L03. Chapter 7 Erythrocyte Morphology and Inclusions PDF

6/28/2024 ERYTHROCYTES: MORPHOLOGY AND INCLUSIONS...

6/28/2024 ERYTHROCYTES: MORPHOLOGY AND INCLUSIONS Chapter 7 ALPINE SKI HOUSE PREAMBLE PowerPoints are a general overview and are provided to help students take notes over the video lecture ONLY. PowerPoints DO NOT cover the details needed for the Unit exam Each student is responsible for READING the TEXTBOOK for details to answer the UNIT OBJECTIVES Unit Objectives are your study guide (not this PowerPoint) Test questions cover the details of UNIT OBJECTIVES found only in your Textbook! ALPINE SKI HOUSE 1  6/28/2024 ERYTHROCYTES: NORMAL AND ABNORMAL Normal mature erythrocytes (discocytes) are biconcave and disc shaped and lack a nucleus. Abnormalities occur due to: Variation in size: called anisocytosis Variation in shape: called poikilocytosis Alteration in color: suffix -chromia Inclusions in the erythrocytes Alterations to the erythrocyte distribution on a PB smear ALPINE SKI HOUSE TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #2 The erythrocyte indices are used to mathematically define cell size and the concentration of hemoglobin within the cell. They are as follows: Mean cell/corpuscular volume (MCV) Mean cell/corpuscular hemoglobin (MCH) Mean cell/corpuscular hemoglobin concentration (MCHC) ALPINE SKI HOUSE 2  6/28/2024 TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #3 Mean corpuscular volume (MCV) The MCV expresses the average volume (size) of an erythrocyte. It is calculated by the following equation: Hct × 10 RBC Units = femtoliters (fL). The reference value of MCV is 80 to 96 fL. ALPINE SKI HOUSE TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #4 Mean corpuscular hemoglobin (MCH) The MCH expresses the average weight (content) of hemoglobin in an average erythrocyte. It is directly proportional to the amount of hemoglobin and the size of the erythrocyte. It is calculated by the following equation: Hgb × 10 RBC MCH = picograms (pg). The reference value of MCH is 27 to 32 pg. ALPINE SKI HOUSE 3  6/28/2024 TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #5 Mean corpuscular hemoglobin concentration (MCHC) The MCHC expresses the average concentration of hemoglobin per unit volume of erythrocytes. It is also defined as the ratio of the weight of hemoglobin to the volume of erythrocytes. It is calculated by the following equation: Hgb × 100 Hct MCHC = g/dL or %. The normal value of MCHC is 32% to 36%. ALPINE SKI HOUSE TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #6 A normal erythrocyte has an average diameter of 7.2 µm with a usual variation of 6.8 to 7.5 µm. The extreme size limits are generally considered to be 6.2 to 8.2 µm. This normal size is referred to as normocytic. Normocytic can also be classified by the MCV falling between 80 and 96 fL. If not normocytic, erythrocytes may be either: Larger than normal (macrocytic; MCV > 96 fL) Smaller than normal (microcytic; MCV < 80 fL) ALPINE SKI HOUSE 4  6/28/2024 TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #7 ALPINE SKI HOUSE TYPES OF VARIATIONS IN ERYTHROCYTE SIZE #8 ALPINE SKI HOUSE 5  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #1 The general term for mature erythrocytes that have a shape other than the normal round, biconcave appearance on a stained blood smear, or variations, is poikilocytosis. The term poikilocytosis is a term used cautiously Can include the following: Acanthocytes, blister cells, echinocytes Elliptocytes, keratocytes, ovalocytes, schistocytes Sickle cells (drepanocytes), target cells (codocytes), spherocytes, and teardrops (dacryocytes) ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #2 ALPINE SKI HOUSE 6  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #4 ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #5 Acanthocytes Pointy irregular shaped projections