From the Research
The relationship between Interferon-Gamma Release Assays (IGRAs) and autoimmune or inflammatory alopecia is primarily indirect and relates to screening for tuberculosis before initiating immunosuppressive therapies. IGRAs have no direct diagnostic role in alopecia itself but are important pre-treatment screening tests for patients who will receive immunosuppressive medications like systemic corticosteroids, methotrexate, JAK inhibitors, or biologics for severe forms of alopecia areata, lichen planopilaris, or other inflammatory alopecias, as supported by recent studies such as 1. These medications can reactivate latent tuberculosis, making IGRA testing essential before starting treatment, a concept also discussed in the context of managing autoimmune diseases like alopecia areata in 2 and 3. The test results don't typically increase or decrease in relation to the alopecia condition itself. For patients with positive IGRA results, prophylactic anti-tuberculosis treatment (usually isoniazid 300mg daily for 6-9 months) may be necessary before or concurrently with immunosuppressive therapy, highlighting the importance of considering tuberculosis screening in the management of autoimmune conditions as mentioned in 4 and 5. This screening is particularly important in regions with high tuberculosis prevalence. The scientific basis for this practice is that immunosuppressive treatments can impair T-cell function and interferon-gamma production, which are critical for containing tuberculosis infection, potentially leading to reactivation of latent disease. Key considerations in the management of autoimmune or inflammatory alopecia include:
- The use of immunosuppressive therapies and their potential to reactivate latent infections
- The importance of screening for tuberculosis before initiating such therapies
- The role of interferon-gamma in both the pathogenesis of alopecia areata and the containment of tuberculosis infection
- The need for prophylactic anti-tuberculosis treatment in patients with positive IGRA results who are about to start immunosuppressive therapy.