Circulating cell-free DNA levels in Portuguese patients with psoriasis vulgaris according to severity and therapy.
BACKGROUND
Inflammation has a key role in the pathogenesis of psoriasis. Circulating cell-free DNA (CFD) is a marker of tissue cell damage closely associated with inflammation.


OBJECTIVE
We aimed to understand the relation of CFD levels with psoriasis severity, defined by the Psoriasis Area and Severity Index (PASI), with inflammation and with psoriasis therapy.


METHODS
Forty-six patients with psoriasis vulgaris were evaluated before (T0) and after 12 weeks (T12) of treatment with narrowband ultraviolet light B (NB-UVB; n = 17), psoralen plus UVA (PUVA; n = 20) or topical therapy (n = 9). We evaluated interleukin (IL)-6 and circulating CFD levels.


RESULTS
Compared with controls, at T0, patients presented significantly higher levels of circulating CFD. CFD presented a significant positive correlation with IL-6 and a trend towards a positive correlation with PASI. Multiple linear regression analysis identified IL-6 as an independent variable associated with CFD circulating levels. As shown by the PASI score, a trend towards higher values of CFD was observed in the severe psoriasis forms; moderate and severe psoriasis presented also significantly higher CFD values, compared with control. Both NB-UVB and PUVA treatments significantly decreased the levels of CFD.


CONCLUSIONS
Patients with psoriasis, at the active stage of the disease, presented an increased inflammation associated with raised circulating CFD levels, which seem to be linked to psoriasis severity. Both NB-UVB and PUVA, anti-inflammatory therapies, were effective in decreasing CFD values. We propose that the evaluation of circulating CFD may provide a new biomarker to monitor psoriasis, its severity and its treatment.
Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Rua Campo Alegre 823, Porto, 4150, Portugal; CESPU, Instituto de Investigação e Formação Avançada em Ciências e Tecnologias da Saúde, Gandra-PRD, Portugal.
S
S
Coimbra
C
C
Catarino
E
E
Costa
H
H
Oliveira
A
A
Figueiredo
P
P
Rocha-Pereira
A
A
Santos-Silva
D000328:Adult; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D016022:Case-Control Studies; D004247:DNA / Q000378:metabolism*; D003879:Dermatologic Agents / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D015850:Interleukin-6 / Q000378:metabolism; D008297:Male; D011701:PUVA Therapy; D011565:Psoriasis / Q000378:metabolism / Q000628:therapy*; D012720:Severity of Illness Index; D014467:Ultraviolet Therapy
D000893:Anti-Inflammatory Agents; D015415:Biomarkers; D003879:Dermatologic Agents; D015850:Interleukin-6; D004247:DNA