P. Thomas et L. Forstrom, IN-111 LABELED PURIFIED GRANULOCYTES IN THE DIAGNOSIS OF SYNTHETIC VASCULAR GRAFT INFECTIONS, Clinical nuclear medicine, 19(12), 1994, pp. 1075-1078
Indium-111 labeled enriched granulocytes should have improved accuracy
in diagnosing synthetic vascular graft infections compared to labeled
mixed leukocyte preparations because of the reduced numbers of reinje
cted erythrocytes and platelets, thereby reducing blood pool and nonsp
ecific platelet adhesion to the graft. To test the use of enriched gra
nulocytes in the diagnosis of vascular graft infections, the authors r
eviewed 153 studies in 106 patients. All were imaged with In-111 oxine
labeled enriched autologous granulocytes prepared using Volex (Americ
an Critical Care, McGaw Park, IL) enhanced gravity sedimentation and F
icoll-Hypaque (Pharmacia Biotech, Piscataway, NJ; Winthrop Pharmaceuti
cals, New York, NY) double density centrifugation. The diagnosis of in
fection was established or refuted based on operative appearance of in
fection in one third of patients, and the clinical course over a mean
10-month follow-up period in the remainder. Of those patients with inf
ection, 29 of 43 had positive imaging results that yielded a sensitivi
ty of 67%. Of 100 patients without infection, 97 had negative imaging
results that yielded a specificity of 97%. Compared to pooled data of
studies using In-111 oxine labeled mixed leukocyte preparations, the s
ensitivity of enriched granulocytes appears lower and the specificity
higher. The apparent reduced sensitivity may relate to the chronic nat
ure of some graft infections and the markedly reduced number of reinje
cted lymphocytes in enriched granulocyte preparations compared to mixe
d leukocyte preparations. Although the specificity is very high using
enriched granulocyte preparations, there may not be a significant adva
ntage of the method over mixed leukocyte preparations.