Acne Vulgaris Related Microbiology and Serology
Condition: Acne Vulgaris
MeSH terms: Acne Vulgaris
Study type: Observational

Summary: 
      This will be an investigation to determine the quality of the serological immune responses
      against Propionibacterium acnes (P. acnes) in acne patients compared to healthy individuals.
      In particular, the investigators will measure serum antibody titers against P. acnes surface
      antigens, and the efficiency of antibody-mediated phagocytic killing of P. acnes.
    

Detailed description: 
      Acne vulgaris, which affects >85% of teenagers and >10% of adults, was recently re-defined as
      a complex chronic disease associated with Propionibacterium acnes (P. acnes). Until recently,
      the pathogenic role of bacteria Propionibacterium acnes (P. acnes) has been debated due to
      the fact that this bacterium is also found, although in lower density, on the skin of healthy
      individuals. However, in the last few years, genomic sequencing and the comparative analysis
      of >250 P. acnes strains revealed the existence of the strains prevalently associated with
      severe cases of acne. In the study that analyzed more than 200 clinical isolates, it was
      found that 75% of the P. acnes strains that were isolated from acne lesions of acne patients,
      belonged to genetic type I-IA and that this group also represented 85% of the antibiotic
      resistant P. acnes strains isolated in the course of the study. This provided the first clear
      evidence for the virulent potential of P. acnes, that has been previously suspected also in
      some cases of eye, bone and post-operative infections. More recent research studies have
      identified additional virulent strains which can be distinguished based on the ribosomal DNA
      analysis.

      Although these genetic studies have revealed the existence of virulent P. acnes strains, it
      is not yet clear how these strains promote disease pathogenesis and symptoms, and whether the
      host immune response either exaggerates or ameliorates the disease. In particular, there have
      been no systematic studies regarding the role of a central immunity in the protection against
      this pathogen.

      Therefore, this will be one of the first studies to address scientifically and
      therapeutically important questions including:

        1. Immunogenicity of P. acnes in the acne patients compared to healthy individuals who are
           recovered from moderate or severe acne vulgaris.

        2. The role of antibodies in controlling colonization and acne development due to P. acnes

        3. The relationship between P. acnes genetic information and serotype classification, based
           on the immune recognition pattern (the degree of the similarity among genetically
           different strains based on the surface components recognition by the immune system)
           Answering these questions could support development of novel and better treatment
           options, which could significantly improve the outcome in acne vulgaris patients.
           Existing acne treatments either treat the symptoms only on skin surface (e.g. topical
           agents: creams, lotions), or are not offering long-term solutions (antibiotics, vitamin
           A derivatives). Moreover, antibiotics raise antibiotic resistance among P. acnes as well
           as other types of bacteria and increase the risk of super-infection by other pathogens.
           Vitamin A derivatives are not effective in all patients and post-therapy relapse is
           common; besides, they are not routinely prescribed to patients due to serious side
           effects.
    

Intervention name(s): Study of humoral immunity
Intervention type(s): Diagnostic Test
Intervention description(s): Analysis: Surface antigen ELISA, recognition of living P. acnes bacteria via FACS, 16SRNA study of microbiome, SLST typing of P. acnes bacteria
Other intervention name(s): Study of skin microbiome
Observational model: Cohort
Time perspective: Other
Sampling method: Probability Sample
Study population: 
        Subjects for the study will be drawn from:

          -  Study group: Acne patients, 18-40 years of age, currently suffering from moderate or
             severe acne vulgaris

          -  Control group: Healthy individuals of 18-40 years of age, who recovered from moderate
             or severe acne vulgaris
      
Biospecimen description: 
      Patient serum samples and facial swabs for microbiome analysis
    
Keywords: P. acnes; acne vulgaris; humoral immune response; microbiome; SLST