A promising new treatment for solar lentigines

The purpose of this open-label study was to determine the adverse event rate of topical 4HA/tretinoin when used twice daily for up to 24 weeks with concomitant sunscreen in the treatment of solar lentigines and related hyperpigmented lesions. There were two treatment areas: bilateral dorsal forearms, including the back of the hands; and the face, including the forehead and cheek areas. Each treatment area had a target lesion at least 5 mm in diameter and was moderately darker than the surrounding skin. A nine-point bipolar scale was used for evaluation of Target Lesion Pigmentation (0 = extremely lighter than pigment of the surrounding skin, 4 = equal with pigment of surrounding skin, 8 = extremely darker than pigment of surrounding skin). The other solar lentigines present in the treatment areas also had to have an overall pigmentation grade of at least Grade 6. Twice daily applications to individual lesions in each treatment area were made for up to 24 weeks followed by a 4-week follow-up phase. Sunscreen applications (sunscreen with sun protection factor (SPF) 25 or greater) were made every morning and reapplied after six hours if additional sun exposure was expected. Clinical evaluations were performed at weeks 0, 4, 8, 16, 24 and 28. The clinical signs of Target Lesion Pigmentation and Overall Lesion Pigmentation were evaluated at each visit. A total of 96 subjects were enrolled at four study centers; 77 (80%) subjects completed the study. Treatment-related adverse events (AEs) for 4HA/tretinoin included erythema, burning/stinging/tingling, desquamation, pruritus, skin irritation, halo hypopigmentation and hypopigmentation. Five (5%) subjects discontinued from the study due to adverse events considered to be related to study medication. When used with sunscreen of SPF 25 or greater, 4HA/tretinoin was safe and well tolerated and did not produce any unexpected or unusual adverse events.

The roles of the pharmaceutical industry and drug development in dermatology and dermatologic health care

Drug development is becoming shorter, more high-tech and strategic, more costly, and more complicated. The pharmaceutical, biotech, and cosmetic companies, along with regulatory agencies such as the FDA, are struggling to cope with and master the scientific, medical, and economic implications of this new environment. There are rapidly growing new classes of drugs, including biologicals, genomics, antibodies, and novel receptor-ligand antagonists. Dermatologic drug development has several idiosyncrasies, including the vehicle in topical drugs. Development for dermatology is much cheaper than for other therapeutic areas but also generates much less sales. The pharmaceutical industry's search for blockbusters threatens to leave dermatology without access to these new technologies, therapeutic modalities, and drug classes. The pharmaceutical industry is interested, invested, and intertwined, at many different levels, in the efforts and practices of academic dermatology, dermatology specialty organizations, and clinical dermatologists.

The combination of 2% 4-hydroxyanisole (Mequinol) and 0.01% tretinoin is effective in improving the appearance of solar lentigines and related hyperpigmented lesions in two double-blind multicenter clinical studies

BACKGROUND

Solar lentigines are a chronic condition of the aging population resulting from years of cumulative sun exposure. A topical treatment that is both safe and effective would be welcome and useful. Combinations of therapeutic agents are often used and allow synergy of mechanisms with tolerability. A tyrosinase inhibitor in use in Europe, 4-hydroxyanisole (Mequinol), and the retinoid tretinoin have been used singly as depigmenting agents.

OBJECTIVE

The efficacy and safety of the combination product of 2% 4-hydroxyanisole (4HA [mequinol]) /0.01% tretinoin solution (tradename Solagé) were evaluated in two phase III, randomized, controlled, double-blind trials.

METHODS

Subjects were randomized to treatment with 4HA/tretinoin solution, one of the active components (4HA or tretinoin), or vehicle. Subjects applied the test solution with a wand applicator twice daily to all solar lentigines and related hyperpigmented lesions on the face, forearms, and backs of hands for up to 24 weeks. Trial 1 had a 24-week no-treatment regression phase and trial 2 had a 4-week no-treatment regression phase. Information collected included clinical assessments of Target Lesion Pigmentation, Physician's Global Assessment of Improvement/Worsening, an Assessment of Overall Cosmetic Effect, and a Subject's Self-Assessment Questionnaire.

RESULTS

The 4HA/tretinoin combination was clinically superior to each of its active components and to the vehicle in the treatment of solar lentigines. At the end of treatment, in trial 1 and trial 2, 4HA/tretinoin was statistically superior to each of its active components and vehicle on the forearms and face (P </=.03), except versus tretinoin on the face in trial 2 (P =.2). In trial 2, a trend toward greater efficacy of 4HA/tretinoin over tretinoin on the face was demonstrated at the end of treatment (P =.2), which was also increasingly evident at the end of the 4-week follow-up (P =.06). Most skin-related adverse events were mild and were similar for both the 4HA/tretinoin and tretinoin treatment groups.

CONCLUSION

For the treatment of solar lentigines and related hyperpigmented lesions, the topical combination product containing 2% 4HA/0.01% tretinoin solution is well tolerated and superior to either active component.

