ABSTRACT
BACKGROUND: We have previously found that psoriatic patients have IgG autoantibodies that recognize lesions but not autologous normal skin. The reactivity of the autoantibodies can be adsorbed with streptococcal antigens. METHODS: IgG antibodies were determined by immunoblot and ELISA to streptococcal antigens and by ELISA to the recombinants HSP60Sp, HSP70Sp, HSP60Ec and HSP60Hu, in plaque (PP) and guttate (GP) psoriasis patients, in healthy subjects (HC) and in individuals with streptococcal throat infections and high ASO titers, but without history of dermatological disease (ISp). RESULTS: We found by immunoblot that the IgG response to 71-, 60-, and 14-kDa protein fractions of Streptococcus pyogenes is important in psoriasis. We also found by ELISA that the response to the rHSP60Sp in PP was higher than in all the other three groups studied (P < 0.05) with an odds ratio of 11.11 (CI95% of 4.33-28.49). The PP infected with S. pyogenes had higher titers of the antirHSP60Sp, high ASO, and high PASI. The PP patients did not significantly recognize the HSP60Ec or the HSP60Hu. The GP patients had a higher response to the rHSP60Sp than the healthy controls or ISp patients (P < 0.05) but showed no association with the disease. The response of the ISp patients to the HSP60Sp was similar to the healthy controls. The response to the rHSP70Sp was similar in the PP patients and the healthy controls. CONCLUSION: Results suggest that a high response to the HSP60Sp could be associated with the chronic form of psoriasis.
Subject(s)
Antibodies, Bacterial/analysis , Antigens, Bacterial/immunology , Heat-Shock Proteins/immunology , Immunoglobulin G/analysis , Psoriasis/microbiology , Streptococcus pyogenes/immunology , Case-Control Studies , Enzyme-Linked Immunosorbent Assay , Humans , Immunoblotting , Psoriasis/immunology , Streptococcus pyogenes/geneticsABSTRACT
Although several cytokines and their receptors have been involved in the development of psoriasis, the etiology is still unknown. In this study we looked for genes possibly involved in the disease by the reverse transcription-polymerase chain reaction differential display technique in lesional and nonlesional skin biopsies from psoriatic patients. We found the mRNA of the alpha1 chain of the interleukin-13 receptor expressed differentially in psoriatic biopsies. By reverse transcription-polymerase chain reaction, we confirmed an overexpression of the alpha1 chain of the IL-13 receptor and alpha chain of the interleukin-4 receptor mRNA in lesional skin psoriatic biopsies, when compared with skin biopsies from healthy subjects (p<0.01). The nonlesional skin obtained from a region close to a lesional zone in psoriatic patients presented also an overexpression of these mRNA in 50% of the samples. Interleukin-13 and interleukin-4 were not detected either as mRNA or as the proteins in any of the biopsies from psoriatic patients or healthy subjects. A monoclonal antibody to the alpha1 chain of the interleukin-13 receptor detected the receptor in the epidermal keratinocytes of psoriatic patients and of healthy subjects; however, the positive antibody reaction was stronger in skin tissue from healthy subjects than in psoriatic lesional skin tissue (p<0.01), although the mRNA was overexpressed. As interleukin-13 is a pleiotropic immunoregulatory cytokine with a variety of effects on different cell types, including monocytes, B lymphocytes, mast cells, and keratinocytes, we suggest, based on our results, that the interleukin-13 receptor possibly plays an important part in the early inflammatory process of psoriasis; however, its function is lost in the psoriatic keratinocytes.
