Psoriasis is characterized by activation of T cells with a type 1 cytokine profile. IL-12 and IL-23 produced by APCs are essential for inducing Th1 effector cells. Promising clinical results of administration of an Ab specific for the p40 subunit of IL-12 and IL-23 (anti-IL-12p40) have been reported recently. This study evaluated histological changes and mRNA expression of relevant cytokines and chemokines in psoriatic skin lesions following a single administration of anti-IL-12p40, using immunohistochemistry and real-time RT-PCR. Expression levels of type 1 cytokine (IFN-γ) and chemokines (IL-8, IFN-γ-inducible protein-10, and MCP-1) were significantly reduced at 2 wk posttreatment. The rapid decrease of these expression levels preceded clinical response and histologic changes. Interestingly, the level of an anti-inflammatory cytokine, IL-10, was also significantly reduced. Significant reductions in TNF-α levels and infiltrating T cells were observed in high responders (improvement in clinical score, ≥75% at 16 wk), but not in low responders. Of importance, the levels of APC cytokines, IL-12p40 and IL-23p19, were significantly decreased in both responder populations, with larger decreases in high responders. In addition, baseline levels of TNF-α significantly correlated with the clinical improvement at 16 wk, suggesting that these levels may predict therapeutic responsiveness to anti-IL-12p40. Thus, in a human Th1-mediated disease, blockade of APC cytokines by anti-IL-12p40 down-regulates expression of type 1 cytokines and chemokines that are downstream of IL-12/IL-23, and also IL-12/IL-23 themselves, with a pattern indicative of coordinated deactivation of APCs and Th1 cells.

A 57 year old Caucasian man presented with multiple asymptomatic spiny papules on the palms and soles that he had been shaving off with a razor for many years. He was otherwise healthy with no personal or family history of skin disease or malignancy. A diagnosis of spiny keratoderma of the palms and soles or "music box spine dermatosis" was made. The clinical, histologic, and electron microscopic features of spiny keratoderma are distinct. This entity previously had multiple classifications and it is important to distinguish it from other keratodermas as some keratodermas can be linked to cutaneous and internal malignancies and conditions: poly cystic kidney disease, liver cysts, Darier's disease, and hyperlipoproteinemia among others. Spiny keratodermas can have systemic associations and do not resolve spontaneously. Treatment is generally ineffective.

Ustekinumab, a human anti-interleukin (IL)-12/IL-23p40 monoclonal antibody has demonstrated significant efficacy in patients with moderate-to-severe psoriasis. Skin lesion biopsies, cell surface markers on peripheral blood lymphocytes, and ex vivo T-helper (Th)1/Th2 cytokine responses from peripheral blood mononuclear cells (PBMC) from patients receiving ustekinumab 45 or 90 mg, or placebo were evaluated at baseline and week 12. Inflammatory serum protein levels were measured at baseline, week 2 and week 12. At week 12, median epidermal thickness decreased from 312.1 to 132.7 microm, and median levels of cellular proliferation (Ki67) and T-cell infiltration (CD3) decreased by 84.3% and 70.7%, respectively, in the combined ustekinumab group (all P < or = 0.002). Serum levels of tumor necrosis factor (TNF)-alpha, C-C motif ligand 27 (CCL27) and other inflammatory cytokines remained unchanged. Minimal variation in the percentage of T cells expressing cutaneous lymphocyte antigen (CLA) was observed following ustekinumab treatment, with no significant variation in the percentage of cells expressing CD45RA, CD45RO, CD25, human leukocyte antigen-DR (HLA-DR), and C-X-C motif receptor 3 (CXCR3). No apparent effect on the magnitude of Th1/Th2 responses to external stimuli in PBMC was observed following placebo or ustekinumab treatment. Ustekinumab improves histological psoriasis measures, with minimal impact on the systemic immune system.