Different distribution patterns of plasmacytoid dendritic cells in discoid lupus erythematosus and lichen planopilaris demonstrated by CD123 immunostaining

Azadeh Rakhshan,Parviz Toossi,Maliheh Amani,Sahar Dadkhahfar,Arash Bagheri Hamidi

doi:10.1016/j.abd.2019.11.005

Azadeh Rakhshan, Parviz Toossi + Show 3 more

Open Access

https://doi.org/10.1016/j.abd.2019.11.005

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Abstract

BackgroundClinical and histological features may overlap between lichen planopilaris-associated and discoid lupus erythematosus-associated scarring alopecia. ObjectivesThe aim of this study was to demonstrate the cutaneous infiltration of plasmacytoid dendritic cells and to compare their distribution pattern in discoid lupus erythematosus and lichen planopilaris. MethodsTwenty-four cases of discoid lupus erythematosus and 30 cases of lichen planopilaris were examined for immunostaining of the CD123 marker. The percentage and distribution pattern of plasmacytoid dendritic cells and the presence of the plasmacytoid dendritic cells clusters were evaluted in the samples. ResultsThe number of plasmacytoid dendritic cells was higher in the discoid lupus erythematosus specimens. Aggregations of 10 cells or more (large cluster) were observed in half of the discoid lupus erythematosus specimens and only 2 lichen planopilaris, with 50% sensitivity and 93% specificity for differentiating discoid lupus erythematosus from lichen planopilaris. Study limitationsIncidence and prevalence of discoid lupus erythematosus-associated scarring alopecia in the scalp are low, so the samples size of our study was small. ConclusionsWe suggest that a plasmacytoid dendritic cells cluster of 10 cells or more is highly specific for distinguishing discoid lupus erythematosus from lichen planopilaris. It also appears that CD123 immunolabeling is valuable in both active and late stages of the disease.

Highlights

MethodsScarring alopecia refers to disorders that are characterized by the irreversible destruction of hair follicles and permanent alopecia.1---4 Scarring alopecia is categorized into primary and secondary
We suggest that a plasmacytoid dendritic cells cluster of 10 cells or more is highly specific for distinguishing discoid lupus erythematosus from lichen planopilaris
Given that a proper diagnosis of inflammatory conditions that lead to the destruction of hair follicles is mandatory for the prevention of permanent scarring, we aimed to perform the current study to evaluate the presence and distribution pattern of PDCsby immunostaining the CD123 marker in patients with lichen planopilaris (LPP) and discoid lupus erythematosus (DLE), which are the most common causes of primary scarring alopecia

Summary

Introduction

MethodsScarring alopecia (cicatricial alopecia) refers to disorders that are characterized by the irreversible destruction of hair follicles and permanent alopecia.1---4 Scarring alopecia is categorized into primary and secondary. Primary scarring alopecia (cicatricial alopecia) implies disorders that directly damage hair follicles such as lichen planopilaris (LPP), discoid lupus erythematosus (DLE) and dissecting cellulitis. Secondary scarring alopecia is caused by unwanted damage to hair follicles as a result of inflammatory processes such as tinea capitis, sarcoidosis, and radiation dermatites.2---4. LPP and DLE are the most common causes of scarring alopecia.[5] Clinically, both LPP and DLE appear similar on the scalp making the diagnosis difficult. Objectives: The aim of this study was to demonstrate the cutaneous infiltration of plasmacytoid dendritic cells and to compare their distribution pattern in discoid lupus erythematosus and lichen planopilaris. Study limitations: Incidence and prevalence of discoid lupus erythematosus-associated scarring alopecia in the scalp are low, so the samples size of our study was small

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