Granulation tissue that developed after a minor trauma in a psoriatic patient on long-term etretinate therapy

Mohs surgery for squamous cell carcinoma

Cutaneous squamous cell carcinoma (SCC) is the second most common human cancer and can behave aggressively. Mohs micrographic surgery offers the highest cure rates for high-risk SCCs and is particularly useful for SCCs on challenging anatomic sites.

Effect of Acitretin on Wound Healing in Organ Transplant Recipients

BACKGROUND

Systemic retinoids possess significant benefits in cutaneous malignancy chemoprevention; however, retinoids have been associated with excessive granulation tissue and hypertrophic scarring.

OBJECTIVE

The objective of this study was to assess wound healing outcomes in organ transplant recipients, both with and without the concomitant use of systemic acitretin chemoprophylaxis.

METHODS

Twenty-nine immunosuppressed organ transplant recipients underwent treatment of basal cell or squamous cell carcinoma by Mohs or excisional surgery, with a total of 85 wounds. Wounds were evaluated postoperatively at early (average 12.9 days) and late (average 75.8 days) time points. Endpoints for all wounds included infection, hypertrophic granulation tissue, and hypertrophic scarring. Reconstructed wounds were also evaluated for dehiscence.

RESULTS

Eleven patients taking oral acitretin had 41 wounds, of which 33 were reconstructed and 8 healed by second intention. The 18 patients not taking acitretin (control group) had a total of 44 wounds, of which 33 were reconstructed and 11 healed by second intention. There were no statistically significant differences between the acitretin group and the control group in the incidences of infection, dehiscence, hypertrophic granulation tissue, or hypertrophic scarring at early or late evaluation points.

CONCLUSIONS

Systemic acitretin chemoprophylaxis does not appear to increase the risk of wound healing complications in organ transplant recipients.

Stimulation of vitamin A(1) acid signaling by the HIV protease inhibitor indinavir

HIV protease inhibitors (PIs) are effective drugs for the treatment of AIDS. However, PI therapy is sometimes associated with side-effects including increased plasma lipids and altered body fat distribution, although fat redistribution may occur in some patients not treated with PIs. Overdosage with vitamin A(1) acid (all-trans-retinoic acid, ATRA) or its metabolites may cause similar changes in lipid metabolism. Moreover, the PI indinavir and retinoids have been associated with nail, skin, and hair defects, suggesting that indinavir and retinoids may exert their effects through similar molecular mechanisms. This hypothesis was tested by examining the effects of PIs on retinoid signaling in vitro. Mesenchymal stem cells (C3H10T1/2) were cultured in the presence of various PIs (amprenavir, indinavir, nelfinavir, ritonavir, and saquinavir) and synthetic retinoids, and the metabolic response was assessed by measuring the activity of a retinoid-regulated protein, alkaline phosphatase (ALP). Of the PIs tested, only indinavir stimulated ATRA-dependent ALP activity and altered stem cell morphology; the effects of indinavir occurred in the presence of ATRA, but not in its absence. Moreover, indinavir increased the effects of ATRA on lipid accumulation during fat cell differentiation. AGN 193109 (4-[[5,6-dihydro-5, 5-dimethyl-8-(4-methylphenyl)-2-naphthalenyl]ethynyl]-benzoic acid), a retinoic acid receptor (RAR) antagonist, inhibited the synergistic effects of indinavir and ATRA, indicating that indinavir increases RAR signaling. However, indinavir did not potentiate ALP activity in the presence of the RAR agonist CH55 (3,5-di-tert-butylchalcone 4'-carboxylic acid). Unlike ATRA, CH55 does not bind to cytosolic retinoic acid binding protein (CRABP), suggesting that CRABP may regulate the effects of indinavir on RAR signaling. These observations support the proposal that altered retinoid signaling promotes some of the adverse reactions associated with indinavir therapy, such as altered lipid metabolism.