Studies on cross circulation in man. I. Methods and clinical changes.

rFHE LEUKEMIAS OF MAX are commonly considered as diseases characterized by \videsprea(l proliferation of leukocytes and their precursors in the tissues ol the body) This concept has greatly influenced thought and investigations concerning this group of diseases, although indisputable proof of hyperproduction of the white 1)100(1 cells in leukemia is not recorded in the literature. More recently2 attention has been focused upon the possible role of an impaired leukocyte removal mechanism in this condition. Further studies have demonstrated a removal site in the pulmonary circulation of man, capable of removing billions of white cells within the period of one circulation.3 Up to 143 billion leukocytes obtained from leukemic donors were rapidly infused intravenously into nonleukemic recipients. These cells were promptly and almost completely remOve(1 by the lungs of the recipients. These observations were so reproducible and arresting that invest igat ions over more prolonged periods became desiral)le. A large reservoir of leukocytes with a means for rapid transfer of these cells from donor to recipient was required. It also became essential that manipulation of the 1)100(1 be kept at a minimum to avoid introducing an unknown variable resulting from injury or deterioration of the 1)100(1 elements to be transfused. The prerequisites for such a study would 1)e satisfied if a successful method of cross circulation could be attained in man. Nyiri4 described “crossed transfusions” in experimental uremia in (logs but the exchange of 1)100(1 was slow an(1 of short duration since no anticoagulant was uSe(l. Similar exchange transfusions have been performed on other animals for other purposes but none were as successful as those of Thalhimer ’ 6 who used purified heparin as the anticoagulant of choice. By the use of a pump he was able to cross transfuse dogs continuously from artery to vein for twenty-seven consecutive hours.