Sections View Full Chapter Figures Tables Videos Full Chapter Figures Tables Videos Supplementary Content ++ DEFINITION ++ Pure red cell aplasia describes anemia caused by an isolated depletion of erythroblasts characterized by severe reticulocytopenia and absent or markedly diminished marrow erythroid progenitors (erythroblasts). ++ CLASSIFICATION ++ See Table 4–1. ++Table Graphic Jump LocationTABLE 4–1CLASSIFICATION OF PURE ERYTHROID APLASIAView Table|Favorite Table|Download (.pdf) TABLE 4–1 CLASSIFICATION OF PURE ERYTHROID APLASIA Fetal Red Cell Aplasia (non-immune hydrops fetalis, parvovirus 19 infection in utero) Inherited Blackfan-Diamond disease (RPS19 mutations in 25% of cases) Acquired Transient pure red cell aplasia Transient erythroblastopenia of childhood Acute parvovirus B19 infection in the setting of underlying hemolytic anemia Chronic pure red cell aplasia Red cell aplasia in association with another disease (see Table 4–3) ++ ACUTE RED CELL APLASIA ++ May result from transient marrow erythroblastopenia, which occurs in both children and adults. It is most common in the first several years of life. Seen most often in patients with a hemolytic disorder, such as hereditary spherocytosis or sickle cell anemia, when a transient severe reduction in erythropoiesis causes a rapid fall in hemoglobin level—called an (erythroid) aplastic crisis. May also be seen in patients who are hematologically normal. True prevalence is unknown, and it is assumed that many mild cases are not detected. ++ Etiology ++ Most patients with aplastic crises are infected with B19 parvovirus, but occasionally another viral infection may be responsible. IgG inhibitors of erythroid colony formation in vitro have been found in some patients with a condition called transient erythroblastopenia of childhood. Drugs may induce aplastic crises, either by an immunologic mechanism or by direct toxicity. Commonly implicated drugs are listed in Table 4–2. ++Table Graphic Jump LocationTABLE 4–2SOME DRUGS ASSOCIATED WITH THE DEVELOPMENT OF ERYTHROID APLASTIC CRISISView Table|Favorite Table|Download (.pdf) TABLE 4–2 SOME DRUGS ASSOCIATED WITH THE DEVELOPMENT OF ERYTHROID APLASTIC CRISIS Generic Name Alpha-Methyldopa (Aldomet) Azathioprine Aztreonam Sulfobromophthalein sodium (bromsulphthalein) Carbamazepine Cephalothin Chloramphenicol Chlorpropamide Co-trimoxazole D-Penicillamine Diphenylhydantoin Fenoprofen Lindane (gamma benzene hexachloride) Gold Indomethacin Isoniazid Dapsone Methazolamide Pentachlorophenol Procainamide Rifampicin Sulfasalazine Thiamphenicol Valproic acid ++ Clinical Features ++ Frequently, the patient has had a recent febrile illness, often with upper respiratory symptoms, gastrointestinal symptoms, or headache. Listlessness, increasing pallor, and tachycardia are characteristic. Usually no other significant changes are found on physical examination. ++ Laboratory Features ++ Evidence of an underlying hematologic disorder, such as hereditary spherocytosis or sickle cell anemia, may be present. Anemia and reticulocytopenia are characteristic. They are often severe. Granulocyte and platelet counts are usually normal. Erythroid cells are depleted in the marrow early in the illness, but reappear just before recovery; thus, if the marrow is tested during recovery, the erythroblastopenia may be missed. Reticulocytosis is the first sign of recovery, and some nucleated red cells ... GET ACCESS TO THIS RESOURCE Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth Get Free Access Through Your Institution Contact your institution's library to ask if they subscribe to McGraw-Hill Medical Products. What is MyAccess? Create a FREE MyAccess profile to: Use this site remotely Bookmark your favorite content Track your self-assessment progress and more!