Caveats in the work-up of iron deficiency anaemia

Abstract

Given the fact that “pathologies involving upper and lower GI (gastrointestinal) system should always be considered during the diagnostic process for IDA (iron deficiency anaemia)” [ [1] De Franceschi L. Iolascon A. Taher A. Cappellini MD clinical management of iron deficiency anemia in adults: systemic review on advances in diagnosis and treatment. Eur. J. Intern. Med. 2017; 42: 16-23 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ], gastroduodenoscopy should feature early in the work up of IDA. If no obvious underlying cause of IDA is found the same gastroduodenoscopy session should be utilised to evaluate autoimmune gastritis and Helicobacter pylori infection status by gastric biopsy, as well as Giardia lamblia infestation status and coeliac disease status by duodenal biopsy, instead of considering those disorders only “in the presence of unexplained recurrent IDA” [ [1] De Franceschi L. Iolascon A. Taher A. Cappellini MD clinical management of iron deficiency anemia in adults: systemic review on advances in diagnosis and treatment. Eur. J. Intern. Med. 2017; 42: 16-23 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ]. Furthermore, the fact that autoimmune gastritis, H. pylori infection, and Giardia lamblia infestation are risk factors for iron deficiency anaemia [ [1] De Franceschi L. Iolascon A. Taher A. Cappellini MD clinical management of iron deficiency anemia in adults: systemic review on advances in diagnosis and treatment. Eur. J. Intern. Med. 2017; 42: 16-23 Abstract Full Text Full Text PDF PubMed Scopus (57) Google Scholar ], should not undermine awareness that the same aetiological factors also operate for cobalamin deficiency [ 2 Hershko C. Souroujon M. Maschler I. Heyd J. Patz J. Variable hematologic presentation of autoimmune gastritis: age-related progression from iron deficiency to cobalamin depletion. Blood. 2006; 107: 1673-1679 Crossref PubMed Scopus (183) Google Scholar , 3 Campuzano-Maya G. Hematological manifestations of Helicobacter pylori infection. World J. Gastroenterol. 2014; 20: 12818-12838 Crossref PubMed Scopus (44) Google Scholar , 4 Cordingley F.T. Crawford G.P. Giardia lamblia infection causes vitamin B12 deficiency. Aust. NZ Med. 1986; 16: 78-79 Crossref PubMed Scopus (23) Google Scholar ], and that as many as 25.7% patients with giardiasis may be coinfected with Helicobacter pylori [ [5] Zylberberg H.M. Green P.H.R. Turner K.O. Genta R.M. Lobwohl B. Prevalence and predictors of giardia in the United States. Dig. Dis. Sci. 2017; 62: 432-440 Crossref PubMed Scopus (23) Google Scholar ]. The risk that the diagnosis of coexisting cobalamin deficiency may be missed in IDA patients is high when microcytosis is the only manifestation of the coexistence of cobalamin deficiency and iron deficiency [ [2] Hershko C. Souroujon M. Maschler I. Heyd J. Patz J. Variable hematologic presentation of autoimmune gastritis: age-related progression from iron deficiency to cobalamin depletion. Blood. 2006; 107: 1673-1679 Crossref PubMed Scopus (183) Google Scholar ]. In the latter study, comprising 160 subjects with autoimmune gastritis, the haematological profile was characterised by microcytosis (Mean cell volume < 80 fl) in 51.9% of cases. In that study 46% of 83 iron deficient subjects with microcytosis proved to have coexisting cobalamin deficiency [ [2] Hershko C. Souroujon M. Maschler I. Heyd J. Patz J. Variable hematologic presentation of autoimmune gastritis: age-related progression from iron deficiency to cobalamin depletion. Blood. 2006; 107: 1673-1679 Crossref PubMed Scopus (183) Google Scholar ]. Accordingly, early recognition of autoimmune gastritis, H. pylori infection, and Giardia lamblia infestation, respectively, should raise the index of suspicion for the coexistence of cobalamin deficiency and IDA, thereby mitigating the risk of vitamin B 12-related neuropsychiatric complications.