that are unevenly dispersed around the red cell ALPINE SKI HOUSE 7  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #6 Blister cells ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #7 Keratocytes Blister cell ruptured Looks like a bite out of the cell ALPINE SKI HOUSE 8  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #8 Schistocytes Mechanical tearing of the rbc Looks “ripped” Blister cells and Keratocytes are generally grouped together under Schistocytes ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #9 Echinocyte (burr cell) Rounded projections evenly dispersed around the red cell ALPINE SKI HOUSE 9  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #10 Elliptocytes (pencil; single arrow) Ovalocytes (football; double arrow) ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #11 Poikilocytes: Tear drop cells, sickle cells, and fragments ALPINE SKI HOUSE 10  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #12 Schistocytes (single arrow) Polychromasia (double arrow) ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #13 Drepanocytes (sickle cells) ALPINE SKI HOUSE 11  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #14 Spherocytes Very Round NO central pallor ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #15 Stomatocytes ALPINE SKI HOUSE 12  6/28/2024 KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #16 Codocytes (target cells) ALPINE SKI HOUSE KINDS OF VARIATIONS IN ERYTHROCYTE SHAPE #17 Dacryocytes (Tear Drop) (single arrow) Polychromasia (*) ALPINE SKI HOUSE 13  6/28/2024 ALTERATIONS IN ERYTHROCYTE COLOR #1 A normal erythrocyte has a moderately pinkish-red appearance with a lighter-colored center when stained with a conventional blood stain. The color reflects the amount of hemoglobin present in the cell. The lighter color in the middle, thinner portion of the cell does not normally exceed one third of the cell’s diameter and is referred to as the central pallor. Under these conditions, the erythrocyte is referred to as normochromic. ALPINE SKI HOUSE ALTERATIONS IN ERYTHROCYTE COLOR #2 The general term for a variation in the normal coloration is anisochromia. A more specific term, hypochromia, is more commonly used when the central pallor exceeds one third of the cell’s diameter. ALPINE SKI HOUSE 14  6/28/2024 ALTERATIONS IN ERYTHROCYTE COLOR #3 Iron deficiency anemia (microcytic hypochromic) ALPINE SKI HOUSE ALTERATIONS IN ERYTHROCYTE COLOR #4 An alteration in the color of an erythrocyte may also reflect a state of cell immaturity. The term polychromatophilia is used if a nonnucleated erythrocyte has a faintly blue-orange color. ALPINE SKI HOUSE 15  6/28/2024 ALTERATIONS IN ERYTHROCYTE COLOR #5 Polychromatophilia (Polychromasia) ALPINE SKI HOUSE ALTERATIONS IN ERYTHROCYTE COLOR #6 An alteration in the color of an erythrocyte may also reflect a state of cell immaturity. The term polychromatophilia (or polychromasia) is used if a nonnucleated erythrocyte has a faintly blue-orange color when stained with Wright’s stain. A reticulocyte lacks the full amount of hemoglobin, and the blue color is caused by diffusely distributed residual RNA in the cytoplasm. ALPINE SKI HOUSE 16  6/28/2024 VARIETIES OF ERYTHROCYTE INCLUSIONS #1 Reticulocytes under supravital stain (new methylene blue) ALPINE SKI HOUSE VARIETIES OF ERYTHROCYTE INCLUSIONS #2 Parasites, for example, malaria, Babesia, and leishmania Nonparasitic inclusions include the following: Basophilic stippling (both fine and coarse forms) Cabot rings Heinz bodies: Can only be visualized under supravital stain Howell-Jolly bodies Pappenheimer bodies (aka siderotic granules) ALPINE SKI HOUSE 17  6/28/2024 VARIETIES OF ERYTHROCYTE INCLUSIONS #3 Basophilic stippling (fine) appears as tiny, round, solid-staining, dark-blue granules. The granules are usually evenly distributed throughout the cell and often