HUMAN PERIPHERAL BLOOD LEUCOCYTES FORMING ROSETTES WITH RHESUS (D) ISOANTIGEN

Abstract Mononucleated cells which form rosettes in vitro with Rh(D)-positive erythrocytes have been found among the circulating leucocytes of two pregnant Rh-isoimmunised female patients. The number of rosette-forming cells in these two patients fluctuated with time. No rosette-forming cells were found with Rh(d)-negative erythrocytes. Five Rh-negative males who had previously been immunised against the Rh isoantigen were restimulated with Rh-positive erythrocytes. The number of rosette-forming cells was found to increase from the 6th day onwards. They reached a peak on day 10 and then gradually fell. It is considered that the finding of rosette-forming cells in the peripheral blood of pregnant isoimmunised women may be of value in the detection of transplacental haemorrhage.