Effects of oral meclofenamate therapy in psoriasis

The effect of methotrexate on the expression of cell adhesion molecules and activation molecule CD69 in psoriasis

BACKGROUND

The mechanism of the action of methotrexate (MTX) in the treatment of psoriasis has not been completely elucidated.

OBJECTIVE

To assess the effect of MTX on the expression of intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), E-selectin, activation molecule CD69 and T-cell phenotype in skin specimens from patients with psoriasis.

METHODS

We performed an immunohistochemical analysis of the expression of T-cell phenotype and cell adhesion/activation molecules in skin biopsies from patients with psoriasis treated with a fixed dose of MTX (12.5 mg/week). To determine data on the epidermal/dermal T-cell infiltration we carried out a manual quantification.

RESULTS

Skin samples prior to therapy showed a moderate to severe inflammatory infiltrate, mainly due to T lymphocytes with a helper/inducer (CD4) phenotype. Most of these cells also expressed ICAM-1 and VCAM-1. Blood vessels showed expression of E-selectin and VCAM-1, and keratinocytes were positive for ICAM-1 staining. The cell infiltrate was reduced after therapy, as well as the expression of cell adhesion molecules. However, we also noted the persistence of the T lymphocyte phenotype CD8(+), expressing the CD69 activation molecule, after the MTX treatment.

CONCLUSIONS

MTX downregulates the expression of some adhesion molecules, a phenomenon that may contribute to its anti-inflammatory therapeutic effect in psoriasis. The infiltrating T cells post-treatment have an activated cytotoxic phenotype, which may suggest a pathogenic role in the continuation and/or recurrence of psoriasis.

Recent advances in the treatment of psoriatic arthritis

This article provides an overview of recent developments in the treatment of psoriatic arthritis with an emphasis on patent literature for the period January 1998 to December 2002. The main pathogenic pathways thought to be operative in psoriatic arthritis are highlighted and some novel compounds that can potentially interfere with such pathways at different levels are discussed. Among the new agents proposed, the inhibitors of cytokine signaling, angiogenesis, and extracellular matrix degradation appear to be of particular interest for the treatment of psoriatic arthritis resistant to conventional therapies. Finally, new formulations of existing drugs and natural remedies claimed to be useful for the treatment of psoriatic arthritis are reviewed.

Selected drug complications and treatment conflicts in the presence of coexistent diseases

The presence of different coexistent systemic diseases often times complicates the selection of the appropriate treatment of an underlying rheumatologic condition. In this article, some controversial treatment conflicts that are frequently encountered in the daily practice of rheumatology are clarified and guidelines for the best available therapeutic options are provided.

Effects of two novel inhibitors of 5-lipoxygenase, L-651,392 and L-651,896, in a guinea-pig model of epidermal hyperproliferation

The effects of two novel and structurally different 5-lipoxygenase inhibitors, L-651,392 (4-bromo-2,7-dimethoxy-3H-phenothiazin-3-one) and L-651,896 (2,3-dihydro-6-(3-(2-hydroxymethyl)phenyl-2-propenyl)-5-benzo furanol), on epidermal proliferation were examined in the guinea-pig ear stimulated with the calcium ionophore A23187. Topical application of A23187 on the guinea-pig ear induced epidermal hyperproliferation which could be quantitated by tritiated-thymidine incorporation into DNA in the heat-separated epidermis. The ionophore-induced response was inhibited dose dependently by either L-651,392 or L-651,896 when the guinea-pigs were pretreated topically with these compounds. In separate experiments, it was demonstrated that A23187 induced a significant increase in the levels of immunoreactive-LTB4 in the guinea-pig ear which could be blocked by either inhibitors. It was suggested that L-651,392 and L-651,896 inhibited the ionophore-induced epidermal proliferation via their inhibitory action on the 5-lipoxygenase pathway of arachidonic acid metabolism.

Topical application of nonsteroidal anti-inflammatory drugs prevents vehicle-induced improvement of psoriasis

In a double-blind fashion, we compared the effect of topical application of 1% indomethacin cream or 1% meclofenamate cream with the effect of vehicle therapy alone in thirty patients with psoriasis. After 4 weeks' treatment of bilaterally symmetric psoriatic plaques, the indomethacin-treated sides were worse than the vehicle-treated sides in fourteen of twenty patients (p less than 0.01); the meclofenamate-treated sides were worse than the vehicle-treated sides in seven of ten patients (p less than 0.05). We suspect that the nonsteroidal anti-inflammatory drugs contributed to the maintenance of our patients' psoriasis by altering the arachidonic acid transformation cascade.