Objective:To investigate lipid metabolism gene mutations and pathogenicity of hypertriglyceridemia acute pancreatitis (HTG-AP) patients.Methods:Clinical data of 495 HTG-AP patients admitted from June 2018 to June 2020 in the center for severe acute pancreatitis of Eastern Theater General Hospital were retrospectively analyzed. Whole-exome sequencing and mutation verification were performed by next-generation sequencing technology and Sanger sequencing. The pathogenicity of gene mutation was analyzed by population mutation ratio, pathogenicity prediction software, conservation scoring software, protein structure prediction, and in vitro experiments. Results:The mutation ratio of lipid metabolism-related genes, namely LPL, APOA5, LMF1, GPIHBP1, and APOC2, were 14.81%, 55.78%, 43.61%, 1.62%, and 0.61%, respectively. Among them, 44 heterozygous mutations in LPL gene were detected including 36 missense mutations, 5 nonsense mutations and 3 frameshift mutations, which were all rarely carried in single patient. Six HTG-AP patients carried the LPL gene heterozygous mutation c.835C>G (p.Leu279Val). The mean level of serum triglyceride at the onset of HTG-AP was 27.4 mmol/L. All of them had a history of recurrent HTG-AP, and most of them had severe acute pancreatitis. The serum LPL concentration and activity were lower than the normal level. The pathogenicity analysis results suggested that the LPL p.Leu279Val was a rare, highly possible pathogenic and highly conserved gene mutation. The in vitro results showed that the LPL p.Leu279Val could significantly reduce the synthesis and secretion ability of LPL as well as its enzymatic activity. Conclusions:The mutation ratio of lipid metabolism-related genes, including LPL, APOA5, LMF1, GPIHBP1, and APOC2, are relatively high in the HTG-AP patients. The LPL p.Leu279Val is a rare and highly possible pathogenic gene mutation, which may lead to recurrent episodes of HTG-AP.

Objective:To investigate the therapeutic effects of adeno-associated virus vector 5 (AAV5)-mediated hepatic lipoprotein lipase (LPL) expression on serum triglyceride (TG) metabolism and hypertriglyceridemic acute pancreatitis (HTG-AP) in mice.Methods:Ten male C57BL/6 Lpl+/- mice were randomly divided into two groups by a random number table: the Lpl+/- control group and the Lpl+/- gene therapy group, with five mice in each group. The Lpl+/- control group received a tail vein injection of AAV5 vector carrying the enhanced green fluorescent protein (EGFP) gene (AAV5-EGFP), while the Lpl+/- gene therapy group received a tail vein injection of AAV5 vector carrying the human LPLS447X gene (AAV5-LPLS447X). Oral fat tolerance tests were performed at 14, 28, and 56 days post-injection. Twenty wild-type ICR mice were randomly divided into a control group and a gene therapy group, with ten mice in each group. The ICR control group was injected with AAV5-EGFP, and the ICR gene therapy group was injected with AAV5-LPLS447X. Fourteen days after injection, the mice underwent intraperitoneal injection of P407 solution (0.5 g/kg) and caerulein (200 μg/kg) to induce HTG-AP. Serum TG, total cholesterol (TC), amylase, lipase levels, and plasma LPL activity after heparin injection were measured by microplate reader. Plasma LPL concentration was measured using an enzyme-linked immunosorbent assay (ELISA). LPL mRNA expression levels in the liver, heart, and adipose tissue of Lpl+/- mice were determined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). LPL protein expression in the liver tissue of ICR mice was detected by immunohistochemistry at 28 days after gene therapy. Histopathological changes in the pancreas were observed using hematoxylin-eosin staining. Results:Compared to the Lpl+/- control group, the Lpl+/- gene therapy group showed a significant decrease in serum TG levels starting from day 21. After oral administration of olive oil, the increase and peak of serum TG levels were significantly lower than those in the control group. Furthermore, hepatic LPL mRNA expression levels were significantly higher (1.96±0.11 vs 1.02±0.12) with statistical significance ( P<0.05). Compared to the ICR control group, the ICR gene therapy group showed a significant decrease in serum TG and TC levels, and plasma LPL activity (0.17±0.05 mEq/L·h -1vs 0.06±0.02 mEq/L·h -1) was significantly higher at 28 days after heparin injection with statistical significance (all P value <0.05). Immunohistochemical results showed high expression of LPL protein on the hepatocyte membrane in the liver of ICR gene therapy group mice. Moreover, pancreatic edema, inflammatory infiltration, and acinar cell necrosis were significantly alleviated compared to the control group. Conclusions:LPLS447X treatment can promote LPL expression in the liver of mice, significantly reduce TG levels, and alleviate the severity of HTG-AP.

