Measurement of red cell destruction in the spleen.

Abstract

Abstract A method is described for measuring red cell destruction in the spleen. The accumulation of 51 Cr-labeled red cells in the spleen was studied using stationary external counters, and expressed as a percentage of the radioactivity injected by calibrating the counters for each patient. This calibration was effected by measuring the increase in count rate over the spleen following uptake of 51 Cr-labeled, damaged red cells given by a second injection. A quantitative dual detector scanning technique was used to measure this splenic radioactivity. The rate of loss of 51 Cr from the spleen was also measured by quantitative scanning, and a correction was made for this loss in calculating the average daily rate of red cell destruction. The rate of red cell destruction in the spleen in two patients with approximately normal mean cell lifespans was 0.2 per cent per day (representing 13 and 23 per cent of total red cell destruction). In 20 patients with marked hemolytic anemia, the destruction rate in the spleen could exceed 6 per cent per day, and in some cases virtually all red cell destruction took place in the spleen. The indices usually obtained by a surface counting study provide only an indication of the rate of red cell destruction in the spleen; the role of the spleen can be better described by measuring the fraction of the total red cell destruction occurring in the spleen.