Prediction of blood culture results by measuring procalcitonin levels and other inflammatory biomarkers.
BACKGROUND
It would be helpful if we could predict positive or negative blood culture results. This study considered the usefulness of measuring procalcitonin (PCT) level and standard clinical biomarkers such as white blood cell (WBC) count, C-reactive protein (CRP) level, and platelet (PLT) count to predict blood culture results.


METHODS
We retrospectively analyzed the data from 422 specimens collected at our emergency center within the preceding 36 consecutive months. Primary component analysis (PCA) was used for detecting the degree of the relational contribution of each of the 4 biomarkers to the blood culture results.


RESULTS
Procalcitonin alone (cut-off value, 0.5 ng/mL) yielded a positive blood culture rate of 34.0%. Procalcitonin plus 3 biomarkers (WBC, CRP, and PLT) analyzed by PCA yielded 45.9% or 35.3% when a case was in the first or fourth quadrant, which was significantly higher than cases in the second or third quadrant. Primary component analysis also revealed that positive blood culture results were mainly affected by primary component 1, to which PCT and PLT (not WBC or CRP) predominantly contribute.


CONCLUSIONS
Although it is difficult to predict blood culture results, even using 4 biomarkers analyzed by PCA, our new finding that blood culture results are affected not by WBC and CRP, but mainly by PCT and PLT, might help explain the mechanism of sepsis.
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan. Electronic address: qqaraitakao@yahoo.co.jp.
Takao
T
Arai
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Kenichiro
K
Kumasaka
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Katuhiro
K
Nagata
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Taihei
T
Okita
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Taishi
T
Oomura
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Akira
A
Hoshiai
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Masaharu
M
Koyama
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Shoichi
S
Ohta
Department of Emergency and Critical Care Medicine, Trauma and Emergency Center Hachioji Medical Center of Tokyo Medical University, 1163 Tatemachi, Hachioji-shi, Tokyo 193-0998, Japan.
Tetsuo
T
Yukioka
D000368:Aged; D015415:Biomarkers / Q000097:blood*; D002097:C-Reactive Protein / Q000378:metabolism; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D004636:Emergency Service, Hospital; D005260:Female; D006801:Humans; D007958:Leukocyte Count; D049449:Luminescence; D008297:Male; D010976:Platelet Count; D011237:Predictive Value of Tests; D011498:Protein Precursors / Q000097:blood*; D012189:Retrospective Studies; D018805:Sepsis / Q000097:blood*
D015415:Biomarkers; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D002097:C-Reactive Protein; D015740:Calcitonin Gene-Related Peptide