A study recently published in Immunology & Allergy Clinics highlighted the changing landscape for immunoglobulin replacement therapy and offers guidelines for maximizing its clinical benefits in patients with immunodeficiency.
Immunoglobulins are a type of protein that helps regulate immune responses. Though not itself a form of immunodeficiency, some patients with fetal and neonatal alloimmune thrombocytopenia (FNAIT) benefit from immunoglobulin therapy during pregnancy.
What is FNAIT?
Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare but serious condition that affects 0.1% of pregnancies in which a pregnant mother’s immune system produces antibodies against the platelets of her fetus. This occurs when a fetus inherits platelet antigens from the father that are not compatible with the mother, typically involving a protein called human platelet antigen (HPA). The mother’s immune system recognizes the fetal platelets as foreign, attacking and destroying them, leading to low platelet levels (thrombocytopenia) in the fetus or newborn.
In their review, the authors discuss the function, mechanisms and clinical considerations associated with immunoglobulin therapy, with a focus on immunodeficiency disorders.
Primary immunodeficiency is defined as intrinsic immune system dysfunction, while secondary immunodeficiency occurs due to external factors. Patients with either subtype are unable to produce certain antibodies and are therefore at a higher risk of infection.
Read more about FNAIT treatment and care
While immunoglobulin therapy is more often used in patients with primary immunodeficiency, it is becoming more common among individuals with secondary immunodeficiency.
In many cases, health insurance plans will not approve immunoglobulin replacement therapy for patients with suspected immunodeficiency without direct evidence of specific antibody deficiencies or a history of infections, the authors wrote.
Additionally, the study explores the increasing use of intravenous immunoglobulin therapy as an immunomodulator, meaning a modifier of immune system function. This may be used in patients with autoimmune diseases or inflammatory conditions including immune thrombocytopenia. In fact, it is now used more frequently to treat inflammatory conditions than immunodeficiencies.
In general, intravenous and subcutaneous immunoglobulin administration are equivalent. Intravenous administration is generally preferred for immunomodulation, but patient preferences and quality of life should be thoroughly reviewed in all cases.
The authors emphasize the need to individualize immunoglobulin therapy based on unique patient characteristics. Key considerations include cost, access to treatment, and mode of administration.
“Given the increasing demand and therefore potential for shortages, it is incumbent on the clinical immunologist to optimize immunoglobulin use in the management of patients with immunodeficiency,” the authors concluded.
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