Biofluid Biomarkers in Huntington's Disease

Huntington's disease (HD) is a chronic progressive neurodegenerative condition where new markers of disease progression are needed. So far no disease-modifying interventions have been found, and few interventions have been proven to alleviate symptoms. This may be partially explained by the lack of reliable indicators of disease severity, progression, and phenotype.Biofluid biomarkers may bring advantages in addition to clinical measures, such as reliability, reproducibility, price, accuracy, and direct quantification of pathobiological processes at the molecular level; and in addition to empowering clinical trials, they have the potential to generate useful hypotheses for new drug development.In this chapter we review biofluid biomarker reports in HD, emphasizing those we feel are likely to be closest to clinical applicability

Intense Pulsed Light as a Treatment for Senile Purpura: A Pilot Study

Senile purpura is a common condition characterized by recurrent ecchymoses in the elderly on the extensor surfaces of the forearms, hands, and legs. Our objective is to assess the efficacy and safety of a protocol using intense pulsed light (BBL; Sciton Inc., Palo Alto, CA) to improve the appearance of senile purpura on subjects' extensor forearms. Five subjects over 65 years of age, with ecchymotic lesions measuring over 1 cm on each forearm and five younger subjects under 35 years of age, without any ecchymotic lesions, were included in the study. The subjects were treated on one randomized forearm with a new intense pulsed light protocol for four weekly sessions. Photographs and subject questionnaires were taken weekly before each treatment as well as 1 month after all treatments. Skin biopsies were taken 1 day after the last of four weekly treatments. Histological analysis, including hematoxylin and eosin, elastic van Gieson, and Masson's Trichrome staining, were carried out to assess both the epidermal thickness and dermal connective tissue structure. The protocol consists of multiple passes using an intense pulsed light (BBL; Sciton Inc.) device in which the wavelength, filter, and fluence are adjusted for each step. Step 1 uses infrared light (800-1,400 nm), high intensity, a smooth adapter, and a constant motion technique. Step 2 employs a 590-nm filter with two different fluences and step 3 utilizes a 560-nm filter. The fluence of steps 2-3 is increased by 1 J each treatment if no side effects are noted. Using a new intense pulsed light protocol in subjects with senile purpura, both the number and square area of ecchymoses on the treated arm were significantly reduced (P = 0.02 and P = 0.04, respectively, paired t test) as compared with the untreated arm at 1 month after four weekly treatments. Despite this pilot study including challenging cases of subjects on both inhaled and injected corticosteroids and blood thinners, all subjects with senile purpura had at least a 50% reduction in the total square area of their ecchymoses on their treated arm. There were no significant or long-lasting side effects, and all subjects reported satisfaction with the treatment with a desire to continue treatments on their control arm. Blinded evaluators were able to select 100% of the time in the subjects with senile purpura, which was the treated arm as compared with the control arm when reviewing photographs from 1 month after the last treatment. In addition, several subjects were noted to have a significant improvement in the appearance of hemosiderin deposition and photodamage. Histologically, intense pulsed light treatments significantly increased epidermal thickness in elderly subjects by 21.14% (P = 0.0153, two-tailed, paired t test), to levels comparable with young subjects. Such restoration is consistent with the other histological observations by blinded evaluators of more abundant and organized collagen fibers in the dermis and reduced aggregates of disorganized elastin fibers. This new intense pulsed light protocol is safe and effective in improving the clinical appearance of senile purpura as well as preventing future lesions by improving the structure of the skin by increasing epidermal thickness and improving collagen and elastic fiber morphology. The treatment was well-tolerated, adverse effects were minimal, and there was high patient satisfaction. Lasers Surg. Med. 2020. © 2020 Wiley Periodicals LLC