Research Article - Biomedical Research (2017) Volume 28, Issue 11
Accepted on April 10, 2017
The aim of this study was to investigate the early changes in coagulation functions in patients with different degrees of Acute Pancreatitis (AP). Data from a total of 133 AP patients was studied. The differences in the Prothrombin Time (PT), Activated Partial Thromboplastin Time (APTT), Fibrinogen Concentration (FIB), International Normalized Ratio (INR), and serum Ca2+ levels among different groups, and their relationships to the Acute Physiology and Chronic Health Evaluation (APACHE) II score were compared. FIB in the Moderately Severe Acute Pancreatitis (MSAP) group was significantly higher than the Control Group (CG), and the Mild Acute Pancreatitis (MAP) group (P<0.05). Ca2+ levels in the MSAP group were lower than in the control and MAP groups (P<0.05). PT, APTT, and INR in the Severe Acute Pancreatitis (SAP) group were higher than in the control, MAP, and MSAP groups (P<0.05). FIB in the SAP group was higher than in the control and MAP groups (P<0.05), and Ca2+ levels in the SAP group were lower than in the control, MAP, and MSAP groups (P<0.05). The APACHE II score in the MSAP group was higher than in the MAP and control groups (P<0.05), and higher in the SAP group than in the MSAP, MAP, and control groups (P<0.05). Ca2+ levels and the APACHE II score were negatively correlated in the MSAP group. In the SAP group, FIB was positively correlated with the APACHE II score, but Ca2+ levels were negatively correlated with them. In the classification of acute pancreatitis, FIB and Ca2+ levels are associated with the severity of pancreatitis. Patients with early AP show different levels of coagulation dysfunction, which is much more pronounced in patients with MSAP and SAP.
SPSS version 16.0 software (Chicago, SPSS Inc.) was used for statistical analysis. The measurement data were expressed as x̄ ± s. The intergroup comparison used the analysis of variance, and when the overall mean values were not equal, further LSDt- testing was performed for the pairwise comparison among multi-group data. The count data was expressed using the rate, and the comparison used the chi-square test, with the significance level α=0.05. The correlation analysis of coagulation indexes with APACHE II scores used the Pearson analysis.
Comparison of general information
The results in Tables 1 and 2 show there were no significant differences in gender and age (P>0.05), or in the time blood samples were taken after the onset of AP (P>0.05) between the groups. The control group fasted from 8 pm the day before, and blood was taken at 8 am on the day of physical examination.
|Group||Age (years)||Gender (M/F)|
|CG (N=30)||44.27 ± 16.72||18/12|
|MAP (N=49)||45.98 ± 14.25||35/14|
|MSAP (N=30)||42.30 ± 12.17||21/9|
|SAP (N=54)||46.28 ± 13.95||31/23|
Table 1. Comparison of general information among different groups (x̄ ± s, n).
|Group||Blood sampling time (h)|
Table 2. The comparison of different groups in the blood sampling time after the onset of AP.
Changes in coagulation functions and AP classification
Table 3 shows there was no significant difference in prothrombin time, activated partial thromboplastin time, fibrinogen concentration, international normalized ratio, or Ca2+ levels between the control and MAP groups (P>0.05). There was no significant difference in PT, APTT, or INR between the control, MAP and MSAP groups (P>0.05), but FIB in the MSAP group was significantly higher than in the control and MAP groups (P<0.05). Ca2+ levels in the MSAP group were significantly lower than the control and MAP groups (P<0.05). PT, APTT, and INR in the SAP group were significantly higher than in the control, MAP, and MSAP groups (P<0.05). FIB was significantly higher in the SAP group than in the control and MAP groups (P<0.05), but only slightly higher than in the MSAP group, which was not statistically significant (P>0.05). Ca2+ levels in the SAP group were significantly lower than in the control, MAP, and MSAP groups (P<0.05).
|Group||PT (S)||APTT (S)||FIB (g/L)||INR (INR)||Ca2+ (mmol/l)|
|CG (N=30)||13.93 ± 3.39||27.61 ± 7.89||3.70 ± 1.60||1.25 ± 0.56||2.14 ± 0.41|
|MAP (N=49)||15.91 ± 5.26||28.73 ± 8.96||3.57 ± 1.54||1.31 ± 0.56||2.11 ± 0.44|
|MSAP (N=30)||16.90 ± 6.88||30.08 ± 12.24||4.81 ± 2.07ab||1.33 ± 0.58||1.91 ± 0.34ab|
|SAP (N=54)||21.77 ± 7.21abc||34.88 ± 10.40abc||5.38 ± 2.40ab||1.76 ± 0.65abc||1.62 ± 0.40abc|
Note: aComparedwith group CG, P<0.05; bComparedwith group MAP, P<0.05; cCompared with group MSAP, P<0.05.
