PowerPoint Presentation: Absorption and transport of vitamin B12
Pernicious anemia : Pernicious anemia Immunologically mediated, autoimmune destruction of gastric mucosa CHRONIC ATROPHIC GASTRITIS – marked loss of parietal cells Three types of antibodies: Type I antibody- 75% - blocks vitamin B 12 and IF binding Type II antibody – prevents binding of IF-B 12 complex with ileal receptors Type III antibody – 85-90% patients – against specific structures in the parietal cell Associated with other autoimmune diseases like autoimmune thyroiditis
DIAGNOSTIC FEATURES: DIAGNOSTIC FEATURES Low levels of serum B 12 Striking reticulocytosis after parenteral administration of vitamin B 12 Serum antibodies to intrinsic factor
Lab Diagnosis : Lab Diagnosis The Schilling test is a medical investigation used for patients with vitamin B12 deficiency. The purpose of the test is to determine whether the patient has pernicious anemia.
Principles of schilling test : Principles of schilling test Stage 1: oral vitamine B 12 plus intramuscular vitamine B 12 Stage 2: vitamin B 12 and intrinsic factor Stage 3: vitamin B 12 and antibiotics Stage 4: vitamin B 12 and pancreatic enzymes
Schilling test: Schilling test Establishes the cause of vitamin B 12 deficiency Test performed in two parts If parts one & two abnormal: Pernicious anemia If part one only abnormal: malabsorption