Non-invasive short-term assessment of retinoids effects on human skin in vivo using multiphoton microscopy.

BACKGROUND: The occlusive patch test developed for assessing topical retinoids activity in human skin has been extended as a short-term screening protocol for anti-ageing agents. In this model, biopsies are performed at the end of the occlusion period for morphological and immuno-histochemistry analysis. Multiphoton microscopy is a recent non-invasive imaging technique that combined with image processing tools allows the in vivo quantification of human skin modifications. OBJECTIVE: To validate with gold standards of anti-ageing that are retinoids, the relevance of multiphoton microscopy for kinetic and quantitative assessment in this model. METHODS: Twenty women, aged 50-65 years, were enrolled. Retinol 0.3% (RO) and Retinoic acid 0.025% (RA) were applied to the dorsal photo-damaged side of their forearm under occlusive patches for 12 days. A patch alone was applied to a third area as control. Evaluation was performed at day D0, D12 (end of treatment), D18 and D32 using multiphoton microscopy. Epidermal thickness, normalized area of the dermal-epidermal junction (DEJ) and melanin density were estimated using 3D image processing tools. RESULTS: Main significant results are: Epidermal thickening at D12, D18 and D32 with RO and at D12, D18 with RA vs. baseline and vs. CONTROL: Increased DEJ undulation at D32 with RO and at D12 with RA vs. baseline and vs. CONTROL: Decreased melanin content with RO (at D12 and D18 vs. baseline and at D32 vs. baseline and vs. control) and with RA (at D12 vs. baseline). CONCLUSIONS: This study shows that multiphoton microscopy associated to specific 3D image processing tools allows cutaneous effects induced by topical retinoids in this in vivo model to be non-invasively detected, quantified and followed over time. This innovative approach could be applied to the evaluation of other active compounds.

[Bullous pemphigoid in young patients: a retrospective study of 74 cases]. / Pemphigoïde du sujet jeune.

INTRODUCTION: Bullous pemphigoid usually affects elderly people. Only a few isolated cases among people younger than 65 years have been reported. OBJECTIVES: Describe the clinical and biological characteristics of patients younger than 60 years suffering from bullous pemphigoid, compare them with the usual characteristics known among elderly people and search for potential pathological associations. PATIENTS AND METHODS: Retrospective, national, multicenter study. Clinical, biological and histological characteristics were recorded with a standardised questionnaire as well as treatments and associated pathologies. RESULTS: Seventy-four cases of bullous pemphigoid diagnosed between June 1970 and March 2002 were analyzed. Mean age at the beginning of the disease was 46 +/- 11.6 years. Further explorations by indirect immunofluorescence of separated skin and/or immuno-electron microscopy and/or immunoblotting were performed for 42 patients (56.8 p. 100). Clinical characteristics among this restricted population were comparable to those found among the 32 other cases. Compared to usual data on bullous pemphigoid in elderly people, we observed a greater proportion of extensive form of disease (75 p. 100), a more frequent head and neck involvement (39.2 p. 100) and an overexpression of anti-BP180 autoantibodies (48 p. 100). Neoplasm was notified for 7 patients (9.5 p. 100), 18 (24.3 p. 100) suffered from a pathology of the basement membrane zone (6 psoriasis, 6 atopic dermatitis and 6 lichen) and 13 from neurological disease, among which 4 were bedridden. Fourty-six patients (62.2 p. 100) received drugs for the long term (mean 2.12 +/- 2.43), 4 patients were treated by PUVAtherapy and 2 by radiotherapy. DISCUSSION: Our results suggest that bullous pemphigoid among young people is more severe and more active than the usual form in the elderly. This particular form could be the result of a higher expression of anti-BP180 autoantibodies, which are considered as a marker of poor prognosis in this disease. We also found a high frequency of pathological associations and physical treatment, all responsible for damage to the basement membrane zone, which can involve auto-immunization against hemidesmosome components.

[Relationship between clinical findings of patients with bullous pemphigoid and antigens recognized by their circulating antibasement membrane zone antibodies]. / Analyse des signes cliniques des malades atteints de pemphigoïde en fonction des antigènes reconnus par leur sérum en immunotransfert.

