Origin, Presentation, and Clinical Course of Nonpancreatic Hyperlipasemia

Prospective Validation of a Prediction Model for the Diagnosis of Acute Pancreatitis

Importance

While most patients with acute pancreatitis (AP) fulfill diagnostic criteria with characteristic abdominal pain and serum lipase levels of at least 3 times the upper limit of normal (reference range) at presentation, early imaging is often used for confirmation. A prior prediction model and corresponding point-based score were developed using nonimaging parameters to diagnose AP in patients presenting to the emergency department (ED).

Objective

To evaluate the performance of the prediction model to diagnose AP in a prospective patient cohort.

Design, Setting, and Participants

This prospective diagnostic study included consecutive adult patients presenting to the ED between January 1, 2020, and March 9, 2021, at 2 large academic medical centers in the northeastern US with serum lipase levels at least 3 times the upper limit of normal. Patients transferred from outside institutions or with malignant disease and established intra-abdominal metastases, acute trauma, or altered mentation were excluded. Data were analyzed from October 15 to October 23, 2023.

Exposures

Participants were assigned scores for initial serum lipase level, number of prior AP episodes, prior cholelithiasis, abdominal surgery within 2 months, presence of epigastric pain, pain of worsening severity, duration from pain onset to presentation, and pain level at ED presentation.

Main Outcome and Measures

A final diagnosis of AP, established by expert review of hospitalization records.

Results

Prospective scores in 349 participants (mean [SD] age, 53.0 [18.8] years; 184 women [52.7%]; 66 Black [18.9%]; 199 White [57.0%]) demonstrated an area under the receiver operating characteristics curve of 0.91. A score of at least 6 points achieved highest accuracy (F score, 82.0), corresponding to a sensitivity of 81.5%, specificity of 85.9%, positive predictive value of 82.6%, and negative predictive value of 85.1% for AP diagnosis. Early computed tomography or magnetic resonance imaging was performed more often in participants predicted to have AP (116 of 155 [74.8%] with a score ≥6 vs 111 of 194 [57.2%] with a score <6; P < .001). Early imaging revealed an alternative diagnosis in 8 of 116 participants (6.9%) with scores of at least 6 points, 1 of 93 (1.1%) with scores of at least 7 points, and 1 of 73 (1.4%) with scores of at least 8 points.

Conclusions and Relevance

In this multicenter diagnostic study, the prediction model demonstrated excellent AP diagnostic accuracy. Its application may be used to avoid unnecessary confirmatory imaging.

Non-pancreatic hyperlipasemia: A puzzling clinical entity

BACKGROUND

Increased lipase level is a serological hallmark of the diagnosis of acute pancreatitis (AP) but can be detected in various other diseases associated with lipase leakage due to inflammation of organs surrounding the pancreas or reduced renal clearance and/or hepatic metabolism. This non-pancreatic hyperlipasemia (NPHL) is puzzling for attending physicians during the diagnostic procedure for AP. It would be clinically beneficial to identify the clinical and laboratory variables that hinder the accuracy of lipase diagnosis with the aim of improve it. A more precise description of the NPHL condition could potentially provide prognostic factors for adverse outcomes which is currently lacking.

AIM

To perform a detailed clinical and laboratory characterization of NPHL in a large prospective patient cohort with an assessment of parameters determining disease outcomes.

METHODS

A Hungarian patient cohort with serum lipase levels at least three times higher than the upper limit of normal (ULN) was prospectively evaluated over 31 months. Patients were identified using daily electronic laboratory reports developed to support an ongoing observational, multicenter, prospective cohort study called the EASY trial (ISRCTN10525246) to establish a simple, easy, and accurate clinical scoring system for early prognostication of AP. Diagnosis of NPHL was established based on ≥ 3 × ULN serum lipase level in the absence of abdominal pain or abdominal imaging results characteristic of pancreatitis.

RESULTS

A total of 808 patients [male, n = 420 (52%); median age (IQR): 65 (51-75) years] were diagnosed with ≥ 3 × ULN serum lipase levels. A total of 392 patients had AP, whereas 401 had NPHL with more than 20 different etiologies. Sepsis and acute kidney injury (AKI) were the most prevalent etiologies of NPHL (27.7% and 33.2%, respectively). The best discriminative cut-off value for lipase was ≥ 666 U/L (sensitivity, 71.4%; specificity, 88.8%). The presence of AKI or sepsis negatively affected the diagnostic performance of lipase. NPHL was associated with a higher in-hospital mortality than AP (22.4% vs 5.1%, P < 0.001). In multivariate binary logistic regression, not lipase but increased amylase level (> 244 U/L) and neutrophil-to-lymphocyte ratio (NLR) (> 10.37, OR: 3.71, 95%CI: 2.006-6.863, P < 0.001), decreased albumin level, age, and presence of sepsis were independent risk factors for in-hospital mortality in NPHL.

