iRHOM2: A Regulator of Palmoplantar Biology, Inflammation, and Viral Susceptibility

The palmoplantar epidermis is a specialized area of the skin that undergoes high levels of mechanical stress. The palmoplantar keratinization and esophageal cancer syndrome, tylosis with esophageal cancer, is linked to mutations in RHBDF2 encoding the proteolytically inactive rhomboid protein, iRhom2. Subsequently, iRhom2 was found to affect palmoplantar thickening to modulate the stress keratin response and to mediate context-dependent stress pathways by p63. iRhom2 is also a direct regulator of the sheddase, ADAM17, and the antiviral adaptor protein, stimulator of IFN genes. In this perspective, the pleiotropic functions of iRhom2 are discussed with respect to the skin, inflammation, and the antiviral response.

Cutaneous cytomegalovirus manifestations, diagnosis, and treatment: a review

The possible presentations of cytomegalovirus (CMV) are vast not only in its systemic manifestations, but also in the various cutaneous lesions that may result. Cutaneous cytomegalovirus is rarely reported in the literature because the clinical and pathologic features can be difficult to identify. Its identification, however, is vital as cutaneous human CMV infection can signal systemic disease and an unfavorable prognosis. The objective of this study is to aid in recognition, diagnosis, and treatment of CMV according to dermatological evidence. A complete literature search was performed within PubMed, resulting in the inclusion of 58 patient cases. The most common dermatologic manifestation was perianal or oral ulcers, but the locations and types of lesions noted throughout the review were numerous. Treatment is often simple, yet incorrect diagnoses along with concurrent illnesses can often complicate management. It is imperative for CMV to be detected early in its course to prevent mortality, especially in the immunocompromised. Dermatological presentations are often the first sign of this deadly virus' activity and it is essential that these diagnoses are made more efficient and accurate.

Disseminated varicella-zoster virus in an immunocompetent adult

Varicella-zoster is the virus that causes varicella (chicken pox), herpes zoster (shingles), and rarely, severe disseminated disease including diffuse rash, encephalitis, hepatitis, and pneumonitis. Disseminated disease is most often seen in immunocompromised patients. We describe a case of disseminated zoster in an immunocompentent patient who had previously been immune to VZV. This case is also unusual in that his clinical presentation was most consistent with varicella while his laboratory data was most consistent with herpes zoster. For the purpose of rapid diagnosis and initiation of appropriate therapy, clinicians should be aware of these more atypical presentations of VZV infection.

Disseminated Herpes Simplex Virus presenting as crusted papules on the palms and soles of an immunosuppressed patient

Disseminated Herpes Simplex Virus (HSV) may occur in immunosuppressed patients, most commonly causing visceral organ involvement and rarely presenting solely with cutaneous lesions. We report an interesting case of disseminated HSV in a 77-year-old immunocompromised man, presenting as necrotic papules and pustules with no associated systemic involvement.

Cutaneous viral infections in organ transplant patients

Cutaneous infections might occur in up to 80% of organ transplant recipients (OTR) and viral infections are the most common them. The risk of different skin infection is among related to the intensity of immunosuppression. During the first post-transplant period, herpes viruses are most common. After some months following transplantation, human papilloma viruses represent the most significant infections among OTR. Reactivation of herpes simplex virus in OTR can become more invasive, takes longer to heal, and shows greater potential for dissemination to visceral organs compared to the general population. Specific immunosuppressive drugs (namely muromonab and mycophenolate mofetil) have been associated with an increased risk of herpes virus reactivation after transplantation. On the other hand, there is evidence that the mTOR inhibitors, such as everolimus, may be associated with a decreased incidence of herpesvirus infections in transplant recipients. The incidence of herpes zoster in OTR is 10 to 100 fold higher than the general population, ranging from 1% to 12%. The chronic immunosuppression performed in OTR may lead to persistent replication of herpesviruses, dissemination of the virus with multivisceral involvement (hepatitis, pneumonitis, myocarditis, encephalitis and disseminated intravascular coagulation) and eventually, the emergence of antiviral-drug resistance. Viral warts are the most common cutaneous infection occurring in OTR. The number of warts increases with the duration of immunosuppressive therapy. Since warts in organ recipients are frequently multiple and only rarely undergo spontaneous regression, the therapeutic management of warts in patients treated with immunosuppressive drugs might be challenging. Imiquimod, 1% cidofovir ointment, acitretin proved to be useful off-label strategies for recalcitrant cutaneous viral warts in OTR. Extensive and atypical presentation of molluscum contagiosum has been also reported in OTR, with a prevalence between 3% to 6.9%. Giant molluscum contagiosum is a clinical variant in which large nodule greater than 0.5-1 cm in diameter are observed.

Hyperthermia on skin immune system and its application in the treatment of human papillomavirus-infected skin diseases

Hyperthermia is a condition characterized by increased body temperature as a consequence of failed thermoregulation. Hyperthermia occurs when a body produces or absorbs more heat than it dissipates. Hyperthermia also elicits various effects on the physiology of living cells. For instance, fever-range temperature (39°C to 40°C) can modulate the activities of immune cells, including antigen-presenting cells, Tcells, and natural killer cells. Heat shock temperature (41°C to 43°C) can increase the immunogenicity of tumor cells. Cytotoxic temperature (> 43°C) can create an antigen source to induce an anti-tumor immune response. The immunomodulatory effect of hyperthermia has promoted an interest in hyperthermia-aided immunotherapy, particularly against tumors. Hyperthermia has also been used to treat deep fungal, bacterial, and viral skin infections. We conducted a series of open or controlled trials to treat skin human papillomavirus infection by inducing local hyperthermia. More than half of the patients were significantly cured compared with those in the control trial. A series of challenging clinical cases, such as large lesions in pregnant patients or patients with diabetes mellitus, were also successfully and safely managed using the proposed method. However, further studies should be conducted to clarify the underlying mechanisms and promote the clinical applications of hyperthermia.

