Lymphocytes

Question 1

B cell development

Answer 1

Hematopoeitic stem cell → Common Lymphoid Progenitor cell → pre B cell (with IL-7) → mature B cell (in peripheral lymphoid tissues; need Il-2, IL-4, IL-5) → Plasma cell (need IL-6, IL-4, IL-10)

Question 2

T cell development

Answer 2

Common Lymphoid Progenitor cell ⇒ Thymus → pre T cell → T cell (migrate from cortex to medulla) ⇒ travel via blood to lymph nodes, slpeen → Cytotoxic and Helper T differentiation

Need IL-7, IL-1, IL-2, IL-4 for T llymph development

Question 3

Lymphoblasts

Answer 3

• Large
• High nuclear : cytoplasm ratio
• Prominent nucleoli
• Dark staining nuclei
• Dark staining cytoplasm

As they mature to lymphocytes, become:

• smaller
• maintain high nuclear : cytoplasm
• dark stained chromatin
• small rim of cytoplasm

Question 4

Bovine lymphocytes

Answer 4

Lymphocytesa are predominant leukocyte in cattle

2 forms

1. small lymphocytes
2. large lymphocytes
   
   • abundant pale cytoplasm
   • small pink granules

Question 5

Immunologically activated lymphocytes

Answer 5

• large
• very darkly stained nuclei
• darkly stained cytoplasm

Question 6

Lymphocytosis DDx

Answer 6

• chronic antigenic stimulation
• young animals
• acute epinehrine release
• lack of endogenous corticosteroids
• neoplasia

Question 7

Evidence of stress in leukogram of cattle

Answer 7

• Reversal of the neutrophil to lymphocyte ratio indicative of stress. Even if both are still in w/in RI.
• Fibrinogen

Question 8

Grading of leukocytosis and neutrophilia in domestic species

Answer 8

Question 10

Lymphopenia DDx

Answer 10

• glucocorticoids
• infection
• lymphatic drainage/loss
  
  • immunodeficiency