CONCLUSION

NPHL is a common cause of lipase elevation and is associated with high mortality rates. Increased NLR value was associated with the highest mortality risk. The presence of sepsis/AKI significantly deteriorates the serological differentiation of AP from NPHL.

Impact of abdominal imaging on the diagnosis of acute pancreatitis in patients with painless lipase elevation

Abdominal pain is considered a cardinal feature of acute pancreatitis (AP), and abdominal imaging is only required to diagnose AP when the pain is atypical, or serum enzyme elevation does not match the clinical picture. While painless lipase elevation is being increasingly associated with worse outcomes in various diseases, the diagnostic approach to such elevation is so-far unclear. We thus aimed to learn the impact of pain on the diagnosis of AP.

METHODS

All patients presenting to the Mayo Clinic Arizona Hospital emergency department with a serum lipase ≥3x upper limit of normal between April 2016 and January 2020 were prospectively followed. Their charts were reviewed for the nature of pain, serum lipase levels on presentation, abdominal imaging, and whether a diagnosis of AP was made. Chronic pancreatitis was excluded.

RESULTS

Among 320 patients, 85 (26.5%) had painless lipase elevation. These patients had abdominal imaging less often (56/85, 66%) than in those with abdominal pain (201/235, 83%; p = 0.001). The diagnosis of AP increased overall from 31/63 (49%) without imaging to 198/257 (77%) with imaging (P < 0.001). Imaging increased the diagnosis of AP in patients with painless lipase elevation from 2/29 (7%) without imaging to 16/56 (29%; p = 0.025) among those who were imaged.

CONCLUSIONS

Painless lipase elevation >3-fold the upper limit of normal is common in emergency department patients. 1/3 to 1/4 of these may have AP. Abdominal imaging increases the diagnosis of AP in patients with painless lipase elevation. Therefore, abdominal imaging in such patients may help detect AP that otherwise eludes diagnosis.

Predisposing Factors and Neurologic Outcomes of Patients with Elevated Serum Amylase and/or Lipase after Out-of-Hospital Cardiac Arrest: A Retrospective Cohort Study

This study investigated the patient outcomes, incidence, and predisposing factors of elevated pancreatic enzyme levels after OHCA. We conducted a retrospective cohort study of patients treated with targeted temperature management (TTM) after out-of-hospital cardiac arrest (OHCA). Elevation of pancreatic enzyme levels was defined as serum amylase or lipase levels that were at least three times the upper limit of normal. The factors associated with elevated pancreatic enzyme levels and their association with neurologic outcomes and mortality 28 days after OHCA were analyzed. Among the 355 patients, 166 (46.8%) patients developed elevated pancreatic enzyme levels. In the multivariable analysis (odds ratio, 95% confidence interval), initial shockable rhythm (0.62, 0.39−0.98, p = 0.04), time from collapse to return of spontaneous circulation (1.02, 1.01−1.04, p < 0.001), and history of coronary artery disease (1.7, 1.01−2.87, p = 0.046) were associated with elevated pancreatic enzyme levels. After adjusting for confounding factors, elevated pancreatic enzyme levels were associated with neurologic outcomes (5.44, 3.35−8.83, p < 0.001) and mortality (3.74, 2.39−5.86, p < 0.001). Increased pancreatic enzyme levels are common in patients treated with TTM after OHCA and are associated with unfavorable neurologic outcomes and mortality at 28 days after OHCA.

Analysis of Outcomes in COVID-19 Patients With Varying Degrees of Hyperlipasemia

OBJECTIVES

Coronavirus disease 2019 (COVID-19) patients may have varying degrees of hyperlipasemia. The aim was to compare outcomes among different levels of hyperlipasemia in patients with COVID-19.

METHODS

This is a retrospective study examining outcomes among hospitalized COVID-19 patients with a lipase <3× upper limit of normal (ULN), asymptomatic hyperlipasemia (>3× ULN), secondary pancreatitis (typical respiratory COVID-19 symptoms and found to have pancreatitis), and primary pancreatitis (presenting with pancreatitis).

RESULTS

Of 11,883 patients admitted with COVID-19, 1560 patients were included: 1155 patients had normal serum lipase (control group), 270 had elevated lipase <3× ULN, 46 patients had asymptomatic hyperlipasemia with lipase >3× ULN, 57 patients had secondary pancreatitis, and 32 patients had primary pancreatitis. On adjusted multivariate analysis, the elevated lipase <3× ULN and asymptomatic hyperlipasemia groups had worse outcomes with higher mortality (odds ratio [OR], 1.6 [95% confidence interval [CI], 1.2-2.2) and 1.1 [95% CI, 0.5-2.3], respectively), higher need for mechanical ventilation (OR, 2.8 [95% CI, 1.2-2.1] and 2.8 [95% CI, 1.5-5.2], respectively), and longer length of stay (OR, 1.5 [95% CI, 1.1-2.0] and 3.16 [95% CI, 1.5-6.5], respectively).

CONCLUSIONS

Patients with COVID-19 with elevated lipase <3× ULN and asymptomatic hyperlipasemia have generally worse outcomes than those with pancreatitis.

