Monocyte Kinetic Studies in Normal and Disease States

Abstract

S ummary . Monocyte kinetics were studied in eight normal subjects and 27 patients suffering from various diseases: acute, subacute and chronic infections, malignant tumours, Boeck's sarcoid, neutropenia, and diseases associated with chronic exanthemata or splenomegaly. Autotransfusion of blood cells labelled with 3 H‐diisopropylfluorophosphate in vitro was carried out and the fate of these cells in vivo was followed by autoradiographs of leucocyte concentrates prepared from venous samples. Within a few minutes the transfused monocytes equilibrated with the total blood monocyte pool (TBMP). As TBMP proved to be larger than the circulating monocyte pool (CMP), the existence of a marginal monocyte pool (MMP) was postulated. In normal subjects the CMP:MMP ratio averaged 1:3.5. Moderate deviations occurred in disease states. Monocytes left the vascular system at an exponential rate, the mean normal T 4 being 8.4 hr. Slight prolongation of T 4 was observed in some patients with monocytosis, the maximal values reaching 15 hr. Shortened T 4 was found in one patient with acute infection (4.0 hr) and in another with gross splenomegaly (3.5 hr). The monocyte turnover rate (MTR) in normal subjects averaged 6 × 10 8 monocytes/hr or 7 × 10 6 monocytes/hr/kg. Highly significant positive correlations were evaluated between the blood monocyte count and TBMP or MTR respectively.