Skip To Main Content
Lilly
Menu closed
Lilly
  • Medical Home
  • Medical Education
      • All Therapeutic Areas
        • Alopecia Areata
        • Atopic Dermatitis
        • Psoriasis
        • Diabetes
        • Hypoglycemia
        • Inflammatory Bowel Disease
        • Ulcerative Colitis
        • COVID-19
        • Headache Disorders
        • Neurodegeneration
        • Breast Cancer
        • Hematologic Cancer
        • Axial Spondyloarthritis
        • Psoriatic Arthritis
        • Rheumatoid Arthritis
        • Resources
      • All Therapeutic Areas
        • Alopecia Areata
        • Atopic Dermatitis
        • Psoriasis
        • Diabetes
        • Hypoglycemia
        • Inflammatory Bowel Disease
        • Depression
        • Headache Disorders
        • Breast Cancer
        • Gastrointestinal Cancer
        • Oncology General
        • Osteoporosis
        • Rheumatoid Arthritis
        • Resources
  • Independent Medical Education
      • Alopecia Areata
      • Atopic Dermatitis
      • Psoriasis
    • Diabetes
      • Ulcerative Colitis
      • COVID-19
      • Headache Disorders
      • Neurodegeneration
    • Obesity
      • Breast Cancer
      • Gastrointestinal Cancer
      • Hematologic Cancer
      • Non-small Cell Lung Cancer
      • Prostate Cancer
      • Oncology General
      • Precision Medicine and Diagnostics
      • Axial Spondyloarthritis
      • Systemic Lupus Erythematosus
      • Psoriatic Arthritis
      • Rheumatoid Arthritis
  • Chat Contact Us

DIAGNOSIS

PATIENT BURDEN

IMMUNE PRIVILEGE

JAK-STAT PATHWAY

Immune Privilege

Detailed view of a human hair follicle with representation of immune privilege around the follicle with the absence of immune cells and proinflammatory cytokines.

Immune privilege occurs at defined tissue compartments (e.g., anterior chamber of the eye, testis, blood-brain barrier, placenta) and are essential for normal organ function1

  • Immune privilege is established by complex mechanisms that suppress inflammation and promote immune tolerance2

Certain areas of the hair follicle are immune privileged sites:

  • Hair bulge, which contains hair follicle stem cells3
  • Hair bulb during the anagen phase only4

It is hypothesized that the purpose of immune privilege in the hair follicle is to prevent anagen- and/or melanogenesis-associated autoantigens from immune recognition by autoreactive CD8+ T cells1

It is hypothesized that the purpose of immune privilege in the hair follicle is to prevent anagen- and/or melanogenesis-associated autoantigens from immune recognition by autoreactive CD8+ T cells1

Functional studies suggest that CD8+ NKG2D+ T cells are the major effectors in alopecia areata pathogenesis5

Functional studies suggest that CD8+ NKG2D+ T cells are the major effectors in alopecia areata pathogenesis5

Hair follicles that lose their immune privilege during the anagen phase are targeted by CD8+ T and NKG2D+ cells6

Hair follicles that lose their immune privilege during the anagen phase are targeted by CD8+ T and NKG2D+ cells6

Loss of hair follicle immune privilege in the anagen hair bulb is accepted as a key attribute in alopecia areata pathogenesis4

Loss of hair follicle immune privilege in the anagen hair bulb is accepted as a key attribute in alopecia areata pathogenesis4

Related Resources

Chapter 2: Mechanism of Disease of Alopecia Areata

This video describes the mechanism of alopecia areata through the four distinct phases of the human hair cycle.

References

  1. Paus R, Ito N, Takigawa M, Ito T. The hair follicle and immune privilege. Review J Investig Dermatol Symp Proc. 2003;8(2):188-194. doi:10.1046/j.1087-0024.2003.00807.x
  2. Hong S, Van Kaer L. Immune privilege: keeping an eye on natural killer T cells. J Exp Med. 1999;190(9):1197-200. doi:10.1084/jem.190.9.1197
  3. Azzawi S, Penzi LR, Senna MM. Immune privilege collapse and alopecia development: is stress a factor? Skin Appendage Disord. 2018;4(4):236-244. doi:10.1159/000485080
  4. Paus R, Bulfone-Paus S, Bertolini M. Hair follicle immune privilege revisited: the key to alopecia areata management. J Investig Dermatol Symp Proc. 2018;19(1):S12-S17. doi:10.1016/j.jisp.2017.10.014
  5. Pratt CH, King LE Jr, Messenger AG, Christiano AM, Sundberg JP. Alopecia areata. Nat Rev Dis Primers. 2017;3:17011. doi:10.1038/nrdp.2017.11
  6. Paus R, Bertolini M. The role of hair follicle immune privilege collapse in alopecia areata: status and perspectives. J Investig Dermatol Symp Proc. 2013;16(1):S25–S27. doi:10.1038/jidsymp.2013.7

VV-MED-125306

  • Copyright
  • Terms of Use
  • Privacy Statement
  • Accessibility Statement
  • Sitemap

To speak to customer support:
Call (XXX) XXX-XXXX

This site is intended for US Healthcare Professionals only.

4.1.7 03/2023 | GLOOTH00001 04/2015 | © Lilly USA, LLC 2023. All rights reserved.

Product names listed above are trademarks or registered trademarks owned by or licensed to Eli Lilly and Company, its subsidiaries, or affiliates

Facebook Twitter
Lilly