Effect of soluble complement receptor type 1 on reperfusion edema and neutrophil migration after lung allotransplantation in swine.
OBJECTIVE
Soluble complement receptor type 1 inhibits complement activation by blocking C3 and C5 convertases of the classical and alternative pathways. We evaluated the effect of soluble complement receptor type 1 on lung allograft reperfusion injury.


METHODS
Left lung transplantation was performed in 13 weight-matched pigs (25 to 31 kg) after prolonged preservation (20 hours at 1 degree C). One hour after reperfusion the recipient contralateral right lung was excluded to assess graft function only. Complement activity and C3a levels were measured after reperfusion and at the end of the assessment. Extravascular lung water index, intrathoracic blood volume, and cardiac output were assessed during a 5-hour observation period. Gas exchange and hemodynamics were monitored. At the end of the 5-hour assessment period, myeloperoxidase assay and bronchoalveolar lavage were performed to assess neutrophil migration, and C5b-9 (membrane attack complex) deposits in the allograft were detected by immunohistochemistry. Two groups were studied. In group II (n = 6) recipient animals were treated with soluble complement receptor type 1 (15 mg/kg) 15 minutes before reperfusion. Group I (n = 7) served as the control group.


RESULTS
Serum complement activity was completely inhibited in group II. In contrast to group I, C5b-9 complexes were not detected in group II allograft tissue samples. C3a was reduced to normal levels in group II (p = 0.00005). Extravascular lung water index was higher in group I animals throughout the assessment period (p = 0.035). No significant difference in allograft myeloperoxidase activity (p = 0.10) and polymorphonuclear leukocyte count of the bronchoalveolar lavage fluid (p = 0.057) was detected.


CONCLUSIONS
Inhibition of the complement system by soluble complement receptor type 1 blocks local complement activation in the allograft and reduces posttransplantation reperfusion edema but does not improve hemodynamic parameters.
Schmid
R A
RA
Department of Surgery, University Hospital Zürich, Switzerland.
Zollinger
A
A
Singer
T
T
Hillinger
S
S
Leon-Wyss
J R
JR
Schöb
O M
OM
Høgåsen
K
K
Zünd
G
G
Patterson
G A
GA
Weder
W
W
D000818:Animals; D002634:Chemotaxis, Leukocyte / Q000502:physiology*; D003167:Complement Activation / Q000187:drug effects; D003165:Complement System Proteins / Q000187:drug effects / Q000378:metabolism; D004285:Dogs; D015633:Extravascular Lung Water / Q000378:metabolism; D006439:Hemodynamics; D007150:Immunohistochemistry; D016040:Lung Transplantation / Q000009:adverse effects; D009504:Neutrophils / Q000502:physiology*; D009195:Peroxidase / Q000378:metabolism; D011654:Pulmonary Edema / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D011951:Receptors, Complement / Q000008:administration & dosage*; D011994:Recombinant Proteins; D015427:Reperfusion Injury / Q000209:etiology / Q000378:metabolism / Q000517:prevention & control*; D013552:Swine; D014184:Transplantation, Homologous
D011951:Receptors, Complement; D011994:Recombinant Proteins; D003165:Complement System Proteins; D009195:Peroxidase