A 14-year-old female presented with a 2-month history of intermittent abdominal pain, nausea, bloating, and diarrhea. She was diagnosed with CD, with a positive celiac serology (tissue transglutaminase [tTG] IgA 100 U/mL) and Marsh 3b duodenal histology (Figure 1). GFD resulted in mild symptomatic improvement and a drop in the tTG IgA to 11 U/mL. However, abdominal pain and poor weight gain persisted through 10 months of a strict GFD at home. Endomysial antibody titers were negative. Genetic testing was positive for HLA-DQ2 and negative for HLA-DQ8.
Our nutritionist performed a detailed dietary assessment, which did not reveal any gluten exposure. Under close supervision of our nutritionist, the patient tried a modified diet excluding all grains and processed foods for 3 months with no improvement. Subsequently, a diet of only elemental nutritional supplements was attempted for 4 weeks, followed by complete bowel rest with total parenteral nutrition (TPN) for 4 weeks, each with no improvement.
Repeat upper endoscopy and colonoscopy was completely normal. Tests were negative for giardiasis, tropical sprue, post-infectious enteritis, inflammatory bowel disease (including negative p-ANCA, anti-Saccharomyces cerevisiae antibodies, anti-OmpC, and anti-CBir serology), small intestinal bacterial overgrowth, lactase deficiency, HIV, common variable immunodeficiency, eosinophilic gastroenteritis, autoimmune enteropathy, and Mycobacterium tuberculosis. Video capsule endoscopy showed jejunal scalloping (Figure 2). Jejunal biopsies obtained via push enteroscopy showed active CD, Marsh 3a lesions with villous blunting and increased intraepithelial lymphocytes (50 IELs/100 enterocytes). After 20 months of GFD and persistent villous atrophy, the patient was diagnosed with RCD.
Immunostaining of the IELs showed normal CD3 and CD8-positive lymphocytes, and T-cell rearrangement (TCR) analysis showed polyclonal T-cell bands, consistent with the diagnosis of type I RCD. The patient was offered prednisone, budesonide, and azathioprine, but the patient and her family did not want corticosteroids due to the patient's high BMI (>97th percentile), severe acne, a prior diagnosis of polycystic ovarian syndrome, and a family history of hypertension. The patient was started on 5 mg/kg infliximab, and symptoms and serology improved over 8 months of treatment with normalization of mucosa on jejunal biopsy. The patient continues to be on a GFD while receiving 5 mg/kg infliximab every 8 weeks, and remains asymptomatic.