Ultraviolet radiation is a pathogenic factor in various diseases, e. g., autoimmune disorders such as lupus erythematosus. On the other hand, endogenous retroviruses are discussed as etiologic agents in lupus erythematosus. Therefore, we investigated the influence of ultraviolet irradiation on expression of human endogenous retroviral sequences and human endogenous retroviral sequence promoter-driven transcription of cellular genes using human epidermal keratinocytes as a model system. First, conserved sequences of endogenous retroviral pol genes were amplified from cellular mRNA by reverse transcriptase polymerase chain reaction with degenerate oligonucleotide primers. Polymerase chain reaction products were hybridized in a reverse dot blot hybridization assay to a representative number of distinct cloned human endogenous retroviral pol fragments. Using this method, we could show that irradiation with 30 mJ per cm2 ultraviolet B activates transcription of various endogenous retroviral pol sequences in primary epidermal keratinocytes as well as in a spontaneously immortalized keratinocyte cell line (HaCaT). Interestingly, some of these sequences were found to be closely related to pol sequences of human endogenous retroviral sequences which have been shown to be expressed in autoimmune patients. Analysis of human endogenous retroviral pol expression in vivo using skin biopsies of lupus erythematosus patients revealed similar activation patterns. In a second approach, ultraviolet B- induced chimeric transcripts were isolated which are initiated by human endogenous retroviral promoters and proceed into cellular sequences using a newly established modified differential display polymerase chain reaction technique. The activation of human endogenous retroviral sequence transcription by ultraviolet B may contribute to the pathogenesis of lupus erythematosus, where inappropriate antigenic presentation of ultraviolet B-induced viral and cellular proteins could stimulate autoantibody production.
Thalidomide is a potent anti-inflammatory drug in patients with SLE and cutaneous LE, possibly interacting with the recruitment of lymphocytes. It leads to the regrowth of hair in LE-related alopecia and effluvium. Early symptoms of polyneuropathy should be registered and the drug should be withdrawn. Thalidomide should be restricted to patients who show no response to standard therapeutic regimens and should only be used under strict precautions with regard to its known teratogenic risk.
Sixteen patients with generalized granuloma anulare and two patients with localized granuloma anulare received bath-PUVA therapy. Their lesions previously had not responded to conventional therapy. After an average of 55 (11 to 61) treatments and a mean cumulative dose of 69.5 (7.1 to 261.5) J/cm2, complete remission was observed in 5 patients and a clear improvement in 10 patients. Three patients stopped therapy after few treatments. Recurrent lesions appeared in 4 patients; in three of them reinitiation of the bath-PUVA-therapy again led to complete remission. Maintenance therapy for several months may be useful for patients suffering from relapsing granuloma anulare. Potential risks of long-lasting bath-PUVA therapy should be taken into consideration.
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