Overview

• Reptilian lymphocytes are round cells varying in size from small (5-10 μm) to large (15 μm or larger) and exhibit irregularity when they mold around adjacent cells in the blood film or fold at their cytoplasmic margin.
• The nucleus is round and is centrally or slightly eccentric in its position in the cell.
• Nuclear chromatin is heavily clumped in mature lymphocytes.
• The cytoplasm of a normal lymphocyte appears homogenous, generally lacks vacuoles and granules, and is slightly basophilic (pale blue) in the typical small mature lymphocyte.
• Small azurophilic cytoplasmic granules may be found in some lymphocytes.
• Large lymphocytes have more cytoplasmic volume compared to small lymphocytes and the nucleus is often pale staining.
• Lymphocytes typically have a large nucleus to cytoplasm ratio (N:C).
• Plasma cells may be observed in the blood film of reptiles, and are slightly larger than normal lymphocytes:
  • The nucleus is eccentrically placed, is round to oval, and contains clumped chromatin.
  • The cytoplasm of plasma cells stains deep blue, and a perinuclear halo (Golgi) is present.
• Reptilian lymphocytes function in a manner similar to those of birds and mammals:
  • Reptiles have the same two major classes of lymphocytes (B and T lymphocytes) involved in immunologic function.
  • However, unlike endothermic birds and mammals, the immunologic responses of ectothermic reptiles are greatly influenced by the environment, eg low temperatures may suppress or inhibit the immune response in reptiles.

Sampling

Tests

Availability

• Widely available at commercial laboratories. Check expertise in reptile hematology before sending sample(s).
• May be performed in practice.

Result Data

Further Reading

Publications

Refereed papers

• Recent references from PubMed and VetMedResource.
• Troiano J C, Gould E G & Gould I (2008) Hematological reference intervals in argentine lizard Tupinambis merianae (Sauria - Teiidae). Comp Clin Pathol 17 (2), 93-97 Academia.
• Harr K E, Alleman A R, Dennis P M, Maxwell L K et al (2001) Morphologic and cytochemical characteristics of blood cells and hematologic and plasma biochemical reference ranges in green iguanas. JAVMA 218 (6), 915-921 PubMed.
• Alleman A R, Jacobson E R & Raskin R E (1992) Morphologic and cytochemical characteristics of blood cells from the desert tortoise (Gopherus agassizii). Am J Vet Res 53 (9), 1645-1651 PubMed.

Other sources of information

• Campbell T (2015) Peripheral Blood of Reptiles. In: Exotic Animal Hematology and Cytology. 4th edn. Wiley-Blackwell. pp 67-87.
• Saint Girons M C (1970) Morphology of the Circulating Blood Cell. In: Biology of the Reptila. Eds: Gans C & Parsons T. Academic Press, USA.