Non-Malignant Causes of Leukocytosis and Leukopenia

What are the six neutrophil pools? Mitotic pool

Bone Marrow: Mitotic, Maturation, Storage

Peripheral Blood: Circulating and Marginated(stuck on endothelium lining blood vessels)

Tissue Pool

Which chemicals rapidly demarginate(put them into the circulating pool) neutrophils?

Epinephrine and Corticosteroids (thereby inc neutrophil in circulating pool)

Which chemicals widen endothelial gaps to release neutrophils?

Endotoxin (LPS) found in Gram negative bacteria

What are viral causes of lymphocytosis?

EBV, CMV, HIV, MMR, Influenza

What are non‑viral infectious causes of lymphocytosis?

Bartonella henselae, Bordetella pertussis, Toxoplasmosis, Babesiosis

What are causes of Leukocytosis due to Neutrophilia?

Infection, Stress, Smoking, Pregnancy, MI, Iron Deficiency Anemia, Hemolysis, Drugs(GCSF and GMCSF increasing neutrophils)

What are infectious causes of secondary eosinophilia?

Parasites (Strongyloides, hookworm, Toxocara), Aspergillus

What are non‑infectious causes of secondary eosinophilia?

Allergic disease, Medications

What are three causes of non‑malignant neutropenia?

Viral infections(due to marrow suppression and upregulatin of adhesion and migration due to cytokine release), Medication‑induced neutropenia(due to toxicity and immune mediated destruction)

What viral infections can cause neutropenia?

Mononucleosis, Hepatitis B

What autoimmune conditions can cause neutropenia?

Autoimmune hemolytic anemia, Immune thrombocytopenia

What is pseudo‑neutropenia?

Low circulating neutrophils due to marginated pool expansion, patient still demarginates normally and fights infection normally (LAB ERROR vs DANC is genetic)

What is Duffy Null Associated Neutrophil Count (DANC)?

Duffy‑null phenotype causing lower circulating neutrophils but normal total neutrophil stores, common in African‑American patients

How can a low neutrophil count be clinically irrelevant?

If due to marginated pool (pseudo‑neutropenia) or Duffy‑null phenotype, patient has normal infection response

What causes basophilia?

Hypersensitivity reactions, Ulcerative colitis

What is bandemia?

Increase in production of neutrophils(bands are immature neutrophils), seen in acute bacterial infection

What is Leukopenia due to lymphopenia?

Low lymphocytes (think viral infection) due to viral infection, immunodeficiency, chemotherapy, radiation, steroids, congenital disorders

Lymphocytes respond to

VIRAL infections and are therefore elevated in viral illness

What can cause Leukocytosis and Monocytosis?

Acute bacterial infection, Tuberculosis, GM-CSF administration

Cause of Leukocytosis and Primary Eosinophilia

Malignancy (CA) due to bone marrow