ACUTE PANCREATITIS WITH NORMAL LIPASE IN AN 80‐YEAR‐OLD MAN

Abstract

To the Editor: Atypical clinical presentation frequently characterizes illness in older adults. In the context of a diagnosis based on anamnesis, physical examination, and laboratory and imagery findings, the interpretation of biomarkers requires caution and clinical judgment. This letter describes a case of gallstone pancreatitis with atypical clinical presentation and normal lipase. An 80-year-old man with a history of arterial hypertension and type II diabetes mellitus was hospitalized for recurrent falls. On the second day of his stay, an episode of vomiting associated with moderate diffuse abdominal pain occurred. He had no fever, the abdomen was soft and diffusely tender, and he showed signs of cardiac insufficiency and delirium. There was no evidence of pneumonia or urinary tract infection. Electrocardiogram was normal. Laboratory tests showed lipase 21 IU/L (normal range 73–193 IU/L), amylase 22 IU/L (normal range 32–104 IU/L), aspartate aminotransferase 75 IU/L (normal range 15–37 IU/L), alanine aminotransferase 52 IU/L (normal range 12–78 IU/L), alkaline phosphatase 348 IU/L (normal range 50–136 IU/L), blood urea nitrogen 8.5 mg/dL (normal range 2.0–4.0 mg/dL), creatinine 2.8 mg/dL (normal range 0.7–1.2 mg/dL), white blood cell 18,300 cells/μL (normal range 4,000–11,000 cells/μL), neutrophils 94%, C-reactive protein (CRP) 390 mg/L (normal range 1–10 mg/L), procalcitonin 5.69 μg/L, (normal range 0.01–0.50 μg/L), troponin T 0.4 mg/L, (normal range 0.01–0.045 mg/L), partial pressure of oxyten 57 mmHg (normal range 79–109 mmHg), partial pressure of carbon dioxide 42 mmHg (normal range 37.6–42.1 mmHg), and pH 7.50 (normal range 7.35–7.45). Looking for an abdominal origin of infection, an abdominal–pelvic computed tomography (CT) scan was performed (Figure 1), which revealed acute pancreatitis (Balthazar grade C) with lithiasis in the biliary ducts. The Ranson score was calculated at 4. The clinical course was rapidly favorable under adequate medical treatment and after therapeutic endoscopic retrograde cholangiopancreatography (ERCP) on day 14. No alteration of lipase or amylase was found before ERCP. The patient was discharged after 10 days and admitted to the rehabilitation unit. Computed tomography scan indicating acute pancreatitis, Balthazar grade C. High lipase levels are a diagnostic hallmark of acute pancreatitis. Recommendations issued by national and international societies suggest a threshold of three times the upper limit of normal for diagnosis of acute pancreatitis. The severity of pancreatitis can be estimated based on the scores of Ranson and Balthazar, which incorporate clinical and radiological features, respectively. According to the latest French Consensus Conference on Acute Pancreatitis, the association between suggestive clinical features and lipase levels higher than three times the upper limit of normal is sufficient for diagnosis. Radiological findings can support the diagnosis if necessary.1 Guidelines issued by the American College of Gastroenterology state that the diagnosis of acute pancreatitis requires the presence of two of the following three criteria: characteristic abdominal pain, serum amylase or lipase more than three times the upper limit of normal, and CT scan findings compatible with acute pancreatitis.2 In the present case, diagnosis of acute pancreatitis was based on radiological findings. The decisive finding is the persistent normal lipase (and amylase) level throughout the course of a case of acute pancreatitis. Typically, during acute pancreatitis, the lipase level increases within the first 4 to 8 hours, reaches a peak at 24 hours and remains high for 1 to 2 weeks. Lipase is a highly sensitive and specific marker of pancreatic pathology, giving it a prominent place in the diagnosis of acute pancreatitis.3 According to a recent systematic review, the negative predictive value of lipase varies between 94% and 100%,4 but a normal lipase level cannot exclude the diagnosis of acute pancreatitis. Moreover, lipase level does not correlate with disease severity according to guidelines and studies.5 This is the sixth case described in the literature. Of the previous case descriptions, two died, two were aged 80 and older, and four had diabetes mellitus.6–8 False negatives for amylase were associated with a context of underlying chronic pancreatitis, an alcoholic home, and hypertriglyceridemia.4 None of these situations played a role in the reported case; the possibility of a genetic polymorphism in these two enzymes could be discussed. Morphological examination of reference is the CT scan, which is recommended as part of the initial examination only in cases of diagnostic uncertainty but is used systematically after 48 hours to assess disease severity according to Balthazar score.9 In summary, the diagnosis of acute pancreatitis cannot be excluded according to normal enzyme laboratory tests. Although exceptional, this needs to be taken into account in older adults, in whom atypical clinical presentation occurs frequently. We would like to thank Veronika Steenpass for proofreading the manuscript. Conflict of Interest: The editor in chief has reviewed the conflict of interest checklist provided by the authors and has determined that they have no financial or any other kind of personal conflicts with this paper. Author Contributions: GD: study concept and design, acquisition of subjects and data, analysis and interpretation of data, and preparation of manuscript. VT and CB: acquisition of subject. PC: analysis and interpretation of data. GG: study concept and design, acquisition of subjects and data, analysis and interpretation of data, and preparation of manuscript. Sponsor's Role: No sponsor.