Immune System
Key Points
- The immune system protects against pathogens using specific cellular defenses and nonspecific barriers.
- Malnutrition and obesity both impair immune function and raise infection risk.
- Diligent infection-control practice and early symptom reporting are high-impact interventions.
Pathophysiology
Immune defense relies on coordinated barrier protection (skin/mucosa) and cellular responses (white blood cells in blood and lymph). When functioning is adequate, pathogens are identified and cleared before major illness develops.
Immune dysfunction can result from nutrient deficiency, chronic disease, autoimmune activity, or immune-system cancers/viral injury. In autoimmune conditions, self-tissue is misidentified as foreign, causing inflammatory damage and multisystem symptoms.
Classification
- Nonspecific defenses: Skin and mucosal barriers preventing pathogen entry.
- Specific defenses: White-cell mediated pathogen identification and destruction.
- Immune compromise states: Malnutrition, malignancy-related dysfunction, HIV-related immunodeficiency.
- Autoimmune states: Self-targeted inflammation (for example, thyroid, joint, and neurologic contexts).
Nursing Assessment
NCLEX Focus
Priority questions test which early findings indicate infection progression in immunocompromised clients.
- Monitor for fatigue, weakness, fever patterns, and localized or systemic infection signs.
- Observe skin integrity and wound changes as early barrier-failure indicators.
- Track respiratory and functional changes in clients with asthma, autoimmune, or immune-compromise conditions.
- Report sudden status changes promptly, especially in clients with known immunosuppression.
Nursing Interventions
- Apply strict hand hygiene and PPE practices according to transmission risk.
- Support nutrient-dense intake patterns that improve immune resilience.
- Encourage activity as tolerated and condition-specific trigger avoidance.
- Reinforce infection-prevention education for clients and caregivers.
Infection Escalation Risk
In immunocompromised clients, subtle early symptoms can progress rapidly to severe infection and must be escalated early.
Pharmacology
| Drug Class | Examples | Key Nursing Considerations |
|---|---|---|
| antiretroviral-therapy | HIV-management context | Adherence support and infection surveillance remain essential. |
| immunomodulators | Autoimmune-condition context | Monitor for infection signs because immune suppression may mask classic symptoms. |
Clinical Judgment Application
Clinical Scenario
A client with leukemia develops new fatigue, low-grade fever, and productive cough over 24 hours.
Recognize Cues: Early infection indicators in an immune-vulnerable condition. Analyze Cues: Host defenses may be insufficient, increasing progression risk. Prioritize Hypotheses: Immediate priority is rapid escalation and infection-control containment. Generate Solutions: Report findings, apply enhanced hygiene/PPE, and monitor trend changes closely. Take Action: Initiate protocol communication and protective interventions. Evaluate Outcomes: Timely treatment begins and signs of deterioration are prevented.
Related Concepts
- infection-control - Core prevention framework for immune-vulnerable populations.
- signs-and-symptoms-of-infection - Early detection supports rapid treatment.
- endocrine-system - Type 1 diabetes and thyroid autoimmunity link endocrine and immune pathways.
- respiratory-system - Pulmonary infections are a common high-risk presentation.
- caring-for-clients-with-mental-health-or-substance-use-disorders - Whole-person support improves adherence and recovery engagement.
Self-Check
- How do nonspecific and specific immune defenses differ in function?
- Why can malnutrition and obesity both increase infection susceptibility?
- Which symptoms in an immunocompromised client require immediate escalation?