Hypochromia Information and Courses from MediaLab, Inc.

Beta Thalassemia Silent Carrier Beta Thalassemia Minor Beta Thalassemia Intermedia Beta Thalassemia Major Delta-Beta Thalassemia Anemia Absent Mild to absent Moderate Severe Mild Red blood cell (RBC) count Normal Increased Decreased to normal Decreased Decreased to normal Hemoglobin(Hb) Normal Decreased to normal (10 - 12 g/dL) Decreased (7 - 10 g/dL) Marked decrease (<7 g/dL) Decreased to normal (8 - 13 g/dL) Mean corpuscular volume (MCV) Slight to no decrease Marked decrease Marked decrease Marked decrease May be slightly decreased Mean corpuscular hemoglobin concentration (MCHC) Slight to no decrease Marked decrease Marked decrease Marked decrease May be slightly decreased Red blood cell distribution width (RDW) Normal Normal to slightly increased Increased Increased Normal RBC morphology Normal Marked hypochromia and microcytosis Codocytes (target cells) Possible basophilic stippling Nucleated RBCs are usually not present Marked hypochromia and microcytosis Codocytes (target cells) Possible basophilic stippling Nucleated RBCs are usually not present Marked hypochromia and microcytosis Codocytes (target cells) schistocytes ovalocytes basophilic stippling polychromasia nucleated RBCs Possible hypochromia and microcytosis Codocytes (target cells) Basophilic stippling Reticulocyte count Normal May be slightly increased Slightly increased (<5%) Mildly increased (5 - 10%) Mildly increased Hb electrophoresis Normal pattern Decreased amount of Hb A Variable amounts of Hb A2 and Hb F Decreased amount of Hb A Variable amount of Hb A2 Hb F is usually increased Severly decreased amount of Hb A Variable amount of Hb A2 Usually an increased amount of Hb F Decreased amount of Hb A and Hb A2 Increased amount of Hb F (15 - 20%) If red blood cells are normochromic and normocytic, the RBC, Hb, and Hematocrit (HCT) test values follow in three-fold progression (i.e., RBC x 3 = Hb and Hb x 3 = HCT). This is sometimes referred to as "the rule of threes." This rule will usually not apply in cases of beta thalassemia, particularly beta thalassemia minor where the RBCs are not normochromic and are microcytic, and where there is a disproportionate number of RBCs for the amount of hemoglobin that is present.

Two photographs of a peripheral blood smear are submitted for review . The smears are from a 9-month-old baby with a heart valve replacement. In the upper photograph is a nucleated RBC and platelets are decreased. Nucleated red cells and occasional giant platelets indicate an active marrow response. In the process of forcing blood cells through the heart valve, erythrocytes are damaged, schistocytes are formed, and platelets are destroyed leading to thrombocytopenia. In the lower field are schistocytes, acanthocytes, echinocytes (burr cells), spherocytes, and the absence of platelets. The presence of burr cells could represent an artifact of smear preparation, but with the history of valve replacement, the red cell changes are likely the result of red cell damage as the cells circulate through the new valve. This situation is described as Waring Blender Effect because of damage to blood cells passing through the new valve, looking as if they had suffered the onslaught of a blender. Target cells and mild hypochromia may reflect iron deficiency through the loss of iron from destruction of RBC's. Iron loss through red cell destruction may be reflected in some hypochromia.

The family (cited in the previous case history) was from a region of Thailand where the physician knew HbE carriers are prevalent. Homozygous hemoglobin E is common in Southeast Asia and presents with very mild anemia and seldom requires transfusion. Over 30 million people in the world are HbE carriers, making this abnormal hemoglobin almost as common as HbS. Hemoglobin E is uncommon in North America and in Europe, but with changing immigration patterns, hemoglobinopathy E cannot be ignored. Peripheral blood smear findings of target cells, microspherocytes, red cell hypochromia, a few red blood cell fragments, and nucleated red blood cells require evidence from hemoglobin electrophoresis to establish a diagnosis. Clinically, a very important and severe syndrome is hemoglobin E/beta thalassemia in which there is hemolysis requiring repeated transfusions. The patient has a severe anemia, low MCV (50's), and high RBC. This is characteristic of Hgb E/beta thalassemia.

Examples of hypochromic cells are seen in this slide. Notice the thin rim of hemoglobin and the large area of central pallor present in most of these cells. Hypochromic cells are cells which are unusually thin, or in which the hemoglobin concentration is decreased. Decreased hemoglobin concentration can be caused by decreased amounts of iron available for hemoglobin production. The MCHC for this patient was significantly decreased (26 gm/dl of RBCs) indicating a severe degree of hypochromia. When hypochromia is less severe, not all cells will be affected; thus some cells may appear almost normal whereas others show hypochromia.