Understanding the Reasons for Abnormal Liver Enzymes in Pediatric Inflammatory Bowel Disease

A recent large single center study (Pusateri AJ et al. JPGN 2015; 60: 592-97) provides some very practical information regarding elevated liver enzymes in the setting of inflammatory bowel disease (IBD).  Because there are some serious liver diseases associated with IBD and due to the potential for liver toxicity from many of the medications, bumps in liver enzymes need to be carefully considered.

This retrospective study with 514 patients indicates that 77% of these elevations are transient. Table 1 lists the definitions (chronicity, severity) and patterns that were analyzed.  Transient elevations were broken down into brief (<30 days), prolonged <180 days, chronic >180 days and either intermittent or continuously abnormal. The three types were the following:

  • Hepatic: elevated ALT and/or AST; normal alkaline phosphatase (AP), GGT, and direct bilirubin (DB)
  • Cholestatic: elevated AP, GGT, and/or DB; normal ALT and AST
  • Mixed

Severity or degree was classified as follows:

  • 1 –peak liver enzyme 0-1 x ULN
  • 2 –peak liver enzyme >1-2 x ULN
  • 3 –peak liver enzyme >2-4 x ULN
  • 4 –peak liver enzyme >4 x ULN

Key findings:

  • 219 of 514 patients had 1 or more episode of abnormal liver enzymes; five patients with preexisting liver disease were excluded from the analysis.
  • Of 214 patients (152 with Crohn’s disease [CD], 62 with Ulcerative colitis [UC]) with abnormalities, 69% had a hepatitic pattern, 8% had a cholestatic pattern, and 23% had a mixed pattern. There was no association between the pattern and the final diagnosis (eg. idiopathic vs defined etiology)
  • Only 128 had adequate data to assess chronicity.  In this group, 77% had transient elevations (CD 75%, UC 80%)
  • 87% of elevations were considered idiopathic.  65% of patients with idiopathic elevation had levels < 2 times ULN.
  • Among patients with levels <2 times ULN, 95.3% had an idiopathic etiology.
  • Among patients with levels >4 times ULN, 63% had a benign idiopathic etiology
  • Figure 1 provides a pie chart of diagnoses.  Among the 12.6% with a specific etiology for elevated liver tests, drug toxicity was the most common reason: 51.9% were considered due to 6-MP therapy, 3.7% due to methotrexate, 3.7% due to acetaminophen.
  • Other identified causes among the 12.6% with a defined etiology included NAFLD in 11.1%, infections (CMV,EBV, Histoplasmosis) in 14.8%, cholelithiasis in 3.7%, autoimmune hepatitis in 3.7%, primary sclerosing cholangitis/overlap in 3.7%, and vascular malformation in 3.7%.

As with any retrospective study, there are a number of limitations, especially underdiagnosis given a lack of uniform approach to evaluation.  That being said, all patients had a minimum follow-up of at least nine months and most patients with prolonged liver enzyme elevation would have been examined closely.

Bottomline: This study provides reassurance that liver enzyme elevations are common in children with IBD, occurring in >40% of patients over 3 years at this center; most often these elevations are benign and transient.

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Celiac hepatopathies

There has been a longstanding recognition that celiac disease can be associated with elevated liver enzymes.  Two articles provide further information about celiac hepatopathies.

  • JPGN 2013; 56: 663-70
  • JPGN 2013; 56: 671-74

The first study describes a review of nine studies identified in a MEDLINE search for celiac disease and hypertransamminasemia (HTS) or autoimmune hepatitis (AIH). In total 2046 patients were identified.

Key findings:

  • 12% of patients with mild persistent HTS had celiac disease.  Among individuals with HTS, the relative risk for celiac disease was 11.59 compared to general population.
  • 36% of newly diagnosed children with celiac disease, has elevated aminotransferases.  A gluten-free diet normalized transaminases in 77% within 4 to 8 months.
  • Among children with celiac disease, 1.4% had AIH.  Among children with AIH, 6.3% had celiac disease.

While this meta-analysis had many limitations, it is clear that celiac disease needs to be considered in patients presenting with elevated aminotransferases and in patients with AIH.  In addition, other liver conditions like primary biliary cirrhosis and sclerosing cholangitis, which are infrequent in the pediatric population, are more common in patients with celiac disease.

The second study involved both retrospective (1995-2000) and prospective evaluation (2000-2012) of patients followed at a single center.  The authors sought to determine the long-term response to immunosuppressive treatment in children with autoimmune hepatitis (AIH) and celiac disease.

In their cohort of 79 AIH patients, 15 (9%) had celiac disease.  There was a similar frequency of type 1, type 2 and seronegative AIH among the celiac patients (47%, 20%, and 33%) compared with the entire cohort (55%, 34%, and 11%).  All 15 patients responded to treatment with prednisone and azathioprine or cyclosporine, along with a gluten-free diet.  When immunosuppressive treatment was withdrawn in 9 patients, 4 relapsed and 5 were maintained off immunosuppression for a mean period of 89 months. A much lower rate of immunosuppression withdrawal was achieved in those AIH patients without celiac disease.  24 of 64 attempted to stop immunosuppression; 5 (8%) were successful.

Take-home point of second study: All AIH patients should be screened for celiac disease as a gluten-free diet may increase the likelihood of withdrawal of immunosuppression.