Table 3. Comparison of coagulation-related indexes among different groups (x̄ ± s).
Comparison of the APACHE II scores
The APACHE II scores (Table 4) show no significant difference between the control and MAP groups (P>0.05). The APACHE II scores in the MSAP group were significantly higher than in the control and MAP groups (P<0.05), and significantly higher in the SAP group than in the control, MAP and MSAP groups (P<0.05).
|Group||APACHE II score||F||P|
Note: aCompared with group CG, P<0.05; bCompared with group MAP, P<0.05; cCompared with group MSAP, P<0.05.
Table 4. Comparison of the APACHE II score among different groups (x̄ ± s).
Correlations of PT, APTT, INR, FIB, and Ca2+ levels with APACHE II scores
The correlation analysis results are shown in Table 5. There was no linear correlation between PT, APTT, FIB, INR, and Ca2+ levels and the APACHE II score in the control and MAP groups. In the MSAP group, Ca2+ levels were negatively correlated with the APACHE II score (P<0.05, r=-0.639), and PT, APTT, FIB, and INR had no linear correlation with the APACHE II score. In the SAP group, FIB was positively correlated with the APACHE II score (P<0.05, r=0.654), and Ca2+ levels were negative correlated with the APACHE II score (P<0.05, r=-0.835). There was no linear correlation between PT, APTT, and INR and the APACHE II score in the SAP group.
Table 5. Correlations of PT, APTT, INR, FIB, and Ca2+ with APACHE II score.
The currently recognized theories on the pathogenesis and evolution of pancreatitis include not only trypsin self-digestion [9,10], white blood cell activation, cascade of inflammatory cytokines, apoptosis, and overload of intracellular calcium in pancreatic acinar, but also the theory of pancreatic microcirculation disturbance, which plays an important role in it. Maeda et al.  confirms that activated pancreatin in pancreatic trypsin is a prerequisite for local inflammation of the pancreas.
In AP, kallikrein can transform kallikreinogen into kinin and bradykinin, thus increasing vasodilation and permeability, leading to microcirculation disorders. Particularly in the SAP group, abnormal coagulation parameters are significantly associated with the severity of the AP. The early coagulation functions in SAP patients show a hypercoagulable state in the blood, followed by secondary activation of the fibrinolysis system, which may be related to the changes in the relevant cytokines, and this is the main cause of microcirculation disorder in AP. Therefore, when SAP occurs, if the patient's microcirculation disorders cannot be corrected timeously, it can affect multiple organs, and cause MODS [12,13].
It is well known that platelets, blood vessel walls, coagulation factors, anticoagulant factors, the fibrinolytic system, hemodynamic integrity, and the physiological regulation and balance between them, are all involved in the normal mechanisms of coagulation. The activation of coagulation factors is a chain cleavage reaction. The hemostatic roles of coagulation factors include three pathways, namely the intrinsic coagulation pathway, the extrinsic coagulation pathway, and the common coagulation pathway. In addition, we know that PT and APTT are sensitive indices, which can reflect the exogenous and endogenous coagulation functions, and shortening of PT and APTT can suggest that the patient is in a hypercoagulable state, and indicate clotting mechanism disorder . Among many indices for clinically detecting the coagulation functions, the current most commonly used include PT, APTT, FIB, and INR.
In our study, we found that in the SAP group, PT, APTT, and INR are obviously prolonged compared with the control, MAP, and MSAP groups, which can indicate that patients with SAP may have clotting mechanism disorders. In this study, those in the MSAP and SAP groups show statistically significant differences from the MAP and control groups, but FIB in the MSAP and SAP groups showed no significant difference, indicating that patients with MSAP and SAP may be in a hypercoagulable state in the early stages of AP, which implies FIB can be used as a reference index to assess the severity of AP. This study showed that the serum Ca2+ levels in the MSAP and SAP groups are significantly reduced compared with the MAP group. Studies have shown that the overload of intracellular calcium in pancreatic acinar is an important mechanism underlying the large amounts of pancreatin secreted in the early stages of AP . The mechanisms of pancreatic acinar cell injury include autophagy activated by zymogen, oxidative stress injury, calcium overload, and the influx of extracellular calcium, which is one of the most important factors in calcium overload. In addition, it has been confirmed recently that the release of various cytokines in patients with SAP, such as Tumor Necrosis Factor (TNF)-α , interleukin (IL)-1, or IL-6 can cause a decrease in serum Ca2+ concentration. Kawa et al.  proposes that hypocalcemia is an early sensitive index of MODS in SAP patients. This study also confirms that the serum Ca2+ concentration is negatively correlated with the severity of AP. It confirms that Ca2+ plays a vital role in the progression of pancreatitis from mild to moderate, and then severe acute pancreatitis, in the early stages.