INTRODUCTION: Clinical features and extent of bullous pemphigoid lesions differed widely among patients. The pathogenic role of anti-BPAG2 antibodies has been recently demonstrated. The aim of this study was to analyze the relationship between clinical features of bullous pemphigoid patients and the antigens recognized by their serum. PATIENTS AND METHODS: One hundred and twelve bullous pemphigoid patients were included in this prospective multicenter study. Inclusion criteria were the following: 1) diagnosis of bullous pemphigoid established on the presence of 3 of the 4 clinical features of bullous pemphigoid, histological picture of bullous pemphigoid and positive direct immunofluorescence; 2) serum available for immunoblotting studies. The clinical and biological findings were prospectively recorded on standard forms. Sera were collected and analyzed using indirect immunofluorescence and immunoblotting on human epidermal extracts. RESULTS: Analysis of patient's clinical features depending on the antigens recognized by their serum showed that patients whose serum contained anti-BPAG1 antibodies had more frequently pruritus, blisters on the lower limbs and a positive indirect immunofluorescence. Patients whose serum contained anti-BPAG2 antibodies had blisters more frequently localized on the head, and a more frequently negative indirect immunofluorescence. Patients whose serum was negative by immunoblotting had less frequently urticarial and/or eczematous lesions, bullae less frequently localized on the lower part of the trunk, abdomen and lower limbs, lower eosinophilia and a more frequently negative indirect immunofluorescence. CONCLUSION: Patients with circulating anti-BPAG1 antibodies exhibited the most typical, clinical and biological features of bullous pemphigoid.

Clinical criteria for the diagnosis of bullous pemphigoid: a reevaluation according to immunoblot analysis of patient sera.

BACKGROUND: We previously proposed a set of 4 clinical criteria for the diagnosis of bullous pemphigoid (BP) that consisted of age greater than 70 years, absence of atrophic scars, absence of mucosal involvement and absence of predominant bullous lesions on the neck and head. These results have been challenged because direct immunoelectron microscopy (IEM), which was used as the standard diagnostic criterion in our initial study, does not identify the different antigens of the basement membrane zone. OBJECTIVE: To reassess the validity of these clinical criteria for the diagnosis of BP using immunoblot analysis of patient sera as the main diagnostic criterion, in order to precisely identify the antigens recognized by patient sera. METHODS: One hundred and eighty-nine sera from patients with various subepidermal autoimmune blistering diseases (AIBDs) were tested by immunoblotting using dermal and epidermal extracts. IEM was used as a complementary diagnostic procedure in a few patients whose serum recognized BPAG2 exclusively or was negative in immunoblotting. RESULTS: 142 patients (75%) had at least 3 of the 4 clinical diagnostic criteria. Sera from patients who lacked the set of BP clinical criteria were more frequently immunoblot negative (34%) than sera from patients who had the criteria (18%; p = 0.025). BPAG1 was more frequently recognized by sera from patients with the set of BP clinical criteria (78%) than by sera from patients without the criteria (45%; p = 5.10(-4)). In contrast, BPAG2 was recognized by a great number of sera from patients who lacked the criteria of BP (71%), which was in accordance with the presence of numerous patients with cicatricial pemphigoid in this group. Among patients with various subepidermal AIBDs, the diagnosis of BP could be made with a sensitivity of 86%, a specificity of 90% and an excellent prognostic positive value over 95%, if 3 of these clinical criteria were present. CONCLUSION: These results confirm the interest of this set of clinical criteria for the rapid diagnosis of BP.

Schönlein-Henoch purpura in adult patients. Predictive factors for IgA glomerulonephritis in a retrospective study of 57 cases.

OBJECTIVES: To evaluate the incidence of extracutaneous manifestations and to identify predictive factors for renal involvement in adult patients with Schönlein-Henoch purpura. DESIGN: Retrospective study with a comparative analysis of patients with and without renal involvement. SETTING: Patients who were attending the dermatologic department of an academic medical center. PATIENTS: In patients with purpura of the lower limbs and cutaneous vascular IgA deposits for which cases were recorded from 1985 to 1993, the following selection criteria were used: age older than 15 years and absence of thrombocytopenia, of IgA deposits in the basement membrane zone, and of a known hematologic or connective tissue disorder. MAIN OUTCOME MEASURES: Clinical and biological data, results of histological studies, and findings from direct immunofluorescence studies of skin biopsy specimens were compared in patients with and without renal involvement. RESULTS: Fifty-seven patients were included: 23% had an IgA glomerulonephritis confirmed by results of a renal biopsy, and a further 26% showed abnormalities on urine microscopy. Joint and gastrointestinal involvement was noted in, respectively, 33% and 19% of the patients. A comparative analysis of patients with and without renal involvement failed to reveal significant differences with regard to age, sex, the presence of bullous or necrotic cutaneous lesions, gastrointestinal or joint involvement, histological features, and findings from direct immunofluorescence studies. An IgA glomerulonephritis was significantly associated with purpura above the waist (P = .03), a recent infectious history (P = .02), pyrexia (P = .01), and biological markers of inflammation (P = .006). CONCLUSIONS: Despite a lower incidence of systemic involvement compared with that in other published series, the incidence of renal involvement remained high (ie, between 23% and 49%). A recent infectious history, pyrexia, the spread of purpura to the trunk, and biological markers of inflammation were predictive factors for renal involvement.

