Lachmann P J, Halbwachs L
Clin Exp Immunol. 1975 Jul;21(1):109-14.
Minor elevation of the concentration of the C3b inactivator (KAF) in whole serum (by 15-25%) markedly inhibits the capacity of the serum to support complement activation by inulin, aggregated IgG and by low concentrations of CVF. However, there was no effect when large concentrations of CVF were used nor was the spontaneous ageing of C3 slowed by increased KAF concentrations. These findings show that the activity of the C3b feedback cycle can be reduced by raising the KAF concentration above physiological levels. This finding may provide a mechanism for damping down complement activation locally in vivo. It seems that the spontaneous ageing of C3 in vitro does not involve a KAF-inhibitable step and therefore cannot be involved to explain the 'C3 tickover' in vitro.
全血清中C3b灭活因子（KAF）浓度的轻微升高（升高15%-25%）会显著抑制血清支持菊粉、聚合IgG以及低浓度眼镜蛇毒因子（CVF）激活补体的能力。然而，使用高浓度CVF时则无此效应，而且KAF浓度升高也不会减缓C3的自然衰变。这些发现表明，将KAF浓度提高到生理水平以上可降低C3b反馈循环的活性。这一发现可能为体内局部抑制补体激活提供一种机制。体外C3的自然衰变似乎不涉及KAF可抑制的步骤，因此无法用其来解释体外的 “C3周转”。
