Objective        To observe the dynamic changes of plasma circulating DNA in burn patients and investigate its clinical significance.        Methods       According to clinical stages after burn

total 108 plasma samples were collected from 32 cases of burn patients (burn surface area 30%) during post-burn days 1-3

4-7

8-14

and 15-21 respectively. They were subjected in March to July 2013

including

25 males and 7 females at a mean age of 42. Twenty-five patients were thermal injuries

and 7 were chemical burns with a median time of 6.5 h after injury. Plasma circulating DNA was extracted with QIAamp DNA Blood Mini Kit and quantified with Quant-iT PicoGreen fluorescent dye reagent. Combined with clinical data

plasma circulating DNA level was analyzed for its variation after burns and its clinical significance.        Results       Plasma circulating DNA levels in the first blood sample of 32 burn patients (taken within 1-3 d after burns) had a significantly positive correlation with percentage of total body surface area (TBSA)

burn index

third degree burn area

and Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score (

P

0.01). Plasma DNA levels of burn patients presented a slight uplift firstly

and then a reduction as time went by. The patients with  ≥50% TBSA burnt and those died had significantly higher DNA levels compared to the patients with 30% to 50% TBSA burnt and the survival patients respectively (

P

0.01). DNA levels were positively related to Multiple Organ Dysfunction Score (MODS) (

P

0.01) and some clinical and laboratory indicators (

P

0.05). Plasma DNA level of first blood sample

APACHE Ⅱ score

MODS

burn surface area (BSA)

third-degree burn area and burn index on admission were all significant correlated with the clinical outcome.       Conclusion       Plasma DNA level is closely correlated with burn conditions and  clinical processes

and might be regarded as a helpful indicator for burn severity and prognosis.