The clinical significance of the glucocorticoid receptors: Genetics and epigenetics

The impacts of glucocorticoids (GCs) are mainly mediated by a nuclear receptor (GR) existing in almost every tissue. The GR regulates a wide range of physiological functions, including inflammation, cell metabolism, and differentiation playing a major role in cellular responses to GCs and stress. Therefore, the dysregulation or disruption of GR can cause deficiencies in the adaptation to stress and the preservation of homeostasis. The number of GR polymorphisms associated with different diseases has been mounting per year. Tackling these clinical complications obliges a comprehensive understanding of the molecular network action of GCs at the level of the GR structure and its signaling pathways. Beyond genetic variation in the GR gene, epigenetic changes can enhance our understanding of causal factors involved in the development of diseases and identifying biomarkers. In this review, we highlight the relationships of GC receptor gene polymorphisms and epigenetics with different diseases.

Hypereosinophilic Syndrome Subtype Predicts Responsiveness to Glucocorticoids

BACKGROUND

Glucocorticoids (GCs) are considered first-line treatment for platelet-derived growth factor α (PDGFRA)-negative hypereosinophilic syndromes (HESs). Despite this, little is known about clinical predictors of GC responsiveness in HES.

OBJECTIVE

Knowledge of clinical and laboratory predictors of GC response before initiation of GC could lead to more rational selection of subjects with HES for whom earlier institution of second-line and alternative therapies would be appropriate.

METHODS

Response to GC, as defined by the reduction of the absolute eosinophil count to below 1000/mm³ and control of symptoms, was assessed by a retrospective chart review of subjects with PDGFRA-negative HES evaluated on an institutional review board-approved protocol. Demographic, clinical, and laboratory parameters obtained before institution of GC, as well as final diagnosis, were evaluated to determine predictors of GC response. Proportional odds models were used for univariate and multivariate assessment of predictors with permutation adjusted P values to correct for multiple comparisons.

RESULTS

A total of 164 subjects with PDGFRA-negative HES were categorized according to GC response. Of them, 39% of the subjects responded to low dose (≤10 mg) prednisone, 9% did not respond to GC, and the remainder (52%) had variable responses to GC. The HES subtype diagnosis was the best predictor of response to GC with myeloid forms and lymphocytic variants of HES being the least responsive to GC.

CONCLUSIONS

In a large cohort of well-characterized subjects with HES, the odds of response to GC was predicted by HES subtype. Using this model, clinicians may more readily proceed to second-line agents in subjects with confirmed lymphocytic or myeloid forms of HES.

Effectiveness of cyclosporine as a treatment for steroid-resistant Cronkhite-Canada syndrome; two case reports

BACKGROUND

Cronkhite-Canada syndrome (CCS) is a rare non-inherited disorder, characterized by gastrointestinal polyposis and ectodermal changes. The pathophysiology remains unclear. Treatment with corticosteroids is considered the mainstay treatment because of its high efficacy. However, some patients have steroid-resistant CCS. The therapeutic strategy for steroid-resistant CCS is not yet established. We report two cases with steroid-resistant CCS that were effectively treated with cyclosporine (CyA). We evaluated the therapeutic strategy for steroid-resistant CCS based on reviews of previous reports.

CASE PRESENTATION

Our patients with CCS were first treated with prednisolone. No clinical response was noted, and treatment with CyA was initiated. After beginning CyA treatment, both clinical symptoms and polyposis markedly improved. Up to the present, 55 cases of CCS treated with corticosteroids and their response were reported. Out of the 57 patients, including our 2 cases, 9 (16 %) did not respond clinically to corticosteroids. In 7 of the 9 steroid-resistant cases, the prognosis after corticosteroids treatment was described. In 5 of the 7 steroid-resistant cases, immunosuppressive treatments induced remission. In 4 of these 5 cases, moreover, the key drug of treatments was calcineurin inhibitor.

CONCLUSIONS

Treatment with calcineurin inhibitor, such as CyA, could be a potential option for steroid-resistant CCS.

Granulocytapheresis in steroid-dependent and steroid-resistant patients with inflammatory bowel disease: a prospective observational study

BACKGROUND

Despite the mounting importance of granulocytapheresis (GCAP) for inflammatory bowel disease (IBD) treatment, its effectiveness in steroid-dependent (SD) and steroid-resistant (SR) patients has not been clearly evaluated. This prospective observational study describes the use of GCAP in SD and SR patients with either Ulcerative Colitis (UC) or Crohn's Disease (CD).

METHODS

118 patients, 83 affected by UC (55 SD and 28 SR) and 35 by CD (22 SD and 13 SR), were treated with GCAP, using Adacolumn™, for 5 consecutive weeks, 1 session/week. All patients were followed for 12 months after the end of GCAP. Clinical remission was defined as Clinical Activity Index (CAI) ≤6 for UC patients and Crohn's Disease Activity Index (CDAI) <150 for CD patients.

RESULTS

All patients completed the study; no major complications were reported. At the end of GCAP 71% of UC and 63% of CD patients showed clinical remission. At 6 months the remission was maintained by 66% and 54% of UC and CD patients respectively, while at 12 months the percentages were 48% and 43%, respectively. No differences between SD and SR subgroups were reported at any timepoint. CAI and CDAI values significantly dropped after GCAP treatment and at 6 and 12 months' follow-up (p<0.05 vs baseline for both timepoints). No differences were measured in CAI and CDAI between SD and SR patients.

CONCLUSION

GCAP therapy is safe and effective in inducing and maintaining clinical remission both in SD and in SR patients affected by either UC or CD.