An unexpected deterrent in diagnosing refractory celiac disease and enteropathy-associated T-cell lymphoma: a gluten-free diet

Enteropathy-associated T-cell lymphoma (EATL) is a rare disease found in the small bowel and is seen most commonly in patients with refractory celiac disease (RCD). We present a case of an elderly male with celiac disease (CD) diagnosed in childhood with months of abdominal pain and diarrhea despite attempting to avoid gluten in his diet. After persistent symptoms for months, the patient was admitted for an acute abdomen and was found to have small bowel perforation due to a jejunal mass that was diagnosed as an EATL. In 2–5% of adult onset CD, serious complications such as RCD or malignancy develop. The clinical course for EATL is aggressive and generally has a poor prognosis. This case highlights the importance of early clinical suspicion for a small bowel malignancy in patients with a long-standing history of CD and acute worsening of symptoms. Early workup and diagnosis is vital in improving morbidity and mortality in patients with EATL.

Artifactual hyperbilirubinemia due to paraprotein interference

CONTEXT

Paraprotein interference in automated chemistry is uncommon. We describe 2 patients with paraproteinemia and elevated total bilirubin levels measured erroneously using the Roche total bilirubin assay.

OBJECTIVES

To explain the mechanism of this artifactual hyperbilirubinemia and to determine its frequency in patients with monoclonal or increased immunoglobulins.

MATERIALS AND METHODS

The assay was performed manually using serum from 2 index patients and from control patients (without M proteins). Total bilirubin was also determined using another manufacturer's assay. A prospective study was then undertaken using serum from 100 consecutive patients with various monoclonal gammopathies and from 13 patients with polyclonal hypergammaglobulinemia and cryoglobulins. For all patients, serum immunoglobulin (Ig) G, IgA, IgM, total and direct bilirubin, creatinine, and a direct spectrophotometric assessment of icterus were measured.

RESULTS

After the addition of assay reagents, a white precipitate formed in the reaction mixtures containing serum from the index patients, but not in other samples. This turbidity, rather than the expected color change to pink, increased the absorbance and falsely elevated the total bilirubin value. Serum from both index patients was anicteric, their direct bilirubin measurements were unaffected, and total bilirubin measured using an alternate assay was normal. Among the 113 patients studied, no additional spurious total bilirubin values were detected.

CONCLUSION

Paraprotein interference with the Roche automated total bilirubin assay is caused by precipitate formation. This interference is rare and probably idiosyncratic. Spurious hyperbilirubinemia from paraprotein interference may cause clinical confusion. If artifactual elevation of total bilirubin is suspected, the laboratory should examine the specimen for icterus (manually or by spectrophotometry) or measure total bilirubin using a different method.