From the Guidelines
The diagnosis of celiac disease requires four key clinical features: positive serological tests, characteristic histological findings on small intestinal biopsy, presence of HLA-DQ2 or HLA-DQ8 genetic markers, and clinical response to a gluten-free diet. These features work together to confirm the diagnosis as celiac disease is an immune-mediated enteropathy triggered by gluten ingestion in genetically susceptible individuals 1. It's essential that serological testing be performed while the patient is on a gluten-containing diet to avoid false negatives. The intestinal biopsy remains the gold standard for diagnosis in adults, showing the characteristic damage to the small intestinal mucosa, with a threshold for abnormal intraepithelial lymphocytes (IELs) of ≥25/100 enterocytes, and villous atrophy required for a definite diagnosis 1. The genetic testing helps rule out celiac disease if negative, as virtually all celiac patients carry one of these genetic markers. Finally, clinical improvement on a strict gluten-free diet confirms the diagnosis, with symptoms typically improving within weeks of gluten elimination.
Some key points to consider in the diagnosis of celiac disease include:
- The importance of taking multiple biopsies from the bulb and the more distal duodenum to increase the diagnostic rate 1
- The use of endoscopic markers of villous atrophy, such as scalloping or reduction of duodenal folds and nodularity, although these are not sensitive enough to preclude a biopsy 1
- The role of video capsule endoscopy in supporting a CD diagnosis in patients with persistently positive coeliac serology but a normal mucosa 1
- The need for careful disease work-up and robust diagnostic criteria due to the diversity of clinical presentation of CD 1
In terms of management, the treatment of celiac disease is a lifelong and strict gluten-free diet, with the goal of relieving symptoms, achieving mucosal healing, avoiding complications of CD, and having a good quality of life with a nutritionally complete gluten-free diet 1. Follow-up of CD is needed to ensure response to symptoms, prevention of consequences, and continued maintenance of motivation to remain gluten-free.
From the Research
Clinical Features of Celiac Disease
The clinical features of celiac disease can be varied and may include:
- Diarrhea
- Weight loss
- Iron deficiency anemia
- Dermatitis herpetiformis, which is pathognomonic for celiac disease 2 These features are commonly seen in patients with celiac disease, although the presence of all four may not be required for a diagnosis.
Diagnosis of Celiac Disease
Diagnosis of celiac disease is typically supported by:
- A positive tissue transglutaminase serologic test
- A small bowel biopsy showing the characteristic histology associated with celiac disease 2, 3
- The presence of human leukocyte antigen alleles DQ2, DQ8, or both, which is essential for the development of celiac disease 2, 3
Extraintestinal Manifestations
Extraintestinal manifestations of celiac disease may include:
- Decreased bone mineral density
- Neuropathy 2 These manifestations can occur in addition to the primary gastrointestinal symptoms of the disease.
Importance of Small Bowel Biopsy
Small bowel biopsy is an important diagnostic tool for celiac disease, particularly in patients with iron deficiency anemia 4. It can help to confirm the presence of villous atrophy and intraepithelial lymphocytosis, which are characteristic of celiac disease.