Factors associated with the seroprevalence of 26 cutaneous and two genital human papillomavirus types in organ transplant patients

Viral skin infections are commonly present in organ transplant recipients (OTR). In this study, we aimed to identify factors associated with human papillomavirus (HPV) infections in OTR. Patients with solid-organ transplants were recruited from the outpatient nephrology and dermatology clinics in five European countries. Only patients with no current or past skin cancer were included in this analysis. Serum samples were analysed for antibodies to the L1 proteins of 26 cutaneous and two genital HPV types from five phylogenetic genera (α, β, γ, μ and ν). The most consistent association was found between recreational sun exposure and the seroprevalence of all tested genera, except α. The antibody presence of any β type was higher among people who had been transplanted at least 23 years prior to participation than in those who had been transplanted for less than 7 years. The prevalence of two γ-HPV types (60 and 65) and three β-HPV types (15, 38 and 49) was associated with time since transplantation. The presence of a high number of warts was associated with the presence of any μ-PV or ν-PV types, and having greater than 50 keratotic skin lesions was almost significantly associated with the presence of antibodies to two or more γ-PV. Discrepancies in the results of the present study, as well as in previous reports, may depend on different methodologies and on geographical variations. Our results also indicate that further research with more standardized methods is needed to clarify the role of cutaneous HPV in OTR.

Increased susceptibility to cutaneous viral infections in atopic dermatitis: the roles of regulatory T cells and innate immune defects

Much attention has been focused on the elucidation of mechanisms whereby atopic dermatitis (AD) skin lesions are especially susceptible to certain viral infections, such as herpes simplex virus (HSV). Although one of the most likely hypotheses is that the primary defect is in an impaired epidermal barrier function, alternative hypotheses include an imbalance between antiviral immune responses and regulatory T (T(reg)) cells, and the defects in the innate immune system. Eczema herpeticum (EH) occurs almost exclusively in patients with AD, particularly in those who fail to control skin inflammation. According to our scenario, expansions of T(reg) cells would be initially required for preventing such excessive inflammation resulting from the failure, and the expansions could in turn contribute to HSV reactivation, resulting in the initiation and progression of EH. A selective impairment of Toll-like-receptor-2-mediated proinflammatory cytokine production by monocytes could be the additional mechanism responsible for the increased susceptibility of AD subjects to curtain viral infections. Here we provide several potential explanations for why AD patients are at greater risk for eczema molluscatum.

The role of human beta defensins and cathelicidins in atopic dermatitis

PURPOSE OF REVIEW

Atopic dermatitis is a chronic inflammatory skin disease associated with significant barrier disruption, T-helper type 2 mediated skin inflammation, and an impaired innate immune response. These characteristics increase the susceptibility of atopic dermatitis patients to recurrent skin infections, some of which may have potentially fatal implications. The mechanisms resulting in this increased propensity for skin infections have been an area of active investigation.

RECENT FINDINGS

Antimicrobial peptides are an integral component of the innate immune response due to their broad spectrum activity against invading pathogens. Recent studies have shown that these peptides are effective at killing Staphylococcus aureus, herpes simplex virus, vaccinia virus, and the Malassezia species, pathogens associated with significant morbidity in patients with atopic dermatitis. Additionally, these peptides are deficient in the skin of atopic dermatitis patients, suggesting that the increased propensity of patients towards skin infection is due to the lack of antimicrobial peptide expression.

SUMMARY

The current review will examine recent literature on the role of antimicrobial peptides in atopic dermatitis in an effort to improve our understanding of why patients with the condition suffer from recurrent infections.

Virus-specific CD8+ T cells accumulate near sensory nerve endings in genital skin during subclinical HSV-2 reactivation

Cytotoxic CD8⁺ T cells play a critical role in controlling herpes simplex virus (HSV) infection and reactivation. However, little is known about the spatiotemporal dynamics of CD8⁺ T cells during HSV lesion evolution or about their involvement in immune surveillance after lesion resolution. Using quantum dot–conjugated peptide–major histocompatibility complex multimers, we investigated the in vivo localization of HSV-2–specific CD8⁺ T cells in sequential biopsies of human genital skin during acute, resolving, and healed stages of HSV-2 reactivation. Our studies revealed that functionally active CD8⁺ T cells selectively infiltrated to the site of viral reactivation. After lesion healing in concert with complete reepithelialization and loss of HSV DNA from skin biopsies, HSV-2–specific CD8⁺ T cells persisted for more than two months at the dermal–epidermal junction, adjacent to peripheral nerve endings. In two out of the six sequentially studied individuals, HSV-2 DNA reappeared in clinically and histologically normal–appearing skin. Detection of viral DNA was accompanied by increased numbers of both HSV-specific and total CD8⁺ T cells in the dermis. These findings indicate that the frequency and clinical course of HSV-2 reactivation in humans is influenced by virus-specific CD8⁺ T cells that persist in peripheral mucosa and genital skin after resolution of herpes lesions.

T-cell memory: the importance of chemokine-mediated cell attraction

A recent study demonstrates the involvement of certain chemokines in immune response initiation and CD8+ T-cell memory formation. These seminal findings broaden our understanding of the role of chemokines in adaptive immune processes.

