Sex- and gender-associated clinical and psychosocial characteristics of patients with psoriasis.

BACKGROUND: Sex and gender may affect disease prevalence, adverse effects and response to therapy. AIM: To analyse sex and gender differences in outpatients with psoriasis. METHODS: A cross-sectional study was conducted at IDI-IRCCS, Rome, over a 3-year period. In total, 3023 patients with psoriasis were enrolled. Anthropometric and demographic characteristics were recorded, and a dermatologist evaluated the clinical severity of disease. Quality of life (QoL) questionnaires were collected. Univariate and multivariate analyses were performed to examine factors associated with sex. RESULTS: We found sex- and gender-associated differences in clinical characteristics, disease severity, psychological distress and quality of life. Male sex was associated with body mass index, smoking, alcohol consumption, Psoriasis Area Severity Index ≥ 10 and age at onset ≥ 20 years. Female sex was associated with family history of diabetes, joint involvement, clinical type other than diffuse plaque psoriasis, higher psychological distress and a greater effect on QoL. CONCLUSION: Our study identified sex and gender differences of potential clinical relevance in psoriasis.

Negative impacts of COVID-19 lockdown on mental health service access and follow-up adherence for immigrants and individuals in socio-economic difficulties.

OBJECTIVES: Lockdown measures in response to the coronavirus disease 2019 (COVID-19) pandemic can have serious mental health effects on the population, especially in vulnerable groups, such as those living in poor socio-economic conditions, those who are homeless, migrant workers and asylum seekers/refugees. In addition, these vulnerable groups frequently have greater difficulty accessing health services and in treatment adherence. The aim of this study is to estimate the impact of the COVID-19-related lockdown on service utilisation and follow-up adherence in an Italian mental health outpatient service for migrants and individuals in socio-economic difficulties. STUDY DESIGN: The design of this study is a retrospective cross-sectional study. METHODS: All patients who visited the mental health outpatient service in the months of February and March in the years 2017-2020 were included in the study. To compare service utilisation before and after the lockdown, the number of patients who visited the mental health outpatient service for psychiatric interview were recorded. Follow-up adherence was calculated as the percentage of patients who visited in February and subsequently attended a follow-up visit in March of the same year. RESULTS: The number of patients who visited the outpatient service between February 2017 and February 2020 was continuously increasing. In March 2020, fewer patients visited the service for psychiatric interview, in line with the introduction of lockdown measures. In addition, the number of the patients who visited in February 2020 and returned for their follow-up visits in March 2020 declined from approximately 30% over the same months in 2017-2019 to 17.53% in March 2020. CONCLUSIONS: The lockdown-related reduction in numbers of patients accessing the mental health service makes it difficult to help vulnerable populations during a period of time in which their mental health needs are expected to increase. Moreover, the reduction seen in follow-up compliance increases the risk of treatment discontinuation and possible relapse. Proactive alternative strategies need to be developed to reach these vulnerable populations.

Skewed T-cell receptor variable ß repertoire and massive T-cell activation in idiopathic orofacial granulomatosis.

Orofacial granulomatosis (OFG) is a clinicopathologic entity describing oral lesions with noncaseating granulomas including a spectrum of diseases such as the Melkersson-Rosenthal syndrome. The involvement of abnormal T-cell responses has been suggested in the pathogenesis of OFG although few and contrasting data are currently available on this issue. In a patient with OFG, we observed virtually complete CD4 and CD8 T-cell receptor (TCR) ß-chain variable region (BV) repertoires at the lesion level and in circulation. However, oligoclonal profiles were found in CD4 and, to a greater extent, in CD8 subsets. These findings were seen in association with a massive peripheral T-cell activation, decreased naive T cells, reduced thymic output, altered cytokine production, and increased apoptosis. Our data, pointing to a random influx of T cells at the site of inflammation, argue against the hypothesis of a main allergen acting at the level of oral mucosa. The profound dysregulation of the peripheral T-cell compartment suggests that OFG should be regarded as a systemic disorder with localized manifestations.

Immune regulatory mechanisms in allergic contact dermatitis and contact sensitization.

