Nailfold capillaroscopy alterations in androgenetic alopecia: A case–control study

Background: Androgenetic alopecia is considered to be an independent predictor of mortality from diabetes mellitus and heart disease. However, whether androgenetic alopecia causes changes in microcirculation is unknown. Objective: The objective of the study was to investigate whether alterations in nailfold capillaries occur in androgenetic alopecia patients. Methods: The nailfold capillaroscopy images of androgenetic alopecia patients and matched controls were collected and analyzed. Results: The frequencies of avascular areas, dilated, bushy and bizarre capillaries and capillary disorganization, nailfold capillaroscopy scores of 2 or scores both 2 and 3 were significantly higher in the androgenetic alopecia group than in the healthy controls (9.0% vs. 0%, 57.7% vs. 19.2%, 3.8% vs. 0%, 2.8% vs. 1.3%, 3.8% vs. 0%, 38.5% vs. 12.8% and 39.7% vs. 12.8%, respectively). Limitations: The results of this study may be biased on account of the limited sample size or the presence of an undiagnosed disease in participants which could alter the nailfold capillaries. Conclusion: Bushy, bizarre and dilated capillaries, capillary disorganization, avascular areas and nailfold capillaroscopy scores of 2 or 2 and 3 were more common in androgenetic alopecia patients than in healthy controls. These findings indicate that abnormalities in microcirculation may be involved in androgenetic alopecia.

Nailfold capillaroscopy in diabetes mellitus. literature review

Nailfold capillaroscopy is currently one of the highly informative methods for assessing the state of microcirculation. The advantages are ease of implementation, non-invasiveness, accessibility of the research object, instant visualization of the microvasculature, painlessness. The object of the study is the nailfold capillaries of the fingers or toes, due to their horizontal position in relation to the surface of the body, which makes it possible to evaluate the capillary throughout. Many authors have shown pronounced microvascular anomalies in type 1 and type 2 diabetes mellitus: tortuosity and dilation of capillaries, a decrease in their density, microhemorrhages, avascular zones, ectasias and aneurysms, newly formed capillaries; a relationship with the duration and compensation of diabetes mellitus as well as the severity of diabetic retinopathy was revealed. Thus, nailfold capillaroscopy can be used as a method for diagnosing and predicting diabetic retinopathy in patients with diabetes mellitus with the aim of early detection of initial changes in the microvasculature and timely retinopathy treatment. Key words: capillaroscopy; nailfold; diabetes mellitus.

Cutaneous microcirculation in patients with peripheral arterial occlusive disease: Comparison of capillary blood circulation in the nail fold of finger and toe

In patients with peripheral arterial occlusive disease (PAOD) a restricted circulation in cutaneous microvessels has been reported. In this study the velocity of erythrocytes (very) in finger nailfold capillaries - a vascular area without upstream macroangiopathy - and also in toe nailfold capillaries - a post-stenotic area –was investigated using capillary microscopy in apparently healthy subjects and patients with PAOD. Already in finger nailfold capillaries very of patients with PAOD under resting conditions was significantly lower than in capillaries of healthy subjects. This was also true for the circulation in toe capillaries. In addition, the erythrocyte velocities under resting conditions in the toe capillaries were significantly lower than in the finger capillaries. Similar results were found for the duration and the maximum velocity of postocclusive hyperemia. It is concluded that the resting blood flow in the skin microcirculation is impaired in PAOD patients, both under resting conditions and during postocclusive hyperemia in finger as well in toe nailfold capillaries.

Abnormal Nailfold Capillaries in Patients after Hand Transplantation

Background: The development of graft vasculopathy may play a role in the long-term deterioration of hand grafts. The aim of study was to examine the patterns of the nailfold capillaries in hand transplant recipients. Methods: the study was performed on six patients who received hand transplantation. To normalize for the effect of immunosuppression an age- and sex-matched group of 12 patients with active kidney transplant was selected. As an additional control group, 12 healthy volunteers were recruited. Nailfold videocapillaroscopy was performed in all participants. Additionally, serum concentrations of vascular endothelial growth factor (VEGF) were measured. Results: Videocapillaroscopic examination of the hand allografts revealed significant abnormalities: including capillary disorganization and microhaemorrhages. The number of capillaries was reduced, the vessels were enlarged and branched. Surprisingly, similar, albeit slightly less pronounced, changes were seen in the nailfolds of healthy hands of the limb transplant recipients. In kidney transplant recipients the capillaroscopic pattern was general normal and comparable to healthy individuals. Moreover, serum concentrations of VEGF in all participants correlated with average capillary diameter in capillaroscopy. Conclusions: in hand transplant recipients advanced microvascular abnormalities are found in nailfold capillaroscopic pattern in both transplanted and own extremities connected with elevated levels of VEGF.

Three-dimensional optoacoustic imaging of nailfold capillaries in systemic sclerosis and its potential for disease differentiation using deep learning

The autoimmune disease systemic sclerosis (SSc) causes microvascular changes that can be easily observed cutaneously at the finger nailfold. Optoacoustic imaging (OAI), a combination of optical and ultrasound imaging, specifically raster-scanning optoacoustic mesoscopy (RSOM), offers a non-invasive high-resolution 3D visualization of capillaries allowing for a better view of microvascular changes and an extraction of volumetric measures. In this study, nailfold capillaries of patients with SSc and healthy controls are imaged and compared with each other for the first time using OAI. The nailfolds of 23 patients with SSc and 19 controls were imaged using RSOM. The acquired images were qualitatively compared to images from state-of-the-art imaging tools for SSc, dermoscopy and high magnification capillaroscopy. The vascular volume in the nailfold capillaries were computed from the RSOM images. The vascular volumes differ significantly between both cohorts (0.216 ± 0.085 mm3 and 0.337 ± 0.110 mm3; p < 0.0005). In addition, an artificial neural network was trained to automatically differentiate nailfold images from both cohorts to further assess whether OAI is sensitive enough to visualize anatomical differences in the capillaries between the two cohorts. Using transfer learning, the model classifies images with an area under the ROC curve of 0.897, and a sensitivity of 0.783 and specificity of 0.895. In conclusion, this study demonstrates the capabilities of RSOM as an imaging tool for SSc and establishes it as a modality that facilitates more in-depth studies into the disease mechanisms and progression.