Corticosteroid therapy for rheumatoid arthritis

Mechanisms of glucocorticoid action and insensitivity in airways disease

Glucocorticoids are the mainstay for the treatment of chronic inflammatory diseases including asthma and chronic obstructive pulmonary disease (COPD). However, it has been recognized that glucocorticoids do not work well in certain patient populations suggesting reduced sensitivity. The ultimate biologic responses to glucocorticoids are determined by not only the concentration of glucocorticoids but also the differences between individuals in glucocorticoid sensitivity, which is influenced by multiple factors. Studies are emerging to understand these mechanisms in detail, which would help in increasing glucocorticoid sensitivity in patients with chronic airways disease. This review aims to highlight both classical and emerging concepts of the anti-inflammatory mechanisms of glucocorticoids and also review some novel strategies to overcome steroid insensitivity in airways disease.

Discovery of GW870086: a potent anti-inflammatory steroid with a unique pharmacological profile

BACKGROUND AND PURPOSE

Glucocorticoids are highly effective therapies for a range of inflammatory diseases. Advances in the understanding of the diverse molecular mechanisms underpinning glucocorticoid action suggest that anti-inflammatory molecules with reduced side effect liabilities can be discovered. Here we set out to explore whether modification of the 17α position of the steroid nucleus could generate molecules with a unique pharmacological profile and to determine whether such molecules would retain anti-inflammatory activity.

EXPERIMENTAL APPROACH

The pharmacological properties of GW870086 were compared with fluticasone propionate (FP) using a range of cellular and in vivo model systems, including extensive gene expression profiling.

KEY RESULTS

GW870086 repressed inflammatory cytokine release from lung epithelial cells in a similar manner to FP but antagonized the effect of dexamethasone on MMTV-driven reporter gene transactivation. GW870086 had a strong effect on the expression of some glucocorticoid-regulated genes (such as PTGS2), while having minimal impact on the expression of other known target genes (such as SGK). GW870086 retained the ability to strengthen tight junctions in epithelial cell culture but, unlike FP, was unable to protect the culture from elastase-mediated damage. In murine models of irritant-induced contact dermatitis and ovalbumin-induced allergic inflammation, GW870086 showed comparable anti-inflammatory efficacy to FP.

CONCLUSION AND IMPLICATIONS

GW870086 is a potent anti-inflammatory compound with a unique ability to regulate only a subset of those genes that are normally affected by classical glucocorticoids. It has the potential to become a new topical steroid with a different safety profile to existing therapies.

Acute perforation of the colon associated with chronic corticosteroid therapy

Perforation of the colon occurred in thirteen patients receiving corticosteroids for diseases unrelated to the bowel. Treatment averaged 3.5 years. The paucity of symptoms, signs, and laboratory indexes of visceral perforation led to frequent delays in treatment and to incorrect preoperative diagnoses in all but three patients. The perforations were often unusual in location (cecum, hepatic flexure, and multiple points in the transverse and descending colon) and often resulted from single punched-out ulcers in otherwise normal bowel. In seven patients the lesion could not be distinguished from perforated sigmoid diverticulitis, but in two of these patients the ulcerations were found in adjacent diverticula. The evidence strongly suggests that corticosteroids can be responsible for ulceration and perforation of the colon either by direct injury or by interference with normal mechanisms of bowel repair.