Contact allergy is a very common disease due to an uncontrolled immune response to chemically reactive small molecular compounds penetrating the skin. The reaction is mostly sustained by specific CD8+and CD4+type 1 T lymphocytes, which are recruited at the site of chemical challenge thanks to the expression of specific homing and chemokine receptors. Evidence exists that specialized subsets of T lymphocytes with regulatory function modulate immune responses to haptens by preventing the occurrence of the hypersensitivity reactions in non-allergic individuals exposed to the sensitizer. In addition, the magnitude of the inflammatory reaction in allergic individuals is also tightly regulated not only by the exhaustion/ apoptosis of effector T cells at the site of chemical challenge, but also by the intervention of T-regulatory cells. Most of the T-regulatory cells involved in this process belong to the CD4+ subset, such as the IL-10-producing T cells, namely Tregulatory cells 1, and the CD4+CD25+T-regulatory lymphocytes. In addition, reports suggest the existence of Treg activity among the CD8+ subpopulation. The currently held view is that contact allergies are the consequences of the exaggerated expansion of specific CD8+ effector T lymphocytes due to an impaired development of efficient regulatory T cells.

T-cell subpopulations in the development of atopic and contact allergy.

Remarkable progress has been made in our understanding of the pathogenesis of skin diseases mediated by T cells. T-cell subsets responsible for the expression and regulation of allergic contact dermatitis to small chemicals or 'haptens' have been defined further, and the dynamics of T cells involved in the pathogenesis of atopic dermatitis have been clarified. In addition, studies are beginning to reveal the important contribution of skin resident cells to atopic dermatitis and the underlying molecular mechanisms.

Novel key cytokines in allergy: IL-17, IL-22.

The biology of the T cell cytokines Interleukin (IL-)17 and IL-22 has been a main focus in the field of clinical immunology in the last decade. This intensive interest in both cytokines has resulted in almost 5,000 scientific publications (www.pubmed.com) dealing with the molecular structure, extra- and intracellular signaling pathways, specific transcription factors and the function of IL-17 and IL-22. This review article highlights the main findings concerning IL-17 and IL-22 in the last years.

Luteolin-7-glucoside inhibits IL-22/STAT3 pathway, reducing proliferation, acanthosis, and inflammation in keratinocytes and in mouse psoriatic model.

The epidermis is a dynamic tissue in which keratinocytes proliferate in the basal layer and undergo a tightly controlled differentiation while moving into the suprabasal layers. The balance between keratinocyte proliferation, differentiation, and death is essential, and its perturbation can result in pathological changes. Some common skin diseases, such as psoriasis, are characterized by hyperproliferation accompanied by inflammatory reactions, suggesting that molecules with topical anti-inflammatory and ROS scavenging abilities may be useful for their treatment. Here we investigate the potential of the flavone Luteolin-7-glucoside (LUT-7G) as a treatment for psoriasis. We show that LUT-7G leads to a modification of the cell cycle and the induction of keratinocyte differentiation, with modification of energy, fatty acid, and redox metabolism. LUT-7G treatment also neutralizes the proliferative stimulus induced by the proinflammatory cytokines IL-22 and IL-6 in HEKn. Moreover, in the Imiquimod (IMQ) mouse model of psoriasis, topical administration of LUT-7G leads to a marked reduction of acanthosis and re-expression of epidermal differentiation markers. Dissection of the IL-22 signalling pathway, activated by IMQ treatment, demonstrates that LUT-7G impairs the nuclear translocation of phosphorylated (activated) STAT3, blocking the IL-22 signalling cascade. Thus LUT-7G appears to be a promising compound for the treatment of hyperproliferative and inflammatory skin diseases, such as psoriasis.

A cytokine-to-chemokine axis between T lymphocytes and keratinocytes can favor Th1 cell accumulation in chronic inflammatory skin diseases.

The recruitment of T cells into the skin is regulated by chemokines released by resident cells. In this study, we found that normal human keratinocytes activated with Th1-derived supernatant (sup) expressed early (6-12 h) IP-10/CXCL10, MCP-1/CCL2, IL-8/CXCL8, and I-309/CCL1 mRNAs and with slower kinetics (24-96 h), RANTES/CCL5 and MDC/CCL22 mRNAs. Upon stimulation with the Th1 sup, keratinocytes secreted high levels of RANTES, IP-10, MCP-1, and IL-8 and moderate levels of I-309 and MDC. Although much less efficiently, Th2 sup could also induce keratinocyte expression of IL-8, IP-10, RANTES, and MCP-1 but not of I-309 and MDC. TARC/CCL17 was not significantly induced by any stimuli. Sup from keratinocytes activated with Th1-derived cytokines elicited a strong migratory response of Th1 cells and a limited migration of Th2 cells, whereas sup from Th2-activated keratinocytes promoted a moderate migration of Th1 and Th2 lymphocytes. Thus, keratinocytes appear considerably more sensitive to Th1- than to Th2-derived lymphokines in terms of chemokine release and can support the preferential accumulation of Th1 lymphocytes in the skin.

