Mononuclear cells in atopic dermatitis in vivo: immunomodulation of the cutaneous infiltrate by medium-dose UVA1 phototherapy.

INTRODUCTION: Recently, medium-dose UVA1 phototherapy (50 J/cm2) has achieved great therapeutic success within the treatment of severe atopic dermatitis (AD). Histologically, AD is recognised by a pathological perivascular dermal infiltrate including T lymphocytes, eosinophils and Langerhans cells. The purpose of our study was to investigate the extent to which UVA1 irradiation is able to modulate the mononuclear dermal inflammatory infiltrate using different monoclonal antibodies. PATIENTS AND METHODS: Biopsy specimens before and after treatment with medium-dose UVA1 irradiation (cumulative dose: 750 J/cm2) from 15 patients suffering from severe AD were analysed immunohistochemically concerning the presence of CD4+ and CD8+ T lymphocytes, CD1a+ Langerhans cells and EG2+ activated eosinophils. RESULTS: Compared to lesional skin of patients with AD before UVA1 irradiation, the relative number of CD4+ cells, CD1a+ dendritic cells and activated EG2+ eosinophils within the dermal infiltrate could be decreased significantly after treatment. In contrast, medium-dose UVA1 phototherapy led to a significant increase of the percentage of dermal CD8+ cells. These alterations were closely linked to a decrease of the absolute skin-infiltrating cells and a substantial clinical improvement of the skin. CONCLUSIONS: In summary, our findings demonstrate that medium-dose UVA1 irradiation leads to a remarkable modulation of the dermal mononuclear infiltrate in patients with severe atopic dermatitis referring to a decrease of dermal Langerhans cells, activated eosinophils and CD4 cell count as well as to a relative increase of CD8+ lymphocytes. The immunomodulation of the cutaneous infiltrate is associated with a depletion of cytotoxic agents, the defective IgE overproduction and the aberrant presence of T lymphocytes combined with the pathological cytokine pattern.

Opposing effects of UVA1 phototherapy on the expression of bcl-2 and p53 in atopic dermatitis.

Recently, medium-dose UVA1 phototherapy (50 J/cm2) has been introduced as an effective treatment for severe atopic dermatitis (AD). In order to further elucidate the mechanisms by which medium-dose UVA1 irradiation leads to an improvement in skin status in patients with AD, biopsy specimens from ten patients before and after treatment were analysed immunohistochemically for features of apoptosis. We sought to determine the extent to which UVA1 irradiation was able to modulate the balance between p53 and bcl-2 expression in vivo using monoclonal antibodies labelling these proteins. As compared with lesional skin of patients with AD before UVA1 irradiation, the number of dermal cells, apparently lymphocytes, that were positive for p53 had significantly increased after treatment and, in addition, some basal keratinocytes showed slight positive staining for p53. An increased expression of the bcl-2 gene before treatment in predominately dermal lymphocytes was significantly downregulated by UVA1 therapy. The increase in p53+ cells and the decrease in bcl-2+ cells were closely linked to a significant reduction in dermal T cells (CD3+) and a substantial clinical improvement in skin condition. In summary, medium-dose UVA1 irradiation led to a marked modulation of the expression of p53 and bcl-2, and this plays a key role in regulating UVA1-induced apoptosis.

UVA1 irradiation induces deoxyribonuclease dependent apoptosis in cutaneous T-cell lymphoma in vivo.

Cutaneous T-cell lymphoma (CTCL) is a malignancy of mature T-cells, predominantly of the helper phenotype, that primarily invade the skin. Different photo- and chemotherapeutic treatments are known to be beneficial in early-stage CTCL. This observation has initiated prospective investigations into the efficacy of phototherapeutic regimens. The purpose of our study was to investigate the ability of medium-dose UVA1 phototherapy (60 J/cm2) to induce apoptosis (programmed cell death) in skin infiltrating T-cells of CTCL in vivo. We describe the results of three different staining methods for formalin-fixed, paraffin-embedded tissue sections. The in situ end-labeling (ISEL) procedure, nuclear staining using the DNA-binding fluorochrome Hoechst 33342, and immunohistochemistry using polyclonal antibodies against recombinant mouse deoxyribonuclease I (DNase I) demonstrated that UVA1 irradiation was able to induce marked apoptosis in CTCL. Thereby, ISEL and Hoechst staining clearly revealed DNA-condensation and nuclear fragmentation, accompanied by the formation of typical "apoptotic bodies". The accumulation of DNase I immunoreactivity in the cytoplasm of lymphocytes in UVA1 irradiated skin indicated that DNase I or DNase I-related endonucleases may have acted as apoptotic endonuclease(s) which were synthesized after UVA1 irradiation prior to their apoptotic elimination.

