Efficacy of different modes of fractional CO2 laser in the treatment of primary cutaneous amyloidosis: A randomized clinical trial

Background

Primary cutaneous amyloidosis (PCA) comprises three main forms: macular, lichen, and nodular amyloidosis. The current available treatments are quite disappointing.

Objectives

Assess and compare the clinical and histological changes induced by different modes of Fractional CO₂ laser in treatment of PCA.

Patients and Methods

Twenty five patients with PCA (16 macular and 9 lichen amyloidosis) were treated by fractional CO₂ using; superficial ablation (area A ) and deep rejuvenation (area B ). Each patient received 4 sessions with 4 weeks intervals. Skin biopsies were obtained from all patients at baseline and one month after the last session. Patients were assessed clinically and histologically (Congo red staining, polarized light). Patients were followed‐up for 3 months after treatment.

Results

Both modes yielded significant reduction of pigmentation, thickness, itching, and amyloid deposits (P‐value < 0.001). However, the percentage of reduction of pigmentation was significantly higher in area A (P‐value = 0.003). Pain was significantly higher in area B. Significant reduction in dermal amyloid deposits denotes their trans‐epidermal elimination induced by fractional photothermolysis.

Conclusion

Both superficial and deep modes of fractional CO₂ laser showed comparable efficacy in treatment of PCA. Superficial mode being better tolerated by patients, is recommended as a valid therapeutic option. Lasers Surg. Med. 47:388–395, 2015. © 2015 Wiley Periodicals, Inc.     

Genetic and Environmental Variances of Bone Microarchitecture and Bone Remodeling Markers: A Twin Study

All genetic and environmental factors contributing to differences in bone structure between individuals mediate their effects through the final common cellular pathway of bone modeling and remodeling. We hypothesized that genetic factors account for most of the population variance of cortical and trabecular microstructure, in particular intracortical porosity and medullary size – void volumes (porosity), which establish the internal bone surface areas or interfaces upon which modeling and remodeling deposit or remove bone to configure bone microarchitecture. Microarchitecture of the distal tibia and distal radius and remodeling markers were measured for 95 monozygotic (MZ) and 66 dizygotic (DZ) white female twin pairs aged 40 to 61 years. Images obtained using high‐resolution peripheral quantitative computed tomography were analyzed using StrAx1.0, a nonthreshold‐based software that quantifies cortical matrix and porosity. Genetic and environmental components of variance were estimated under the assumptions of the classic twin model. The data were consistent with the proportion of variance accounted for by genetic factors being: 72% to 81% (standard errors ～18%) for the distal tibial total, cortical, and medullary cross‐sectional area (CSA); 67% and 61% for total cortical porosity, before and after adjusting for total CSA, respectively; 51% for trabecular volumetric bone mineral density (vBMD; all p < 0.001). For the corresponding distal radius traits, genetic factors accounted for 47% to 68% of the variance (all p ≤ 0.001). Cross‐twin cross‐trait correlations between tibial cortical porosity and medullary CSA were higher for MZ (r_MZ = 0.49) than DZ (r_DZ = 0.27) pairs before (p = 0.024), but not after (p = 0.258), adjusting for total CSA. For the remodeling markers, the data were consistent with genetic factors accounting for 55% to 62% of the variance. We infer that middle‐aged women differ in their bone microarchitecture and remodeling markers more because of differences in their genetic factors than differences in their environment. © 2014 American Society for Bone and Mineral Research.