Human interferon-γ induces expression of HLA-DR on keratinocytes and melanocytes

Summary Primary human epidermal cell cultures composed of keratinocytes and melanocytes were exposed to supernatants of phytohaemagglutinin (PHA)-stimulated T cells, various lymphokines and interferon-, and checked for the emergence of HLA-DR antigen using immunofluorescence and immunoelectron microscopy. HLA-DR expression was induced by the supernatants and human recombinant interferon- (rIFN-), whereas recombinant ₂, interleukin-2 and non-recombinant human interferon- had no such effect. The threshold concentration of rIFN- required to induce this phenomenon was 10 IU/ml; no further increase of reaction intensity was observed using doses of more than 100 IU/ml. Maximum reaction intensity was achieved after 72 h of incubation; a minimum of 3 h of incubation with rIFN- followed by 72 h incubation in rIFN--free medium proved sufficient to induce HLA-DR expression. The inductive effect of the supernatants and rIFN- could be completely abrogated by pretreatment with excess doses of the monoclonal antibody GZ4 specific for human IFN-. Keratinocytes and melanocytes reacted in an identical fashion both qualitatively and quantitatively in all experiments. These data indicate that IFN- possesses specific signal functions in the induction of HLA-DR expression on epidermal cells.Abbreviations IFN- interferon- - rIFN- recombinant interferon- - r IFN-₂ recombinant interferon-₂ - nrIFN- nonrecombinant interferon- - IL-2 interleukin-2 - EC epidermal cells - K keratinocytes - M melanocytes     

Contact allergy to 4-isopropyl dibenzoylmethane and 3-(4''-methylbenzylidene) camphor in the sunscreen Eusolex 8021

10 cases of contact allergy from the sunscreen Eusolex 8021 are reported. 5 patients were sensitized to a lipstick, 4 to a sunscreen cream, and 1 reacted to several cosmetic creams. Of 9 patients tested with the 2 ingredients of Eusolex 8021, 5 proved to be allergic to both (chemically unrelated) constituents: 4-isopropyl-dibenzoylmethane and 3-(4'-methylbenzylidene) camphor; 4 were allergic to 4-isopropyl-dibenzoylmethane only. Contact allergy to this recently introduced broad spectrum sunscreen may not be rare. The relevant literature is reviewed.     

Immediate and delayed photocontact dermatitis from isopropyl dibenzoylmethane

Immediate and delayed photocontact dermatitis from the UVA absorber isopropyl dibenzoylmethane is described in 1 patient. In a dose response study in a 2nd patient with delayed photocontact dermatitis, the minimal dose of UVA needed to elicit a positive photopatch to isopropyl dibenzoylmethane 2% was determined to be 2 J/cm2.     

Evaluation of customers'' complaints about sunscreen cosmetics sold by the Swedish pharmaceutical company

Sweden's pharmacies hold more than a 1/3 of the country's market for sunscreen cosmetics (sunscreens). Customers complaining of skin problems associated with the use of sunscreens obtained from the pharmacies were offered dermatological investigation and tests with standard allergens and sunscreens. 27 of 58 complaining customers were fully investigated, and another 8 partly tested. 2 disease entities, a burning sensation and erythema for one or a few days, and dermatitis with scaling lasting for up to 3 weeks, were about equally common. Contact or photocontact allergy to 2-hydroxy-4-methoxybenzophenone caused severe contact dermatitis in 3 individuals.