Page 11 - 麻醉与监护论坛2015年第5期

Establishment of a Quantum- dot Cytometric Assay for Detecting
PCT and the Value of Clinical Detection

Jian Li, Zi-li Chen

Department of ICU, the 94th Hospital of PLA, Nanchang, Jiangxi Province, China 330002

Abstract

Objectives: We purified quantum-dots fluorescence probe used in cytometric assay. We aim to establish a quantum dots cytometric assay
for detecting PCT and study its precision, linearity and sensitivity.

Methods: Microsphere surface were labeled by sheep against PCT antibody, combined with PCT, adding rabbit against PCT antibody,
last added biotinylation sheep against rabbit IgG antibody and QDs-SA conjugate. The mean fluorescent intensity (MFI) was detected by flow
cytometer. Elderly-patients with heavy-hurt who enrolled in ICU were retrospectively investigated and analyzed, using the new assay for
detecting PCT.

Results: The sensitivity (45.42pg/ml) and linearity (45.42pg/ml-10ng/ml) of quantum-dots cytometric assay were better. The positive limit
is 0.56ng/ml. A method to detect PCT prediction elderly trauma in patients with the sensitivity of infection was 100%, respectively is 24.5%, the
accuracy is 84.4%, PCT better than CRP, has a good correlation with APACHE Ⅱ.

Conclusions: The method can be used as clinical detection serum PCT method to diagnose and monitor old trauma patients with merge
infection sensitivity and higher specific degree, and it is also suitable for clinical diagnosis.

Key Words: Quantum dots; Cytometric assay; PCT; Mean fluorescent intensity
Corresponding Author: Zi-li Chen, E-mail: chenziliczl@yahoo.com.cn

As urban development, the incidence of traffic in elderly patients with trauma of PCT level change
accidents increased year by year, trauma patients often tendency; Monitoring the PCT level, the APACHE Ⅱ score
accompanied by serious damage, bleeding, shock, and CRP level change trend, analysis of correlation between
physiological disorders and other characteristics, indicators, to explore the clinical early correct diagnosis
immunocompromised and elderly patients, the infection in elderly patients with traumatic condition, monitoring
occurred more often lead to multiple organ dysfunctions, condition change, the clinical value of concurrent infection
so early accurate evaluation and monitoring is essential and prognosis.
to the elderly trauma patients. Geriatric trauma patients
often accompanied by central high fever, irritability white Data and Methods
cells increased, diagnosis check cycle long and positive rate
is low. Procalcitonin a former of calcitonin [1], the body 1.1 Specimens
produce much after traumatic, which is closely related Between January 2012 and August 2012 in our intensive
to the trauma severity and prognosis [2]. At present, the care unit (ICU) in elderly patients with trauma treated
clinical tests of PCT mainly using the semi-quantitative 77 cases, accord with a standard: (1) age 60 or higher; (2)
method. This study combines quantum dot fluorescent combined SIRS; (3) trauma severity scores ISS 16 or higher;
probes and streaming technology, to establish a method of (4) injury to the ICU admission < 4h. All of the patients
quantitative detection of PCT, and through this method to gave life support, gave enteral nutrition in order to reduce
test the PCT level in elderly patients with trauma, observed bacteria within 24 h to reduce migration. According to the
severity of trauma, low ISS group: 16 ≤ISS ≤25; High ISS

Laboratory and ClinicalCInovveesrtiTghaetsioisn 92 FAM 2013 Mar/Apr Vol.20 Issue 2