Cutting edge: central memory T cells do not show accelerated proliferation or tissue infiltration in response to localized herpes simplex virus-1 infection

Memory T cells mount an enhanced response to secondary infections. Such an enhancement has been attributed in part to the ability of memory cells to more rapidly respond to cognate stimulation. In this study we have examined the rapidity with which murine CD8(+) memory T cells respond to a localized infection with HSV. Although central memory T cells (TcM), but not the effector memory T cells, mounted a strong recall response to secondary infection, the kinetics of TcM proliferation, the magnitude of their expansion, and their infiltration into infected nonlymphoid tissues were not advanced compared with that observed for naive T cells. These findings imply that it is the lack of accelerated proliferation kinetics and the subsequent delayed dissemination into the periphery that limits the ability of TcM to rapidly control localized virus replication.

Characteristics of cutaneous cytomegalovirus infection in non-acquired immune deficiency syndrome, immunocompromised patients

BACKGROUND

Although cytomegalovirus (CMV) disease is a severe complication among immunocompromised patients, its cutaneous features have not been frequently reported. As herpes simple virus (HSV) infection commonly develops in CMV skin lesions, a study is needed on the pathogenetic role of CMV in cutaneous lesion formation.

OBJECTIVES

The purpose of this study is to characterize the clinical and histopathological features of cutaneous CMV infection and to determine whether CMV plays a true pathogenetic role in cutaneous lesions, or if it is just an innocent bystander during HSV infection among non-AIDS (acquired immune deficiency syndrome), immunocompromised patients.

PATIENTS AND METHODS

A total of nine human immunodeficiency virus-negative patients diagnosed with cutaneous CMV infection from July 1999 to February 2005 at Samsung Medical Center were analysed in terms of their clinical and histopathological characteristics. In addition, we examined for the co-presence of HSV by performing immunohistochemical analysis and polymerase chain reaction.

RESULTS

All the patients were immunocompromised; five had haematological diseases and four were organ transplant recipients. The clinical and histopathological features were similar to those of previous studies of patients with AIDS. Multiple anogenital ulcerations were the most frequent cutaneous presentation (66.7%). Most cytopathic changes were found in the dermis, particularly within the vascular endothelial cells (77.8%) and macrophages (66.7%). However, the association of CMV with concurrent HSV infection was even lower than that seen in patients with AIDS. Only one patient revealed a co-existing cutaneous HSV infection.

CONCLUSIONS

In non-AIDS individuals, the cutaneous lesions from CMV infection showed similar clinical and histopathological features to those of patients with AIDS. However, skin lesions may not be highly associated with HSV, and CMV does seem to contribute to lesion development as a cutaneous manifestation among the CMV infected, non-AIDS, immunocompromised patients.

In vivo ablation of CD11c-positive dendritic cells increases susceptibility to herpes simplex virus type 1 infection and diminishes NK and T-cell responses

The precise role of each of the seven individual CD11c+ dendritic cell subsets (DCs) identified to date in the response to viral infections is not known. DCs serve as critical links between the innate and adaptive immune responses against many pathogens, including herpes simplex virus type 1 (HSV-1). The role of DCs as mediators of resistance to HSV-1 infection was investigated using CD11c-diphtheria toxin (DT) receptor-green fluorescent protein transgenic mice, in which DCs can be transiently depleted in vivo by treatment with low doses of DT. We show that ablation of DCs led to enhanced susceptibility to HSV-1 infection in the highly resistant C57BL/6 mouse strain. Specifically, we showed that the depletion of DCs led to increased viral spread into the nervous system, resulting in an increased rate of morbidity and mortality. Furthermore, we showed that ablation of DCs impaired the optimal activation of NK cells and CD4+ and CD8+ T cells in response to HSV-1. These data demonstrated that DCs were essential not only in the optimal activation of the acquired T-cell response to HSV-1 but also that DCs were crucial for innate resistance to HSV-1 infection.

The role of CD4 and CD8 cytotoxic T lymphocytes in the formation of viral vesicles

BACKGROUND

Herpetic vesicles caused by herpes simplex virus and varicella zoster virus, and hydroa vacciniforme (HV) are characterized by umbilicated vesicule formation.

OBJECTIVES

To understand the histogenesis of umbilicated vesicles in herpetic vesicles and HV, we demonstrated the presence of the virus-associated molecules in the lesions, and the pathogenic role of cytotoxic T-lymphocyte (CTL) immune responses.

METHODS

Phenotyping of infiltrating cells was carried out in biopsy specimens from herpes simplex, varicella, herpes zoster and HV, and compared with nonviral contact dermatitis. Viral antigens and Epstein-Barr virus-encoded small nuclear RNA (EBER) were detected by immunostaining and by in situ hybridization, respectively. Infiltrating CTLs expressing granzyme B and granulysin were determined by double immunostaining using confocal laser scanning microscopy.

RESULTS

In all herpetic vesicles, the corresponding viral antigens were observed in the cytopathic keratinocytes, and infiltration of lymphoid cells was present in the upper dermis and around the vessels. In all HV lesions studied, EBER+ T cells made up 5-10% of the dermal infiltrates and the dermal infiltrates contained almost no CD56 cells. CTLs expressing granzyme B and granulysin were present in both herpetic and HV lesions, in which they made up 10-30% of the total dermal infiltrates, whereas they comprised less than 5% of the infiltrates of biopsy specimens from nonviral contact dermatitis. Confocal laser microscopic examination demonstrated that both CD4+ and CD8+ T cells expressed granzyme B and granulysin.

