Human herpesvirus 7 in dermatology: what role does it play?

Atypical exanthem with acral involvement in adult patients associated with human herpesvirus 7 active replication: A case series

An "atypical exanthem" (AE) is an eruptive skin eruption that differs in morphology and etiology from classical exanthems and is often a reason for urgent medical evaluation. The most frequent cause of AEs is a viral infection, but an accurate etiology cannot be established basing on the sole clinical features. Human herpesviruses (HHV) have been often suspected as etiologic agents or cofactors in atypical rashes. We performed a retrospective analysis of adult patients presenting an atypical exanthem associated with HHV-7 active replication in our center. The charts of patients were reviewed and the demographic, clinical and laboratory data collected. Nine patients (six males and three females) were included in the study, with a mean age of 43 years for men and of 26 years for women. All patients presented active HHV-7 replication in plasma during the rash, which turned negative after the exanthem resolved. The exanthem displayed a maculopapular pattern involving the trunk, limbs and, notably, the acral regions, in six patients. In three cases the exanthem was confined to only the acral sites. In most cases, there was no fever and the inflammatory indices remained unchanged. Antihistamines, topical and systemic corticosteroids were used as treatment, with excellent symptom control. We propose adding skin manifestation associated with HHV-7 to the concept of atypical exanthems, in particular those localized to the acral regions.

Toxic epidermal necrolysis induced by human herpesvirus 7 treated with a tumor necrosis factor-α inhibitor

Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) is a life-threatening hypersensitivity reaction. Long-term sequelae include dry eyes, visual impairment and psychological complications. TEN is mostly induced by medication; however, viral infections, such as coxsackievirus A6, are known triggers of this disease. However, how to define the role of infection in SJS/TEN is still a problem. Most patients develop SJS/TEN over the course of symptoms of the infection first, and then take medication. Therefore, virus culture and nucleic acid detection at the acute stage cannot predict that the virus itself will indeed produce such a serious reaction. Furthermore, many SJS/TEN patients who are diagnosed with an infection are afraid of receiving the drug rechallenge test. Thus, we report the first case worldwide of a patient who suffered from TEN caused by herpesvirus 7 infection, which was confirmed by both real-time polymerase chain reaction and lymphocyte transformation test.

[Development of a set of reagents for detection of class G immunoglobulins to human herpes virus type 7 by the method of immune blotting in the format «Western blot».]

A new original domestic set of reagents has been developed for the determination of class G immunoglobulins to individual human herpes virus antigens of type 7 by the method of immune blotting in the "Western-blot" format. Preliminary clinical trials were conducted using 134 serums of healthy children aged 1-16 years who underwent diagnostic testing. Stud y of diagnostic efficiency ofthe new kit showed high sensitivity, comparable to the sensitivity of the reaction indirect immunofluorescence and high specificity, which is manifested in the absence of false positive results when testing samples containing immunoglobulin G to herpes virus 6 type.

Pityriasis Rosea, Gianotti-Crosti Syndrome, Asymmetric Periflexural Exanthem, Papular-Purpuric Gloves and Socks Syndrome, Eruptive Pseudoangiomatosis, and Eruptive Hypomelanosis: Do Their Epidemiological Data Substantiate Infectious Etiologies?

Many clinical and laboratory-based studies have been reported for skin rashes which may be due to viral infections, namely pityriasis rosea (PR), Gianotti-Crosti syndrome (GCS), asymmetric periflexural exanthem/unilateral laterothoracic exanthem (APE/ULE), papular-purpuric gloves and socks syndrome (PPGSS), and eruptive pseudo-angiomatosis (EP). Eruptive hypomelanosis (EH) is a newly discovered paraviral rash. Novel tools are now available to investigate the epidemiology of these rashes. To retrieve epidemiological data of these exanthema and analyze whether such substantiates or refutes infectious etiologies. We searched for articles published over the last 60 years and indexed by PubMed database. We then analyzed them for universality, demography, concurrent patients, temporal and spatial-temporal clustering, mini-epidemics, epidemics, and other clinical and geographical associations. Based on our criteria, we selected 55, 60, 29, 36, 20, and 4 articles for PR, GCS, APE/ULE, PPGSS, EP, and EH respectively. Universality or multiple-continental reports are found for all exanthema except EH. The ages of patients are compatible with infectious causes for PR, GCS, APE/ULE, and EH. Concurrent patients are reported for all. Significant patient clustering is demonstrated for PR and GCS. Mini-epidemics and epidemics have been reported for GCS, EP, and EH. The current epidemiological data supports, to a moderate extent, that PR, GCS, and APE could be caused by infectious agents. Support for PPGSS is marginal. Epidemiological evidences for infectious origins for EP and EH are inadequate. There might be growing epidemiological evidence to substantiate or to refute our findings in the future.

