[Pernicious anemia: a teenager with an unusual cause of iron-deficiency anemia]

Autoimmune Gastritis in the Pediatric Age: An Underestimated Condition Report of Two Cases and Review

Background: Diagnosis of pediatric autoimmune gastritis (AIG) in children is important due to poor outcome and risk of malignancy. This condition is often underestimated in the clinico-pathologic diagnostic work-up, leading to delayed time-to-diagnosis. To increase the awareness of this condition in the pediatric population, we present two cases encountered at our institution, discuss their clinical, biological, and histological presentations in relation with evidence from the literature, and propose an algorithm for diagnosis and follow-up of AIG in children. Case presentation: Two patients (12 and 17 years old) presented with iron deficiency anemia and negative family history for autoimmune disorders. In both cases, the final diagnosis of autoimmune gastritis was delayed until pathological examination of endoscopic gastric biopsies showed atrophy of oxyntic glands. Helicobacter pylori search was negative. Follow up biopsies revealed persistent disease. Literature review on this condition shows unclear etiology and poor long term outcome in some patients because of increased risk of malignancy. Conclusions: AIG should be considered in the differential diagnosis of iron deficiency anemia in the pediatric population.Standardized clinico-pathologic work-up is mandatory. Endoscopic follow-up should be performed due to the risk of malignancy.

Autoimmune gastritis presenting as iron deficiency anemia in childhood

AIM: To characterize clinical, laboratorial, and histological profile of pediatric autoimmune gastritis in the setting of unexplained iron deficiency anemia investigation.

METHODS: A descriptive, observational study including pediatric patients with a diagnosis of autoimmune gastritis (positive parietal cell antibody and gastric corpus atrophy) established in a 6 year period (2006-2011) in the setting of refractory iron deficiency anemia (refractoriness to oral iron therapy for at least 6 mo and requirement for intravenous iron therapy) investigation, after exclusion of other potentially contributing causes of anemia. Helicobacter pylori (H. pylori) infection and anti-secretory therapy were also excluded. Data were retrospectively collected from clinical files, including: demographic data (age, gender, and ethnic background), past medical history, gastrointestinal symptoms, familial history, laboratorial evaluation (Hb, serum ferritin, serum gastrin, pepsinogen I/ pepsinogen II, B12 vitamin, intrinsic factor autoantibodies, thyroid autoantibodies, and anti-transglutaminase antibodies), and endoscopic and histological findings (HE, Periodic Acid-Schiff/Alcian blue, gastrin, chromogranin A and immunochemistry analysis for CD3, CD20 and CD68). Descriptive statistical analysis was performed (mean, median, and standard deviation).

RESULTS: We report a case-series concerning 3 girls and 2 boys with a mean age of 13.6 ± 2.8 years (3 Caucasian and 2 African). One girl had type I diabetes. Familial history was positive in 4/5 cases, respectively for autoimmune thyroiditis (2/5), sarcoidosis (1/5) and multiple myeloma (1/5). Laboratorial evaluation on admission included: Hb: 9.5 ± 0.7 g/dL; serum ferritin: 4.0 ± 0.9 ng/mL; serum gastrin: 393 ± 286 pg/mL; low pepsinogen I/ pepsinogen II ratio in 1/5 patients; normal vitamin B12 levels (analyzed in 3 patients). Endoscopy findings included: duodenal nodularity (2/5) and gastric fold softening (2/5), and histological evaluation showed corpus atrophic gastritis with lymphocytic infiltration (5/5), patchy oxyntic gland mononuclear cell infiltration (5/5), intestinal and/or pseudo-pyloric metaplasia in corpus mucosa (4/5), and enterochromaffin cell hyperplasia (4/5). Immunochemistry for gastrin on corpus biopsies was negative in all cases. Duodenal histology was normal. All biopsies were negative for H. pylori (Giemsa staining and cultural examination).

CONCLUSION: We highlight autoimmune gastritis as a diagnosis to be considered when investigating refractory iron deficiency anemia in children, particularly in the setting of a personal/familial history of autoimmune disease, as well as the diagnostic contribution of a careful immunohistological evaluation.

Optimal management of pernicious anemia

Pernicious anemia (also known as Biermer's disease) is an autoimmune atrophic gastritis, predominantly of the fundus, and is responsible for a deficiency in vitamin B12 (cobalamin) due to its malabsorption. Its prevalence is 0.1% in the general population and 1.9% in subjects over the age of 60 years. Pernicious anemia represents 20%-50% of the causes of vitamin B12 deficiency in adults. Given its polymorphism and broad spectrum of clinical manifestations, pernicious anemia is a great pretender. Its diagnosis must therefore be evoked and considered in the presence of neurological and hematological manifestations of undetermined origin. Biologically, it is characterized by the presence of anti-intrinsic factor antibodies. Treatment is based on the administration of parenteral vitamin B12, although other routes of administration (eg, oral) are currently under study. In the present update, these various aspects are discussed with special emphasis on data of interest to the clinician.