CONCLUSIONS

CD4+ and/or CD8+ CTLs reactive to the virus-infected cells might be responsible for the histogenesis of herpetic and HV lesions characterized by umbilicated vesicles.

Interleukin-4 induced down-regulation of skin homing receptor expression by human viral-specific CD8 T cells may contribute to atopic risk of cutaneous infection

Factors controlling the expression of cutaneous lymphocyte-associated antigen (CLA) by T cells are poorly understood, but data from murine and human CD4(+) T cell systems have suggested that cytokines play an important role. However, there are no data examining the influence of cytokines on the expression of CLA by human antigen-specific CD8(+) T cells. Peripheral blood mononuclear cells (PBMC) were isolated from 10 HLA-A*0201-positive healthy individuals. Using HLA-peptide tetrameric complexes refolded with immunodominant peptides from Epstein-Barr virus (EBV), cytomegalovirus (CMV) and influenza A virus, we investigated the temporal associations of CLA expression by viral-specific CD8(+) T cells following stimulation with antigen. Ex vivo influenza matrix-specific CD8(+) T cells expressed significantly (P < 0.05) greater levels of CLA than EBV BMLF1 and CMV pp65-specific CD8(+) T cells (mean 9.7% influenza matrix versus 1.4% BMLF1 versus 1.1% pp65) and these differences were sustained on culture. However, regardless of viral specificity, interleukin (IL)-12 and IL-4 induced significant (P < 0.05) dose-dependent up-regulation and down-regulation of CLA expression, respectively, with IL-4 showing a dominant negative effect. In many cases, IL-4 resulted in complete abrogation of detectable CLA expression by the viral-specific CD8(+) T cells. Overall these data demonstrate that CLA expression by human viral-specific CD8(+) T cells is highly dynamic and that IL-4 causes significant down-regulation. Disorders associated with a type 2 cytokine shift may reduce the efficiency of skin homing by viral-specific CD8(+) T cells. Furthermore, the ability to modify the local and systemic microenvironment may offer novel therapeutic strategies that influence tissue-specific T cell homing.

The juvenile variant of papular-purpuric gloves and socks syndrome and its association with viral infections

BACKGROUND

Papular-purpuric gloves and socks syndrome (PPGSS) occurs mostly in adults and has been shown to be related to several possible viral infections. However, childhood-onset PPGSS seems to be not so rare as previously thought in our clinical experience.

OBJECTIVES

To survey the general characteristics of childhood-onset PPGSS and to determine the possible association between this juvenile variant of PPGSS and various viral infections.

PATIENTS AND METHODS

Thirty-three children with erythematopurpuric papular eruptions on the hands and/or feet were enrolled. Detailed history-taking and physical examination were performed on all of them. Blood samples were obtained from 25 patients about 1-5 weeks after the appearance of cutaneous eruptions to check complete blood counts, differential white blood cell counts, and IgM and IgG antibodies to parvovirus B19, cytomegalovirus (CMV), viral capsid antigen of Epstein-Barr virus (EBV) and measles.

RESULTS

The median age of these 33 patients was 23 months. The mean duration of the skin eruption was 4.8 weeks (SD 2.7, 95% CI 3.9-5.0). Lymphocytosis was present in 13 patients (52%) while mild eosinophilia occurred in only three patients (12%). Five patients (20%) were positive for IgM antibodies against CMV and seven (28%) were positive for IgM antibodies against EBV. Only one patient (4%) was detected to have IgM antibodies against parvovirus B19.

CONCLUSIONS

Childhood-onset PPGSS shows somewhat different clinical features from the adult type. It may represent a nonspecific manifestation of several viral infections, including CMV, EBV and parvovirus B19 infections.

Cutaneous T-cell lymphoma sparing resolving dermatomal herpes zoster lesions: an unusual phenomenon and implications for pathophysiology

Exclusion of cutaneous T-cell lymphoma (CTCL) by another dermatosis has not been reported. The mechanism for the epidermotropism of helper T lymphocytes in this indolent malignancy is not known. Although there is evidence that Langerhans cells (LC) play a role in the epidermotropism of lymphocytes in CTCL, clinical or in vivo support is lacking. We describe a patient with CTCL who developed herpes zoster involving the left T8 dermatome. When his CTCL became widespread after the herpes zoster healed, the previously affected areas of herpes zoster and their periphery were clinically free of lymphoma. Immunohistochemical analysis of a clinically uninvolved patch revealed absence of CD1a(+) cells in the epidermis, consistent with loss of LC in the areas spared by CTCL. There was no loss of LC in areas affected by CTCL. This is an unusual inhibition of CTCL by a prior viral infection. The loss of LC in the clinically spared skin suggests a role for LC in the epidermotropism of lymphocytes in CTCL.

Severe cutaneous papillomavirus disease after haemopoietic stem-cell transplantation in patients with severe combined immune deficiency caused by common gammac cytokine receptor subunit or JAK-3 deficiency

Haemopoietic stem-cell transplantation is a life-saving treatment for severe combined immune deficiency. However, there has been little long-term follow-up of this treatment. There is evidence for the persistance of partial immunodeficiency associated with significant infections, including severe human papillomavirus (HPV) disease. We did a retrospective analysis of severe HPV disease in a group of 41 patients with severe combined immune deficiency from one centre who were alive 10 years or longer after haemopoietic stem-cell transplantation. Nine of the 41 patients had extensive chronic HPV disease limited to the skin, with a median onset at 8 years after transplantation. Four had lesions typical of epidermodysplasia verruciformis, a rare genodermatosis. Transplant characteristics, immune status, and chimerism of these nine patients did not differ significantly from those of the other patients. The nine patients with HPV disease had severe combined immune deficiency associated with either common gammac receptor cytokine subunit or Janus kinase-3 (JAK-3) deficiency. By contrast, patients with other forms of severe combined immune deficiency did not have any signs of HPV disease. That genetic causes are the only predisposing factor to be identified for severe combined immune deficiency, suggests that natural-killer cells or gammac/JAK-3-dependent signalling in keratinocytes could have a role in anti-HPV immunity.

