Walter Volpi

Regulatory T cells in the skin lesions and blood of patients with systemic sclerosis and morphoea

Background  Systemic sclerosis (SSc) and morphoea are connective tissue diseases characterized by fibrosis of the skin. Although to date their pathogenesis has not been clearly defined, it is thought that autoimmunity may play a role in the development of the skin lesions observed in both these diseases. As regulatory T cells (Tregs) play a key role in the modulation of immune responses, it has recently been suggested that Treg impairment may lead to the development of autoimmune diseases.

Expression of cytokines and chemokine receptors in the cutaneous lesions of erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis

Background  Erythema multiforme (EM) and Stevens–Johnson syndrome/toxic epidermal necrolysis (SJS/TEN) are caused by a dysregulation of cellular immunity.

Chronic Idiopathic and Chronic Autoimmune Urticaria: Clinical and Immunopathological Features of 68 Subjects

Skin tests with autologous serum elicit an immediate wheal-and-flare response in about 30-50% of chronic idiopathic urticaria subjects, suggesting that an autoimmune mechanism might be involved in the pathogenesis of this disease. The aim of the present work, involving 68 subjects with chronic idiopathic urticaria, was to distinguish between the serum-positive and serum-negative cases and highlight the clinical differences between the two groups on the basis of the Breneman scale score. We also tried to correlate the finding of a positive response to the autologous serum skin test with other autoimmune diatheses or fully developed autoimmune disorders. Our results did not demonstrate any significant differences between the two groups with regard to mean age, sex distribution, angioedema and mucosal/cutaneous atopy. However, all subjects with positive autologous serum skin test presented more severe clinical features than serum-negative subjects. We found no differences between the two groups in the incidence of autoimmune disease.

Infiltrating cells, related cytokines and chemokine receptors in lesional skin of patients with dermatomyositis

Background  There have been only two reports on immunophenotypic characterization in the cutaneous lesions of dermatomyositis (DM) that emphasize the importance of the infiltrating CD4+ T lymphocytes.

The CD40/CD40 ligand system is expressed in the cutaneous lesions of erythema multiforme and Stevens-Johnson syndrome/toxic epidermal necrolysis spectrum.

Background  Erythema multiforme (EM) and Stevens–Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) are determined by a dysregulation of cellular immunity.

The effects of tacrolimus ointment on regulatory T lymphocytes in atopic dermatitis.

Only very recently studies were conducted in order to evaluate the impact of regulatory T (Treg) cells in the pathophysiology of atopic dermatitis (AD). Nine adult patients with moderate-to-severe AD in riacutization period of a chronic disease were given tacrolimus ointment, while seven hydrocortisone butyrate ointment, that served as controls. We performed lesional-skin biopsies before and after treatment, that were stained immunohistochemically with monoclonal antibodies to CD4, CD25, forkhead/winged helix transcription factor (FoxP3), interleukin (IL)-10 and transforming growth factor (TGF)-β. CD4+ cells were significantly reduced in post-treatment series. Tacrolimus treatment achieved a significant reduction of CD25+ cells. FoxP3+ cells were present in untreated AD lesions. Both treatments did not significantly modify the number of FoxP3+ cells. The number of IL-10+ cells increased in post-treatment series. Tacrolimus enhanced the production of TGF-β, while hydrocortisone did not.Restoration of TGF-β-producing Treg cells may represent another important pharmacodynamic effect of tacrolimus on AD.

Infiltrating cells and related cytokines in lesional skin of patients with chronic idiopathic urticaria and positive autologous serum skin test

Abstract:  In approximately one‐third of patients with chronic idiopathic urticaria (CIU), autoantibodies against the high‐affinity IgE receptor and/or against IgE can be detected and a wheal‐and‐flare response can be provoked by the intradermal injection of autologous serum (ASST). In this study we aimed to further characterize the inflammatory response observed in the subgroup of CIU patients with positive ASST and serum‐evoked histamine‐release in vitro from basophils in comparison with unaffected skin and healthy donors. An immunohistochemical analysis of infiltrating cells (CD4, MPO, EG1, EG2, tryptase), cytokines (IL‐4, IL‐5, IFN‐γ), chemokines and chemokine receptors (IL‐8, CCR3, CXCR3), and adhesion molecules (ICAM‐1, VCAM‐1, ELAM‐1) was performed on seven selected patients (four males and three females; median age: 45 years; range: 22–57) and five healthy donors. Cytokine evaluation was also performed in five psoriatic patients to obtain an additional control.

The comparative effects of tacrolimus and hydrocortisone in adult atopic dermatitis: an immunohistochemical study

Background  While many studies have demonstrated the efficacy and safety of tacrolimus ointment in the treatment of atopic dermatitis (AD), only a few have investigated the effects of tacrolimus on inflammatory cells and their cytokine gene expression in patients with AD.

Immunopathogenesis of folliculitis decalvans: clues in early lesions.

Folliculitis decalvans (FD) is a rare variant of primary cicatricial alopecia, for which the etiopathogenesis remains unclear. Our purpose was to evaluate whether certain immunologic mechanisms might have a significant role in the pathogenesis of FD. Lesional scalp biopsy specimens from 7 patients with FD, 7 with lichen planopilaris, and 4 with alopecia areata were studied immunohistochemically by using monoclonal antibodies to CD1a, CD3, CD4, CD8, CD20, CD25, HLA-DR, interleukin (IL)-1beta, IL-4, IL-8, interferon gamma, tumor necrosis factor alpha, basic fibroblast growth factor (b-FGF), transforming growth factor (TGF)-beta, endothelial leukocyte adhesion molecule 1, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule. We showed that early FD lesions are characterized by an infiltration of activated T-helper cells, featuring mixed TH1/TH2 polarization. IL-8 and ICAM-1 may contribute to the infiltration of neutrophils, whereas b-FGF and TGF-beta may represent important mediators of the fibrosis that characterizes late-phase FD.

