Dear George,

I am finding reference to the use of aged serum or adsorbed plasma in mixing study board  review questions, yet no information in the current texts. Are those  out of date procedures?

Thank you, Tania Puro

Our UAB coagulation lab specialists have noticed a series of prolonged PTTs associated with reduced factor XII in specimens from our sickle cell patient clinic. We found one 24-year old reference, Gordon EM, Klein BL, Berman BW, et al. Reduction of contact factors in sickle cell disease. J Pediatr 1985; 106: 427-30, that documents a significant reduction of factor XII, prekallikrein, and high molecular weight kininogen in sickle cell anemia. Conversely, a more recent publication, Koc A, Gumruk F, Gurgey A. The effect of hydroxyurea on the coagulation system in sickle cell anemia and beta-thalassemia intermedia patients: a preliminary study. Pediatr Hematol Oncol 2003; 20: 429-34, records factor VIII and protein C reduction, but specifically excludes the contact factors. Assuming for now that what UAB has seen results from contact factor consumption, has anyone else seen factor XII reduction in sickle cell, thalassemia, or other hemolytic anemias?

Kim Kinney from Clarian headed this "one last question." Kim, I hope this is not your last question, we love to hear from you.

We at Clarian are moving our Bethesda assay from our MDA to our TOP.  We use a residual VIII method where we calculate the residual VIII in a mixture of patient and normal pool using a control mixture VIII.  This method has worked well on the MDA.  When we tried to set up the same test on our TOP, our control is assaying much lower compared to what we get on the MDA.  We used an unknown purchased from George King and we were very close with the MDA method, but not so great (lower) on the TOP method.  I was wondering if anyone would like to share their procedure so I can compare to what we are doing.  Any advice would be welcome!

Kim Kinney at Clarian brings question only when she has a really tough problem, as she can resolve most coagulation issues that come along. She is converting her central lab and a number of satellite labs from MDA to Beckman-Coulter Inc. (BCI, TOP) instrumentation, and most recently is moving her factor V and VII activity levels to the new instrument and reagents. Factors V and VII assays are based on the prothrombin time reagent, and although it is rare to have a single factor V or VII deficiency, they are often assayed to confirm liver disease and to distinguish the coagulation effects of liver disease from vitamin K deficiency.
Anyway, her problem is this...