Herpes simplex virus-specific CD8+ T cells can clear established lytic infections from skin and nerves and can partially limit the early spread of virus after cutaneous inoculation

HSV infects skin or mucosal epithelium as well as entering the sensory nerves and ganglia. We have used TCR-transgenic T cells specific for the immunodominant class I-restricted determinant from HSV glycoprotein B (gB) combined with a flank zosteriform model of infection to examine the ability of CD8+ T cells to deal with infection. During the course of zosteriform disease, virus rapidly spreads from the primary inoculation site in the skin to sensory dorsal root ganglia and subsequently reappears in the distal flank. Virus begins to be cleared from all sites about 5 days after infection when gB-specific CD8+ T cells first appear within infected tissues. Although activated gB-specific effectors can partially limit virus egress from the skin, they do so only at the earliest times after infection and are ineffective at halting the progression of zosteriform disease once virus has left the inoculation site. In contrast, these same T cells can completely clear ongoing lytic replication if transferred into infected immunocompromised RAG-1-/- mice. Therefore, we propose that the role of CD8+ T cells during the normal course of disease is to clear replicating virus after infection is well established rather than limit the initial spread of HSV from the primary site of inoculation.

Immunodeficiency and infections in ataxia-telangiectasia

OBJECTIVE

To characterize the immunodeficiency in ataxia-telangiectasia (A-T) and to determine whether the immunodeficiency is progressive and associated with increased susceptibility to infections.

STUDY DESIGN

Records of 100 consecutive patients with A-T from the Johns Hopkins Ataxia-Telangiectasia Clinical Center (ATCC) were reviewed.

RESULTS

Immunoglobulin (Ig) deficiencies are common, affecting IgG4 in 65% of patients, IgA in 63%, IgG2 in 48%, IgE in 23%, and IgG in 18%. Lymphopenia affected 71% of patients, with reduced B-lymphocyte number in 75%, CD4 T lymphocytes in 69%, and CD8 T lymphocytes in 51%. There was no trend for increased frequency or severity of immune abnormalities with age. Recurrent upper and lower respiratory tract infections were frequent: otitis media in 46% of patients, sinusitis in 27%, bronchitis in 19%, and pneumonia in 15%. Sepsis occurred in 5 patients, in 2 patients concurrent with cancer chemotherapy. Warts affected 17% of patients, herpes simplex 8%, molluscum contagiosum 5%, candidal esophagitis 3%, and herpes zoster 2%. Uncomplicated varicella infection occurred in 44% of patients; 2 patients had more than one clinical episode. No patient had Pneumocystis jerovici pneumonia or a complication of live viral vaccine.

CONCLUSIONS

In spite of the high prevalence of laboratory immunologic abnormalities, systemic bacterial, severe viral, and opportunistic infections are uncommon in A-T. Cross-sectional analysis suggests that the immune defect is rarely progressive.

Unusual presentation of herpes zoster in an immunocompromised patient: case report

We present a case of an immunocompromised patient with unusual presentation of herpes zoster infection. After having been treated with corticosteroids for several weeks, the patient developed the zoster infection with atypical clinical course and skin localization. Parenteral treatment with acyclovir for 10 days resulted in a complete clinical resolution of the skin lesions. Similar cases of unusual presentation of herpes zoster have been described in immunocompromised patients.

Skin infections and ageing

Elderly individuals have an increased susceptibility to skin infections due to age-related anatomical, physiological and environmental factors. The types of organisms that cause primary skin and soft tissue infections are diverse, and include bacterial, viral and fungal pathogens as well as parasites. In the elderly, these infections and infestations may present with atypical signs and symptoms or may complicate underlying chronic skin disorders. Clinical features, investigations and management of the following important and common skin infections are described in more detail: cellulitis, erysipelas, necrotizing fasciitis, impetigo, folliculitis, furunculosis and carbunculosis, erythrasma, herpes zoster and postherpetic neuralgia, herpes simplex, warts, molluscum contagiosum, dermatophytosis of the skin, hair and nails, candidiasis, and scabies. Treatment should be based on the results of the appropriate diagnostic tests. Correct diagnosis and therapy of skin infections lead to satisfactory outcome in the majority of elderly patients.

Vesicular and pustular eruption related to cytomegalovirus in an immunocompetent patient

Cytomegalovirus (CMV), a member of the herpesviridae family, can cause various dermatologic and systemic disorders especially in immunosuppressed subjects. However, immunocompetent individuals rarely present with cutaneous eruptions related to CMV. We describe an immunocompetent patient who developed a skin eruption and mild hepatitis related to CMV.