Hematopoietic cell transplantation and emerging viral infections

Viral infections remain important causes of morbidity and mortality in hematopoietic cell transplant recipients. More recent developments in preparative regimens and graft manipulations, as well as the control of well-recognized post-transplant infections by the introduction of prophylaxis and preemptive strategies, have influenced the timing and the epidemiology of infections. As new pathogens, such as human metapneumovirus (HMPV), human bocavirus, human coronaviruses HCoV-NL63 and HCoV-HKU1, human herpesviruses HHV-6 and HHV-7, and polyomaviruses, have emerged, it is fundamental to determine the significance of the newly discovered viruses and their role in the transplantation field. This article summarizes recent data on epidemiology and laboratory diagnosis of new pathogens, as well as clinical features and management of the associated infectious complications. J. Med. Virol. 82:528-538, 2010. (c) 2010 Wiley-Liss, Inc.

Development of a LUX real-time PCR for the detection and quantification of human herpesvirus 7

Human herpesvirus 7 is a highly seroprevalent beta-herpesvirus that, following primary infection, remains latent in CD4+ T cells and determines a persistent rather than a latent infection in various tissues and organs, including the lung and skin. This paper describes the development of an in-house light upon extension real-time PCR assay for quantification of human herpesvirus 7 DNA in clinical samples. The efficiency, sensitivity, specificity, inter- and intra-assay variability, and dynamic range have been determined. Subsequently, the assay has been validated by evaluating the human herpesvirus 7 load in bronchoalveolar lavages and skin specimens, chosen as 2 persistency sites, from healthy and pathological individuals. The real-time PCR assay developed in this study could be a useful tool to detect and quantify human herpesvirus 7 DNA in different clinical specimens to elucidate its epidemiological and pathogenic roles.

Human herpesvirus 7 detection by quantitative real time polymerase chain reaction in primary cutaneous T-cell lymphomas and healthy subjects: lack of a pathogenic role

BACKGROUND

Primary cutaneous T-cell lymphomas (CTCLs) are a heterogeneous group of lymphomas where the tumour population emerges within a multiple subclone pattern. Mycosis fungoides (MF) and Sézary syndrome (SS) are characterized by the expansion of clonal CD4+/CD45RO+ memory T cells. Lymphomatoid papulosis (LyP) is a chronic, lymphoproliferative disorder included in the CD30+ primary CTCL spectrum. Several studies have suggested a role of viral infection for super-antigenic activation of T lymphocytes; however, evidence of their association with CTCLs is still lacking. Human herpesvirus (HHV) 7 is a CD4+ T-lymphotropic herpesvirus; its restricted cellular tropism and the ability to induce cytokine production in infected cells could make it an important pathogenic cofactor in lymphoproliferative disorders.

OBJECTIVES

To investigate the presence of HHV7 DNA on CTCL and healthy skin donors (HD).

METHODS

We used quantitative real time polymerase chain reaction to evaluate the potential pathogenic role of HHV7.

RESULTS

Twenty-seven of 84 (32.1%) HD were positive for HHV7 DNA. Twenty-one of 148 (14.2%) patients with CTCLs were positive for HHV7 DNA: nine of 39 (23.1%) SS, six of 14 (42.9%) CD30+ CTCLs and six of 24 (25.0%) LyP, and HHV7 DNA was negative in all 71 patients with MF.

CONCLUSIONS

These results seem to exclude a pathogenic role of HHV7 in CTCLs, suggesting the possibility of skin as a latency site.

Is human herpesvirus 7 the causative agent of pityriasis rosea?--A critical review

BACKGROUND

Conflicting results on the association of pityriasis rosea and human herpesvirus 7 infection have been reported by different investigators.

AIM

To review the level of evidence for such an association.

METHODS

Medline was searched with unlimited data entry and 13 reports were retrieved. The data were analyzed for a causative association according to the criteria of Fredericks and Relman, which take into consideration latent infection and the reactivation of viruses characteristic of herpesviruses, and the roles of sequence-based detection methods.

RESULTS

None of the criteria was substantiated by the findings of most investigators. Factors leading to the discrepancies of the results were discussed.

CONCLUSION

There is currently insufficient evidence that human herpesvirus 7 infection is causally related to pityriasis rosea.

The role of human herpes virus 6 and 7 in the pathogenesis of pityriasis rosea

Pityriasis rosea (PR) is an acute exanthematous inflammatory skin disease in which many epidemiological studies suggest a viral infection in its pathogenesis. Several viruses such as picornaviruses, parvoviruses and herpes viruses were accused as causative agents in PR. Human herpes virus-6 (HHV-6) and HHV-7 are newly discovered members of herpesviridae family. Several diseases including roseola infantum and PR have been linked with HHV-6 and HHV-7 in dermatology. We aimed to investigate the role of HHV-6 and HHV-7 in the pathogenesis of PR. Blood samples from 35 patients with acute PR and 30 healthy volunteers were examined to obtain titres for HHV-6 and HHV-7 antibodies. Anti-HHV-6 and -HHV-7 immunoglobulin (Ig) G antibodies were detected by IFA. The high titres of anti-HHV-6 IgG were determined in four patients and anti-HHV-7 IgG in only two of four patients. In our study, we haven't found any significant relationship between HHV-6, HHV-7 and PR. Our results were supported with the data of several previous studies.