A randomized controlled trial of fractional laser therapy and dermabrasion for scar resurfacing.

BACKGROUND: Dermabrasion has been the standard resurfacing procedure for postsurgical scars, but recovery can be long. Fractionated carbon dioxide (CO2 ) laser is a safe, effective tissue resurfacing modality, but no prospective trial has compared its safety or efficacy with that of dermabrasion for postsurgical scar resurfacing. OBJECTIVE: To compare the safety and efficacy of single-treatment fractional photothermolysis with that of single-treatment dermabrasion for postsurgical scar resurfacing on the face. METHODS AND MATERIALS: A split-scar method was used to compare fractionated CO2 laser and diamond fraise dermabrasion on postsurgical scars of the face. Primary endpoint was safety at day 0, 1 week, and 1 month. Secondary endpoint was efficacy at 3 months as measured by blinded evaluation of standardized photographs. RESULTS: Safety data revealed that there was less erythema (p = .001) and bleeding (p = .001) at day 0, less erythema (p = .01) and edema (p = .046) at 1 week, and a trend toward less erythema at 1 month (p = .06) with fractionated CO2 . Efficacy data at 3 months revealed equivalent scar improvements (p = .77). CONCLUSION: Fractionated CO2 laser therapy should be considered a safe alternative for surgical scar resurfacing on the face. The safety profile exceeds that of dermabrasion, and it has a quicker clinical recovery and equivalent cosmetic efficacy.

Kruppel-like factor 2 regulates thymocyte and T-cell migration.

Mammalian Kruppel-like transcription factors are implicated in regulating terminal differentiation of several tissue types. Deficiency in Kruppel-like factor (KLF) 2 (also known as LKLF) leads to a massive loss of the peripheral T-cell pool, suggesting KLF2 regulates T-cell quiescence and survival. Here we show, however, that KLF2 is essential for T-cell trafficking. KLF2-deficient (Klf2-/-) thymocytes show impaired expression of several receptors required for thymocyte emigration and peripheral trafficking, including the sphingosine-1-phosphate (S1P) receptor S1P1, CD62L and beta7 integrin. Furthermore, KLF2 both binds and transactivates the promoter for S1P1--a receptor that is critical for thymocyte egress and recirculation through peripheral lymphoid organs. Our findings suggest that KLF2 serves to license mature T cells for trafficking from the thymus and recirculation through secondary lymphoid tissues.

Phenotypic analysis of T-cells in extensive alopecia areata scalp suggests partial tolerance.

This study demonstrates the feasibility and efficacy of using flow cytometric analysis with intracellular cytokine staining for characterization of T-cell phenotype and functional status in extensive alopecia areata (EAA) scalp skin. Cell suspensions were made from scalp punch biopsies taken from 12 patients with long-standing EAA (average disease duration 14 years, 95% hair loss) and six control subjects. EAA samples had a lower percentage of CD-3-expressing cells, but CD-4/CD-8 ratios remained similar to controls. Expression of CD-69 was found only in EAA scalp biopsies, suggesting that T-cells from EAA scalp have undergone activation. No difference was found in tumor necrosis factor alpha expression. Surprisingly, EAA scalp T-cells produced less IL-2 and CD-8 T-cells produced less IFN-gamma. Immunohistochemical staining of formalin-fixed paraffin-embedded specimens demonstrated that IFN-gamma-producing cells in EAA scalp were not greater in number than in normal specimens. The few identified IFN-gamma-producing cells demonstrated no tendency to localize to the perifollicular region, and were similarly distributed as in control specimens. The abnormalities in cytokine production may explain the relative paucity of inflammatory change observed in the clinical setting and suggest that T-cell responses in EAA scalp are tightly, albeit aberrantly, regulated via mechanisms of peripheral T-cell tolerance.

Differential role for IL-7 in inducing lung Kruppel-like factor (Kruppel-like factor 2) expression by naive versus activated T cells.

Kruppel-like Factor 2 [KLF2, also called lung Kruppel-like factor (LKLF)] is a transcription factor shown to be necessary for the maintenance of naive T cells. KLF2 is expressed in both naive and memory cells, and is proposed to promote quiescence in these populations. During T cell stimulation, both KLF2 protein and mRNA are down-regulated, and loss of KLF2 appears to be critical for full T cell activation. It is unclear, however, how KLF2 expression is maintained in naive T cells. Recently it was proposed that IL-7, which is known to promote KLF2 re-expression in antigen-stimulated T cells, may also induce KLF2 expression in naive T cells. Here we address this issue by comparing the impact of IL-7 on KLF2 expression in naive and activated T cells. Use of bcl-2 transgenic T cells allowed us to uncouple the requirements for IL-7 in preserving naive T cell survival from its role in maintaining KLF2 expression. Our data demonstrates that IL-7 signals are not required for KLF2 maintenance in naive T cells, suggesting that this cytokine has distinct effects on KLF2 expression in naive versus activated T cells.