The kinetics of ¹¹¹Indium distribution following injection of ¹¹¹Indium labelled autologous granulocytes in man

Abstract

The kinetics of human autologous granulocytes, separated and labelled with 111In without isolation from plasma, have been studied in subjects with and without sepsis with the aim of identifying the fate and sites of destruction of granulocytes in man. In subjects without inflammatory disease, 111In granulocyte recovery in faeces, urine and saliva over 4 d was less than 1% of the dose, so that the activity visualized by the gamma camera represented almost 100% of the dose. On images taken at 24 and 48 h, this activity was distributed between spleen, bone marrow and liver, with foci of additional abnormal activity in subjects with inflammatory disease. Splenic activity fell between 40 min and 24 h, consistent with the presence of a splenic granulocyte pool, but remained constant after 24 h. Since granulocyte clearance from the blood was predominantly completed by 24 h, the residual splenic activity at that time reflected splenic granulocyte destruction. In patients with sepsis, the fall in splenic activity was greater than in those without, implying diversion of granulocytes from splenic destruction to tissue utilization when inflammation is present. Bone marrow activity increased between 40 min and 24 h and then remained stable. Granulocytes that were extensively manipulated in saline prior to labelling failed to localize in marrow, suggesting that visualization of the latter reflected destruction of intact, normal granulocytes. Although the changes in splenic and marrow activities terminated at 24 h, at which time granulocyte clearance from blood was at least 80% completed, plasma 111In remained essentially unchanged between 40 min and 48 h at less than 5% of the dose, discounting it as the source of splenic and marrow activities.

Use of 111-Indium–labeled autologous eosinophils to establish the in vivo kinetics of human eosinophils in healthy subjects

“…Of note, the 9-hour blood recirculation peak coincided with a significant reduction of activity in the liver, and to a lesser extent, in the bone marrow signal. In contrast to neutrophils, 23,24 very little signal was seen within the axial skeleton at any time point ( Figure 2C). This implies that the bone marrow is not a major site for eosinophil disposal, with the principal sites being the liver and spleen ( Figure 2D).…”

Cerebral Neutrophil Recruitment, Histology, and Outcome in Acute Ischemic Stroke

“…Previous studies for 111 In troponolate human granulocyte cell recovery are Ϸ40%. 14,15 Labeling efficiency was calculated by measuring radioactivity in labeled cells versus that in washes, expressed as a percentage of radioactivity incorporated into cells. Labeling efficiency may vary with cell number, and incubation time and figure from previous studies are Ϸ72% for 111 In troponolate.…”

The Role of Proteinase 3 and Neutrophils in ANCA-Associated Systemic Vasculitis

“…In normal situations, the short-lived neutrophils die by apoptosis and are subsequently phagocytosed by macrophages. Circulating apoptotic neutrophils are cleared from circulation by macrophages located in the liver (29%), spleen (31%) and the bone marrow (32%) (Saverymuttu, 1985). Tissue neutrophils, which migrate to tissues during infections, are removed by local macrophages that secrete anti-inflammatory cytokines TGF- and IL-10 upon phagocytosis of these neutrophils.…”