CD123 Immunohistochemistry for Plasmacytoid Dendritic Cells Is Useful in the Diagnosis of Scarring Alopecia

The study from 2016 examined the effectiveness of CD123 immunohistochemistry in identifying plasmacytoid dendritic cells (PDCs) for the diagnosis of scarring alopecia, analyzing 45 biopsies from patients with chronic cutaneous lupus erythematosus (CCLE), lichen planopilaris (LPP), and central centrifugal cicatricial alopecia (CCCA). It found that PDCs were more abundant and often clustered in CCLE, with a specific pattern of localization, compared to LPP and CCCA where PDCs were mainly single, interstitial cells. The presence of clusters of more than 20 PDCs was specific for CCLE, and the localization of PDCs in certain areas could essentially rule out CCCA and LPP. The study concluded that CD123+ PDCs are a useful diagnostic marker for differentiating CCLE from other types of scarring alopecia, with a p-value of less than 0.0001 indicating statistical significance.