A Clinical Model for the Early Diagnosis of Acute Pancreatitis in the Emergency Department

OBJECTIVE

This study aimed to develop a diagnostic model that predicts acute pancreatitis (AP) risk before imaging.

METHODS

Emergency department patients with serum lipase elevated to 3 times the upper limit of normal or greater were identified retrospectively (September 1, 2013-August 31, 2015). An AP diagnosis was established by expert review of full hospitalization records. Candidate predictors included demographic and clinical characteristics at presentation. Using a derivation set, a multivariable logistic regression model and corresponding point-based scoring system was developed to predict AP. Discrimination accuracy and calibration were assessed in a separate validation set.

RESULTS

In 319 eligible patients, 182 (57%) had AP. The final model (area under curve, 0.92) included 8 predictors: number of prior AP episodes; history of cholelithiasis; no abdominal surgery (prior 2 months); time elapsed from symptom onset; pain localized to epigastrium, of progressively worsening severity, and severity level at presentation; and extent of lipase elevation. At a diagnostic risk threshold of 8 points or higher (≥99%), the model identified AP with a sensitivity of 45%, and a specificity and a positive predictive value of 100%.

CONCLUSIONS

In emergency department patients with lipase elevated to 3 times the upper limit of normal or greater, this model helps identify AP risk before imaging. Prospective validation studies are needed to confirm diagnostic accuracy.

Serological diagnosis and prognosis of severe acute pancreatitis by analysis of serum glycoprotein 2

BACKGROUND

Glycoprotein 2 (GP2), the pancreatic major zymogen granule membrane glycoprotein, was reported to be elevated in acute pancreatitis in animal models.

METHODS

Enzyme-linked immunosorbent assays (ELISAs) were developed to evaluate human glycoprotein 2 isoform alpha (GP2a) and total GP2 (GP2t) as specific markers for acute pancreatitis in sera of 153 patients with acute pancreatitis, 26 with chronic pancreatitis, 125 with pancreatic neoplasms, 324 with non-pancreatic neoplasms, 109 patients with liver/biliary disease, 67 with gastrointestinal disease, and 101 healthy subjects. GP2a and GP2t levels were correlated with procalcitonin and C-reactive protein in 152 and 146 follow-up samples of acute pancreatitis patients, respectively.

RESULTS

The GP2a ELISA revealed a significantly higher assay accuracy in contrast to the GP2t assay (sensitivity ≤3 disease days: 91.7%, specificity: 96.7%, positive likelihood ratio [LR+]: 24.6, LR-: 0.09). GP2a and GP2t levels as well as prevalences were significantly elevated in early acute pancreatitis (≤3 disease days) compared to all control cohorts (p<0.05, respectively). GP2a and GP2t levels were significantly higher in patients with severe acute pancreatitis at admission compared with mild cases (p<0.05, respectively). Odds ratio for GP2a regarding mild vs. severe acute pancreatitis with lethal outcome was 7.8 on admission (p=0.0222). GP2a and GP2t levels were significantly correlated with procalcitonin [Spearman's rank coefficient of correlation (ρ)=0.21, 0.26; p=0.0110, 0.0012; respectively] and C-reactive protein (ρ=0.37, 0.40; p<0.0001; respectively).

CONCLUSIONS

Serum GP2a is a specific marker of acute pancreatitis and analysis of GP2a can aid in the differential diagnosis of acute upper abdominal pain and prognosis of severe acute pancreatitis.

Defining the diagnostic value of hyperlipasemia for acute pancreatitis in the critically ill

BACKGROUND/OBJECTIVES

Hyperlipasemia is frequently encountered in patients in the intensive care unit (ICU). The degree to which it should be valued in making the diagnosis of acute pancreatitis (AP) in critically ill patients remains uncertain. We sought to determine the diagnostic accuracy of hyperlipasemia and the optimal lipase cutoff for diagnosing AP in critically ill patients.

METHODS

Four hundred and seventeen ICU patients with hyperlipasemia, defined as lipase greater than three times the upper limit of normal from 2009 to 2012 were retrospectively identified. A diagnosis of AP was confirmed by the additional presence of either characteristic abdominal pain or cross-sectional imaging.

RESULTS

The overall positive predictive value (PPV) of hyperlipasemia was 38.1%. Median initial lipase levels were 1164 IU/L in patients with AP and 284.5 IU/L in patients without AP (p < 0.001). The optimal diagnostic lipase cutoff of 532 IU/L correlated with a sensitivity, specificity, negative predictive value and PPV of 77.4%, 78.0%, 84.9%, and 67.0% respectively. The most common primary diagnoses in non-AP patients with elevated lipase included shock, cardiac arrest and malignancy.

CONCLUSIONS

Physicians should maintain caution when interpreting hyperlipasemia in the critically ill due its relatively low PPV. However, a greater lipase cutoff improves its diagnostic value in AP and helps to reduce unnecessary imaging in these patients.