Stress-induced changes in pathophysiology and interferon gene expression during primary HSV-1 infection

Herpes simplex viruses (HSV) are the cause of the most common clinically recognized herpesvirus infections. The severity and duration of the primary HSV infection have been correlated with the frequency and severity of subsequent recurrences. Reactivation of latent HSV-1 can occur as a result of physical or emotional stress; however, the effects of stress on the modulation of the clinical pathophysiology of primary HSV-1 infections are not well understood. Although it is known that stress can be immunosuppresive, the immunological mechanisms by which stress modulates early immune responses, such as type I interferon gene expression during a primary HSV-1 infection are still not understood. It was hypothesized that due to suppressed early immune responses, stress would increase the severity of a cutaneous primary HSV-1 infection. In this investigation, a cutaneous HSV-1 model in the SKH-1 mouse was characterized and utilized to study the effect of restraint stress on the modulation of the clinical pathophysiology of primary HSV-1. Despite prolonged viral replication at the site of primary infection, restraint stress decreased the clinical severity of primary HSV-1 in the skin of SKH-1 mice. A decrease in type I and type II IFN expression was found in the skin of acutely infected restrained mice when compared to controls at day 3 post-infection using competitive RT-PCR. Using the glucocorticoid-receptor antagonist RU486, IFN-beta and INF-gamma expression were restored in restrained animals to control levels. Treatment with RU486 also increased the clinical severity of the cutaneous infection to control levels in restrained mice. Thus, RST masked the severity of an HSV-1 infection by decreasing its clinical signs while impairing the ability of the host to control viral replication prolonging the infectious period.

A kinetic analysis of immune mediators in the lungs of mice infected with vaccinia virus and comparison with intradermal infection

The early inflammatory response to a virus may be critical in restricting infection and in shaping the subsequent adaptive immune response. In this study we have examined the early inflammatory response of mice following infection with vaccinia virus (VV) strain Western Reserve (WR). Respiratory challenge of BALB/c mice with VV led to early virus replication in the lung and upper respiratory tract followed by dissemination of virus to other visceral organs and to the brain. The number of inflammatory cells, largely macrophages and T lymphocytes, recovered from bronchoalveolar lavage (BAL) fluid increased markedly during infection and coincided with the expression of CC chemokine ligands (CCL) 3, 2 and 11 and CXC chemokine ligands (CXCL) 1 and 2/3 in BAL. The peak of the inflammatory response occurred around day 10 and declined thereafter. The antiviral cytokines IFN-gamma and TNF-alpha, and the reactive nitrogen intermediate nitric oxide (NO), were also detected in BAL from VV-infected mice. A markedly different inflammatory response was observed after intradermal inoculation of WR into the ear pinnae of mice. Intradermal challenge was followed by highly localized virus replication and by a cellular influx, consisting largely of neutrophils and T lymphocytes, into the dermal compartment of the infected ear. Together these findings highlight differences in the pathogenesis and in the cellular inflammatory response to WR following intranasal and intradermal inoculation of mice.

[Topical immunomodulators in dermatology]

Immunomodulators include both immunostimulatory and immunosuppressive agents. Obligate contact sensitizers such as diphencyprone or dinitrochlorobenzene have been used against viral and autoimmune diseases. Newer agents such as the toll-like receptor agonists imiquimod and resiquimod have been clinically used to treat viral infections and skin cancers in immunocompetent and immunosuppressed patients. On the other hand, the topical immunosuppressive agents tacrolimus and pimecrolimus have been used with great success in the treatment of chronic inflammatory diseases in children and adults. The introduction of this new class of drugs (i.e. Calcineurin inhibitors) marked the beginning of the post-cortisone era in clinical dermatology. Toll-like receptor agonists and calcineurin antagonists will supplement corticosteroids to improve specific dermatological therapy. Topical immunotherapy with both immunostimulatory and immunosuppressive agents show potential for effective and patient-friendly treatment of inflammatory, infectious and neoplastic skin diseases. Long-term evaluation will define the tolerability and the safety profile.

Rapid cytotoxic T lymphocyte activation occurs in the draining lymph nodes after cutaneous herpes simplex virus infection as a result of early antigen presentation and not the presence of virus

Localized cutaneous herpes simplex virus type 1 (HSV-1) infection leads to arming and initial expansion of cytotoxic T lymphocytes (CTLs) in the draining popliteal lymph nodes (PLNs) followed by migration and further proliferation in the spleen. To accurately characterize the sequence of events involved in the activation and generation of anti-HSV CTLs, we used T cell receptor (TCR) transgenic mice specific for the immunodominant epitope from HSV glycoprotein B (gB(498-505)). We describe the detection of the initiation of antigen presentation in the draining lymph nodes by 4-6 h after infection with HSV-1. Analysis of CD69 up-regulation revealed activation of gB-specific CD8(+) T cells by 6-8 h after infection. Furthermore, we show that T cell proliferation begins no sooner than 24 h after activation and is marked by the concurrent appearance of CTL activity in the PLNs. These events are not dependent on the presence of virus in the draining lymph nodes, and suggest a requirement for recruitment of professional antigen-presenting cells to the site of T cell activation. Consequently, we have defined the initiation of the CD8(+) T cell-mediated response to cutaneous HSV-1 infection, demonstrating that the immune response to localized viral infection depends only on the appearance of cells presenting virus-derived antigen and commences with remarkable swiftness.

Alterations in molecular killing mechanisms: implications in skin disease

Cytolytic T lymphocytes exert two main specific molecular killing mechanisms against target cells, namely (i) they can synthesize and release soluble cytolytic factors, and (ii) they can express effector molecules that act as ligands of receptors expressed by target cells on the cell surface; by these two pathways cytolytic T lymphocytes kill several targets, e.g. cells infected with intracellular pathogens, cells transformed by malignancy and cells producing autoantibodies. This review investigates the contribution from alterations in these molecular killing mechanisms to the pathogenesis of cutaneous diseases. In fact, molecular components involved in such killing mechanisms are often altered or distorted in skin pathology, e.g. cutaneous viral infections, skin cancer, contact hypersensitivity and autoimmune diseases with cutaneous involvement. Treatments capable of repairing the molecular components operating in such killing mechanisms could presumably favour the resolution of these skin diseases.