The Treg/Th17 cell ratio is reduced in the skin lesions of patients with pyoderma gangrenosum

DEAR EDITOR, Pyoderma gangrenosum (PG) is a rare, inflammatory skin disease that, together with other conditions such as Sweet syndrome (SS), is included within the group of neutrophilic dermatoses. Although its pathogenesis remains poorly understood, the treatments with the best clinical evidence are tumour necrosis factor inhibitors, high-dose systemic corticosteroids and ciclosporin, suggesting the pivotal role of inflammatory pathways in the development of PG. Interestingly, recent studies have highlighted the role of T helper (Th)17 cells in neutrophilic dermatoses, and an increase of interleukin (IL)-17 and IL-23 expression was found in PG lesions. Together with Th17 cells, regulatory T cells (Tregs) play a major role in human disease. Accordingly, recent reports suggest that controlling the balance between Tregs and Th17 cells may be a promising therapeutic strategy for inflammatory diseases. However, no data are present in the literature about Tregs in PG. In this study, we investigated the proportions of Tregs and Th17 cells in the skin of 15 patients with PG (seven male, eight female; age range 27–69 years), on neither immunosuppressive treatment nor topical steroids for at least 4 weeks prior to entering the study. Their clinical findings are presented in Table S1 (see Supporting Information). As a control, skin samples from five patients with SS (two male, three female; age range 31–64 years) and six healthy subjects (HS) (three male, three female; age range 28–59 years) were collected. The trial was approved by the local ethics committee and conducted according to the Declaration of Helsinki. All of the patients and controls provided written informed consent. Treg and Th17 markers were analysed by immunohistochemistry using the monoclonal antibodies anti-CD4 (1 : 20; Dako, Copenhagen, Denmark), anti-CD25 (1 : 25; Histo-Line Laboratories, Milan, Italy), anti-CD161 (1 : 80; AbD Serotec, Oxford, U.K.), antiforkhead box protein P3 (anti-FOXP3) (1 : 80; Abcam, Cambridge, U.K.), anti-IL-10 (1 : 300; Dako), anti-IL-17 (1 : 1000; Abcam), anti-RORct (1 : 2000; R&D Systems, Minneapolis, MN, U.S.A.) and antitransforming growth factor (anti-TGF)-b1 (1 : 2000; Abcam), as described previously. The results of quantitative analysis of these markers are described in Table S2 (see Supporting Information). The stained cells were counted in three consecutive microscopic fields (4009). Furthermore, FOXP3/CD4, TGF-b/CD4, IL-10/CD4 and RORct/CD4 cell ratios were calculated. The results were analysed with the Mann– Whitney U-test and were considered significant with a P-value < 0 05. In PG and SS, CD4 and CD25 cells were located in the whole dermis, with some cells scattered in the epidermis (Fig. 1a,b,d,e). The number of CD4 cells in PG was significantly higher than in SS (P < 0 001), while no differences were found for CD25 cells. By contrast, CD4 and CD25 cells were significantly less represented in HS than in the other two groups (P < 0 001) (Fig. 2a). Some FOXP3 cells were detected within the superficial dermis of patients with PG (Fig. 1g); their number was higher than in HS (P = 0 004) but lower than in SS (P < 0 001) (Fig. 2a). Interestingly, the FOXP3/CD4 cell ratio was significantly lower in PG than in SS (P < 0 001) and HS (P < 0 001) (Fig. 2a). Some IL-10 cells were found in the superficial dermis of patients with PG (Fig. 1j); their number was significantly lower than in SS (P < 0 001) and higher than in HS (P < 0 001). Moreover, the IL-10/CD4 cell ratio was reduced in PG vs. SS and HS (P < 0 001 and P = 0 03, respectively) (Fig. 2a). TGF-b staining was diffusely distributed within the superficial and medium dermis in PG and SS. Moreover, some TGF-b cells could be detected in the same areas (Fig. 1m,n). Their number was similar in both PG and SS. By contrast, the TGF-b/CD4 cell ratio was significantly reduced in PG (P = 0 01). Moreover, although HS showed a lower number of TGF-b cells than PG (P < 0 001) and SS (P < 0 001), their TGF-b/CD4 cell ratio was significantly higher (HS vs. PG, P = 0 001; HS vs. SS, P < 0 001) (Fig. 2a). Regarding Th17 markers, RORct cells were distributed in the upper dermis in PG (Fig. 1p); their number was similar to that found in SS. By contrast, the RORct/CD4 ratio was significantly lower in PG than in SS (P = 0 008) (Fig. 2a). As expected, no RORct expression was found in HS. The numbers of both CD161 and IL-17 cells, which were distributed predominantly in the superficial and medium dermis (Fig. 1s, t,v,w), were similar in PG and SS, while no CD161 nor IL-17 expression was detected in HS (Fig. 2a). Finally, in order to quantify the balance between Tregs and Th17 cells, we calculated the ratio between FOXP3 and RORct, which was significantly lower in PG than in SS (P < 0 001) (Fig. 2b).