Immunocompromised describes a state in which an individual’s immune system is weakened or impaired, reducing the ability to fight infections and disease.
Explanation
Immunocompromised individuals have reduced immune function, leaving them more vulnerable to infections and less able to clear pathogens. This state can result from primary immunodeficiency disorders, which are genetic defects affecting components of the immune system, or from secondary causes. Secondary immunosuppression can be due to diseases such as HIV infection, cancers that infiltrate bone marrow, chronic kidney disease, malnutrition, or conditions requiring immunosuppressive therapy. Pharmacologic agents like corticosteroids, chemotherapy drugs, calcineurin inhibitors and biologic therapies used to treat autoimmune diseases or prevent organ rejection can suppress immune cell activity. Age also influences immune competence; newborns and older adults have diminished responses. Depending on the underlying defect, both innate and adaptive immune mechanisms may be impaired. People who are immunocompromised are prone to recurrent and severe infections, including those caused by opportunistic organisms that rarely cause disease in healthy hosts. Their responses to vaccines can be suboptimal, and live attenuated vaccines are often contraindicated. Management includes monitoring for early signs of infection, prophylactic antimicrobials, immunoglobulin replacement for certain conditions and tailored vaccination schedules. Infection control practices such as hand hygiene, avoiding exposure to sick contacts and environmental precautions are essential. Ongoing research aims to improve therapies that restore immune function without increasing the risk of rejection or autoimmune complications.
Clinical contexts
Common scenarios of immunocompromise include patients receiving chemotherapy for leukemia, who often develop neutropenia and are susceptible to bacterial sepsis; individuals with uncontrolled HIV infection, who are at risk for opportunistic infections like Pneumocystis jirovecii pneumonia; and organ transplant recipients taking tacrolimus and corticosteroids to prevent rejection. People with congenital disorders such as severe combined immunodeficiency lack functional T and B cells and require protective isolation until they receive curative therapy. Use of biologic agents such as rituximab can lead to depletion of B cells and hypogammaglobulinemia, necessitating immunoglobulin replacement. Healthcare providers often recommend avoiding live vaccines in these patients and ensuring that close contacts are vaccinated to provide herd protection.
An immunocompromised state can be transient or lifelong, depending on the cause. Awareness of the causes and consequences helps guide preventive measures and tailored treatments. Protecting these individuals from infection is a key component of clinical care.
Related Terms: Immunodeficiency, immunosuppression, opportunistic infection, HIV, transplantation