Evaluation of the Diagnostic Value of Plasmacytoid Dendritic Cells in Differentiating the Lymphocytic Cicatricial Alopecias.

BACKGROUND: Differentiating lymphocytic scarring alopecias may be difficult clinically as well as histopathologically. OBJECTIVE: To investigate plasmacytoid dendritic cell (PDC) presence and distribution patterns and their diagnostic value in differentiating scarring alopecias of lupus erythematosus (LE) from lichen planopilaris (LPP) and frontal fibrosing alopecia (FFA). METHODS: Seventeen LE-associated alopecia, 20 LPP and 10 FFA cases were immunohistochemically tested for PDC presence/distribution and activity. RESULTS: LE-associated alopecia showed increased PDC content (≥10% PDCs in all cases and ≥50% in 94% of cases), PDC clusters (100% of cases), and deeper dermal and perieccrine distribution (100% of cases) with involvement of the dermoepidermal junction (DEJ, 94% of cases), while the majority of LPP and FFA had <10% PDC content that was mainly confined to the upper dermis surrounding the hair infundibulum with rare DEJ involvement and rare clustering. CONCLUSIONS: Specific PDC-related parameters may serve as a useful diagnostic adjunct in the differentiation between LE-associated alopecia versus LPP and FFA.

Poliosis circumscripta: overview and underlying causes.

Although traditionally known as "white forelock," poliosis circumscripta, defined as a localized patch of white hair in a group of hair follicles, can involve any hairy area on the body including the scalp, eyebrows, and eyelashes. Microscopically, poliosis demonstrates either decreased or absent melanin and/or melanocytes in the hair bulbs of the affected hair follicles. Classically, poliosis is known to occur in the setting of several genetic syndromes including piebaldism, Waardenburg, and tuberous sclerosis. In addition, poliosis has been described in association with various acquired conditions. These include inflammatory conditions, benign and malignant neoplastic entities that are mainly melanocytic, medications, and others. In this review, we aim to describe the different conditions where poliosis may be encountered, with the aim of helping the clinician to better evaluate any patient presenting with poliosis.

A homozygous frameshift mutation in the HOXC13 gene underlies pure hair and nail ectodermal dysplasia in a Syrian family.

Pure hair and nail ectodermal dysplasia (PHNED) is a rare genetic disorder characterized by hypotrichosis or complete alopecia, as well as nail dystrophy. Mutations in the type II hair keratin gene KRT85 and the HOXC13 gene on chromosome 12q have recently been identified in families with autosomal-recessive PHNED. In the present study, we have analyzed a consanguineous Syrian family with an affected girl having complete alopecia and nail dystrophy since birth. The family clearly showed linkage to chromosome 12q13.13-12q14.3, which excluded the KRT85 gene. Sequencing of another candidate gene HOXC13 within the linkage interval identified a homozygous frameshift mutation (c.355delC; p.Leu119Trpfs*20). Expression studies in cultured cells revealed that the mutant HOXC13 protein mislocalized within the cytoplasm, and failed to upregulate the promoter activities of its target genes. Our results strongly suggest crucial roles of the HOXC13 gene in the development of hair and nails in humans.

Maximizing diagnostic outcomes of skin biopsy specimens.

Skin biopsy is a common dermatologic procedure that is typically required to assess cutaneous neoplasms and to evaluate indistinct skin eruptions for which a clinical differential diagnosis is considered. Although plenty of literature exists on the histopathologic features of different skin diseases, clues and methods that help maximize the diagnostic results and avoid common pitfalls in the processing of skin biopsies have received little attention. In cutaneous biopsy, interpretation is very important, as is the process of choosing the appropriate biopsy technique. As soon as the decision to perform a skin biopsy is taken and until microscopic slide evaluation occurs, multiple opportunities for error may arise, any of which may disadvantage the pathologist in efforts to reach a definitive diagnosis. Therefore, it is exceptionally important that clinicians work closely with pathologists to optimize biopsy results. The purpose of this review is to increase awareness of the potential for error in the course of obtaining and interpreting biopsy specimens. The process consists of several steps that refer to, respectively: choice of biopsy site; choice of technique; tissue fixation; tissue processing; the pathologist's interpretation; and clinicopathologic correlation. Avoiding these pitfalls may, in turn, maximize the pathologist's ability to make the correct diagnosis and thus provide better patient care.

Plasma myeloperoxidase concentration predicts the presence and severity of coronary disease in patients with chest pain and negative troponin-T.

BACKGROUND: A non-negligible proportion of patients with chest pain with negative cardiac troponin may harbor a disrupted coronary plaque. A marker of plaque rupture upstream from myocardial necrosis may help identify high-risk patients among this patient population. The purpose of this study was to investigate the correlation of plasma myeloperoxidase (MPO) concentration and angiographic coronary disease among patients with suspected troponin-negative coronary syndromes. PATIENTS AND METHODS: Patients presenting with chest pain and negative cardiac troponin-T concentration and undergoing coronary angiography were enrolled in our study. Plasma MPO concentration was measured using a single blood sample collected prior to cardiac catheterization. The primary angiographic endpoint was the presence of at least one coronary stenosis causing a 70% or more diameter reduction; secondary endpoints were number of diseased vessels, presence of coronary thrombus, and lesion ulceration. The main clinical endpoint was coronary revascularization. RESULTS: Three hundred and eighty-nine patients were enrolled. Presence of coronary stenosis causing a 70% or more diameter reduction increased with increasing quartiles of myeloperoxidase concentration (P<0.0001), as did the presence of coronary thrombus (P<0.0001) and plaque ulceration (P<0.0001). The need for percutaneous coronary revascularization also increased with increasing quartiles of systemic myeloperoxidase levels (P<0.0001). Coronary surgical revascularization did not differ among myeloperoxidase quartiles. CONCLUSION: Among patients with chest pain without troponin elevation, a single measurement of plasma MPO concentration can help identify patients with a higher risk of having significant coronary stenoses and high-risk angiographic features.