Infantile Pyknocytosis: An Under-Recognized Form of Neonatal Hemolytic Anemia?

Abstract

Infantile pyknocytosis (IP) is an under-recognized hematological entity of newborns that can cause a severe neonatal hemolytic anemia. A careful, prompt, and accurate peripheral blood smear examination is essential to establish the diagnosis. Here we describe the clinical features and histological parameters of 1 case of IP. Spontaneous resolution usually occurs by 4 to 6 months, but red blood cell transfusion may be needed if the anemia is severe.

Infantile Pyknocytosis: End-Tidal CO, %Micro-R Measurements, Next-Generation Sequencing, and Transfusion Avoidance with Darbepoetin

“…Since 1959, patients with infantile pyknocytosis have been reported from the USA [1, 4, 20], France [2, 8, 15, 16, 18, 21], Greece [3], Mexico [5], Australia [6], Lebanon [7, 9], Italy [10, 14, 17], Belgium [11], Israel [12], Brazil [13], and the United Kingdom [19]. Similarities in the reported cases are striking; all have pyknocytes on the blood film, all have anemia and jaundice that resolves after 2–6 months, and practically all received multiple red blood cell transfusions.…”

“…That initial publication and all subsequent case reports [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] did not reveal the cause of this condition. Though these accounts are heterogeneous, there are several unifying elements: (1) neonatal presentation with Coombs-negative jaundice and anemia, (2) blood smears show abundant contracted burr cells (pyknocytes), (3) erythrocyte transfusions are generally needed for 2 or 3 months, (4) complete remission with no residual effects.…”