Immunodeficiency disorders - Secondary: Nursing

Definitions & Key takeaways

Secondary immunodeficiency disorders are conditions that impair the immune system as a result of other underlying medical conditions or other extrinsic factors affecting the immune system. Such disorders can occur as a result of malnutrition; other diseases like cancer, infectious diseases like HIV/AIDS; adverse environmental conditions, like high UV light exposure or extreme cold; surgery and trauma; and medications, such as immunosuppressive agents. Symptoms vary depending on the site of infection, and the treatment focuses on treating the underlying cause, stopping the offending medication, or vaccination and prophylaxis when recommended. As a nurse, the care of a patient with secondary immunodeficiency involves monitoring and managing symptoms, administering medications, patient education, and implementing standard precautions to prevent the spread of infections.

Chapters:

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Introduction0:00–0:11

Secondary immunodeficiencies are acquired disorders that occur as a result of some extrinsic factor affecting the immune system.
Let’s start with some immune system physiology. The immune system consists of white blood cells that protect us from pathogens, like viruses, bacteria, and fungi; but, also, foreign substances, such as toxins and chemicals, and destroy abnormal cells, such as those that might develop into cancer.

Physiology0:11–1:45

Now, the immune system consists of two main branches: innate immunity and adaptive immunity. The innate immune response involves non-specific defense mechanisms, meaning they don’t differentiate one pathogen from another.
These include complement proteins and cells like phagocytes and natural killers; as well as dendritic cells, which activate the adaptive immune response.
The adaptive immune response is highly specific, meaning that it recognizes different pathogens and is mediated by cells called lymphocytes, which include T and B cells.
T cells can be further divided into CD4+ and CD8+ T cells. CD4+ T cells are also known as T helper cells, because they interact with dendritic cells, and in turn help activate the rest of the lymphocytes.
On the other hand, CD8+ T cells, also known as cytotoxic T cells, are in charge of cell-mediated immunity, where they attack abnormal cells.
Finally, B cells mediate a specific adaptive response, called humoral immunity, by secreting antibodies that bind to and destroy extracellular antigens.
These antibodies can be classified into several classes, including IgA, IgG, IgM, and IgE.Now, there are several causes of secondary immunodeficiency, including calorie and protein malnutrition; adverse environmental conditions, like UV light, extreme cold, or high altitude; surgery and trauma; and medications, such as glucocorticoids, chemotherapy, and immunosuppressive agents used to treat autoimmune disorders or to prevent organ transplant rejection.

Causes & risk factors1:45–3:11

Additionally, secondary immunodeficiency can be also caused by several medical conditions, including various types of cancer, specifically hematological malignancies, like leukemia, lymphoma, and multiple myeloma; metabolic disorders, like diabetes mellitus or chronic kidney disease; and genetic conditions, such as Down syndrome or trisomy 21.
Finally, other causes include trauma, surgery, as well as infectious diseases, the most common of which is acquired immunodeficiency syndrome, or AIDS, resulting from HIV infection.
On the other hand, risk factors for secondary immunodeficiencies include engaging in high-risk sexual behaviors, since that can increase the risk of contracting an HIV infection; undergoing chemotherapy or immunosuppresive treament; as well as being critically ill or hospitalized for a long period of time.
Additionally, newborns and elderly clients are especially susceptible to immunodeficiency, since they naturally have a decreased immune response to pathogens.Secondary immunodeficiencies affect the immune system in different ways, but what they all have in common is that they leave clients more vulnerable to developing frequent infections, as well as unusual complications from infections that a healthy immune system would typically be able to fend off.

Pathology3:11–5:09

Conditions that lead to weakened mucosal barriers, such as malnutrition and burns, can increase the risk of diarrhea and skin or respiratory tract infections.
In contrast, those that affect cellular immunity, such as HIV, and genetic and metabolic diseases reduce the overall effectiveness of the immune response, thereby increasing the risk of all sorts of infections.
Finally, trauma and some surgical procedures, like a splenectomy, can affect organs involved in the immune system, thereby increasing the risk of infection with encapsulated bacteria like Streptococcus pneumoniae and Haemophilus influenzae.
Now, there are also certain infections that occur more frequently or have more severe symptoms in people who are immunocompromised, and these are called opportunistic infections.
For example, most people infected with toxoplasma, a type of parasite, don’t have symptoms; but in people with immunodeficiency it can cause encephalitis.
Another example is a fungus called Candida albicans, which normally lives on the skin and mucous membranes in small numbers.
However, in people with immunodeficiency, there can be a Candida overgrowth that causes oral or vaginal candidiasis. Next, there’s Mycobacterium avium, which usually causes isolated lung disease; however, in the context of an immune deficiency, it can cause disseminated disease which means it spreads throughout the body and causes nonspecific symptoms like fever and weight loss.
Finally, in addition to fighting off infections, the immune system is also in charge of eliminating mutated or defective cells in the body, so people with immunodeficiencies are at a higher risk of developing certain types of cancer like leukemias and lymphomas.

Clinical manifestations5:09–5:38

Now, although the clinical manifestations of secondary immunodeficiencies are highly variable, most clients experience an increased susceptibility to infection; and clinical manifestations depend on the site of infection.
Secondary immunodeficiencies should be suspected in clients with recurrent infections that last longer than usual and are more difficult to treat; as well as unusual infectious complications, such as abscesses or life-threatening sepsis.The diagnosis of secondary immunodeficiencies starts with the client’s history and physical assessment, followed by additional diagnostic tests aimed at identifying the underlying cause of immunodeficiency.

Diagnosis5:38–6:08

Depending on the suspected cause, these may include blood tests to rule out metabolic disorders, imaging studies to detect any cancer lesions, a bone marrow biopsy and peripheral blood smear to investigate hematological malignancies, and genetic testing to rule out chromosomal abnormalities.Regarding treatment, most secondary immunodeficiencies are transient and can be resolved by treating the underlying disease or stopping the offending medication.

Treatment6:08–6:45

In the case of HIV infection, clients are prescribed antiretroviral medications that can help them live longer and reduce the risk of transmission.
Depending on the degree of immunodeficiency, other treatments include a specific vaccination plan to prevent certain infections; early treatment of infections or prophylaxis against common infectious pathogens; and intravenous immunoglobulins to help reinforce the immune system’s capacity to deal with infections.Alright, as a quick recap… Secondary immunodeficiencies are acquired disorders that occur as a result of some extrinsic factor affecting the immune system.

Review6:45–8:13

Secondary immunodeficiency can be caused by calorie and protein malnutrition; adverse environmental conditions, like UV light, extreme cold, or high altitude; surgery and trauma; and medications, such as glucocorticoids, chemotherapy, and immunosuppressive agents.
Medical conditions that can cause secondary immunodeficiency include various types of cancer, specifically hematological malignancies, like leukemia, lymphoma, and multiple myeloma; metabolic disorders, like diabetes mellitus or chronic kidney disease; and genetic conditions, such as Down syndrome or trisomy 21.
Other causes include trauma and surgery, as well as infectious diseases like AIDS. Pathology-wise, secondary immunodeficiencies leave clients more vulnerable to developing frequent infections, as well as unusual complications from infections that a healthy immune system would typically be able to fend off.
Clinical manifestations vary depending on the site of infection, and diagnosis requires specific lab work depending on presentation.
Treatment is geared at treating the underlying cause, stopping the offending medication, or prescribing antiretroviral medications for an HIV infection.
Other options include vaccination; early treatment of infections
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