Development of antitissue factor antibodies in patients after liver surgery
H Tsuda, S Higashi, S Iwanaga, T Kubota, T Morita and K Yanaga
Clinical Laboratory, Kyushu University Hospital, Fukuoka, Japan.
After liver surgery, two patients developed unexplainable prolonged
prothrombin times (PT) that were not associated with bleeding tendency. The
substitution of rabbit thromboplastin for either human or monkey
thromboplastin in performing PT tests resulted in a normal clotting time.
Tissue factor (TF) procoagulant activity assays and an immunoblotting
analysis showed that these patients had developed IgG lambda-type immediate
anticoagulants directed against both rabbit and bovine TF that did not
crossreact with human or monkey TF. In a chromogenic assay, the patient IgG
caused a decrease in both the Km and the Vmax of the factor X activation by
rabbit TF-factor VIIa complex. The lack of reactivity of the patient IgG
with human TF presumably explained why there was no clinical bleeding. Both
patients had been treated earlier with a topical hemostatic agent prepared
from bovine corium, microfibrillar collagen hemostat, while undergoing
previous surgery. In an immunoblotting analysis, the patient IgG stained a
42-Kd band in the Triton extract of the collagen preparation under either
reducing or nonreducing conditions. The Triton extract of the collagen
preparation blocked the binding of the patient IgG to bovine TF. Thus, it
is suggested that the iatrogenic immunization by intraoperative exposure of
bovine TF retained in the collagen preparation may be responsible for the
development of anti-TF antibodies in these patients. The anti-TF antibodies
resulted in a clinical error in the evaluation of coagulation status after
the use of rabbit thromboplastin.
Volume 82,
Issue 1,
pp. 96-102,
07/01/1993
Copyright © 1993 by The American Society of Hematology
