ULTRASTRUCTURAL OBSERVATIONS ON THE HAIR BULB MELANOCYTES AND MELANOSOMES IN ACUTE ALOPECIA-AREATA

被引:78
作者
TOBIN, DJ [1 ]
FENTON, DA [1 ]
KENDALL, MD [1 ]
机构
[1] UNITED MED & DENT SCH,GUYS & ST THOMAS HOSP,ST THOMAS HOSP,DIV BIOCHEM,DOWLING SKIN UNIT,LONDON SE1 7EH,ENGLAND
关键词
D O I
10.1111/1523-1747.ep12874660
中图分类号
R75 [皮肤病学与性病学];
学科分类号
100206 ;
摘要
It is well recognized that alopecia areata (Aa) may preferentially affect pigmented hair and may spare white hair, and that regrowing hair in the disease is often initially white. In addition, there is an association with vitiligo and ocular depigmentation. To date, the pathomechanisms of the melanocyte effects are unclear. We have studied 10 patients with untreated acute alopecia areata, and three normal patients without hair loss. Morphologic changes, studied by conventional light and electron microscopy, in the cytoplasm of affected melanocytes often predated nuclear hyperchromatism. Increased numbers of bizarre melanosomes were found in affected melanocytes compared with normal ones; such melanosomes had incomplete or "aborted" melanization, resulting in poor pigment deposition, and were disrupted, enlarged and rounded, with loss of normal ellipsoidal shape. An unusual outer root sheath (ORS) distribution of hair bulb melanocytes was seen. Other atypical melanosome effects included marked pigment displacement into peribulbar and DP melanophages. In the DP clumped melanin granules formed giant spherical complexes without discernible limiting membranes, which were sometimes associated with lymphocytes. These morphologic changes indicate an active involvement of hair bulb melanocytes in alopecia areata. © 1990.
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页码:803 / 807
页数:5
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