Lepromatous neuropathy

Leprosy still remains a major cause of peripheral neuropathy, particularly in Asia, Africa, and immigrants from these endemic regions of the world. Lepromatous neuropathy can manifest as mononeuropathies, mononeuropachy multiplex, or as a generalized sensorimotor polyneuropathy. The electrophysiologic studies reveal a primarily axoral process, although there may be demyeltnating features as well. Long-term treatment with dapsone, rifampin, and clofazimine is required, A potential complication of therapy, particularly in the borderline patient, is the reversal reaction, a condition caused by upregulation of the cellular immune response. In this condition, patients may develop an exacerbation of their skin lesions and neuropathy, Because lepromatous neuropathy is not rare, neurologists need to be aware of the complex nature of the clinical manifestations, pathogenesis, and treatment of leprosy.

Productive infection of dendritic cells by HIV-1 and their ability to capture virus are mediated through separate pathways

There is substantial evidence that dendritic cells (DC) residing within epithelial surfaces (e.g., Langerhans cells) are the initial cells infected with HIV after mucosal exposure to virus. To study DC-HIV interactions in detail, we propagated Langerhans cell-like DC from cord blood CD34(+) cells and from adult blood plastic-adherent PBMC in the presence of cytokines (GM-CSF, IL-4, and/or TNF-alpha). DC pulsed overnight with HIVBaL or HIVIIIB were infected productively with both viral subtypes (as assessed by PCR, supernatant p24 protein levels, electron microscopy, and antibody staining). Productive infection could be blocked by anti-CD4 mAbs, RANTES (regulated upon activation, normal T cell expressed and secreted) (for HIVBaL), stromal cell-derived factor-1 (for HIVIIIB), or azidothymidine added during the HIV pulse, as well as by blocking DC proliferation. However, pulsing DC with HIV under these blocking conditions had no effect on the ability of DC to capture virus and transmit infection to cocultured antigen-stimulated CD4(+) T cells. Thus, we show by several criteria that (a) productive infection of DC and (b) the ability of DC to capture virus are mediated through separate pathways. We suggest that strategies designed to block mucosal transmission of HIV should consider interfering with both virus infection and virus capture by DC.

Interleukin-15 mRNA is expressed by human keratinocytes Langerhans cells, and blood-derived dendritic cells and is downregulated by ultraviolet B radiation

Interleukin (IL)-15 is a recently described cytokine that shares many functional activities with IL-2; however, unlike IL-2, IL-15 is produced by monocytes/macrophages, and not by lymphocytes. In this report, we assessed IL-15 mRNA expression by freshly isolated human epidermal cells, as well as by negatively selected keratinocytes and positively selected Langerhans cells, utilizing reverse transcription and polymerase chain reaction. In addition, cultured keratinocytes, immortalized keratinocytes (HaCaT cells), and dendritic cells expanded from adult peripheral blood in the presence of granulocyte/macrophage-colony stimulating factor and IL-4 were examined for IL-15 transcripts. Using cultured keratinocytes, we also studied the regulation of IL-15 mRNA expression by ultraviolet B radiation in vitro. Freshly isolated keratinocytes, HaCaT cells, and cultured keratinocytes all constitutively expressed IL-15 mRNA, and IL-15 expression was downregulated by ultraviolet B radiation in cultured keratinocytes in a time- and dose-dependent manner. In addition, IL-15 transcripts were constitutively expressed by freshly isolated Langerhans cells. IL-15 produced by keratinocytes, Langerhans cells, and other tissue-specific dendritic cells may be important in attracting and activating antigen-specific Th1 T cells. Furthermore, ultraviolet B-induced downregulation of keratinocyte IL-15 production may contribute to the relative state of immunosuppression induced by sun exposure.

A transforming growth factor beta 2 (TGF-beta 2)-like immunosuppressive factor in amniotic fluid and localization of TGF-beta 2 mRNA in the pregnant uterus

This report describes a murine amniotic fluid (MAF) immunosuppressive factor that has properties similar to transforming growth factor beta (TGF-beta). The MAF factor exhibits TGF-beta-like activity in stimulating soft agar colony formation by AKR-2B cells and inhibiting thymidine uptake by Mv1Lu cells. We demonstrate that both the immunosuppressive and TGF-beta-like activities of the MAF factor are completely neutralized by anti-TGF-beta 2-specific antibodies and not by anti-TGF-beta 1-specific antisera. The immunosuppressive factor in MAF is novel in that it appears to be identical or very closely related to TGF-beta 2 and is active in its native state. This active and anti-TGF-beta 2-neutralizable factor chromatographs at approximately 70 kD on Sephadex at neutral pH and appears to be able to complex with alpha-fetoprotein in native amniotic fluid. Chromatography of native MAF under acidic conditions demonstrates a lower molecular mass protein that chromatographs on BioGel in the same position as the mature 25-kD TGF-beta. This protein has the biological properties of TGF-beta and is immunosuppressive. Both of these activities are neutralizable with anti-TGF-beta 2 but not with anti-TGF-beta 1 or other antisera. By Northern analysis, we find high levels of TGF-beta 2 mRNA (with little or no TGF-beta 1) in the pregnant uterus that peak around day 15 of gestation and then fall rapidly by day 19 as birth approaches. The TGF-beta 2-like factor could possibly play a role in maternal immunity, in the retention of the fetal allograft, as well as in regulating fetal and neonatal immunological competence.