QUANTITATIVE-EVALUATION OF PLASMA-OPSONIZING ACTIVITY FROM THE LAG PERIOD OF PHAGOCYTOSIS-CONNECTED OXYGEN-CONSUMPTION BY LEUKOCYTES IN WHOLE-BLOOD

  • 1 January 1981
    • journal article
    • research article
    • Vol. 97  (1) , 39-49
Abstract
The lag period preceding the O2 consumption burst by [human] phagocytes was measured with an O2 electrode after the addition of unopsonized zymosan in CO-treated and diluted whole blood. The lag period duration correlated with the phagocytic index (r = 0.98, P < 0.001). The phagocytic index was defined as the mean zymosan particle number/phagocyte. The lag period was termed opsonizing time and used for evaluation of plasma opsonizing activity. The opsonizing time was inversely related to the plasma concentration used (< 15%) and was independent of phagocyte concentration. Mg ions were required throughout the opsonizig time, but Ca ions were essential only during the initial phase, indicating that the alternative complement pathway plays a major role in the observed opsonizing time. The mean opsonizing times in blood from normal adults and newborn infants were 5.6 .+-. 0.7 min (no. = 7) and 9.1 .+-. 0.7 (no. = 4), respectively. The opsonizing time, expressed as its reciprocal value, correlated significantly with phagocytic index, CH50 [complement hemolysis] activity, and immunochemically assayed C3 [complement component 3] but not C4, concentration in plasma.