require careful examination to detect them. Coarse basophilic stippling is sometimes referred to as punctate stippling. These granules are larger than in the fine form and are considered to be more serious in terms of pathological significance. Stippling represents granules composed of ribosomes and RNA that are precipitated during the process of staining of a blood smear. Stippling is associated clinically with disturbed erythropoiesis (defective or accelerated heme synthesis), lead poisoning, and severe anemias. ALPINE SKI HOUSE VARIETIES OF ERYTHROCYTE INCLUSIONS #4 Basophilic stippling ALPINE SKI HOUSE 18  6/28/2024 VARIETIES OF ERYTHROCYTE INCLUSIONS #5 Cabot Ring ALPINE SKI HOUSE VARIETIES OF ERYTHROCYTE INCLUSIONS #6 Hgb C Crystals ALPINE SKI HOUSE 19  6/28/2024 VARIETIES OF ERYTHROCYTE INCLUSIONS #7 Heinz bodies Are 0.2 to 2.0 µm in size Can be seen with a stain such as crystal violet or brilliant cresyl blue Represent precipitated, denatured hemoglobin Are clinically associated with congenital hemolytic anemia, G6PD deficiency, hemolytic anemias secondary to drugs such as phenacetin, and some hemoglobinopathies ALPINE SKI HOUSE VARIETIES OF ERYTHROCYTE INCLUSIONS #8 Howell-Jolly bodies Are round, solid-staining, dark-blue to purple inclusions (only one or two), 1 to 2 µm in size. Are nuclear remnants predominantly composed of DNA and not seen in normal erythrocytes. This remnant DNA is normally pitted out by the macrophages in the spleen, so the presence of H-J bodies are a sign of splenic dysfunction or absence. ALPINE SKI HOUSE 20  6/28/2024 VARIETIES OF ERYTHROCYTE INCLUSIONS #9 Pappenheimer bodies (siderotic granules) May be observed in Wright-stained smears as three to four purple dots aggregated in one area of the cell Are infrequently seen in peripheral blood smears Are aggregates of mitochondria, ribosomes, and iron particles Are clinically associated with iron-loading anemias, hyposplenism, and hemolytic anemias ALPINE SKI HOUSE VARIETIES OF ERYTHROCYTE INCLUSIONS #10 Pappenheimer bodies in PB versus siderotic granules in BM Pappenheimer bodies and siderotic granules are probably identical structures. Siderotic granules are dark-staining particles of iron in the erythrocyte that are visible with a special iron stain—Prussian blue. They appear as blue dots and represent ferric (Fe3+) ions. Siderotic granules can also be visualized around the nucleus in ringed sideroblasts in sideroblastic anemias, refractory anemias, and iron overload conditions. ALPINE SKI HOUSE 21  6/28/2024 ALTERATIONS IN ERYTHROCYTE DISTRIBUTION #1 Agglutination Defined as the clumping of erythrocytes in a random, nonspecific arrangement. Rouleaux formation, in contrast to agglutination, is the arrangement of erythrocytes in groups that resemble stacks of coins. Is usually present in the thick portions of normal blood smears. If the rouleaux exist in thin areas of the blood smear where the erythrocytes should just touch each other or barely overlap, pathological rouleaux are present. True agglutination is caused by the presence of antibodies reacting with antigens on the erythrocyte. Rouleaux formation is associated with the presence of circulating cryoglobulins or paraproteins. ALPINE SKI HOUSE PARASITIC INCLUSIONS: MALARIA #1 ALPINE SKI HOUSE 22  6/28/2024 PARASITIC INCLUSIONS: MALARIA #2 Plasmodium vivax ALPINE SKI HOUSE PARASITIC INCLUSIONS #3 Plasmodium falciparum ALPINE SKI HOUSE 23  6/28/2024 PARASITIC INCLUSIONS #4 Plasmodium malariae Plasmodium ovale ALPINE SKI HOUSE PARASITIC INCLUSIONS #5 Leishmania spp. Babesia microti ALPINE SKI HOUSE 24  6/28/2024 POSTAMBLE READ the TEXTBOOK for the details to answer the UNIT OBJECTIVES. USE THE UNIT OBJECTIVES AS A STUDY GUIDE All test questions come from detailed material found in the TEXTBOOK (Not this PowerPoint) and relate back to the Unit Objectives ALPINE SKI HOUSE 25