A colleague in the UK wonders if any institutions use platelets for intrauterine transfusion that are resuspended in any form of platelet additive solution. If so, what technique is used for the manufacturing of these platelets, what is the final platelet concentration of the product, and have any toxicities been seen? He reports that his center uses platelets for intrauterine transfusion for women with known platelet specific antibodies who are currently pregnant and who have previously had an affected thrombocytopenic fetus/neonate. Less commonly they use intrauterine platelet transfusions for women who have an antibody detected in a current pregnancy when screening as a result of a possible intrauterine fetal bleed on scanning. The platelets are collected so as to be available at the time of fetal blood sampling in case fetal platelet transfusion is required. The platelets are collected from donors known to be HPA1a negative, HPA5b negative, CMV negative, and who lack HPA and HLA antibodies, as well as lack high titer anti-A /anti-B. The platelets are collected by apheresis and have a platelet concentration of 2-4 x 10¹²/L. If the mother has an antibody other than anti-HPA1a or anti-HPA 5b, donors whose platelets lack the corresponding antigen are used.

The following comments have been received.

ADDENDA July 7, 2005

1. A transfusion medicine colleague in Wisconsin reports that at his hospital they occasionally perform an intrauterine platelet transfusion. When such a transfusion is necessary, their approach is to use SALINE WASHED platelets for the following three reasons:

1. They can use the same method (saline washing) when preparing platelets that have been collected from the mother, or from an "antigen negative" platelet donor.
2. Washing helps to avoid any ABO incompatibilty issues.
3. Washing then helps with resuspending in a smaller volume, suitable for a small volume transfusion.

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Ira A. Shulman, MD
CBBS e-Network Forum Editor & Moderator