Detection of cellular cytokine mRNA expression during orf virus infection in sheep: differential interferon-gamma mRNA expression by cells in primary versus reinfection skin lesions

In sheep infected with the parapoxvirus orf virus, primary infection orf skin lesions developed and resolved within 8 weeks. Reinfection lesions were smaller and resolved within 3 weeks. The host response in the skin was characterized by an accumulation of neutrophils, dendritic cells, CD4+ T cells, CD8+ T cells, B cells and T19+ gammadelta T cells. The magnitude of this accumulation paralleled orf virus replication in the skin. In situ hybridization was used to detect cells expressing interferon-gamma (IFN-gamma), tumor necrosis factor-alpha (TNF-alpha) and interleukin-4 (IL-4) mRNAs in orf skin. Cells expressing IL-4 mRNA were not detected at any time after infection. Cells expressing IFN-gamma mRNA were detected after reinfection but not after primary infection. Cells expressing TNF-alpha mRNA included epidermal cells, vascular endothelium and uncharacterized cells that increased more rapidly in the skin after reinfection compared to primary infection. The results are consistent with a prominent role for IFN-gamma in the host immune response controlling the severity of the disease.

Understanding the pathogenesis of HSV-associated erythema multiforme

Erythema multiforme (EM) is a polymorphic, often recurring eruption caused by exposure to medication or various infections, notably herpes simplex virus (HSV). Understanding the pathogenesis of HSV-associated EM (HAEM) is essential for patient management. We suggest that HAEM results from the combination of viropathic effects mediated by HSV proteins, notably DNA polymerase (Pol), and an immunological reaction to viral antigens. Presumably, viral DNA and proteins ingested by macrophages at HSV lesion sites undergo fragmentation and processing for presentation to T cells with HSV memory. HSV DNA is deposited on the skin, where it is expressed. Activated T cells are recruited to the skin site of Pol expression, directly or indirectly resulting in the generation of an inflammatory cascade. Factors potentially involved in the incidence of recurrences, lesion severity and anatomical localization include the identity of the deposited HSV genes, cutaneous capillary size, degree of vasoconstriction and ambient temperature. Evidence in support of this interpretation is reviewed.

Current understanding of cytomegalovirus infection in immunocompetent individuals

Human cytomegalovirus (CMV) is a member of the herpes family of viruses. After primary infection, it undergoes latency/persistence. Significant progress has been made in the last few years in detecting CMV. The most available approach to the diagnosis of CMV infection is the direct detection of CMV antigen in nuclei of peripheral blood leukocytes, an assay known as pp65 direct antigenemia test. CMV infection is well controlled in the immunocompetent hosts; however, there are various immunological changes in immune function during and after recovery from CMV infections. Characteristic changes in lymphocyte subsets occur during CMV infection, mainly involving expansion and activation of CD8+ T lymphocytes and NK cells. On the other hand, CMV has an array of immune escape strategies for establishing a life long latent state: CMV inhibits major histocompatibility complex (MHC) class I expression within infected cells and impairs IFN-gamma-induced MHC class II-dependent antigen presentation by macrophages; it can also encode proteins that can interfere with the presentation of viral peptide antigens to T cells. While cutaneous manifestations of CMV seen in immunocompromised patients have been extensively reported, those in adult immunocompetent individuals have received relatively little attention: in this setting the primary CMV infection appears as CMV mononucleosis. At the time of occurrence of the mononucleosis syndrome, a variety of extracutaneous and cutaneous manifestations occur. These clinical symptoms are not the direct consequence of proliferation of CMV in given tissues but indicative of the immunological response toward CMV. The incidence of the appearance of eruptions in CMV mononucleosis is variable. Certain drugs given in the early stage of this disease play an important role in the development of eruption, just as with the ampicillin rashes in the Epstein-Barr virus mononucleosis. Although the mechanism by which drugs trigger the development of rashes in patients with CMV mononucleosis is unknown, it is assumed that CMV is likely to be a potential amplifier of drug rashes induced by activation of drug-specific T cells. By improving methods for detection of CMV, we can recognize that many types of eruptions other than CMV mononucleosis could be induced by primary infection or reactivation of CMV.

Langerhans cells migrate to local lymph nodes following cutaneous infection with an arbovirus

Whereas there has been recent interest in interactions between dendritic cells and pathogenic viruses, the role of dendritic cells in the initiation of protective immunity to such organisms has not been elucidated. The aim of this study was to examine whether a resident dendritic cell population in the skin, Langerhans cells, respond to cutaneous viral infections which are effectively cleared by the immune system. We therefore characterized the ability of Langerhans cells to migrate to local draining lymph nodes following infection with the arthropod-borne viruses, West Nile virus or Semliki Forest virus. The data show that major histocompatibility complex class II+/NLDC145+/E-cadherin+ Langerhans cell numbers are increased in the draining lymph nodes of infected mice and this increase is accompanied by a concomitant decrease in the Langerhans cell density in the epidermis. Langerhans cell migration is associated with an accumulation of leukocytes in the lymph node, which is one of the earliest events in the initiation of an immune response. Both the migratory response and the draining lymph node leukocyte accumulation were abrogated if ultraviolet-inactivated instead of live viruses were used, suggesting the activation and subsequent migration of Langerhans cells requires a live, replicating antigen. Our findings are likely to have wider implications for the development of epidermally delivered vaccines and suggest that mobilization of dendritic cells may be involved in the development of immune responses to arthropod-borne viruses.