Objective:To investigate the association between early reduction (within 3 days of admission) of serum triglyceride (TG) to 5.65 mmol/L and clinical outcomes in patients with acute pancreatitis extremely severe hypertriglyceridemia-induced (HTG-AP).Methods:The clinical data were derived from the PERFORM database, which prospectively collected clinical information on 613 HTG-AP patients admitted to 38 medical centers across China between November 2020 and June 2023 with serum TG level ≥11.3 mmol/L at admission. This study further screened extremely severe HTG patients with TG≥22.6 mmol/L. Patients were divided into the target-reaching group (TG≤5.65 mmol/L on day 3 after admission) and non-target-reaching group (TG>5.65 mmol/L on day3 after admission). The effect of early reduction of serum triglyceride to standard level on organ failure was observed. The primary outcome was organ failure-free days (OFFD) to 14 days of admission. Secondary outcomes included the presence of organ failure on day 7 and day 14, persistent organ failure (POF) to day 14, new-onset organ failure to day 14, maximum sequential organ failure assessment (SOFA) score to day 14, incidence of infected pancreatic necrosis (IPN) by day 60 of admission, length of ICU and hospital stay, mortality by day 60 of admission. The linear regression model was used for multivariate analysis. The subgroup forest plot was drawn to assess the effect of early reduction of TG on OFFD in different subgroups. The Kaplan-Meier method was used to plot the cumulative recurrence rate curve for the time to organ failure resolution and Log-Rank test was used for comparison between two groups.Results:Overall, 212 patients with HTG-AP were enrolled, with 118 in the target-reaching group and 94 in the non-target-reaching group. There was no significantly statistical difference on baseline TG level between two groups, but patients in non-target-reaching group had higher total cholesterol, LDL and CRP than those in target-reaching group. The median OFFD with 14 days of admission in target-reaching and non-target-reaching group was 14.0(11.0, 14.0) and 14.0(13.0, 14.0) days, respectively, without significant difference ( P=0.279). Moreover, there was no significant difference on the presence of organ failure on day 7 and day 14, POF to day 14, new-onset organ failure to day 14, maximum SOFA score to day 14, incidence of IPN by day 60 of admission, length of ICU and hospital stay, mortality by day 60 of admission between two groups. Results of multivariate analysis revealed that there was no significant difference on OFFD between two groups. Subgroup analyses were performed according to age, body mass index, baseline acute physiology and chronic health evaluation-Ⅱ (APACHE-Ⅱ) score, and whether there was organ failure at baseline. However, no association of early reduction of TG with OFFD to day 14 was shown in any subgroup. Among the 67 patients with organ failure at baseline, there was no significant difference in the time to organ failure resolution between target-reaching group and non-target-reaching group ( HR=1.256, 95% CI 0.746-2.116; P=0.343). Conclusions:For patients with acute pancreatitis complicated with extremely severe HTG (TG≥22.6 mmol/L), rapid TG decline (TG≤5.65 mmol/L on day 3 after admission) is not associated with reduced incidence and shorter duration of organ failure.

Objective:The high-quality clinical studies published in the field of hypertriglyceridemia associated acute pancreatitis (HTG-AP) were summarized to analyze the incidence and trends of HTG-AP in China.Methods:Clinical studies related to acute pancreatitis in PubMed, Medline, Cochrane Library and Web of Science from January 1, 2000 to November 12, 2021 were searched and screened. Keywords included China, acute pancreatitis, and clinical study. According to the inclusion and exclusion criteria, related literature were accurately selected and evaluated before extracting data. Meta-analysis was performed using R4.2 and RevMan5.3 software. The effect sizes of annual average percentage change (AAPC) for acute pancreatitis in different regions were merged and forest plot was drawn. Patients were divided into severe acute pancreatitis (SAP) group, moderately severe acute pancreatitis (MSAP) group and mild acute pancreatitis (MAP) group, and forest plot was drawn to analyze the AAPC of HTG-AP. Regression curve for time-dependent changes in the percentage of AP with different etiological factors was constructed.Results:Totally, 67 articles (33 randomized clinical trials, 34 retrospective cohort study) and 30 421 patients were included. The meta-analysis showed that the proportion of HTG-AP among AP patients was increasing over the past 20 years, with an AAPC of 0.52% (95% CI 0.34-1.39). In subgroup analyses, the proportion of HTG-AP in SAP and MSAP group both increased significantly, with the AAPC of 0.74% (95% CI 0.23-1.24) and 3.12% (95% CI 1.62-4.63), respectively. Furthermore, the proportion of HTG-AP among AP patients has shown an upward trend over the past 20 years with faster speed. The proportion of biliary pancreatitis among AP patients has also shown an upward trend, with the rate of increase gradually slowed. The proportion of alcohol-associated pancreatitis among AP patients has remained stable. Conclusions:Since 2000, the incidence proportion of HTG-AP has significantly increased in China with the rate of increase gradually quicker.