Medium-dose UVA1 cold-light phototherapy in the treatment of severe atopic dermatitis.

BACKGROUND: Recently, conventional high-dose UVA1 phototherapy (340-400 nm) has been shown to be more effective than combined UVA-UVB therapy in the treatment of severe atopic dermatitis (AD). However, there are limitations of this treatment, such as intense sweating caused by the immense heat load during therapy and the high cumulative UVA1 doses that are required. For this reason, lavish UVA1 equipment was developed containing an advanced filtering and cooling system resulting in almost complete absence of heat load and sweating during therapy. OBJECTIVE: In this study we compared the monotherapeutic efficacy of conventional medium-dose UVA1, medium-dose UVA1 cold-light, and combined UVA-UVB phototherapy in the treatment of severe AD. METHOD: The study involved 120 patients with severe AD. Fifty patients each received conventional UVA1 or UVA1 cold-light phototherapy (15 days, 50 J/cm(2)/day), and 20 patients were treated with combined UVA-UVB (15 days, minimal erythema dose dependent). Severity of AD was scored by means of the SCORAD score, and clinical improvement was additionally monitored by serologic cytokine markers. RESULTS: Six (12%) of 50 patients treated with UVA1, 2 (4%) of 50 patients treated with UVA1 cold-light therapy, and 4 (20%) of 20 patients treated with combined UVA-UVB therapy discontinued treatment prematurely because of an unsatisfactory clinical outcome or adverse reactions. Skin status improved or even cleared completely in 77.3% of the patients treated for 3 weeks with conventional UVA1 therapy and in 85.4% of the patients treated for 3 weeks with UVA1 cold-light therapy, resulting in a significant decrease in the SCORAD score in both UVA1 groups (P <.05 each). In the group treated with combined UVA-UVB, the SCORAD score also decreased but significantly less than in both groups treated with UVA1 photo-therapy (P <.05 each). At follow-up after 4 weeks, the patients treated with UVA1 displayed a more prolonged therapeutic benefit than the patients treated with UVA-UVB therapy. Plasma levels of soluble interleukin 2 receptors and soluble interleukin 4 receptors significantly decreased under both UVA1 and UVA1 cold-light phototherapy but not under combined UVA-UVB phototherapy. CONCLUSION: Our study demonstrates that medium-dose UVA1 cold-light phototherapy displays advantages compared with conventional UVA1 phototherapy caused by the almost complete absence of heat load and intense sweating and is more effective than UVA-UVB phototherapy in the treatment of severe AD.

[Balneologic photochemotherapy of prurigo simplex subacuta]. / Balneophotochemotherapie der Prurigo simplex subacuta.

Seventeen patients with extensive subacute prurigo, often resistant to different regimens of prior external and internal therapy, were treated with PUVA bath photochemotherapy (psoralen bath followed by UVA irradiation) using bath water containing 0.5 mg/l of 8-methoxypsoralen (8-MOP). In 15 of 17 patients treated, the skin lesions showed a significant improvement or even complete clearance within 8 weeks of therapy. In two patients, only limited clinical improvement was achieved. Follow-up after 6 weeks revealed sustained improvement in the successfully treated patients. The mean cumulative UVA dose given until clearance was 30.3 (SD +/- 12.6) J/cm2. Therefore, a mean of 24.1 (SD +/- 5.3) PUVA bath treatments was necessary. No side effects were seen except phototoxic reactions in two patients manifested as slight erythema. The results of this trial show that PUVA bath photochemotherapy with 8-MOP is an effective therapeutic alternative to other known therapies in subacute prurigo. Compared to oral PUVA therapy or other topical and systemic treatments, PUVA bath photochemotherapy with 8-MOP shows an excellent efficiency-side effect ratio. The clearance of chronic skin lesions refractive to other topical or systemic treatments by PUVA bath photochemotherapy with 8-MOP demonstrates that this therapy can be even superior to other common therapeutic modalities used for subacute prurigo.