This case study is presented to highlight how medical calculators can be useful clinical decision making tools for celiac disease diagnosis. Throughout the discussion, links to medical calculators that healthcare providers can use are provided. Incorporating these resources into a clinician’s workflow can lead to better outcomes through more accurate diagnoses and better management for this often difficult condition.

Case History

Sue is a 36 year old female who presented a year ago with chronic low-grade diarrhea, abdominal pain and anemia. She had no significant travel history and was not taking any medications. The symptoms had shown an insidious onset over a few years.

A small bowel biopsy showed partial villous atrophy and was suspicious for celiac disease. Serologic tests to confirm the diagnosis could not be performed because her immunoglobulins were “too low”.

She was placed on a gluten-free diet but failed to improve over the next 12 months. The patient swore that she was rigorously compliant with the gluten-free diet, and the gastroenterologist believed her despite initial skepticism.

He biopsied her again, with the biopsies showing the same histologic changes. This time the gastroenterologist mentioned that the patient had common variable immunodeficiency (CVID).


Today many people eat gluten-free foods, but not everyone doing so knows why. Some people eat gluten-free cereals since these are considered to be more nutritious. However, for patients with allergy to gluten (celiac disease, also known as gluten-sensitive enteropathy) it is essential. The diagnosis of celiac disease can be challenging, and many affected patients may go undiagnosed with complaints such as abdominal pain, diarrhea. anemia or joint pain for years.

  • Clinical Presentations for Patients with Celiac DiseaseClinical Presentations for Patients with Celiac Disease

The diagnosis of celiac disease usually involves the demonstration of chronic inflammatory changes in a small bowel biopsy together with serum tests such as antibodies to gliadin, endomyosium or tissue transglutaminase. Problems in diagnosis can occur when the small bowel biopsy is equivocal or the serologic tests cannot be performed due to lack of availability or an antibody deficiency.

  • Evaluating a Patient for Whom the Diagnosis of Celiac Disease Is UncertainEvaluating a Patient for Whom the Diagnosis of Celiac Disease Is Uncertain
  • Evaluating a Patient for Celiac Disease in the Presence of IgA DeficiencyEvaluating a Patient for Celiac Disease in the Presence of IgA Deficiency

An accurate celiac disease diagnosis is important for the patient. While most patients have a mild, chronic disorder some can have a more significant disease with clinical “crisis”, autoimmune disease or other extraintestinal complications.

  • Classification for Complicated Celiac DiseaseClassification for Complicated Celiac Disease

The primary treatment of celiac disease is avoidance of all sources of gluten. This can be difficult since gluten is present in a wide range of prepared foods and drugs. Compliance with a gluten-free diet can be challenging and requires support from family and friends. If all gluten can be avoided then the person will gradually improve. Follow-up small bowel biopsies will show eventual restoration of the normal villous architecture. Relapses occur if the patient is re-exposed to gluten.

A person diagnosed with celiac disease who fails to improve often has not been compliant with the diet or has an unidentified exposure to gluten. Some patients with celiac disease who fail to improve despite strict gluten exclusion may have what is termed refractory disease. For others the diagnosis of celiac disease was incorrect.

  • Failure of a Patient with Celiac Disease to Respond to a Gluten-Free DietFailure of a Patient with Celiac Disease to Respond to a Gluten-Free Diet

There are other disorders that can cause villous atrophy in a small bowel biopsy. One of these is common variable immunodeficiency (CVID). This is associated with an enteropathy which may show increased plasma cells in the small bowel biopsy. Most patients do not benefit from a gluten-free diet,  but may respond to therapy with corticosteroids.

  • Differential Diagnosis of Celiac Disease-Like Changes in a Small Bowel BiopsyDifferential Diagnosis of Celiac Disease-Like Changes in a Small Bowel Biopsy
  • Common Variable Immunodeficiency (CVID)Common Variable Immunodeficiency (CVID)

The patient clinically improved after being started on corticosteroid therapy.

Take-Home Messages

  • Celiac disease diagnosis can be challenging, and it may take an astute clinician to differentiate between it and conditions that can mimic it.
  • Medical algorithms can be helpful in systematically evaluating the patient and in recognizing conditions that make the diagnosis or management difficult.