Interferon-gamma-stimulated human keratinocytes express the genes necessary for the production of peptide-loaded MHC class II molecules.

Keratinocytes exposed to interferon (IFN)-gamma synthesize major histocompatibility complex class II antigens both in vivo and in vitro; however, the expression of class II accessory genes has not yet been investigated. In this study, we examined the capacity of normal human keratinocytes activated with IFN-gamma to express HLA-DR, HLA-DM, and invariant chain genes as well as two major transcription regulatory genes, class II transactivator and RFX5. Cultured keratinocytes were shown to synthesize low levels of DM alpha, invariant chain p33, and RFX5 transcription factor. Upon treatment with IFN-gamma, expression of RFX5, DM alpha, and invariant chain p33 mRNA increased, whereas class II transactivator mRNA appeared de novo, followed by the expression of DR alpha, DMbeta, and invariant chain p41 genes. Western blot analysis showed that both p33 and p41 invariant chain forms and DM became detectable in keratinocytes after stimulation with IFN-gamma, with a higher p41/p33 ratio compared with Raji B cells. Finally, HLA-DR molecules present on IFN-alpha-treated keratinocytes were shown to be remarkably resistant to sodium dodecyl sulfate denaturation at room temperature, a feature that class II molecules acquire when their groove is properly loaded with peptide. These results suggest that human keratinocytes activated with IFN-gamma possess the biochemical requirements for the generation of functional class II peptide complexes.

Contact hypersensitivity in MHC class II-deficient mice depends on CD8 T lymphocytes primed by immunostimulating Langerhans cells.

Studies to determine if CD4+ and/or CD8+ T cells are critical for the initiation and propagation of contact hypersensitivity (CHS) reactions have yielded conflicting results regarding their roles. We studied the induction and expression of CHS to trinitrochlorobenzene (TNCB) using major histocompatibility complex class II-deficient mice that display normal numbers of CD8+ T cells but lack CD4+ T cells. CHS to TNCB, detected as an increase in ear thickness 24 h after epicutaneous challenge, was significantly enhanced in major histocompatibility complex class II-deficient mice compared with wild-type controls. Ear swelling responses in major histocompatibility complex class II-deficient mice were decreased by treatment with anti-CD8 antibody or by injection of wild-type CD4+ T cells. To further characterize mechanisms involved in the initiation of CHS responses, phenotypical and functional characteristics of both freshly isolated and cultured Langerhans cells were studied. Like Langerhans cells from wild-type controls, Langerhans cells from major histocompatibility complex class II-deficient mice upregulated B7-1 and B7-2 costimulatory molecules and enhanced major histocompatibility complex class I expression upon short-term culture. Cultured Langerhans cells induced a 3.5-fold increase in the stimulation of autologous hapten-specific CD8+ T cell proliferation compared with fresh Langerhans cells. Finally, TNP-coupled Langerhans cells from major histocompatibility complex class II-deficient mice primed naive mice to TNCB after transfer. These results demonstrate that hapten-specific CD8+ T cells are sufficient for the expression of CHS and that CD8 priming does not require the presence of CD4+ T cells or major histocompatibility complex class II antigen. Key words: CD8 lymphocytes/MHC class II deficiency.

Interleukin-17 is produced by both Th1 and Th2 lymphocytes, and modulates interferon-gamma- and interleukin-4-induced activation of human keratinocytes.

