The German Multicenter EPO
Stroke Trial, which investigated safety and efficacy of
erythropoietin (EPO) treatment in
ischemic stroke, was formally declared a negative study. Exploratory subgroup analysis, however, revealed that patients not receiving thrombolysis most likely benefited from EPO during clinical recovery, a result demonstrated in the findings of the Göttingen EPO
Stroke Study. The present work investigated whether the positive signal on clinical outcome in this patient subgroup was mirrored by respective poststroke
biomarker profiles. All patients of the German Multicenter EPO
Stroke Trial nonqualifying for thrombolysis were included if they (a) were treated per protocol and (b) had at least two of the five follow-up blood samples for circulating damage markers drawn (n = 163). The glial markers S100B and
glial fibrillary acid protein (GFAP) and the neuronal marker
ubiquitin C-terminal hydrolase (UCH-L1) were measured by
enzyme-linked
immunosorbent assay in serum on d 1, 2, 3, 4 and 7 poststroke. All
biomarkers increased poststroke. Overall, EPO-treated patients had significantly lower concentrations (area under the curve) over 7 d of observation, as reflected by the composite score of all three markers (Cronbach α = 0.811) and by UCH-L1. S100B and GFAP showed a similar tendency. To conclude, serum
biomarker profiles, as an outcome measure of brain damage, corroborate an advantageous effect of EPO in
ischemic stroke. In particular, reduction in the neuronal damage marker UCH-L1 may reflect neuroprotection by EPO.