Jd. Gemmill et al., PRE-DOSING ANTIBODY-LEVELS AND EFFICACY OF THROMBOLYTIC DRUGS CONTAINING STREPTOKINASE, British Heart Journal, 72(3), 1994, pp. 222-225
Objective-To evaluate the influence of pretreatment streptokinase resi
stance titre and the concentration of IgG antibodies to streptokinase
on the efficacy of thrombolytic drugs containing streptokinase in rest
oring coronary patency in acute myocardial infarction. Design-Comparat
ive observational study. Setting-City general hospital. Patients-One h
undred and twenty four previously unexposed patients presenting within
six hours of onset of acute myocardial infarction. Interventions-Stre
ptokinase, 1.5 MIU as intravenous infusion over 60 minutes (60 patient
s), or anistreplase, 30 units as intravenous injection over five minut
es (64 patients). Main outcome measures-Pretreatment streptokinase res
istance titre and concentration of IgG antibodies to streptokinase wer
e measured in 96 and 124 patients respectively and coronary patency as
sessed angiographically at 90 minutes and 24 hours. Results-Pretreatme
nt streptokinase resistance titre and concentrations of IgG antibodies
to streptokinase were low and skewed towards higher values. Those pat
ients with coronary occlusion at 24 hours had a significantly higher m
edian streptokinase resistance titre (100 v 50 streptokinase IU ml(-1)
, P = 0.02). There were trends towards a higher streptokinase resistan
ce titre in those patients with coronary occlusion at 90 minutes (50 v
20 streptokinase IU ml(-1), P = 0.06) and higher concentrations of Ig
G antibodies to streptokinase in those with coronary occlusion at both
90 minutes and 24 hours (1.53 v 0.925, P = 0.03; 1.65 v 1.04 mu g str
eptokinase binding ml(-1), P = 0.06). Coronary patency rates were simi
lar in the two treatment groups. Conclusions-In the range measured in
previously unexposed patients the streptokinase resistance titre has a
small, but significant, negative influence on the efficacy of strepto
kinase and anistreplase. This effect should be considered if retreatme
nt with streptokinase or anistreplase is proposed.