PUVA Therapy and Human Papillomavirus Type 5 Detection in Psoriasis

Abstract

To the Editor: Michel Favre et al. reported in this Journal a high prevalence of human papillomavirus 5 (HPV5) infection in psoriatic patients and proposed that psoriasis is a reservoir for this virus (Favre et al., 1998Favre M. Orth G. Majewski S. Baloul S. Pura A. Jablonska S. Psoriasis: a possible reservoir for human papillomavirus type 5, the virus associated with skin carcinomas of epidermodysplasia verruciformis.J Invest Dermatol. 1998; 110: 311-317Abstract Full Text Full Text PDF PubMed Scopus (139) Google Scholar). These conclusions were based on (i) the presence of antibodies against HPV5 VLP in 24.5% of 155 psoriatic patients, contrasting with the 2%–5% observed in the two other groups (atopic dermatitis and renal transplant recipients); (ii) the detection of HPV5 DNA sequences by nested polymerase chain reaction in lesional and uninvolved skin of 91.9% psoriatic patients and in no patient in the atopic dermatitis group, respectively. These results are very exciting but we question whether the high prevalence of HPV5 infection is related to the psoriasis itself or to a possible irradiation with ultraviolet (UV) via phototherapy. Indeed, Bayle-Lebey et al. have already reported the detection of HPV5 DNA sequences in a keratosic skin lesion in a psoriatic patient, although this patient had been treated for a long time with UVA phototherapy (Bayle-Lebey et al., 1994Bayle-Lebey P. Labadie F. Basset-Seguin N. Bazex J. Carcinomes cutanés et papillomavirus 5. Révélation lors d’une photochimiothérapie UVA prolongée.Ann Dermatol Venereol. 1994; 121: 496-498PubMed Google Scholar). Unfortunately, data on the previous treatments of Favre psoriatic patients are unknown. Moreover, the reported detection of HPV DNA sequences in both involved and nonlesional skin in psoriatic patients suggests the role of an extrinsic factor such as UV. The role of UV in epidermodysplasia verruciformis (EV) is well known (Orth, 1987Orth G. Epidermodysplasia verruciformis.in: Howley P.M. Salzman N.P. The Papillomaviruses. Vol. 2. New York, Plenum Press1987: 199-243Google Scholar), and excessive sun exposure is avoided in EV patients. Pityriasis versicolor-like skin lesions observed in EV and associated with HPV infection are particularly located in sun-exposed areas. The role of UV is clearly demonstrated in the induction of HPV5-associated skin carcinomas in EV and in renal transplant recipients. Few data are available concerning the search of EV-associated HPV infection in patients under phototherapy. Spradbrow et al. reported the presence of a possible papillomavirus in sun-exposed skin (Spradbrow et al., 1983Spradbrow P.B. Beardmore G.L. Francis J. Virions resembling papillomaviruses in hyperkeratotic lesions for sun damaged skin.Lancet. 1983; 1PubMed Google Scholar); but most reported data are related to HPV16. UV may act either via a local immunosuppression that could facilitate HPV DNA replication, or transcription of HPV. It can be hypothesized that EV-related HPV are widespread and that some factors such as local (UV) or general immunosuppression (EV, immunosuppressive agents, AIDS) may facilitate their replication and/or persistence. On the other hand, it is difficult to understand the general good efficiency of phototherapy in psoriatic patients and its detrimental effect in EV patients if EV-related HPV play a pathogenic role in these two disorders. If the high prevalence of EV-related HPV in psoriasis was confirmed, the use of phototherapy or immunosuppressive agents might be reconsidered. It would be of interest to look for an HPV5 infection in other skin disorders such as mycosis fongoid or prurigo, which are currently treated with phototherapy. Department of Dermatology, Bichat Hospital, Paris, France