Apoptosis of Circulating Heterophils; Implications for the Interpretation of the Heterophil/Lymphocyte Ratio

Abstract

The aim is to demonstrate a variety of apoptotic heterophils (equivalents of mammalian neutrophils) occurring in hemograms of 50 apparently healthy pullets housed in cages. These atypical cells are found in blood with normal total white cell levels (TWBC, ~20K) and in those ranging up to 100(K) a leukocytosis/leukemoid reaction level. Conversely heterophil/lymphocyte (H/L) ratios in all hens ranged between 0.14 – 0.50 (homeostasis). The Arneth index (a heterophil age measure) of 1.8 computed using only intact heterophils indicated a “left-shift”, suggesting inflammation even in the context of a normal hemogram.