Macroamylasemia in a Two-Year-Old Boy as the First Manifestation of Celiac Disease: A Case Report.

INTRODUCTION

Macroamylasemia is a rare biochemical disorder in which the amylase molecule binds to other macromolecules, most commonly immunoglobulin A or G. The increased molecular weight of this complex reduces renal excretion of the enzyme, resulting in chronically elevated serum amylase levels. It can be associated with various non-pancreatic conditions, including celiac disease. In some reported cases, macroamylasemia resolved with a gluten-free diet. We present a pediatric case in which macroamylasemia was the initial manifestation of celiac disease.

CASE PRESENTATION: A two-year-old boy presented with a 3-month history of abdominal pain, anemia, and constipation. Physical examination revealed paraumbilical tenderness. Laboratory tests showed hypochromic anemia; elevated serum amylase (171 U/L); low serum iron (2.5 µmol/L); vitamin D3 deficiency (15.9 ng/mL), and low urine amylase with an amylase/creatinine clearance ratio below 1%, confirming macroamylasemia. Imaging studies were normal. HLA typing revealed the HLA-DQ2 haplotype. Celiac serology was positive for tissue transglutaminase-IgA (87.55 IE/mL) and endomysial antibody-IgA (1:>100). Duodenal biopsy confirmed Marsh type IIIb histology. A gluten-free diet was initiated alongside iron and vitamin D3 supplementation. Symptoms resolved within 2 months, accompanied by normalization of serum amylase levels and a weight gain of over 1 kg. Vitamin D3 therapy was continued until serum levels normalized.

CONCLUSION

Celiac disease should be considered in patients with unexplained macroamylasemia, even in the absence of classical gastrointestinal symptoms. The primary treatment in such cases is a strict gluten-free diet, which can lead to the normalization of serum amylase levels when macroamylasemia is associated with celiac disease.