Interleukin-17 is a T-cell-derived cytokine, detected in skin affected by allergic contact dermatitis and psoriasis, which regulates keratinocyte expression of adhesion molecules and chemokines. In this study, we have analyzed whether interleukin-17 production segregates with a particular T helper (Th) cell subset, and have examined the capacity of interleukin-17 to modulate the activation of keratinocytes induced by Th1 and Th2 cytokines. A panel of 80 nickel-specific CD4+ T cell clones (36 Th0, 30 Th1, and 14 Th2) was isolated from peripheral blood or lesional skin of allergic contact dermatitis patients. Significant amounts (> 50 pg per ml) of interleukin-17 were released by about 50% of activated Th0, Th1, and Th2 cells. Interleukin-17 alone and in cooperation with interleukin-4, or to a lesser extent with interferon-gamma, decreased the interleukin-1 receptor antagonist to interleukin-1alpha ratio in the supernatants as well as in cell lysates from keratinocytes. In addition, interleukin-17 stimulated the release of growth-regulated oncogene-alpha, granulocyte-macrophage colony stimulating factor, and interleukin-6, with synergistic or additive effects when used together with interferon-gamma or interleukin-4. Interleukin-17 and interleukin-4 also increased stem cell factor release, a function that was inhibited by interferon-gamma. Moreover, interleukin-17 and interleukin-4 enhanced interferon-gamma-induced expression of intercellular adhesion molecule 1, but not CD40, on keratinocytes. The constitutive expression of interleukin-17 and interferon-gamma receptors on keratinocytes was not modulated by interleukin-17, interferon-gamma, or interleukin-4, whereas the interleukin-4 receptor was significantly downregulated by interferon-gamma. As a whole, the results indicate that interleukin-17 can participate relevantly in T-cell-mediated skin immune responses by amplifying both interferon-gamma- and interleukin-4-induced activation of keratinocytes.

Distinctive integrin expression in the newly forming epidermis during wound healing in humans.

The integrin receptor family plays a fundamental role in mediating cell attachment to a variety of extracellular matrix molecules. In normal human epidermis, the alpha 2 beta 1, alpha 3 beta 1, alpha 6 beta 4, and alpha v beta 5 integrin heterodimers are expressed and appear largely confined to the basal cell layer. In the present study, beta 1, beta 4, and alpha v integrin expression in the epidermis during wound healing in humans was examined. Punch biopsies were performed on healthy volunteers. At daily intervals up to day 8, and at days 11, 14, 21, and 28, the wound site was surgically removed. Using immunofluorescence microscopy, several modifications of the integrin expression pattern were observed on migrating keratinocytes during the re-epithelialization phase of the wound-healing process: i) alpha v expression was strongly enhanced and polarized at the basal pole of basal keratinocytes; ii) among the beta 1 integrins, alpha 3 beta 1 was overexpressed and distributed over the entire basal keratinocyte membrane and a weak alpha 5 beta 1 reactivity became evident; and iii) alpha 6 beta 4 was detected as a linear staining along the newly forming dermal-epidermal junction. Moreover, both during the re-epithelialization phase and during the first 2 weeks after wound closure, alpha 3, alpha 6, alpha v, beta 1, and beta 4 were no longer confined to the basal layer, as in normal epidermis, but were also found on several suprabasal cell layers. These results suggest that alpha v beta 5, alpha 3 beta 1, and alpha 5 beta 1 may be the main integrin receptors mediating keratinocyte spreading and migration over the provisional matrix of the wound bed.

Human CD4+ T lymphocytes with remarkable regulatory functions on dendritic cells and nickel-specific Th1 immune responses.

The contribution of T helper (Th) and T cytotoxic (Tc) type 1 lymphocytes in the expression of allergic contact dermatitis to haptens has been amply documented. Conversely, the existence of T cell-based regulatory mechanisms has been poorly investigated. Here, we examined the properties of a subset of nickel-specific CD4+ T cells displaying the cytokine profile (IL-10 , IL-5 , IFN-gamma+/-, IL-4+/-) of T regulatory cells 1 (Tr1) and with the potential to down-modulate immune responses to nickel. Tr1 clones were isolated from skin challenged with NiSO4 and peripheral blood of nickel-allergic patients, and from the blood of healthy individuals. Tr1 clones expressed CD25, CD28, CD30, CD26, and the IL-12 receptor beta2 chain upon activation, whereas the lymphocyte activation antigen-3 was present on 50% of the clones. Monocytes precultured with Tr1 cells in the presence of nickel, or treated with Tr1-derived supernatant, exhibited a markedly diminished capacity to stimulate nickel-specific Th1 responses. Tr1 supernatants also blocked the differentiation of dendritic cells (DC) from monocytes, as well as DC maturation and IL-12 production induced by lipopolysaccharide. As a consequence, the ability of DC to stimulate nickel-specific Th1 and Tc1 responses was greatly impaired. These inhibitory effects were completely prevented by IL-10, but not IL-5, neutralization. In aggregate, the results indicate that Tr1 cells can potently regulate the expression of Th1-mediated allergic diseases via release of IL-10.