Objective:To investigate the impact of plasmapheresis therapy on the clinical efficacy in predicted severe hypertriglyceridemia-associated acute pancreatitis (HTG-AP) patients.Methods:The clinical data of 500 HTG-AP patients admitted to 36 medical centers across China in the Chinese Acute Pancreatitis Clinical Trials Group-PERFORM database from November 2020 to June 2023 were retrospectively analyzed. Besides the inclusion and exclusion criteria from PERFORM study, patients who had acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score ≥8 or CRP>150 mg/L on admission were included in the final analyses ( n=189). Patients were categorized into the plasmapheresis group ( n=51) and the routine treatment group ( n=138) according to the triglyceride-lowering therapies they received. General data, laboratory findings, AP severity, and clinical outcomes were recorded. Results:Patients undergoing plasmapheresis had higher initial triglyceride levels, APACHEⅡ score, SOFA score, and more organ failure than those receiving routine medical treatment. Results of multivariable logistic regression models showed that the plasmapheresis group, as compared to the routine treatment group, was neither associated with decreased risk of persistent organ failure within 14 days [54.9% (28/51) vs 37.7% (52/138), OR=0.89, 95% CI 0.36-2.21, P=0.810], nor with reduced incidence of organ failure on day 7 [17.7% (9/51) vs 15.9% (22/138), OR=0.60, 95% CI 0.19-1.88, P=0.378]. There was no significant difference on the dynamic changes of serum triglyceride within the first three days of admission ( P=0.108). Conclusions:Early plasmapheresis is not associated with reduced incidence of persistent organ failure in predicted severe HTG-AP patients.

Objective:To investigate lipid metabolism gene mutations and pathogenicity of hypertriglyceridemia acute pancreatitis (HTG-AP) patients.Methods:Clinical data of 495 HTG-AP patients admitted from June 2018 to June 2020 in the center for severe acute pancreatitis of Eastern Theater General Hospital were retrospectively analyzed. Whole-exome sequencing and mutation verification were performed by next-generation sequencing technology and Sanger sequencing. The pathogenicity of gene mutation was analyzed by population mutation ratio, pathogenicity prediction software, conservation scoring software, protein structure prediction, and in vitro experiments. Results:The mutation ratio of lipid metabolism-related genes, namely LPL, APOA5, LMF1, GPIHBP1, and APOC2, were 14.81%, 55.78%, 43.61%, 1.62%, and 0.61%, respectively. Among them, 44 heterozygous mutations in LPL gene were detected including 36 missense mutations, 5 nonsense mutations and 3 frameshift mutations, which were all rarely carried in single patient. Six HTG-AP patients carried the LPL gene heterozygous mutation c.835C>G (p.Leu279Val). The mean level of serum triglyceride at the onset of HTG-AP was 27.4 mmol/L. All of them had a history of recurrent HTG-AP, and most of them had severe acute pancreatitis. The serum LPL concentration and activity were lower than the normal level. The pathogenicity analysis results suggested that the LPL p.Leu279Val was a rare, highly possible pathogenic and highly conserved gene mutation. The in vitro results showed that the LPL p.Leu279Val could significantly reduce the synthesis and secretion ability of LPL as well as its enzymatic activity. Conclusions:The mutation ratio of lipid metabolism-related genes, including LPL, APOA5, LMF1, GPIHBP1, and APOC2, are relatively high in the HTG-AP patients. The LPL p.Leu279Val is a rare and highly possible pathogenic gene mutation, which may lead to recurrent episodes of HTG-AP.

