21 Hemoglobin H (Hb H)
Michelle To and Valentin Villatoro
Images show supravital stained peripheral blood smears with numerous hemoglobin H inclusions (examples indicated by arrows). Note the golf ball-like appearance of the red blood cells. From MLS Collection, University of Alberta.
Image 1: 50x oil immersion. https://doi.org/10.7939/R3GM8243H
Image 2: 100x oil immersion. https://doi.org/10.7939/R33F4M37Z
Appearance:
Hemoglobin H inclusions can only be visualized with supravital stains and not Wright or Romanowsky stains. With supravital stains, such as Brillian Cresyl Blue, the red blood cells are covered with numerous small, dark blue dots that give the cells a “golf ball” or “raspberry” appearance.1,2
Inclusion composition:1,2
Hemoglobin H is made up of 4 𝛃 globin chains in a tetramer formation. Hemoglobin H is unstable and will precipitate over time in the RBC, leading to Heinz Body formation. Precipitation can be induced using supravital stains, and can be used to visualize Hemoglobin H inclusions.
Associated Disease/Clinical States:1,2
Hemoglobin H Disease
References:
1. Randolph TR. Thalassemia. In: Clinical laboratory hematology. 3rd ed. New Jersey: Pearson; 2015. p. 251-276.
2. Rodak BF, Carr JH. Inclusions in erythrocytes. In: Clinical hematology atlas. 5th ed. St. Louis, Missouri: Elsevier Inc.; 2017. p. 107-14.