from two patients with tentative congenital plasma Factor XIII deficiency (based on clot solubility). No activity was found in platelet poor as well as in platelet rich plasma which confirmed the diagnosis. The red blood cell lysate displayed normal transglutaminase activity which means separate genetic determinations of the plasma and red blod cell trans-amidases. By Immunoelectrophoresis, the plasma Factor XIII b-subunit was quantitated to 43 and 44 % of the concentration in normal standard plasma.