Proposal for standardized classification of left shift, toxic change, and increased nuclear segmentation in heterophils and neutrophils in non‐mammalian vertebrates

Left shift and toxic change in heterophils and neutrophils of non‐mammalian vertebrates: A comparative review, image atlas, and practical considerations

“…A classification system characterizing granulocytes as mature or immature has been used in elasmobranchs and selectively in birds and reptiles 6,41,42 . The use of a similar two‐group classification system (mature and immature), combined with descriptive text for the degree of immaturity and cellular morphology, is recommended by the authors 35 …”

“…This table summarizes general features. Recommendations for categorization of immature cells and grading of toxic change are discussed in the text and concurrent Letter to the Editor 35 …”

“…Images of heterophils and neutrophils in health (top row), with toxic change (±left shift), and segmentation or hypersegmentation (bottom row) in mammalian and non‐mammalian vertebrate taxa. Toxic change is recorded as present or severe for all taxa (proposed system as described for non‐mammalian vertebrates) 35 and as 1‐3+ for mammals (conventional system in mammals) 20 . The degree of toxic change designated on individual representative cells here implies a grade inferred across the overall population of heterophils or neutrophils on blood film evaluation; in severe grade, the majority of the population had changes comparable with those pictured.…”

“…With sufficient peripheral demand, both processes often occur concurrently (Figures 6‐12). Due to factors, including the degree of morphologic variation in left shifts across NMV, interobserver variation, and potential prognostic significance based on extrapolation from mammals and clinical experience, the use of a two‐tiered grading system for recording of toxic change in the heterophil or neutrophil population on blood film review, combined with descriptive text, is recommended by the authors 35 …”

“…The bottom two rows show the effects of different staining on representative cells from the same animal stained with methanolic Wright‐Giemsa (WG) (M‐R) or DIFF‐QUIK (DQ) (S‐X). Toxic change is recorded as present or severe for all taxa (proposed system as described for NMV) 35 and as 1‐3+ for mammals (conventional system in mammals) 20 . The degree of toxic change designated on individual representative cells here implies a grade inferred across the overall population of heterophils or neutrophils on blood film evaluation.…”