Validity of S-100 B in patients after brain radiation.
BACKGROUND
S-100B is a calcium binding acute phase protein and a potential biomarker for brain injury. In prior studies elevated plasma S-100B levels were detected in stroke and severe head trauma. The aim of this study was to evaluate whether S-100 B is elevated during cerebral radiotherapy and whether that is associated with adverse outcomes.


METHODS
In this prospective pilot study, 45 patients (25 males, 20 females, median age 58 (17-81)) underwent cerebral radiation therapy because of a primary or metastaic cerebral malignancy. 39 patients were included in the evaluation. 6 patients died during the study period. S-100 plasma concentrations were measured with an electrochemiluminescence immunoassay on admission and weekly during radiation therapy for the duration of 6 weeks. In 10 healthy young volunteers (5 males, 5 females, median age 32 (28-36)) S-100 B plasma levels were measured weekly for 6 weeks as a negative control. Furthermore, in an active control 10 patients (4 males, 6 females, median age 68 (64-76)) with stroke (7 = major stroke, 3 = lacunar infarct) S- 100 B plasma levels were measured for 7 consecutive days after the event.


RESULTS
During radiotherapy S-100 B plasma concentrations increased from median baseline values of 0.030 microg/l to 0.044 microg/l. For the time of radiation therapy most patients showed a mild increase, but absolute plasma values were still within the normal range. In the control group of healthy volunteers S-100 B remained unchanged. In stroke patients S-100 B increased to maximum values of 1.7 microg/l three days after the event. In the 3 patients with lacunar infarcts no increase of S-100 B levels could be detected.


CONCLUSIONS
Brain irradiation leads to a mild increase of S-100 B plasma levels. However, the absolute rise was far weaker compared to that seen in major brain injuries.
Department of Radiation Oncology, University Hospital Düsseldorf, Düsseldorf, Germany. wilfried.budach@uni-duesseldorf.de.
S
S
Gripp
M
M
Peiper
C
C
Matuschek
C
C
Giro
G
G
Steinbach
D
D
Hermsen
M
M
van Griensven
W
W
Budach
R
R
Engers
P A
PA
Gerber
H
H
Hefter
B
B
Spiess
K
K
Orth
E
E
Bölke
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000378:metabolism*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism*; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009414:Nerve Growth Factors / Q000096:biosynthesis*; D010865:Pilot Projects; D011446:Prospective Studies; D011859:Radiography; D011878:Radiotherapy / Q000379:methods; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins / Q000096:biosynthesis*
D015415:Biomarkers; D009414:Nerve Growth Factors; D064568:S100 Calcium Binding Protein beta Subunit; D009418:S100 Proteins