Objective:To investigate the therapeutic effects of adeno-associated virus vector 5 (AAV5)-mediated hepatic lipoprotein lipase (LPL) expression on serum triglyceride (TG) metabolism and hypertriglyceridemic acute pancreatitis (HTG-AP) in mice.Methods:Ten male C57BL/6 Lpl+/- mice were randomly divided into two groups by a random number table: the Lpl+/- control group and the Lpl+/- gene therapy group, with five mice in each group. The Lpl+/- control group received a tail vein injection of AAV5 vector carrying the enhanced green fluorescent protein (EGFP) gene (AAV5-EGFP), while the Lpl+/- gene therapy group received a tail vein injection of AAV5 vector carrying the human LPLS447X gene (AAV5-LPLS447X). Oral fat tolerance tests were performed at 14, 28, and 56 days post-injection. Twenty wild-type ICR mice were randomly divided into a control group and a gene therapy group, with ten mice in each group. The ICR control group was injected with AAV5-EGFP, and the ICR gene therapy group was injected with AAV5-LPLS447X. Fourteen days after injection, the mice underwent intraperitoneal injection of P407 solution (0.5 g/kg) and caerulein (200 μg/kg) to induce HTG-AP. Serum TG, total cholesterol (TC), amylase, lipase levels, and plasma LPL activity after heparin injection were measured by microplate reader. Plasma LPL concentration was measured using an enzyme-linked immunosorbent assay (ELISA). LPL mRNA expression levels in the liver, heart, and adipose tissue of Lpl+/- mice were determined by quantitative reverse-transcription polymerase chain reaction (qRT-PCR). LPL protein expression in the liver tissue of ICR mice was detected by immunohistochemistry at 28 days after gene therapy. Histopathological changes in the pancreas were observed using hematoxylin-eosin staining. Results:Compared to the Lpl+/- control group, the Lpl+/- gene therapy group showed a significant decrease in serum TG levels starting from day 21. After oral administration of olive oil, the increase and peak of serum TG levels were significantly lower than those in the control group. Furthermore, hepatic LPL mRNA expression levels were significantly higher (1.96±0.11 vs 1.02±0.12) with statistical significance ( P<0.05). Compared to the ICR control group, the ICR gene therapy group showed a significant decrease in serum TG and TC levels, and plasma LPL activity (0.17±0.05 mEq/L·h -1vs 0.06±0.02 mEq/L·h -1) was significantly higher at 28 days after heparin injection with statistical significance (all P value <0.05). Immunohistochemical results showed high expression of LPL protein on the hepatocyte membrane in the liver of ICR gene therapy group mice. Moreover, pancreatic edema, inflammatory infiltration, and acinar cell necrosis were significantly alleviated compared to the control group. Conclusions:LPLS447X treatment can promote LPL expression in the liver of mice, significantly reduce TG levels, and alleviate the severity of HTG-AP.

Objective:To investigate the association between early reduction (within 3 days of admission) of serum triglyceride (TG) to 5.65 mmol/L and clinical outcomes in patients with acute pancreatitis extremely severe hypertriglyceridemia-induced (HTG-AP).Methods:The clinical data were derived from the PERFORM database, which prospectively collected clinical information on 613 HTG-AP patients admitted to 38 medical centers across China between November 2020 and June 2023 with serum TG level ≥11.3 mmol/L at admission. This study further screened extremely severe HTG patients with TG≥22.6 mmol/L. Patients were divided into the target-reaching group (TG≤5.65 mmol/L on day 3 after admission) and non-target-reaching group (TG>5.65 mmol/L on day3 after admission). The effect of early reduction of serum triglyceride to standard level on organ failure was observed. The primary outcome was organ failure-free days (OFFD) to 14 days of admission. Secondary outcomes included the presence of organ failure on day 7 and day 14, persistent organ failure (POF) to day 14, new-onset organ failure to day 14, maximum sequential organ failure assessment (SOFA) score to day 14, incidence of infected pancreatic necrosis (IPN) by day 60 of admission, length of ICU and hospital stay, mortality by day 60 of admission. The linear regression model was used for multivariate analysis. The subgroup forest plot was drawn to assess the effect of early reduction of TG on OFFD in different subgroups. The Kaplan-Meier method was used to plot the cumulative recurrence rate curve for the time to organ failure resolution and Log-Rank test was used for comparison between two groups.Results:Overall, 212 patients with HTG-AP were enrolled, with 118 in the target-reaching group and 94 in the non-target-reaching group. There was no significantly statistical difference on baseline TG level between two groups, but patients in non-target-reaching group had higher total cholesterol, LDL and CRP than those in target-reaching group. The median OFFD with 14 days of admission in target-reaching and non-target-reaching group was 14.0(11.0, 14.0) and 14.0(13.0, 14.0) days, respectively, without significant difference ( P=0.279). Moreover, there was no significant difference on the presence of organ failure on day 7 and day 14, POF to day 14, new-onset organ failure to day 14, maximum SOFA score to day 14, incidence of IPN by day 60 of admission, length of ICU and hospital stay, mortality by day 60 of admission between two groups. Results of multivariate analysis revealed that there was no significant difference on OFFD between two groups. Subgroup analyses were performed according to age, body mass index, baseline acute physiology and chronic health evaluation-Ⅱ (APACHE-Ⅱ) score, and whether there was organ failure at baseline. However, no association of early reduction of TG with OFFD to day 14 was shown in any subgroup. Among the 67 patients with organ failure at baseline, there was no significant difference in the time to organ failure resolution between target-reaching group and non-target-reaching group ( HR=1.256, 95% CI 0.746-2.116; P=0.343). Conclusions:For patients with acute pancreatitis complicated with extremely severe HTG (TG≥22.6 mmol/L), rapid TG decline (TG≤5.65 mmol/L on day 3 after admission) is not associated with reduced incidence and shorter duration of organ failure.

