HLA Allele Associations and V‐Beta T‐Lymphocyte Expansions inPatients With Psoriasis, Harboring Toxin‐Producing Staphylococcus aureus

Abstract

HLA alleles have been associated with psoriasis. Toxin-producing strains of Staphylococcus aureus behave as superantigens, and if present in patients, might play a role in the exacerbation of psoriatic lesions by activating certain V-beta (Vβ) T-lymphocyte subsets. Allele frequencies in 22 patients and 22 controls (alleles determined by DNA/SSP typing) were used to calculate a relative risk of 4.7 (P < .05) for HLA-Cw6. S aureus was isolated from the throat of 11 patients. Enterotoxins A and C were detected by agglutination in the culture filtrate of one isolate. The enterotoxin A and/or C genes were detected by PCR in 9 isolates, and transcripts were detected by RT-PCR in 7 of them. None of the isolates from controls harbored enterotoxin genes. Vβ expansions were detected by RT-PCR in all 22 patients. Low or no Vβ expansions were obtained in controls. The association of HLA-Cw6 with psoriasis in Lebanese concurs with that reported for other ethnic groups. Toxin-producing isolates that colonize patients might play a role in the exacerbation of psoriatic lesions.

Bedeutung von Streptokokken für die Psoriasispathogenese

“…Ein Großteil der bei Psoriasispatienten isolierten Staphylokokkenstämme produziert staphylogene Exotoxine wie die "staphylococcal enterotoxins" A (SEA) oder B (SEB), oder das "toxic shock syndrome toxin-1" (TSST-1). Auch eine Rachenkolonisierung mit Enterotoxin-produzierenden Staphylococcus-aureus-Isolaten wurde nachgewiesen [1]. Die immunstimulierende Wirkung der Staphylokokkentoxine wird hierbei ähnlich wie beim atopischen Ekzem mit einer vermehrten unspezifischen immunologischen Aktivierung in Verbindung gebracht [56].…”

“…Die verschiedenen Untersuchungen und Beobachtungen zeigen, dass sowohl Patienten mit akut-exanthematischer als auch chronischer Plaquepsoriasis von einer Tonsillektomie profitieren können, wenn die PsoAbb. 1 9 Chronische Tonsillenhypertrophie bei Psoriasis mit rezidivierenden Streptokokkeninfektionen riasis und ihre Rezidive in direktem Zusammenhang mit einer akuten Streptokokkenangina oder einer chronischen Streptokokkenträgerschaft standen. Etwa zwei Drittel der Patienten erfuhren hierbei eine weitgehende Abheilung oder deutliche Besserung der Psoriasis mit länger-fristigen oder dauerhaften Remissionen in einem Beobachtungszeitraum von bis zu 5 Jahren [8,20,27,32,48].…”

Endosomal Toll-Like Receptors Mediate Enhancement of Interleukin-17A Production Triggered by Epstein-Barr Virus DNA in Mice

“…One of the most studied theories explaining how infections can be the cause of autoimmunity is molecular mimicry. This was suggested by Fujinami and Oldstone, who proposed that similarities between microbial and self-antigens on the molecular or structural level are the reason behind the cross-reactivity of T cells, B cells, and antibodies (11,62). Concerning EBV association with autoimmune diseases, several studies were conducted to explore the link between EBV infection and autoimmunity.…”

Factors involved in the pathogenesis of psoriasis

“…None of the isolates from healthy volunteers possessed enterotoxin genes. Moreover, Vβ expansions determined by RT-PCR were detected in all patients [60]. In an extension of this study Streptococcus B pyrogenic toxin gene was detected in five Streptococcus isolates obtained from psoriatic patients [32].…”