Definition

Immunodeficiency is a condition characterized by a weakened immune system, which impairs the body's ability to effectively fight infections or diseases compared to individuals with a healthy immune system. Some individuals are born with immunodeficiency, while others acquire it later in life due to various causes.

The immune system involves several organs and tissues, including the spleen, parts of the digestive tract, the thymus gland, tonsils, bone marrow, lymph nodes, and proteins and cells in the blood. These components work together to produce and release lymphocytes, a type of white blood cell crucial for producing antibodies and combating foreign substances that enter the body.

A weakened immune system can make it difficult for the body to effectively defend against bacterial, viral, fungal, parasitic, or toxin infections. Patients with immunodeficiency may experience more frequent disease relapses, and illnesses may last longer and be more severe. Additionally, immunodeficiency can increase the risk of developing cancer in affected individuals.

Immunodeficiency disorders are categorized into two main types:

• Primary immunodeficiency

This type of immunodeficiency is present from birth and is typically genetic in nature. However, some disorders may be discovered later in life. Primary immunodeficiency disorders are considered rare diseases.

• Secondary immunodeficiency

These disorders typically develop later in life and are caused by factors such as medications or other medical conditions. Unlike primary immunodeficiency, secondary immunodeficiency is more commonly encountered in clinical practice.

Causes

Immunodeficiency disorders can indeed affect different components of the immune system. As previously mentioned, there are two main types of immunodeficiency disorders: primary and secondary, each with distinct causes.

Primary Immunodeficiency

Immunodeficiency disorders can indeed result from changes or mutations in specific genes, particularly primary immunodeficiency. Over 200 types of primary immunodeficiency disorders have been identified to date. Interestingly, approximately 60% of patients with primary immunodeficiency disorders are male.

Genetic mutations can impact various components of the immune system, including:

• White blood cells (such as B cells) are responsible for antibody production.
• White blood cells recognize and eliminate foreign substances (such as T cells).
• Cells are responsible for killing microorganisms (such as neutrophils) directly.
• Proteins that aid immune cells in recognizing and killing bacteria.

These genetic alterations can result in these components' loss, reduction, or impairment, thereby hindering their ability to function effectively and leaving individuals susceptible to infections and other immune-related disorders.

Secondary Immunodeficiency

Secondary immunodeficiency occurs when exposure to chemical substances, medications, or medical conditions weakens the immune system. Several factors can contribute to secondary immunodeficiency, including:

Medical conditions such as:

• Severe burns
• Diabetes mellitus
• HIV/AIDS
• Blood cell-related cancers such as leukemia or multiple myeloma
• Virus-induced hepatitis
• Malnutrition

Medications known to suppress the immune system such as:

• Corticosteroids
• Chemotherapy agents
• Radiation therapy (although rare)
• Immunosuppressants used in organ transplantation

Risk factor

Several factors can indeed increase the risk of experiencing a weakened immune system:

• Family history of congenital immunodeficiency
• Presence of a serious medical condition or suffering from a long-term illness that compromises the immune system
• Occupational exposure to diseases, particularly in healthcare workers
• Advanced age, as immune function, tends to decline with age
• Prolonged hospitalization can increase susceptibility to infection
• Inadequate intake of essential nutrients, such as protein, calcium, and zinc, is crucial for immune function
• Chronic sleep deprivation or poor-quality sleep can impair immune function over time
• Undergoing therapy with immunosuppressive side effects, such as cancer treatment

Symptoms

Immunodeficiency disorders encompass many conditions, and the symptoms can often be recurrent. Patients with immunodeficiency disorders may experience the following symptoms and complaints:

• Recurrent and frequent infections affect various body systems, including the respiratory tract, eyes, teeth and mouth, gastrointestinal tract, ears, or skin
• Severe infections can lead to complications
• Fever and chills
• Decreased appetite and unintentional weight loss
• Enlargement of the liver or spleen in the abdomen
• Children may experience chronic diarrhea and failure to thrive, characterized by inadequate weight gain and growth
• Abnormal immune responses lead to autoimmune disorders, where the immune system mistakenly attacks healthy tissues in the body

Diagnosis

When you or a family member visit a healthcare facility, the doctor will typically conduct a comprehensive assessment, including a medical interview and physical examination tailored to the patient's condition. During this evaluation, the doctor may inquire about the following:

• Current symptoms experienced
• Current and past medical history
• Family medical history
• Medications are currently being taken
• Allergies or adverse reactions to medications, foods, or environmental factors

If further investigation is warranted to understand the patient's condition better, the doctor may recommend the following tests:

• Complete blood count (CBC) and measurement of antibody levels to assess immune function
• Skin testing involves injecting a small amount of protein from common infection-causing organisms into the skin to evaluate the body's immune response. Any resulting skin reactions, such as swelling, warmth, or redness, can indicate potential immunodeficiency
• Biopsy or sampling of lymph nodes or bone marrow may be performed to aid in the diagnosis of underlying diseases contributing to the symptoms
• Genetic testing to identify any gene mutations associated with immunodeficiency disorders

Management

Treatment for immunodeficiency generally focuses on:

• Preventing infections as much as possible.
• Treating ongoing infections.
• Strengthening components of the immune system.

Commonly used treatments include antibiotic therapy to address bacterial infections and immunoglobulin therapy. Antiviral drugs such as oseltamivir and acyclovir, or interferon drugs, are sometimes used to manage virus infections caused by immunodeficiency.

In cases where the bone marrow does not produce enough white blood cells to support the body's immunity, treatment with bone marrow (stem cell) transplantation may be recommended.

Complications

Complications that may arise from immunodeficiency disorders can include:

• Frequent recurrent or prolonged illnesses.
• Increased risk of certain cancers or tumors.
• Severe complications from diseases that would otherwise not be serious if properly treated.

Prevention

Primary immunodeficiencies can be managed and treated but cannot be prevented. Conversely, the risk of secondary immunodeficiencies can sometimes be mitigated by adopting a healthy lifestyle. For instance, consuming a nutritious diet and engaging in sufficient physical activity can lower the risk of developing type 2 diabetes mellitus.

Engaging in safe sexual activities and avoiding contact with other people's bodily fluids can help prevent HIV/AIDS. It's advisable to consult with a doctor to inquire about medications that can reduce the risk of HIV infection.

Rest is crucial for maintaining a healthy immune system. According to the CDC, chronic sleep deprivation not only leads to various chronic conditions but can also weaken the body's ability to fight infections.

When to see a doctor?

If you frequently get sick or struggle to recover from viral infections and other illnesses, it's advisable to consult a doctor. The doctor will aim to diagnose your condition, provide education, and offer treatment. It's also important to seek medical advice if you experience recurring fungal infections or oral thrush.

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