Objective:The high-quality clinical studies published in the field of hypertriglyceridemia associated acute pancreatitis (HTG-AP) were summarized to analyze the incidence and trends of HTG-AP in China.Methods:Clinical studies related to acute pancreatitis in PubMed, Medline, Cochrane Library and Web of Science from January 1, 2000 to November 12, 2021 were searched and screened. Keywords included China, acute pancreatitis, and clinical study. According to the inclusion and exclusion criteria, related literature were accurately selected and evaluated before extracting data. Meta-analysis was performed using R4.2 and RevMan5.3 software. The effect sizes of annual average percentage change (AAPC) for acute pancreatitis in different regions were merged and forest plot was drawn. Patients were divided into severe acute pancreatitis (SAP) group, moderately severe acute pancreatitis (MSAP) group and mild acute pancreatitis (MAP) group, and forest plot was drawn to analyze the AAPC of HTG-AP. Regression curve for time-dependent changes in the percentage of AP with different etiological factors was constructed.Results:Totally, 67 articles (33 randomized clinical trials, 34 retrospective cohort study) and 30 421 patients were included. The meta-analysis showed that the proportion of HTG-AP among AP patients was increasing over the past 20 years, with an AAPC of 0.52% (95% CI 0.34-1.39). In subgroup analyses, the proportion of HTG-AP in SAP and MSAP group both increased significantly, with the AAPC of 0.74% (95% CI 0.23-1.24) and 3.12% (95% CI 1.62-4.63), respectively. Furthermore, the proportion of HTG-AP among AP patients has shown an upward trend over the past 20 years with faster speed. The proportion of biliary pancreatitis among AP patients has also shown an upward trend, with the rate of increase gradually slowed. The proportion of alcohol-associated pancreatitis among AP patients has remained stable. Conclusions:Since 2000, the incidence proportion of HTG-AP has significantly increased in China with the rate of increase gradually quicker.

Objective:To investigate the impact of plasmapheresis therapy on the clinical efficacy in predicted severe hypertriglyceridemia-associated acute pancreatitis (HTG-AP) patients.Methods:The clinical data of 500 HTG-AP patients admitted to 36 medical centers across China in the Chinese Acute Pancreatitis Clinical Trials Group-PERFORM database from November 2020 to June 2023 were retrospectively analyzed. Besides the inclusion and exclusion criteria from PERFORM study, patients who had acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) score ≥8 or CRP>150 mg/L on admission were included in the final analyses ( n=189). Patients were categorized into the plasmapheresis group ( n=51) and the routine treatment group ( n=138) according to the triglyceride-lowering therapies they received. General data, laboratory findings, AP severity, and clinical outcomes were recorded. Results:Patients undergoing plasmapheresis had higher initial triglyceride levels, APACHEⅡ score, SOFA score, and more organ failure than those receiving routine medical treatment. Results of multivariable logistic regression models showed that the plasmapheresis group, as compared to the routine treatment group, was neither associated with decreased risk of persistent organ failure within 14 days [54.9% (28/51) vs 37.7% (52/138), OR=0.89, 95% CI 0.36-2.21, P=0.810], nor with reduced incidence of organ failure on day 7 [17.7% (9/51) vs 15.9% (22/138), OR=0.60, 95% CI 0.19-1.88, P=0.378]. There was no significant difference on the dynamic changes of serum triglyceride within the first three days of admission ( P=0.108). Conclusions:Early plasmapheresis is not associated with reduced incidence of persistent organ failure in predicted severe HTG-AP patients.