Leucocyte-associated plasma proteins in leucocytes during disease states, and in leukaemic cells.

The concentrations and molecular forms of prealbumin, orosomucoid, albumin, alpha 1-antitrypsin and haptoglobin in leucocytes were studied in patients with alpha 1-antitrypsin deficiency, in acute phase and with leukaemia, by rocket and crossed immunoelectrophoresis. Alpha 1-antitrypsin was the only protein being synthesized by bone marrow cells, blast cells and leucocytes present in the blood during cytotoxic treatment. The other proteins are taken up by the cells. The concentration of alpha 1-antitrypsin in serum and cells was correlated in alpha 1-antitrypsin deficiency and the acute phase, suggesting either that the same signal for synthesis is used in the liver and leucocytes, or that a balance is kept by means of leucocyte uptake. Chronic lymphocytic leukaemia lymphocytes contained only traces of albumin, which may be related to the decreased membrane mobility of these cells. Polycythemia leucocytes, however, contained increased concentrations of all plasma proteins, especially orosomucoid and haptoglobin2 . These two protein forms were found to be markers of mature granulocytes. The cellular concentrations of prealbumin, albumin and transferrin were about 35% of normal in acute myeloid leukaemia cells and no orosomucoid2 and haptoglobin2 was present. Alpha 1-antichymotrypsin was present in a heterogeneous form and the molecular form of alpha 1-antitrypsin (alpha 1 AT4 ) was the same as in monocytes. These findings suggest the existence of a distinct 'AML'-type protein pattern which could be of functional and diagnostic importance.