TLDR Decreased CD200 in hair follicles may cause immune issues in some alopecia areata cases.
The study investigated the expression levels of stem cell markers, particularly CD200, in two elderly female cases of alopecia areata (AA) with unusual lymphocytic infiltrates in both the bulge and bulbar regions of hair follicles. It compared these cases to common AA cases without bulge involvement. The results showed that while K15 levels remained consistent in unaffected bulge lesions across both groups, CD200 levels were decreased in the bulge-involving AA group. In affected bulge lesions, both K15 and CD200 levels were reduced in the bulge-involving AA cases compared to common AA cases. The study concluded that the selective downregulation of CD200 in the bulge area might lead to the loss of immune privilege, contributing to the unusual bulge involvement in a subset of AA.
391 citations,
February 2010 in “Journal of The American Academy of Dermatology” Half of people with Alopecia Areata may see hair regrowth within a year without treatment, but recovery is unpredictable.
54 citations,
March 2009 in “British Journal of Dermatology” Scarring alopecia affects different hair follicle stem cells than nonscarring alopecia, and the infundibular region could be a new treatment target.
550 citations,
December 2005 in “The Journal of clinical investigation/The journal of clinical investigation” Researchers successfully isolated and identified key markers of stem cell-enriched human hair follicle bulge cells.
56 citations,
July 2005 in “Experimental Dermatology” Injected human hair follicle cells can create new, small hair follicles in skin cultures.
148 citations,
December 2018 in “Journal of autoimmunity” Alopecia areata is an autoimmune disease causing patchy hair loss, often with other autoimmune disorders, but its exact causes are unknown.
4 citations,
November 2018 in “JAAD case reports” Alopecia areata can sometimes appear as a straight line of hair loss instead of round patches.
May 2018 in “Journal of cosmetology & trichology” Combining platelet-rich plasma therapy with prostaglandin-F eye drops can significantly regrow hair in alopecia universalis.
