The innermost cell layer of the outer root sheath is positive with Ki-67.
The expression of a cell proliferation-associated human nuclear antigen was immunohistochemically studied in human anagen hair and hair follicles using the monoclonal antibody Ki-67. The reaction of Ki-67 in mature anagen hair follicles was observed in the hair matrix cells and outer root sheath (ORS) cells. Nuclear staining was seen in a small number of matrix cells and in some ORS cells; this finding corresponded to the thymidine or bromodeoxyuridine labeling studies previously reported. In addition, there were two different patterns of cytoplasmic staining in the ORS: strong staining of the innermost cells (IMC) and weaker staining of the other ORS cells in the isthmus. Ki-67 reactivity of the IMC layer was observed at each stage of anagen and was regularly seen from the upper bulb to the isthmus. Ki-67 is a commercially available antibody that detects cycling cells. However, the IMCs in anagen hair follicles showed cytoplasmic labeling by Ki-67 from the matrix cells in the upper bulb to the distal portion of the isthmus.
Miyauchi
S
S
Department of Dermatology, University of Ehime, School of Medicine, Japan.
Hashimoto
K
K
Miki
Y
Y
D000293:Adolescent; D000328:Adult; D000911:Antibodies, Monoclonal; D000954:Antigens, Surface / Q000032:analysis*; D004817:Epidermis / Q000473:pathology; D005260:Female; D006197:Hair / Q000473:pathology*; D006801:Humans; D006945:Hyperhidrosis / Q000473:pathology*; D007124:Immunoenzyme Techniques; D015603:Keratinocytes / Q000473:pathology; D019394:Ki-67 Antigen; D009687:Nuclear Proteins / Q000032:analysis*
D000911:Antibodies, Monoclonal; D000954:Antigens, Surface; D019394:Ki-67 Antigen; D009687:Nuclear Proteins