Simultaneous macroamylasemia and macrolipasemia in a patient with mucosa-associated lymphoid tissue lymphoma

We report a case of simultaneous macroamylasemia and macrolipasemia complicated with mucosa-associated lymphoid tissue (MALT) lymphoma. A 78-year-old man presented with hyperamylasemia and hyperlipasemia for 2 years and was misdiagnosed with chronic pancreatitis at another hospital. However, his other pancreatic enzymes were normal, his amylase-creatinine clearance ratio was low, and no definite findings of pancreatic disease were evident. Immunological analyses revealed that both amylase and lipase were bound to immunoglobulin (Ig) A-κ, and that serum IgA was high (827.1 mg/dL). He was diagnosed with simultaneous macroamylasemia and macrolipasemia. Since these diseases are associated with malignancy, an additional investigation was performed which revealed the complication of MALT lymphoma, and polymerase chain reaction analysis showed monoclonal immunoglobulin light chain gene rearrangement (κ >> λ). In this case, macroamylasemia and macrolipasemia may have developed due to the formation of macroenzymes resulting from excess IgA-κ secreted by the MALT lymphoma. Simultaneous macroamylasemia and macrolipasemia are very rare and difficult to diagnose and can lead to diagnostic and therapeutic errors. When encountering atypical clinical features associated with hyperamylasemia and hyperlipasemia, the possibility of macroenzymes and underlying diseases such as lymphoproliferative disorders should be considered.

High incidence of macrotroponin I with a high-sensitivity troponin I assay

Background:

Cardiac troponin is the preferred biomarker of myocardial injury. High-sensitivity troponin assays allow measurement of very low levels of troponin with excellent precision. After the introduction of a high-sensitivity troponin I assay the laboratory began to receive enquiries from clinicians about clinically discordant elevated troponin I results. This led to a systematic investigation and characterisation of the cause.

Methods:

Routine clinical samples were measured by the Architect High Sensitive Troponin-I (hsTnI) and the VITROS Troponin I ES assays (VitrosTnI). Results that were elevated according to the Architect but not the VITROS assay (Group 1) or results elevated by both assays but disproportionately higher on the Architect (Group 2) were re-analysed for hsTnI after re-centrifugation, multiple dilutions, incubation with heterophilic blocking reagents, polyethylene glycol (PEG) precipitation, and Protein A/G/L treatment. Sephacryl S-300 HR gel filtration chromatography (GFC) was performed on selected specimens.

Results:

A high molecular weight complex containing immunoreactive troponin I and immunoglobulin (macrotroponin I) was identified in 5% of patients with elevated hsTnI. Patients with both macrotroponin and myocardial injury had higher and longer elevation of hsTnI compared with VitrosTnI with peaks of both macrotroponin and free troponin I-C complex on GFC.

Conclusions:

Circulating macrotroponin I (macroTnI) causes elevated hsTnI results with the Architect High Sensitive Troponin-I assay with the potential to be clinically misleading. The assay involved in this investigation may not be the only assay affected by macrotroponin. It is important for laboratories and clinicians to be aware of and develop processes to identify and manage specimens with elevated results due to macrotroponin.

Significant elevations of serum lipase not caused by pancreatitis: a systematic review

BACKGROUND

Many authors advocate lipase as the preferred serological test for the diagnosis of pancreatitis and a cut-off level of three or more times the upper limit of normal (ULN) is often quoted. The literature contains no systematic review that explores alternative causes of a lipase level over three times as high as the ULN. Such a review was therefore the objective of this study.

METHODS

The EMBASE and MEDLINE databases (1985 to August 2013) were searched for all eligible articles. Predetermined data were extracted and independently analysed by two reviewers.

RESULTS

In total, data from 58 studies were included in the final analysis. The following causes other than pancreatitis of lipase levels exceeding three times the ULN were found: reduced clearance of lipase caused by renal impairment or macrolipase formation; other hepatobiliary, gastroduodenal, intestinal and neoplastic causes; critical illness, including neurosurgical pathology; alternative pancreatic diagnoses, such as non-pathological pancreatic hyperenzymaemia, and miscellaneous causes such as diabetes, drugs and infections.

CONCLUSIONS

A series of differential diagnoses for significant serum lipase elevations (i.e. exceeding three times the ULN) has been provided by this study. Clinicians should utilize this knowledge in the interpretation and management of patients who have lipase levels over three times as high as the ULN, remaining vigilant for an alternative diagnosis to pancreatitis. The medical officer should be aware of the possibility of incorrect diagnosis in the asymptomatic patient.

Elevated lipase without pancreatitis in infectious colitis

BACKGROUND

An elevated lipase typically confirms the diagnosis of pancreatitis. Elevated lipase may be associated with other disorders, typically with some influence on the pancreas. The differential is more limited than elevated amylase secondary to the mostly unique production of lipase in pancreatic acinar cells. Elevated lipase has been reported in patients with inflammatory bowel disease, but not previously reported in infectious colitis.

CASE REPORT

A 65-year-old woman presented to the emergency department with left lower quadrant abdominal pain radiating to her left flank worsening over 2 days. She denied epigastric pain. She had occasional nausea and occasional nonbilious and nonbloody emesis, and also reported diarrhea and weight loss over the preceding months. Laboratory values were largely unremarkable except for a grossly elevated lipase level. Computed tomography scan of her abdomen was performed and revealed findings consistent with infectious colitis, without signs of pancreatic inflammation or other findings associated with pancreatitis. She was admitted to the hospital and treated for infectious colitis with antibiotics and improved over 2 days, and was subsequently discharged for follow-up with her gastroenterologist. This is the first reported case of elevated lipase without pancreatitis associated with infectious colitis. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Emergency physicians should be aware of other potential causes of elevated lipase and not assume that all cases of elevated lipase are associated with pancreatitis. This may possibly avoid unnecessary admission in situations that are not clearly pancreatitis.

Persistent hyperlipasemia caused by macrolipase in an adolescent

Serum amylase and lipase frequently rise during bouts of acute pancreatitis, and measurement of these enzymes provides important diagnostic information. We report a pediatric patient with persistent elevations of serum lipase resulting from macrolipasemia, a complex of lipase with IgG, rather than pancreatitis.