Poikilocytosis

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As poikilocytosis ( ancient Greek ποικίλλω poikilo , German , colorful, variously ' and ancient Greek κύτος Cytos , German , cell' ), the occurrence of differently shaped, non-circular erythrocytes at a microscopic examination of the blood smear designated. These differently shaped erythrocytes, which differ from the normal biconcave round shape, must make up at least 3%. The occurrence of poikilocytosis is unspecific; it can occur in all severe anemia .

causes

The most common is poikilocytosis caused by impaired erythropoiesis . Furthermore, malignant diseases can lead to the suppression of erythropoiesis. In addition, disorders and defects of the erythrocyte membrane can lead to poikilocytosis.

Specific diseases associated with poikilocytosis are iron deficiency anemia and pernicious anemia . The Hereditary poikilocytosis (Syn. Pyropoikilocytosis ) is partly with severe hemolytic associated anemia and a consequent regular transfusion required. Pronounced erythrocyte fragmentation occurs, as well as microcytic forms (for microcytes see below in the text) of the erythrocytes are possible. These poikilocytes are sensitive to heat and osmotically unstable. In the severe forms of hereditary poikilocytosis, a deficiency of the spectrin can occur, so that elliptocytes and spherocytes can occur. Patients with this disease are often homozygous for a defect in the 2-alpha spectrin.

Poikilocytosis can also occur if the bone marrow is damaged by drugs (e.g. azidamfenicol , cyclophosphamide ), chemicals, ionizing radiation, but also by infectious diseases (e.g. AIDS ) and malignant diseases such as leukemia and other forms of cancer.

Forms of erythrocytes

The shape of the red blood cells can provide a diagnostic clue as to the cause.

The following deviations are possible:

  • Anulocyte : low hemoglobin erythrocytes with a narrow border. Occurrence: iron deficiency and thalassemia
  • Burr cell : A microcytic erythrocyte with one or more pointed peaks. Occurrence: Various forms of anemia, especially uremia .
  • Dakryozyt or tears cell : This drop-shaped red blood cells have a outgrowth at a cell pole. Occurrence: Especially in osteomyelofibrosis , less often in iron deficiency, myelodysplasias and other myeloproliferative syndromes.
  • Drepanocyte or sickle cell : The erythrocytes can be sickle, crescent or dovetail shaped. This form signals a HbS content of over 50% (see sickle cell anemia )
  • Elliptocyte : The erythrocytes are elliptical in shape. Occurrence: Very rarely congenital in hereditary poikilocytosis (see above), then over 50% of all erythrocytes are in elliptical form and in hyperlipidemia .
  • Fragmentocyte or schistocyte: On the convex side, a smooth, semicircular, intact membrane appears. On the other hand, the concave side shows an irregular border, which arises from the fact that part of its volume has been torn off the erythrocyte on this side. Occurrence: Mechanical damage to the erythrocytes intravascularly e.g. B. in artificial heart valves. Thermal damage in severe burns.
  • Howell-Jolly corpuscles
  • Target cell : Within the central lightened zone of the erythrocytes, there is a circular hemoglobin compression , so that the erythrocytes have a target-shaped appearance. Occurrence: thalassemia, sickle cell anemia, posthepatic jaundice , asplenia
  • Spherocyte : spherical shape of the normal sized erythrocyte.
  • Stomatocyte : slit or mouth-shaped central lightening

Anisocytosis is a large variation in the size of the erythrocytes. There are erythrocytes that are micro- and / or macrocytes and make up more than 3% of all erythrocytes. Anisocytosis is the most common red blood cell abnormality.

literature

  • Detlev Drenckhahn anatomy, macroscopic anatomy, embryology and histology of humans with student consult access: Volume 2: Cardiovascular system, lymphatic system, endocrine glands, nervous system, sensory organs, skin. Elsevier 2007 ISBN 3-437-42351-7
  • Hanns-Wolf Baenkler Internal Medicine Georg Thieme Verlag 2001 ISBN 3-13-128751-9
  • Kai Joachim Bühling Intensive Course : General and Special Pathology Elsevier 2004 ISBN 3-437-42411-4
Individual evidence
  1. ↑ Helmut Gadner Pediatric Hematology and Oncology, pages 133/134 Springer 2006 ISBN 3-540-03702-0
  2. ^ Gerhard Thews , Peter Vaupel : Vegetative Physiology. Springer-Verlag, 2013, ISBN 978-3-662-10747-8 , p. 39 ( limited preview in Google book search).

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