Monocyte count increases the most during which of the following conditions?

• A. Allergic reactions
• B. Chronic infections
• C. Parasitic infestations
• D. Acute viral infections

Answer: (B)

Verified step by step guidance

1. Understand the role of monocytes in the immune system: Monocytes are a type of white blood cell that plays a key role in the body's defense by differentiating into macrophages and dendritic cells, which help in phagocytosis and antigen presentation.
2. Review the typical immune response patterns: Monocytes tend to increase significantly during prolonged or persistent immune challenges, such as chronic infections, because they are involved in sustained inflammation and tissue repair.
3. Analyze each condition: Allergic reactions primarily involve eosinophils and basophils; parasitic infestations often cause eosinophilia; acute viral infections typically cause lymphocytosis rather than a marked increase in monocytes.
4. Identify the condition associated with the highest monocyte increase: Chronic infections stimulate a prolonged immune response, leading to a notable rise in monocyte count as the body attempts to control persistent pathogens.
5. Conclude that among the options, chronic infections cause the greatest increase in monocyte count due to their role in long-term immune defense and inflammation.