Current research has shown that in patients with acute critical conditions, endothelial cell injuries caused by a variety of conditions can activate both intrinsic and extrinsic coagulation systems, as well as cause coagulation and fibrinolysis system disorders, thus exacerbating disease progression [17-20]. It is recognized that the APACHE II scoring system is an important indicator when evaluating disease severity and predicting prognosis and mortality; the higher the score, the more severe the disease, and worse is the prognosis . Given the APACHE II scoring system has been widely recognized for its reliability in determining the condition and prognosis of AP patients , it is important in assessing the severity of AP. This study shows that in AP, the APACHE II scores in the MSAP and SAP groups are significantly different from those in the MAP and control groups, and the comparison of APACHE II scores between the MSAP and SAP groups also shows statistically significant differences, indicating that the APACHE II score is positively correlated with the disease severity; the higher the APACHE II score, the more severe the AP conditions.
The APACHE II scoring system has been widely accepted for evaluating AP patients, but has some limitations, including its lack of indices for evaluating the coagulation functions. It is rarely reported in China and abroad that coagulation-related indices are introduced into the APACHE II scoring system. In this study, looking at correlations between coagulation functions and Ca2+ levels and APACHE II scores in AP patients shows that in the SAP group, PT, APTT, and INR have no linear relationship with the APACHE II score, but FIB is positively correlated with it, indicating that FIB is significantly increased, and the higher the APACHE II score, the more severe the AP conditions. Results from Ou et al.  and Yue et al.  are consistent with ours, indicating that in SAP, FIB is linearly correlated with the APACHE II score. In this study, we found that Ca2+ levels in the MSAP and SAP groups are negatively correlated with the APACHE II score, indicating that the lower the Ca2+ concentration in AP patients, the higher the APACHE II score, and the more severe the AP conditions. Therefore, the reduction in Ca2+ levels in AP patients can be used as an index to evaluate the disease severity, and this study confirms the accuracy of the classical Ranson and Glasgow standards, which use Ca2+ as a scoring index in AP.
The study shows that the early coagulation changes in different degrees of AP are different, so it further validates the theory that coagulation changes also play important roles in the evolution of AP. The possible reasons for this may be the fact that the patients in the MAP group have relatively mild disease conditions, so damage to the coagulation system is relatively minor, but early testing can detect obvious abnormalities. In the MSAP group, although patients exhibit transient organ failure, they recover spontaneously, as the clotting mechanism is still in a state that allows compensation, namely the coagulation changes are not clear yet. In the SAP group, the early coagulation functions show abnormalities, which may be because early severe microcirculation disorders have already occurred in these patients. Therefore, detecting abnormalities in the coagulation functions will have greater significance in evaluating severity in the patients with MSAP and SAP.
The APACHE II score is currently an important index for judging the severity of diseases , as well as judging the severity of AP. We found that the higher the APACHE II score, the more severe the AP conditions were. Currently, both Chinese and international practitioners use an APACHE II score of ≥ 8 points as the index for moderate and severe AP, and there is no clear dividing line between the moderate and severe AP.
This study shows that FIB in the SAP group is linearly correlated with the APACHE II score, and Ca2+ levels in the MSAP and SAP groups are linearly correlated with the APACHE II score. This indicates that early detection of FIB and Ca2+ abnormalities in SAP patients will have important clinical significance with respect to judging the severity and prognosis of the AP, and provide help in understanding the microcirculation disorders in AP patients. It can also provide help in the early prevention of MODS; provide a basis for correcting coagulation disorders and improving the prognosis, so the cure rate in AP can be improved. Further studies on the relationship between coagulation and the severity of acute pancreatitis (organ failure and recurrence) are planned.
In the new classification of acute pancreatitis, FIB and Ca2+ levels are associated with the severity of the pancreatitis. Patients with early AP exhibit different levels of coagulation and serum Ca2+ abnormalities, which are much more obvious in the patients with MSAP and SAP, and early detection of coagulation functions may be significant in assessing the severity. A higher APACHE II score indicates more severe AP conditions.
This work was funded by Agency Issued Joint Fund of Guizhou Province Science and Technology Department of Guiyang Medical University ((2010) 3169).
All authors have no conflict of interest regarding this paper.