Helicobacter Pylori Infection–Related Pancytopenia in a Young Boy

Deficiency of vitamin B12 (VitB12), also known as cobalamin, and Helicobacter pylori infection are commonly seen in our region. Inadequate dietary intake of VitB12, lack of intrinsic factor (IF) secretion by the stomach, impaired intestinal absorption of IF-cobalamin complex, or absence of VitB12 transport protein are the common causes of cobalamin deficiency [1]. Dietary cobalamin is strictly protein bound and requires the action of gastric acid to release it. When the gastric acid secretion is impaired due to H. pylori infection, cobalamin absorption is decreased and that may cause VitB12 deficiency. The association between VitB12 and H. pylori infection have been demonstrated in children and adults [2, 3]. We herein present a patient with VitB12 deficiency who has pancytopenia accepted to be related with H. pylori infection. A 13-year-old-boy was referred to our pediatric hematology outpatient clinic because of very low serum hemoglobin level. His dietary history revealed that he was consuming meat products up to 2 times weekly and consuming eggs up to 4 times weekly. His medical history did not reveal any significant health problem. He complained of weakness, dizziness, and dull abdominal pain in the last 4 weeks. He had pallor on physical examination and his blood test showed the following: hemoglobin (Hb): 5.3 g/dL; mean corpuscular volume (MCV): 106 fL; red cell distribution width (RDW): 20; reticulocyte count: 0.56%; white blood cell count (WBC): 2230/mm3; platelet count: 56000/mm3; total bilirubin: 1.39 mg/dL; and direct bilirubin: 0.2 mg/dL. Additionally at peripheral blood smear, neutrophil hypersegmentation was detected. Megaloblastic changes in normoblasts, giant metamyelocytes, and heterogeneity were seen in bone marrow aspiration. Serum ferritin and folate levels were normal. However, his VitB12 level was 50 pg/mL (180–300 pg/mL) and antiparietal cell antibody was negative. His urea breath test was positive for H. pylori infection. In order to prove etiologic relationship with H. pylori infection and pancytopenia, we need to treat the patient’s H. pylori first before VitB12 treatment. Due to the reduced hemoglobin level of the patient, we held concomitant treatment of both conditions together. We started treatment against H. pylori (amoxicillin and clarithromycin for 15