Non-coeliac sprue possibly related to methotrexate in a rheumatoid arthritis patient

Villous atrophy and negative celiac serology: a diagnostic and therapeutic dilemma

OBJECTIVES

Patients with villous atrophy (VA) and negative celiac disease (CD) serologies pose a diagnostic and therapeutic dilemma. When a definitive etiology for VA is not determined, patients are characterized as having unclassified sprue (US), the optimal management of which is unknown.

METHODS

We studied adult patients with VA on biopsy and negative celiac serologies, evaluated at our tertiary referral center over a 10-year period. Testing for HLA DQ2/8 alleles, antienterocyte antibodies, giardia stool antigen, bacterial overgrowth, total serum immunoglobulins, and HIV was noted. Treatment, response, and repeat-biopsy findings were recorded.

RESULTS

The most common diagnoses of the 72 patients were seronegative CD, medication-related villous atrophy, and US. Of those with US, the majority reported symptomatic improvement with immunosuppressive therapy. Some patients initially labeled as unclassified were found to have VA associated with olmesartan use.

CONCLUSIONS

The role of medications in the development of VA and the optimal dose and length of immunosuppression for patients with US should be investigated further.

Methotrexate induced sprue-like syndrome

A 52 year-old male patient diagnosed of ankylosing spondylitis presented with an iron deficiency anemia after a ten-month treatment of methotrexate. He did not respond to treatment with oral iron not a proton pump inhibitor and an upper endoscopy was performed. The histological study of the duodenal biopsies showed villus atrophy. After removing the methotrexate, administrating intramuscular iron and undertaking a gluten-free diet, the histological and analytical alterations progressively resolved.

The citrulline generation test: proposal for a new enterocyte function test

BACKGROUND

The amino acid citrulline is mainly produced by enterocytes from conversion of glutamine. As fasting plasma citrulline proved disappointing as a biomarker for enterocyte dysfunction in clinical practice, we propose a citrulline generation test (CGT) to assess enterocyte function.

AIM

To assess the feasibility of a CGT in healthy subjects and patients with decreased enterocyte mass.

METHODS

Nineteen healthy subjects, 16 patients with intestinal villous atrophy and nine patients with short bowel syndrome (SBS) were given an oral bolus of 20 g of the dipeptide alanine-glutamine. Subsequent changes in plasma citrulline and other amino acid concentrations were determined using reverse-phase high-performance liquid chromatography.

RESULTS

Following the oral bolus of alanine-glutamine, plasma citrulline concentrations showed a time dependent rise in healthy subjects of 44 +/- 13% (38-55 micromol/L, P < 0.0001). The slope from baseline plasma citrulline to peak concentrations was 0.22 +/- 0.08, 0.13 +/- 0.04 and 0.09 +/- 0.04 micromol/L/min in healthy subjects, patients with coeliac disease (CeD) and refractory CeD, respectively (healthy subjects vs. CeD P < 0.05, healthy subjects vs. refractory CeD P < 0.001). In patients with SBS, the CGT was able to distinguish between non-adapted and adapted SBS by means of the incremental area under the CGT curve till 90 min (iAUC T90). The iAUC T90 was 447 +/- 179 and 1039 +/- 178 micromol/L/min in non-adapted and adapted SBS, respectively (P = 0.04).

CONCLUSION

An oral bolus of alanine-glutamine induces a time-dependent rise in plasma citrulline concentration to an extent dependent on the existence of villous atrophy or enterocyte hyperplasia in CeD, and adapted SBS, respectively.