Infectious complications of pancreatitis: diagnosis and management

The Diagnosis and Treatment of Local Complications of Acute Necrotizing Pancreatitis in China: A National Survey

Background

The optimal management strategy in acute necrotizing pancreatitis (ANP) is debated, and compliance with current guidelines in China is not known. In this study, we performed a national survey on this topic in China.

Methods

An online questionnaire about the diagnosis and treatment of local complications of ANP was distributed through a national collaborative network. The local and systemic complications were defined according to the Revised Atlanta Classification.

Results

There were 321 survey respondents from the 394 who opened the link (response rate 81%) from 208 hospitals located in 30/34 provinces across China. There was a lack of consensus in terms of early diagnosis of infected pancreatic necrosis (IPN) as the respondents chose to depend on clinical symptoms (70/321, 22%), organ failure (82/321, 26%), imaging changes (84/321, 26%), and fine needle aspiration (51/321, 16%), respectively. A “step-up” approach has been widely adopted in patients with IPN (294/321, 92%). The decision for initial intervention (without confirmed/suspected infection) was based on clinical condition, CT imaging, or laboratory indicators for most respondents (229/321, 71%).

Conclusion

While the “step-up” approach has been widely adopted, there is still significant variation in regard to the diagnosis of infection, the best timing for drainage, and the indications for early intervention.

The role of omega-3 fatty acids in acute pancreatitis: a meta-analysis of randomized controlled trials

To determine whether treatment with omega-3 fatty acids (ω-3 FA) provides benefits to patients with acute pancreatitis (AP). The Cochrane Library, PubMed, Embase, Web of Science, and Chinese Biomedical Literature Database were searched. Data analysis was performed using Revman 5.2 software. A total of eight randomized controlled trials (RCTs) were included. Overall, ω-3 FA treatment resulted in a significantly reduced risk of mortality (RR 0.35; 95% CI 0.16 to 0.75, p < 0.05), infectious complications (RR 0.54; 95% CI 0.34 to 0.85, p < 0.05) and length of hospital stay (MD -6.50; 95% CI -9.54 to -3.46, p < 0.05), but not length of ICU stay (MD -1.98; 95% CI -6.92 to 2.96, p > 0.05). In subgroup analysis, only patients who received ω-3 FA parenterally had some statistically significant benefits in terms of mortality (risk ratio (RR) 0.37; 95% confidence interval (CI) 0.16 to 0.86, p < 0.05), infectious complications (RR 0.5; 95% CI 0.28 to 0.9, p < 0.05) and length of hospital stay (mean difference (MD) -8.13; 95% CI -10.39 to -5.87, p < 0.001). The administration of ω-3 FA may be beneficial for decreasing mortality, infectious complications, and length of hospital stay in AP, especially when used parenterally. Large and rigorously designed RCTs are required to elucidate the efficacy of parenteral or enteral ω-3 FA treatment in AP.

The role of Fas expression on the occurrence of immunosuppression in severe acute pancreatitis

BACKGROUND

Severe acute pancreatitis (SAP) is a dangerous illness with high mortality where most patients do not die of excessive inflammation, but die of immunosuppression and multiple infections at a later stage. The mechanism of immunosuppression in SAP is unknown.

AIM

The purpose of this study was to analyze the role of Fas expression on the occurrence of immunosuppression in patients with SAP.

METHODS

Forty-eight patients with pancreatitis were divided into two groups: 20 cases with SAP (7 cases with sepsis, 13 cases without sepsis) and 28 cases with mild acute pancreatitis (MAP). Twenty-eight healthy volunteers were selected as controls. Fas mRNA expression in peripheral blood was detected by qPCR and Fas protein of lymphocyte membranes; T lymphocyte subsets and expression of monocyte Human leukocyte antigen DR (HLA-DR) in peripheral blood were detected by flow cytometry.

RESULTS

Compared with MAP and control groups, expression level of Fas mRNA and lymphocyte Fas protein in peripheral blood were significantly increased in the SAP group (all P < 0.01). There was a further significant increase in the SAP group with sepsis compared to those without sepsis (all P < 0.01). The CD4(+) T cell ratio, CD4(+)/CD8(+) ratio and monocyte HLA-DR expression in the SAP group were decreased significantly compared with MAP and control groups (all P < 0.01). Significant negative relationships were observed between Fas mRNA expression and CD4(+) T-cell ratio, CD4(+)/CD8(+) ratio, and monocyte HLA-DR expression in SAP patients with sepsis (all P < 0.05).

CONCLUSIONS

The results suggest that expression level of Fas is related to severity and immune status of pancreatitis. Overexpression of Fas may lead to the occurrence of immunosuppression and sepsis.

Correlation of Fas expression and apoptosis of lymphocytes with occurrence of sepsis in patients with severe acute pancreatitis

AIM: To investigate Fas expression and apoptosis of lymphocytes in severe acute pancreatitis (SAP) patients with and without sepsis.