Patients with allergic contact dermatitis to nickel and nonallergic individuals display different nickel-specific T cell responses. Evidence for the presence of effector CD8+ and regulatory CD4+ T cells.

To investigate the mechanisms underlying the expression of allergic contact dermatitis, we compared the characteristics of nickel (Ni)-specific T cell responses in 10 patients with allergic contact dermatitis to Ni and in 10 healthy, nonallergic individuals. CD4+ T cells purified from peripheral blood of both allergic and nonallergic subjects proliferated similarly to NiSO4 in vitro, with the responses mostly restricted to CD4+ CD45RO+ memory T cells. In contrast, Ni-specific CD8+ T cell responses were detected only in allergic patients. Limiting dilution assay confirmed a high frequency of Ni-specific CD4+ T cells in both individual categories, and of Ni-specific CD8+ T cells in allergic patients, but not in nonallergic persons. Ni-specific CD4+ T cell clones prepared from nonallergic subjects displayed lower interferon-gamma and higher interleukin-10 production compared with T cell clones from allergic patients. The T cell skin-homing receptor, cutaneous lymphocyte-associated antigen, was expressed on the large majority of specific CD4+ clones from both the groups. Finally, Ni-specific CD8+ clones prepared from patients also expressed the cutaneous lymphocyte-associated antigen receptor, and released high interferon-gamma and no interleukin-4. In aggregate, the results suggest that the presence of specific CD8+ T cells and a distinct pattern of cytokine release (e.g., an augmented production of interleukin-10) by CD4+ T cells can be important elements in determining whether a hapten induces allergy or a silent immune response.

Integrin expression in middle ear cholesteatoma.

Cholesteatoma is lined by a squamous keratinizing epithelium exhibiting most of the features of normal epidermis. In this study, we investigated by immunohistochemistry the expression of integrin adhesion molecules in primary acquired and recurrent cholesteatomas, and compared it with common epidermal cysts and normal human skin. The results showed that cholesteatoma epithelium exhibited a markedly augmented expression of alpha v integrin subunit and a corresponding increased deposition of vitronectin (alpha v ligand) in the surrounding stroma as compared to epidermal cyst and normal human skin. In contrast, the expression pattern of alpha 2 beta 1, alpha 3 beta 1, and alpha 6 beta 4 integrins as well as the distribution of laminin, collagen IV and fibronectin were similar in cholesteatomas, epidermal cysts and normal human skin. Similar staining pattern was observed in primary acquired and recurrent cholesteatoma.

Anti-apoptotic effects of suppressor of cytokine signaling 3 and 1 in psoriasis.

Because of their genetically determined capacity to respond to pro-inflammatory stimuli, keratinocytes have a crucial role in the pathogenesis of psoriasis. Upon IFN-γ and TNF-α exposure, psoriatic keratinocytes express exaggerated levels of inflammatory mediators, and show aberrant hyperproliferation and terminal differentiation. The thickening of psoriasic skin also results from a peculiar resistance of keratinocytes to cytokine-induced apoptosis. In this study, we investigated on the molecular mechanisms concurring to the resistance of psoriatic keratinocytes to cell death, focusing on the role having suppressor of cytokine signaling (SOCS)1 and SOCS3, two molecules abundantly expressed in IFN-γ/TNF-α-activated psoriatic keratinocytes, in sustaining anti-apoptotic pathways. We found that SOCS1 and SOCS3 suppress cytokine-induced apoptosis by sustaining the activation of the PI3K/AKT pathway in keratinocytes. The latter determines the activation of the anti-apoptotic NF-κB cascade and, in parallel, the inhibition of the pro-apoptotic BAD function in keratinocytes. For the first time, we report that phosphorylated AKT and phosphorylated BAD are strongly expressed in lesional psoriatic skin, compared with healthy or not lesional skin, and they strictly correlate to the high expression of SOCS1 and SOCS3 molecules in the psoriatic epidermis. Finally, the depletion of SOCS1 and SOCS3, as well as the chemical inactivation of PI3K activity in psoriatic keratinocytes, definitively unveils the role of PI3K/AKT cascade on the resistance of diseased keratinocytes to apoptosis.