Psoriasis associated with idiopathic CD4+ T-cell lymphopenia: a regulatory T-cell defect?

Idiopathic CD4(+) lymphocytopenia (ICL) is a rare immunodeficiency syndrome of unknown origin for which the increased risks of opportunistic infections and of malignancies have been well established; however, skin dysimmune diseases, including psoriasis, have been scarcely reported up to now. We report herein the severe course of psoriasis in four patients with ICL, and show evidence for a defect in the skin recruitment of regulatory CD4(+) FoxP3(+) T cells. These data raise the apparent paradigm of the occurrence of a severe immunomediated disease together with a profound T-cell defect, a model that might also apply to other immune deficiencies associated with psoriasis.

The mechanistic basis for psoriasis immunopathogenesis: translating genotype to phenotype. Report of a workshop, Venice, 2012

The International Psoriasis Council, a global nonprofit organization dedicated to advancing psoriasis research and treatment, led an initiative to better define the pathogenic mechanisms that constitute psoriasis. In September 2012, a workshop was held at the 42nd Annual European Society for Dermatological Research in Venice, Italy. By assembling a panel of global dermatology and immunology experts, the objective was to evaluate the current status of the science explaining the mechanism of disease in psoriasis, e.g. dysregulation of the skin immune system and perturbations of epidermal homeostasis. The workshop consisted of four oral presentations, which addressed key topics in psoriasis, delivered by Hervé Bachelez (Paris, France), Antonio Costanzo (Rome, Italy), Michelle Lowes (New York, NY, U.S.A.) and Frank Nestle (London, U.K.). A global expert panel was assembled to stimulate dialogue and debate: Kevin Cooper (Cleveland, OH, U.S.A.), Michel Gilliet (Lausanne, Switzerland), Joerg Prinz (Munich, Germany), Martin Röcken (Tubingen, Germany), Jens Schroeder (Kiel, Germany), Manuelle Viguier (Paris, France), Mayte Suárez-Fariñas (New York, NY, U.S.A.) and Cristina Zielinski (Berlin, Germany). Collectively, the presentations demonstrated the significant advances in understanding immune regulation that have occurred over the past decade by virtue of the study of psoriasis subtypes, phenotypic manifestations and genetic associations. Elucidating the pathogenic and genetic basis of psoriasis holds the promise of a complete understanding of disease mechanisms, predictors of treatment response, novel drug development strategies and customized therapeutic regimens for the individual patient.

Sorafenib in advanced melanoma: a critical role for pharmacokinetics?

BACKGROUND

Inter-patient pharmacokinetic variability can lead to suboptimal drug exposure, and therefore might impact the efficacy of sorafenib. This study reports long-term pharmacokinetic monitoring of patients treated with sorafenib and a retrospective pharmacodynamic/pharmacokinetic analysis in melanoma patients.

PATIENTS AND METHODS

Heavily pretreated patients with stage IV melanoma were started on sorafenib 400 mg twice daily (bid). In the absence of limiting toxicity, dose escalation of 200 mg bid levels was done every 2 weeks. Plasma sorafenib measurement was performed at each visit, allowing a retrospective pharmacodynamic/pharmacokinetic analysis for safety and efficacy.

RESULTS

In all, 19 of 30 patients underwent dose escalation over 400 mg bid, and 28 were evaluable for response. The overall disease control rate was 61% (95% confidence interval (CI): 42.6-78.8), including three confirmed responses (12%). Disease control rate and progression-free survival (PFS) were improved in patients with high vs low exposure (80% vs 32%, P=0.02, and 5.25 vs 2.5 months, P=0.005, hazard ratio (HR)=0.28 (95% CI: 0.11-0.73)). In contrast, drug dosing had no effect on PFS. In multivariate analysis, drug exposure was the only factor associated with PFS (HR=0.36 (95% CI: 0.13-0.99)). Diarrhoea and anorexia were correlated with drug dosing, while hypertension and hand-foot skin reaction were correlated with drug exposure.

CONCLUSIONS

Although sorafenib had modest efficacy in melanoma, these results suggest a correlation between exposure and efficacy of sorafenib. Therefore, dose optimisation in patients with low exposure at standard doses should be evaluated in validated indications.