The characteristics of lacking and/or impaired antibody functions can be related to illnesses such as X-Linked Agammaglobulinemia and Common Variable Immune Deficiency

Secondary immunodeficiencies
Secondary immunodeficiencies, also known as acquired immunodeficiencies, can result from various immunosuppressive agents, for example, malnutrition, aging, particular medications (e.g., chemotherapy, disease-modifying antirheumatic drugs, immunosuppressive drugs after organ transplants, glucocorticoids) and environmental toxins like mercury and other heavy metals, pesticides and petrochemicals like styrene, dichlorobenzene, xylene, and ethylphenol. For medications, the term immunosuppression generally refers to both beneficial and potential adverse effects of decreasing the function of the immune system, while the term immunodeficiency generally refers solely to the adverse effect of increased risk for infection. Many specific diseases directly or indirectly cause immunosuppression. This includes many types of cancer, particularly those of the bone marrow and blood cells (leukemia, lymphoma, multiple myeloma), and certain chronic infections. Immunodeficiency is also the hallmark of acquired immunodeficiency syndrome (AIDS), caused by the human immunodeficiency virus (HIV). HIV directly infects a small number of T helper cells, and also impairs other immune system responses indirectly. Various hormonal and metabolic disorders can also result in immune deficiency including anemia, hypothyroidism and hyperglycemia. Smoking, alcoholism and drug abuse also depress immune response. Heavy schedules of training and competition in athletes increases their risk of immune deficiencies. Diagnosis
Patients with immune deficiencies can present with variable clinical phenotypes. This often translates into a significant delay in their diagnosis, and resultant patient morbidity.
In autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) also autoimmunity and infections coexist: organ-specific autoimmune manifestations (e.g., hypoparathyroidism and adrenocortical failure) and chronic mucocutaneous candidiasis. Finally, IgA deficiency is also sometimes associated with the development of autoimmune and atopic phenomena. Causes
The cause of immunodeficiency varies depending on the nature of the disorder. The cause can be either genetic or acquired by malnutrition and poor sanitary conditions. Only for some genetic causes, the exact genes are known. Treatment
Available treatment falls into two modalities: treating infections and boosting the immune system. Prevention of Pneumocystis pneumonia using trimethoprim/sulfamethoxazole is useful in those who are immunocompromised. In the early 1950s Immunoglobulin(Ig) was used by doctors to treat patients with primary immunodeficiency through intramuscular injection. Ig replacement therapy are infusions that can be either subcutaneous or intravenously administrated, resulting in higher Ig levels for about three to four weeks, although this varies with each patient. Prognosis
Prognosis depends greatly on the nature and severity of the condition. Some deficiencies cause early mortality (before age one), others with or even without treatment are lifelong conditions that cause little mortality or morbidity. Newer stem cell transplant technologies may lead to gene based treatments of
debilitating and fatal genetic immune deficiencies. Prognosis of acquired immune deficiencies depends on avoiding or treating the causative agent or
condition (like AIDS). See also
Acquired immune deficiency syndrome (AIDS)
Immune disorder
Autoimmune disease, immune response to self-proteins
Allergy, immune response to harmless non-self proteins
Histamine
Immunosenescence, age-associated immune deficiency
Steroids, commonly administered drugs like prednisone that suppress the immune system
Human genetic enhancement
Immune system
Immunology

References
External links

Immune Deficiency Foundation
The European Society of Immunodeficiencies