Acta Dermato-Venereologica 97-6 97-6CompleteContent | Page 8

685 INVESTIGATIVE REPORT Skin Microbiome in Small- and Large-plaque Parapsoriasis Alexander SALAVA 1 , Pedro PEREIRA 2 , Velma AHO 2 , Liisa VÄKEVÄ 1 , Lars PAULIN 2 , Petri AUVINEN 2 , Annamari RANKI 1 and Antti LAUERMA 1 Department of Dermatology and Allergology, University of Helsinki, and Helsinki University Hospital, and 2 Institute of Biotechnology, DNA Sequencing and Genomics Laboratory, University of Helsinki, Helsinki, Finland 1 Staphylococcal enterotoxins have been shown to pro- mote lymphoma-associated immune dysregulation. This study examined changes in the skin microbiome of parapsoriasis compared with intact skin. Swab mi- crobiome specimens were taken of the parapsoriasis lesions of 13 patients. Control samples were taken from contralateral healthy sides of the body. Micro- biotas were characterized by sequencing the V1–V3 region of the 16S ribosomal RNA bacterial genes on the Illumina MiSeq platform. The most common ge- nera in the microbiome data were Propionibacterium (27.13%), Corynebacterium (21.20%) and Staphylo- coccus (4.63%). Out of the Staphylococcus sequences, 39.6% represented S. epidermidis, with the rest inclu- ding S. hominis, S. capitis and unidentified species. No significant differences were observed between the patients’ parapsoriasis and contralateral healthy skin or between large- and small-plaque parapsoriasis. No- table interpersonal variation was demonstrated. The- se results suggest that parapsoriasis is not associated with significant alterations in the cutaneous bacterial microbiome. Key words: skin microbiome; cutaneous microbial diversity; cutaneous microbes; large-plaque parapsoriasis; small-plaque parapsoriasis; cutaneous T-cell lymphoma. Accepted Feb 7, 2017; Epub ahead of print Feb 8, 2017 Acta Derm Venereol 2017; 97: 685–691. Corr: Alexander Salava, Department of Dermatology and Allergology, Helsinki University Hospital, Meilahdentie 2, FIN-00029 Helsinki, Finland. E-mail: [email protected] N ovel molecular techniques have greatly improved our knowledge of the skin microbiome (1). Genomic studies with targeted sequencing of parts of the gene co- ding for ribosomal 16S RNA have shown that cutaneous microbial colonization is more complex than previously thought (2). Studies characterizing the microbiota of different body sites in humans have revealed that the spectrum of micro-organisms varies depending on nu- merous intrinsic and extrinsic factors (3–5). Common skin diseases, such as atopic dermatitis, have been linked to specific changes in the microbiome (6, 7). However, it remains unclear whether these changes are caused by microbes, or are secondary to factors such as changes in the skin barrier or immunological factors (8). Parapsoriasis refers to a group of cutaneous lympho­ proliferative disorders, ranging from a chronic dermati- tis-like picture at one end to a picture mimicking patch- stage cutaneous T-cell lymphoma (CTCL) at the other (9). Clinical findings are traditionally used to classify the disease into small-plaque parapsoriasis (SPP), i.e. clas- sical digitate dermatitis, and large-plaque parapso