Biophysical characteristics of skin in diabetes: a controlled study

Background  Cutaneous complications are common in diabetes. Previous assays suggest that hyperglycemia and decreased insulin signal are involved in the impairment of skin function. The aim of this study was to evaluate the biophysical characteristics of skin in patients with diabetes mellitus and compares them with healthy non-diabetic controls.
Objective  To measure biophysical characteristic of skin including transepidermal water loss (TEWL), water content, sebum and skin elasticity in patients with diabetes mellitus and compare them with healthy non-diabetic controls.
Methods  This case-control study was conducted on 38 patients with diabetes and 40 age- and sex-matched healthy people. The biophysical properties of skin including stratum corneum (SC) hydration, sebum content, TEWL and skin elasticity were measured and compared between the two groups at three different locations of the body.
Results  The measurement of SC hydration and TEWL showed no significant difference between diabetics and controls. The skin surface lipids on the forehead but not other sites were significantly lower in the diabetics than in the controls. Acoustic wave propagation speed, a measurement related to skin elasticity, was significantly lower in forearm and forehead of diabetics.
Conclusion  Diabetes affects some functional properties of epidermis and dermis that may responsible for many cutaneous manifestations of diabetes. These results suggest that patients with diabetes mellitus tend to show a normal hydration state of the SC together with decreased sebaceous gland activity and impaired skin elasticity, without any impairment of the SC barrier function.

Conflicts of interest

None declared     

Cutaneous lymphomas showing prominent granulomatous component: clinicopathological features in a series of 16 cases

Background  The presence of a prominent granulomatous tissue reaction in skin biopsies from primary cutaneous or systemic malignant lymphomas with secondary cutaneous involvement is a rare but well-known phenomenon.
Objective  This paper aims to characterize and study a series of cutaneous lymphomas showing a prominent granulomatous component.
Patients and methods  The clinical, histopathological and evolutive features of granulomatous variants of mycosis fungoides (5 patients, 2 of them associating 'granulomatous slack skin' features), Sézary syndrome (1 patient), CD30⁺ cutaneous T-cell lymphoma (2 patients), CD4⁺ small/medium pleomorphic cutaneous T-cell lymphoma (1 patient), primary cutaneous B-cell lymphoma (3 patients) and peripheral T-cell lymphoma with secondary epithelioid granulomatous cutaneous involvement (4 patients) were reviewed.
Results  The observed features were clinically non-distinctive. Only those cases presenting with granulomatous slack skin features were clinically suspected (2 patients). Non-necrotizing granulomata (11 patients) and granuloma annulare-like (4 patients) were the most frequently observed histopathological patterns. In five cases, no diagnostic lymphomatous involvement was initially observed. From our series, no definite conclusions regarding prognosis could be established.
Conclusion  The diagnosis of cutaneous lymphoma may be difficult when a prominent cutaneous granulomatous inflammatory infiltrate obscures the true neoplastic nature of the condition. However, the presence of concomitant lymphoid atypia may help to suspect the diagnosis. In doubtful cases, the clinical evolution and the demonstration of a monoclonal lymphoid B- or T-cell population may lead to a definite diagnosis.

Conflicts of interest

None declared.     

Epidermal Langerhans cells in actinic prurigo: a comparison between lesional and non-lesional skin

Background  Actinic Prurigo (AP) is a chronic pruritic dermatosis of unknown cause affecting sun exposed skin in defined ethnic groups with characteristic MHC alleles. However, the cutaneous dendritic cells have not been assessed.
Objective  To assess in situ the epidermal Langerhans Cell (LC) status in Actinic Prurigo.
Study design  Fresh skin samples from three AP patients were used to evaluate in situ the epidermal LC, comparing lesional and non-lesional sites in each subject.
Setting  AP patients attending the Dermatology Department at the Hospital M. Gea-Gonzalez in Mexico city.
Methods  Lesional and non-lesional skin samples were taken from each subject to prepare both epidermal sheets and conventional tissue sections. Three markers restricted to LC in epidermis (CD1a, ATPase, MHC-II) were used to quantify the LC per area in epidermal sheets.
Results  Compared to non-lesional skin from the same subject, a significant reduction in the number of LC per area of epidermis was found in lesional skin; with any of the three markers evaluated.
Conclusion  The frequency of epidermal LC decreases importantly in lesional skin from AP patients.     

Annexin V for flow cytometric detection of phosphatidylserine expression on B cells undergoing apoptosis

Apoptosis, or programmed cell death, is a general mechanism for removal of unwanted cells from the immune system. It is characterized by chromatin condensation, a reduction in cell volume, and endonuclease cleavage of DNA into oligonucleosomal length fragments. Apoptosis is also accompanied by a loss of membrane phospholipid asymmetry, resulting in the exposure of phosphatidylserine at the surface of the cell. Expression of phosphatidylserine at the cell surface plays an important role in the recognition and removal of apoptotic cells by macrophages. Here we describe a new method for the detection of apoptotic cells by flow cytometry, using the binding of fluorescein isothiocyanate-labeled annexin V to phosphatidylserine. When Burkitt lymphoma cell lines and freshly isolated germinal center B cells are cultured under apoptosis inducing conditions, all cells showing chromatin condensation strongly stain with annexin V, whereas normal cells are annexin V negative. Moreover, DNA fragmentation is only found in the annexin V-positive cells. The nonvital dye ethidium bromide was found to stain a subpopulation of the annexin V-positive apoptotic cells, increasing with time. Our results indicate that the phase in apoptosis that is characterized by chromatin condensation coincides with phosphatidylserine exposure. Importantly, it precedes membrane damage that might lead to release from the cells of enzymes that are harmful to the surrounding tissues. Annexin V may prove important in further unravelling the regulation of apoptosis.