| Red cell morphology in PKD | Comments |
|---|---|
| Irregularly contracted cells | |
| Also known as | Echinocytes, spiculated red cells, prickle cells |
| Definition/description | Small, densely staining cells with loss of central pallor and variable number of spicules of varying width and length. Though they are frequently referred to as echinocytes, they more closely resemble acanthocytes in appearance. |
| Frequency | A variable proportion of red cells (5–20%), increased in number after splenectomy. |
| Mechanism of formation | ATP depletion and dehydration of red cells. |
| Other red cell phenotypes | |
| Polychromatophilia | These polychromatophilic cells represent reticulocytes, which can exceed > 50% of the total red cell count in a patient with PKD who has undergone splenectomy. |
| Nucleated red cells | From a hyperactive erythropoietic bone marrow. |
| Post-splenectomy changes | Howell Jolly bodies, acanthocytes, target cells |
| History | The first paper to report a patient with PKD described the spiculated red cells as “irregularly contracted or crenated erythrocytes. Lancet. 1963;2(7300):169-70. A paper published the following year stated: “Examination of a Wright-stained smear of the peripheral blood revealed the presence of contracted cells with pseudopod-like horns projecting from multiple sites. Approximately 80 per cent of the cells were of this form… oddly prickled cells… similarity between the appearance of the patient’s red cells and those observed in the syndrome of acanthocytosis.” N Engl J Med. 1964;270:1023-30. |
| Source/author | William Aird |
| References | Am J Hematol. 2019 January ; 94(1): 149–161. |