Reticulocytopenia in autoimmune hemolytic anemia.

ETICULOCYTOSIS is gemserally regarded as a characteristic feature of the hensolytic symsdrome. The outpouring of young red cells is ouse of the bone marrow’s reactiomss to the challenge of aisemia, atsd the numssber of reticulocytes it produces is oftets a good measure of the severity of the hemolytic process. Whets the red cell life spams is very short mssost of the cells ims the circulation nsay be reticulocytes, imsdicatimsg that few cells live niuch beyomsd their reticulum-bearimsg babyhood. Perisicious aisensia is au insportamst exceptions. The bomse niarrow in pertsicious amsemia may produce four or five times the tiormal number of red cells yet the reticulocyte coumst is low . Examimsation of bone nsarrow from cases of pernicious anemnia reveals the reason for this.’ Vital stainimsg of aspirated nsarrow demomsstrates aniple reticulum substamsce its the cytoplasm of the msucleated erythroid cells. But the cytoplasm matures aisd the reticulum substamsce disappears before the msucleus is lost . As a comssequence, the youmsg cells issuing from the marrow are msot reticulocytes. Another imsstance of reticulocytopenia in the presence of hemsiolytic disease occurs during the aregemserative or aplastic crises that may strike patients with chronic hemolytic anensia of various kinds. The aregenerative crisis was first identified ims patients with hereditary spherocytosis,2 but it also occurs its autoimmumse hemolytic anemia.3 For one reasoms or another the boise nsarrow abruptly stops its hematopoietic activity amid may actually become aplastic. Thems imstervenes a period of reticulocytopenia, leukopenia and thronibocytopemsia. Because hemolytic disease is already presemst severe anemia rapidly develops. Fortunately the crisis is usually short lived. Ims coisditions where the bone marrow is obliterated by iseoplastic or fibrous tissue hensolytic disease amid reticulocytopenia may occur together. With these exceptions there is a getseral impressioms that it is unusual to find severe hemolytic disease, erythroid hyperplasia of the marrow and reticulocytopenia simultaneously. In a survey of cases of autoimniune hemolytic anemia (AHA) from the files of the Armned Forces Institute of Pathology it was noted that a number of patients exhibited, at omse time or another, a definite reticulocytopemsia in the presence of severe hensolytic anemia with a bone marrow that presented a picture of imstense erythroid proliferation. The phenomenon appears to have a simsister significance.