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Recognition of Streptococcus pyogenes and skin autoantigens in guttate psoriasis
G Villeda-Gabriel1, L C Santamaría-Cogollos, R Pérez-Lorenzo
1Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional (IPN), México, D.F.
Background:
Guttate psoriasis is associated with infections by Streptococcus pyogenes and cross-reactions between skin and streptococcal antigens have been reported, suggesting an autoimmune component in the disease.
Methods:
In this work, the authors looked for antibodies against S. pyogenes M-5 antigens by immunoblot in 52 sera of psoriasis patients and in 52 sera of normal individuals. Histological and immunohistochemical analysis in skin biopsies from lesions of another group of 16 clinically diagnosed guttate psoriasis patients and four healthy controls were also carried out.
Results:
All guttate psoriasis patients studied (11) had IgG antibodies that intensively recognized three different proteins of 70, 60 and 14 kDa, as compared to sera from patients with other forms of psoriasis or from healthy controls. The diagnosis of psoriasis was confirmed in 14 of the patients by hematoxylineosin staining. Of the other two patients, one was diagnosed as parapsoriasis and the other as liquen. By indirect immunofluorescence (IFI), all 14 psoriatic patients had autoantibodies against their own lesional skin that did not recognize normal skin from control subjects or from the two non-psoriatic patients. The parapsoriatic and the liquen patients did not have autoantibodies. A rabbit immune serum against S. pyogenes antigens reacted with lesional skin from the 14 guttate psoriatic patients, but not with normal skin from controls or with lesional skin from the 2 non-psoriatic patients.
Conclusions:
The recognition by immunoblot of streptococcal antigens by serum of guttate psoriasis patients, the presence of autoantibodies against their own skin, and recognition of the same skin antigens by anti-streptococcal rabbit antibodies confirm the participation of the immune system and of streptococcal infections in guttate psoriasis.
Insights
Guttate psoriasis patients show antibodies against Streptococcus pyogenes and their own skin, indicating an autoimmune link to infections. This study confirms the immune system
Area of Science:
- Immunodermatology
- Microbial immunology
- Autoimmunity
Background:
- Guttate psoriasis is frequently linked to Streptococcus pyogenes infections.
- Previous reports suggest cross-reactivity between skin and streptococcal antigens.
- This points to a potential autoimmune mechanism in guttate psoriasis pathogenesis.
Purpose of the Study:
- To investigate the presence of antibodies against Streptococcus pyogenes antigens in guttate psoriasis patients.
- To examine autoantibodies targeting lesional skin in guttate psoriasis.
- To explore the role of the immune system and streptococcal infections in guttate psoriasis.
Main Methods:
- Immunoblot analysis of patient sera against Streptococcus pyogenes M-5 antigens.
- Histological and immunohistochemical analysis of skin biopsies from guttate psoriasis lesions.
- Indirect immunofluorescence (IFI) to detect autoantibodies against lesional skin.
Main Results:
- Guttate psoriasis patients exhibited IgG antibodies recognizing specific S. pyogenes proteins (70, 60, 14 kDa).
- All psoriatic patients displayed autoantibodies against their own lesional skin, not normal skin.
- Anti-streptococcal antibodies cross-reacted with antigens in lesional skin of guttate psoriasis patients.
Conclusions:
- The study confirms the involvement of the immune system in guttate psoriasis.
- Streptococcal infections play a significant role in the disease's autoimmune component.
- Specific streptococcal antigens may trigger autoimmune responses in susceptible individuals.