METHODS: Fas expression and apoptosis of lymphocytes were examined by flow cytometry. Serum soluble Fas (sFas) levels were measured by enzyme-linked immunosorbent assay (ELISA) in 18 SAP patients (10 cases with sepsis, 8 cases without sepsis), 20 patients with mild acute pancreatitis (MAP), and 20 healthy volunteers (control).

RESULTS: Compared to the MAP and control groups, Fas expression, apoptosis of lymphocytes, and serum sFas levels increased significantly in the SAP group (all P < 0.01), and these changes were more significant in SAP patients with sepsis than in those without sepsis (38.37% ± 4.33% vs 26.34% ± 2.65%, 13.45% ± 2.99% vs 6.33% ± 2.05%, 9.89 ng/mL ± 1.25 ng/mL vs 7.36 ng/mL ± 0.95 ng/mL, all P < 0.01). There was no significant difference in Fas expression, apoptosis of lymphocytes, and serum sFas levels between the normal control group and MAP group. A significant positive relationship was observed between Fas expression and apoptosis of lymphocytes in SAP patients with sepsis (r = 0.988, P < 0.01).

CONCLUSION: The Fas signaling pathway may be involved in apoptosis of lymphocytes and is closely related to the severity of pancreatitis. Excessive apoptosis of lymphocytes appears to be related to immunosuppression and thereby results in the occurrence and development of sepsis in SAP patients.

Advances in management of severe acute pancreatitis

Severe acute pancreatitis (SAP) is a systemic disease that can induce many complications such as multiple organ dysfunction syndrome and cause a high mortality rate. Because of the complicated pathogenesis of SAP, a comprehensive treatment program involving internal medicine, surgery, endoscopic intervention, Chinese traditional medicine and biological treatment, is needed. This article reviews the recent advances in management of SAP.

When should we be concerned about pancreatic necrosis? Analysis from a single institution in Mexico City

BACKGROUND/AIM

Although pancreatic necrosis classifies acute pancreatitis (AP) as severe, many patients with tomographic evidence of necrosis never develop systemic complications. Our aim was to analyze the incidence of pancreatic necrosis, organ failure (OF), and the relationship between them.

METHODS

Medical records from 165 patients with a first AP episode and in whom a contrast-enhanced computed tomography (CECT) was performed were analyzed. Pancreatic necrosis was diagnosed as non-enhancing areas of the pancreas on the CECT and was graded as <30%, 30%-50%, and >50%. Pancreatic infection was assessed by guided percutaneous aspiration. Organ failure was defined according to the Atlanta criteria.

RESULTS

Of 165 patients (mean age 42 years, 85 men), 54 (33%) had pancreatic necrosis. Necrosis was graded as <30% in 25 subjects (46%), 30%-50% in 16 (30%), and >50% in 13 (24%). Pancreatic infection was diagnosed in 14 cases (26%). Organ failure occurred in 49 patients: in 20 patients (37%) with necrosis, and in 29 patients (26%) without necrosis (P = 0.20). Extensive pancreatic necrosis (>50%) (P < 0.05) and infected necrosis (P < 0.05) were significantly associated with OF. Eight patients, all of them with OF, died. In 6 of these cases infected pancreatic necrosis was present.

CONCLUSIONS

Patients with pancreatic necrosis are not necessarily at risk of developing OF. However, it should be considered an important risk factor when the necrotizing process compromises more than 50% of the gland and is infected.

Role of macrophage migration inhibitory factor in acute lung injury in mice with acute pancreatitis complicated by endotoxemia

Acute pancreatitis accompanied by a subsequent infectious attack can often lead to multisystem organ dysfunction, including acute lung injury (ALI), but the molecular mechanisms are poorly defined. In this study, we explored the role of the priming insult by induction of cerulein pancreatitis, which was followed by the second attack due to endotoxemia, in the development of ALI in mice. Experiments revealed that LPS injection in mice with acute pancreatitis caused the development of ALI, as indicated by blood-gas derangements, pulmonary vascular hyperpermeability, increased inflammatory cell counts in bronchoalveolar lavage, and histologic lung damage. This was associated with the pancreatitis-induced increase in expression of macrophage migration inhibitory factor (MIF) in the lungs, together with elevated expression of Toll-like receptor (TLR)-4, both of which were inhibited by administration of anti-protease-activated receptor (PAR)-2 antibody. Furthermore, anti-MIF antibody treatment suppressed the pancreatitis-induced elevation of TLR-4 pulmonary expression. Genetic removal of MIF from mice resulted in less development of ALI in the setting of acute pancreatitis complicated by endotoxemia. These findings demonstrate that activation of protease-activated receptor-2 with trypsin, which can be released after pancreatitis induction, positively regulates the transcript level of MIF, and increased MIF results in exaggerated pulmonary expression of TLR-4, leading to the development of ALI with a subsequent infectious attack. We thus suggest that interventions designed to modulate MIF may have therapeutic advantages in treating ALI in patients with acute pancreatitis complicated by bacterial infection.