Megaloblastic anemia in GI deseases

Megaloblastic anemia in GI deseases Dr Elias MAKHOUL Head of Gastro-Enterology department H.N.D.Secours Jbeil Megaloblastic anemia: • Characterized by large, immature, nucleated erythrocytes • Second most common type of anemia. • Vitamin B12/Folic acid deficiency • Pernicious anaemia – Biermer – autoimmune, Gastric atrophy, VitB12 def. MEGALOBLASTIC ANEMIA Causes of Vit.B12 deficiency(1) 1-Malabsorption a) Inadequate production of intrinsic factor - pernicious anemia - gastrectomy, partial or total - Atrophy of gastric mucosa and glands b) Inadequate releasing vit. B12 from food (partial gastrectomy, abnormality of stomach function, chronic pancreatic insufficiency) c) Terminal ileum disease (sprue, celiac disease, ilea resection, Crohn disease, Imerslund syndrome) d) Competition for intestinal B12 : - bacterial overgrowth: jejunal diverticula, intestinal stasis and obstruction due to strictures. MEGALOBLASTIC ANEMIA Causes of Vit.B12 deficiency(1) 2. Inadequate intake - vegetarians 3. Inadequate utylisation Drugs: PAS, Neomycin, Colchicin, Nitrous oxide MEGALOBLASTIC ANEMIAS- Causes of Folic acid deficiency 1. Inadequate intake 2. Malabsorption - diet lacking fresh, slightly cook food; chronic alcoholism, total parenteral nutrition, - small bowel disease (sprue, celiac disease,) - alcoholism 3. Increased requirements: - pregnancy and lactation - infancy - chronic hemolysis - hemodialysis 4. Defective utilisation Drugs:folate antagonists(methotrexate, trimethoprim, triamteren), purine analogs (azathioprine), primidine analogs (zidovudine), RNA reductase inhibitor 2. Maladie de Biermer • Mecanisme: · Rarely before 40 years => 60-70 years. · Carence in vitamin B12, due to a deficit on IF · Auto-immune pathology, with parietals cells and IF anti- body. · Association with others immunologic pathologies thyroïdites, diabetes, vitiligo. CLINICS • Clinics: – Anemic syndrome with variable severity • Patient pale • Middle jaundice – Neurological symptom – Digestive symptom • • • Myelite => spasmodic paraplegia. • Pyramidal and posterior cordonal lesions. • Due to causal affections – Gastro-intestinal resection Glossites Dyspepsia Pre neoplastic conditions • Biermer • Atrophic gastritis • Intestinal metaplasia • H pylori MEGALOBLASTIC ANEMIA Gastric cancer • 1th suggestion : by autopsies of patient MA – 10% of AM gastric cancer • Multiple studies demonstrate: 1-12% risk of cancer • Hoffman:48 patients for 11 years0% cancer • Boch:123 patient8.1% • Retrospective study: 5161 patients3.2% – Rq : - the risk is well known - small risk - suggestion: the existence of pre cancer stage MEGALOBLASTIC ANEMIA Intestinal metaplasia • IM@ CAG is a risk factor to develop gastric cancer • Gastric cancer is often associated with – Diffuse atrophic gastric – IM • In chronic atrophic gastritis – Decrease of normal gastric glands – Replacement by intestinal metaplasia MEGALOBLASTIC ANEMIA Intestinal metaplasia • Different types of IM – Type I: • Complete • (small bowel mucosa) – Type II • Incomplete • Colic mucosa – a: non acid sulfate mucine – b: acide sulfate mucine – Suggestion: • Generally IM it is not a risk • Type II b predispose to cancer MEGALOBLASTIC ANEMIA Helicobacter-Pylori – HP play an important role in the developement of • Chronic gastritis • Atrophic gastritis • Intestinal metaplasia – The intestinale métaplasieis higher in patient infected with H. pylori – The relatif risk to develop cancer with the presence of hp • X4 • X5 in atrophic gastritis insuperficiel gastric cancer – the irradication of hp is important to prevent gastric cancer MEGALOBLASTIC ANEMIA Helicobacter-Pylori • !!!! H pylori is usually not found in IM • 24 patients with 15 patients normal patients +dyspepsia – CAG +IM – Detection of Hp • Histology • Breath test • Urease • Serology • Non correlation • To prevent false _ in histology – We have to do others exam a good correlation  Copelman and all Gastroenterology 2005 MEGALOBLASTIC ANEMIA Diagnosis 1. Diagnosis megaloblastic anemia 2. Establishing a type of deficiency (vit. B12 and/or folic acid) 3. Establishing a cause of deficiency MEGALOBLASTIC ANEMIA Diagnosis • 1/ Hemogram – Anémie macrocytaire (> 100) – Rerticulocytes • Low reticulocites  ageneratif – megaloblastes • 2/ Myelogram • 3/ Complementary exam • 4/ Fibroscopy • 5/ Test de Schilling MEGALOBLASTIC ANEMIA Diagnosis • 3/ Complementary exam – Vit B12 / Folic acid – Gastrine • High – Biermer – Zollinger Eddison – Stimulation Pentagastrin test • Absence of hydrogen ion secretion (achlorhydria) with maximal histamine stimulation – Intrinsic factor, parietal cell and IF-vit.B12 complex MEGALOBLASTIC ANEMIA Diagnosis • SCHILLING TEST • Deficit of IF • Deficit absorption of vit B12 • Radiolabeled Vit b12 * cobalt 159 absorption test (Schilling urinary excretion test) : very reduced absorption of the B12-isotope, – 2 groups  Respond to oral FI  Not respond MEGALOBLASTIC ANEMIA Diagnosis • Endoscopy : – Depistage • Pre- neoplastic lesions – Biopsies • To confirm diagnosis • H Pylori – Atrophic gastritis – Intestinal metaplasia • Lower endoscopy or Radiology: – If absence of atrophic lesions Conclusions • Megaloblastic anemia is well known • The risk of gastric cancer is etablished • But!!!!!!!!!!! THE QUESTIONS ? Frequence of endoscopie? Nombre of biopsies? Conclusions • Preconise: – If atrophic gastritis: endoscopy every 2 years – Biopsies: • multiples • Antral, fundus, corps – If H pylori : breath test – If intestinal metaplasia: • Type I and II a = atrophic gastritis • Type II b: Endoscopy every year