Daniel Vollmar (second from the left in the picture) wanted to donate to his mother, Josephine (on the left in the picture), but Josephine developed immunity to Daniel's tissues when she was pregnant with him. Rose Meyer (on the right in the picture) wanted to donate to her husband, Paul, but her blood type (blood type A) was not compatible with Paul's blood type (blood type O). The Meyers were entered into the PDC web-based computer matching program by their transplant coordinator at the Christ Hospital in Cincinnati, and the Vollmars were entered by their transplant coordinator at the Medical University of Ohio.
After they were matched by the computer, and crossmatching testing was performed to assure sure that Daniel's kidney was compatible with Paul and that Rose's kidney was compatible with Josephine. After these tests were completed, they met each other (see CNN story "A Vital Trade" below.
A few weeks later, in a paired donation procedure, Rose donated her kidney to Josephine, and Daniel donated to Paul. Josephine would have likely waited three years or more for a kidney on the deceased donor wait list. Paul never had to go on dialysis, where he would have also waited for three or more years. All four are doing well today, and have become close friends because of the extraordinary experience they had in the paired donation procedure.