White Blood Cells | My Hematology

Hypersensitivity Reactions: Causes and Mechanisms

Hypersensitivity is an exaggerated, undesirable immune response to an antigen, causing tissue damage. It encompasses four types: IgE-mediated (allergies), cytotoxic, immune complex, and delayed cell-mediated reactions.

Basophilia (High Basophils)

Basophilia is when basophil count are elevated. It often signals underlying issues like MPNs, allergies, or inflammation.

Lymphopenia (Low Lymphocytes)

Lymphopenia is a low lymphocyte count, weakening immunity. It increases infection risk and flags underlying issues like cancer or severe illness.

Hypersensitivity Reactions: Causes and Mechanisms

White Blood Cells

Basophilia (High Basophils)

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Basophilia is when basophil count are elevated. It often signals underlying issues like MPNs, allergies, or inflammation.

Lymphopenia (Low Lymphocytes)

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Lymphopenia is a low lymphocyte count, weakening immunity. It increases infection risk and flags underlying issues like cancer or severe illness.

Leukemoid Reaction

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Leukemoid reaction is a benign, reactive process with elevated LAP & no Philadelphia chromosome, unlike malignant CML.

Causes of Atypical Lymphocytes (Reactive Lymphocytes)

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Atypical lymphocytes are activated immune cells, often seen in infections. Their unique look aids diagnosis, but distinguishing it from cancer is important.

Hypersensitivity Reactions: Causes and Mechanisms

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Neutropenia

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Neutropenia is a condition with a low count of neutrophils, key infection-fighting white blood cells. This increases susceptibility to various infections.

Infectious Mononucleosis (Mono)

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Infectious mononucleosis (Mono), the “kissing disease,” is a common viral illness (EBV). Symptoms include sore throat, fever, fatigue, and swollen glands. Usually resolves on its own.