Interferon-alpha treatment for severe atopic dermatitis

Off-label uses of biologics in dermatology: Interferon and intravenous immunoglobulin (Part 1 of 2)

The introduction of a number of biologic therapies into the market has revolutionized the practice of dermatology. These therapies include interferons, intravenous immunoglobulin, infliximab, adalimumab, etanercept, efalizumab, alefacept, and rituximab. Most dermatologists are familiar with the Food and Drug Administration-approved indications of these medications. However, numerous off-label uses have evolved. As part 1 of a 2-part series, this article will review the literature regarding the off-label uses of the interferons and intravenous immunoglobulin in dermatology.

Analysis of IFN-kappa expression in pathologic skin conditions: downregulation in psoriasis and atopic dermatitis

Interferon-kappa (IFN-kappa) is a type I IFN expressed by keratinocytes, monocytes and dendritic cells (DCs). In human keratinocytes, it is produced in response to double-stranded RNA (dsRNA) and other IFNs and protects from viral infections. In monocytes and DCs, IFN-kappa induces tumor necrosis factor-alpha (TNF-alpha) and interleukin-10 (IL-10) and inhibits lipopolysaccharide (LPS)-induced IL-12. In this study, we evaluated IFN-kappa expression in skin lesions of patients with common immune-mediated inflammatory disorders using immunohistochemical techniques. IFN-kappa was not detectable in healthy skin but was strongly expressed in allergic contact dermatitis and lichen planus-affected skin. IFN-kappa was localized mainly in basal and suprabasal keratinocytes and in some leukocytes infiltrating the dermis. In contrast, IFN-kappa expression in psoriatic or atopic dermatitis (AD) pidermis was weak and detectable in only 2 of 5 patients examined. Consistently, cultured keratinocytes and monocytes obtained from psoriatic and AD patients expressed null or low levels of IFN-kappa in response to IFN-gamma, which strongly upregulates IFN-kappa in normal keratinocytes. IFN-kappa accumulated in keratinocyte cytoplasm and plasma membrane, and only limited amounts were released extracellularly. Soluble IFN-kappa did not influence keratinocyte proliferation or chemokine and membrane molecule expression, and only its membrane-associated form activated IFN-stimulated response element (ISRE) signaling. Given the difference in IFN-kappa expression levels in the skin disorders examined, IFN-kappa presence or deficiency might have different pathogenetic consequences depending also on other disease-specific intrinsic alterations.

Variation in the type I interferon gene cluster on 9p21 influences susceptibility to asthma and atopy

A genome-wide screen for asthma and atopy susceptibility alleles conducted in the Hutterites, a founder population of European descent, reported evidence of linkage with a short tandem repeat polymorphism (STRP) within the type I interferon (IFN) gene cluster on chromosome 9p21. The goal of this study was to identify variation within the IFN gene cluster that influences susceptibility to asthma and atopic phenotypes. We screened approximately 25 kb of sequence, including the flanking sequence of all 15 functional genes and the single coding exon in 12, in Hutterites representing different IFNA-STRP genotypes. We identified 78 polymorphisms, and genotyped 40 of these (in 14 genes) in a large Hutterite pedigree. Modest associations (0.003<P<0.05) with asthma, bronchial hyper-responsiveness (BHR), and atopy were observed with individual variants or genes, spanning the entire 400 kb region. However, pairwise combinations of haplotypes between genes showed highly significant associations with different phenotypes (P<10(-5)) that were localized to specific pairs of genes or regions of this cluster. These results suggest that variation in multiple genes in the type I IFN cluster on 9p22 contribute to asthma and atopy susceptibility, and that not all genes contribute equally to all phenotypes.

Diffuse inflammatory lesions in patients treated with interferon alfa and ribavirin for hepatitis C: a series of 20 patients

BACKGROUND

Cutaneous side-effects of treatment with interferon alfa or interferon alfa plus ribavirin in patients with hepatitis C have already been reported but they are mostly local with inflammation and, much less frequently, necrosis at the injection points. By contrast, very few data are available with regard to distant skin reactions, particularly inflammatory lesions on other parts of the body.

OBJECTIVES

To assess the clinical and histological pattern of inflammatory skin lesions outside the injection points in patients treated with interferon alfa and ribavirin for chronic hepatitis C.

METHODS

Twenty patients attending a University Hospital in Southern France (secondary referral centre) were evaluated regard to clinical history, type and localization of lesions, progression and histology. Skin testing was performed in some patients and the relevance of the results was evaluated.

RESULTS

Eczema-like skin lesions were mainly distributed on the extremities, sometimes associated with photosensitivity. They usually occurred between 2 and 4 months of treatment. Histology was nonspecific, with a dermal, mainly perivascular, mononuclear infiltrate. Skin testing was poorly informative and was not predictive of relapse. Treatment had to be interrupted in half the patients, of whom two of three relapsed on resuming therapy.

CONCLUSIONS

The incidence of inflammatory skin lesions at a distance from injection sites in patients treated with interferon alfa and ribavirin for chronic hepatitis C is currently unknown, but this adverse event must be taken into consideration as it may lead to the transient or definitive interruption of treatment.

[Interferon-alpha and auto-immunity]

PURPOSE

To assess the role of endogenous interferon alpha (IFN) in auto-immune experimental models and human diseases, and to evaluate its iatrogenic potential as a therapeutic agent.

MAIN POINTS

IFN is a cytokine involved in cellular immunity, that promotes both differentiation of dendritic cells and the TH1 pathway. Auto-immune side-effects of recombinant IFN depend on IFN dosage and the pathology concerned. The spectrum extends from occurrence of auto-antibodies in an asymptomatic patient to overt disease such as systemic lupus. Antigenic targets of auto-antibodies are diverse: blood cells coagulation factors, immunoglobulin, hormones, intrinsic factor, intracellular components. Thyroiditis is the most frequently reported auto-immune disease occurring during IFN treatment, including hypothyroidism, hyperthyroidism or a bi-phasic pattern. Currently, true incidence of thyroiditis remains debated. It appears very low (under 1%) in hepatologic series using low-dose IFN. The fact that auto-immunity may be related to the treated disease--before use of IFN--must also be addressed: e.g. antinuclear factors and anti-DNA antibodies in chronic myeloid leukemia or anti-actin and anti-LKM antibodies in chronic C hepatitis.

FUTURE PROSPECTS

Recombinant alpha interferon appears more as a trigger than a de novo inducer of auto-immune disorders. Its use as an immunomodulator agent should be treated with caution.

Complete remission of hypereosinophilic syndrome after interferon-alpha therapy: report of a case and literature review

Hypereosinophilic syndrome (HES) is a multisystem disease with a significant mortality rate. It is characterized by peripheral blood eosinophilia and infiltration of eosinophils into many organs including skin. We describe a patient with cutaneous, pulmonary, and gastric symptoms of HES. He was first treated with systemic and topical corticosteroids, antihistamines, and photochemotherapy. Therapy was switched to interferon-alpha, because we had to consider side effects of corticosteroids and no significant improvement had been achieved. During the period of usage of interferon-alpha for 50 weeks, his symptoms of HES nearly cleared. There has been no recurrence in the eight months since the discontinuation of interferon-alpha therapy.

Recent developments in the treatment of atopic eczema

Atopic eczema remains a therapeutic challenge. However, new developments in the understanding of the pathogenesis of this complex disease have prompted new therapeutic strategies. This review focuses on recently described treatment modalities for atopic eczema that are currently available or under investigation. The effectiveness of phototherapy, cytokines, and immunosuppressive drugs is evaluated. In addition, some new and promising but still experimental approaches are discussed.