Early quantitative and functional deficiency of NK1+-like thymocytes in the NOD mouse.

An immunoregulatory role has recently been attributed to the discrete subset of major histocompatibility complex class I-restricted NK1+ mature heat-stable antigen- (HSA-) thymocytes expressing an unusual Vbeta8-biased T cell receptor repertoire. NK1+ T cells are the main interleukin (IL)-4 producers upon priming. We have studied the size and the function of this subset in the nonobese diabetic (NOD) mouse, a model of spontaneous T cell-mediated autoimmune insulin-dependent diabetes. This study was complicated by the absence in this strain of the NK1.1 allele, the only one for which an antibody is available. To circumvent this difficulty, the cells, hereafter designated the NK1+-like T subset, were characterized by the use of monoclonal antibodies which showed the Vbeta8 bias in the CD44+ Ly-49+ MEL-14- 3G11- thymocyte subset of non-autoimmune strains and of its absence in class I-deficient (beta2-microglobulin-/-) mice. A clear deficit in the number of NK1+-like cells was evidenced at 3 weeks of age in NOD mice. It was still present at 8 weeks of age in the double-negative CD4-CD8- population. The functional anomaly was even more striking: NOD mouse NK1+-like thymocytes virtually lacked the ability to produce IL-4 at 3 weeks and still showed a very reduced capacity at 8 weeks. NK1+ T cell deficiency was also suggested in the periphery by the reduction of Ly-49A+ cells in the spleen of 3- and 8-week-old NOD mice and the absence of short-term production of IL-4 in vitro by NOD mouse spleen cells 90 min after the administration of anti-CD3 antibody, a response attributed to NK1+ T cells. Taken together, these data demonstrate a very early defect in NK1+-like T cells which could be involved in the genesis of autoimmunity in NOD mice through a deficiency in Th2 cell function.

IL-7 reverses NK1+ T cell-defective IL-4 production in the non-obese diabetic mouse.

Converging data suggest an important role for IL-7 in T lymphocyte maturation as illustrated by the severe T lymphopenia observed in IL-7-deficient mice. We recently reported that IL-7 preferentially promotes the in vitro expansion of a discrete MHC class I-dependent lymphocyte subset comprising both CD4+ and CD4-CD8- TCR alpha beta + cells bearing several NK cells markers such NK1.1 and Ly-49. These T cells, designated as NK1+ T cells, have the unique property among thymocytes of producing large amounts of IL-4 upon primary stimulation via the TCR. We have further demonstrated that thymic NK1+ T cells of non-obese diabetic (NOD) mice, a spontaneous model of autoimmune type I diabetes, are markedly deficient in maturation both quantitatively and functionally (IL-4 production). In the present experiments, the addition of exogenous IL-7 completely restored IL-4 production by anti-TCR alpha beta-stimulated mature (HSA-CD8-) thymocytes in NOD mice. A short 2 h preincubation with IL-7 was sufficient to restore both the expression of IL-4 mRNA and IL-4 production capacity. This was related to a direct effect on NK1+ thymocytes since: (i) the effect of IL-7 was restricted to the non-mainstream MEL-14- 3G11- TCR alpha beta + subset which mostly concentrates the IL-4-producing capacity and (ii) IL-7 did not restore IL-4 production in class I-deficient mice which lack the NK1+ T cell subset. Importantly, this activity of IL-7 on NK1+ T cells was also demonstrated in non-autoimmune strains of mice. These results were extended in vivo by showing that the IL-7 treatment significantly increased the anti-CD3 triggered IL-4 production by NK1+ T spleen cells. These findings confirm the role of IL-7 in NK1+ T cell maturation and suggest that the NK1+ T cell defect in NOD mice could be related to insufficient intrathymic IL-7 bioavailability.

Early defect of immunoregulatory T cells in autoimmune diabetes.

A potential immunoregulatory function has recently been attributed to the discrete subset of major histocompatibility complex (MHC) class I-restricted TCR-alpha beta mature thymocytes expressing an unusual V beta 8-biased T cell receptor repertoire. This T cell subset which also selectively express the CD44 marker is the main IL-4 producer in the thymus. Nonobese diabetic (NOD) mice were found to have a marked deficit in the number and functional capacity of CD44+ TCR-alpha beta+ thymocytes from as early as 3 weeks of age. The deficiency in IL-4 production was completely corrected after incubation with interleukin-7 (IL-7), a selective growth factor for CD44+ TCR-alpha beta+ mature thymocytes. This abnormality in T cell differentiation could explain the Th2 functional deficiency that may be a key element in the emergence of Th1-driven autoimmune disease in NOD mice.