Complications of varicella zoster virus reactivation in HIV-infected homosexual men

OBJECT

To study the complication rate of varicella zoster virus (VZV) reactivation and the relationship between complications, presentation and localization of zoster and immune function in HIV disease.

DESIGN AND METHODS

A total of 142 episodes of VZV reactivation in 113 out of 544 HIV-1-infected participants in the Amsterdam Cohort Study of homosexual men were studied. Persistent hyperkeratotic or necrotic skin lesions, post-herpetic neuralgia, other neurological events, ocular events and pneumonitis occurring within 6 months of the onset of the last episode of VZV reactivation were defined as complications, provided that other possible diagnoses were excluded and the event had been previously described in the literature as related to VZV reactivation.

RESULTS

Twenty-four complications occurred in 15 (11%) of these 142 episodes. Complications occurred exclusively in the 40 episodes with either multidermatomal or disseminated presentation, or a trigeminal localization, or both. In the group of episodes of unidermatomal zoster at a non-trigeminal localization no complications occurred. Twenty-one episodes of herpes zoster were localized in the trigeminal area. Localization was not significantly associated with the level of immune function. Compared to unidermatomal presentation (n = 120), multidermatomal (n = 15) and disseminated presentation (n = 7) occurred at lower median CD4+ cell counts (330, 240 and 50 x 10(6)/l, respectively; P = 0.003) and significantly lower levels of CD3 monoclonal antibodies or phytohaemagglutinin-induced T-cell reactivity in vitro. Complications were related to CD4+ cell counts, but in the cases of disseminated, multidermatomal or trigeminal zoster a CD4+ cell measurement provided no additional information on the risk of complications.

CONCLUSION

In HIV-infected individuals the extent of the clinical presentation and the occurrence of complications of VZV reactivation are related to the degree of immunodeficiency. In episodes of VZV reactivation with either multidermatomal or disseminated presentation or a trigeminal localization, or both the complication rate was high. CD4+ cell counts provided no additional information on the complication risk. Oral acyclovir appears to be sufficient as therapy for unidermatomal zoster at a non-trigeminal localization.

Characteristic but unfamiliar--the cowpox infection, transmitted by a domestic cat

An 11-year-old girl had been suffering from 2 recently developed reddish ulcerated nodules on the right side of her neck and, concomitantly, from a very hard swelling as well as from painless lymphadenopathy. Subsequently, thick black eschars appeared on the surface of the ulcers. Using the negative staining technique, an orthopox virus infection could be identified by electron microscopy. The patient's characteristic history as well as her close contact with a cat frequently hunting nice indicated the diagnosis of a cowpox infection, which was unequivocally confirmed by identification of both the viral culture and specific antibodies in the serum of the patient.

Decreased CD7 expression in cutaneous infiltrates of HIV-1+ patients. Military Medical Consortium for the Advancement of Retroviral Research (MMCARR)

CD7 is an early T-cell marker that has been used in the diagnosis of stem cell leukemias. Loss of expression of CD7 with a battery of other mature T-cell markers has also been used as one criteria in the diagnosis cutaneous T-cell lymphomas. More recently, CD7-negative T cells have been shown to be a normal population of T cells in the peripheral blood and the skin, and may represent a mature T-cell population with a different pattern of maturation and activation. In addition, in HIV-1 disease expansion of CD7-negative T cells has been found in the peripheral blood. We evaluated the number of CD7-negative T cells in skin infiltrates to determine whether there was an increase of CD7-negative T cells. We studied T-cell markers including CD3, CD4, CD7, CD8, CD20, CD29, and HLA-DR on cutaneous biopsy material from inflammatory dermatoses in 57 patients with HIV-1 disease in Walter Reed stages (WR) 1-6, and in 14 HIV-1-negative patients WR0. The inflammatory infiltrates showed a moderate to marked decrease in CD7 expression on CD3+ T cells in benign inflammatory infiltrates of the majority of HIV-1+ patients. The majority of HIV-1-negative patients showed no decrease in CD7 expression, although 5 of 14 showed a moderate decrease and 1 of 14 showed a marked decrease. Although the nature of CD7- T cells has not been clearly defined, this population of mature T cells appears to have distinct immunologic properties as well as a trophism for skin. Better characterization of these T cells, as well as factors that promote their maturation and activation, may give clues to the high incidence as well as the pathogenesis of skin disease in HIV-1+ patients.

Involvement of LFA-1 and ICAM-1 in the herpetic disease resulting from HSV-1 corneal infection

Herpes simplex virus type 1 (HSV-1) corneal infection in immunologically normal mice results in a transient epithelial lesion followed in about 2 weeks by a potentially blinding inflammatory response in the corneal stroma, and a mild blepharitis. Similarly infected T cell-deficient mice do not develop corneal stromal inflammation, but exhibit severe periocular skin disease and succumb to viral encephalitis. The role of certain adhesion molecules in both T cell activation, and in the extravasation of inflammatory cells from the blood into inflammatory sites is now being established. These studies investigated the involvement of the adhesion pair LFA-1/ICAM-1 in the disease that results from HSV-1 corneal infection in mice. Treatment of mice with mAb to LFA-1 beginning 1 day before HSV-1 corneal infection resulted in a delay in the onset of stromal inflammation, but ultimately stromal inflammation developed to a normal extent. This treatment also caused a significant exacerbation of periocular skin disease, but did not render mice susceptible to encephalitis. Treatment with mAb to ICAM-1 beginning 1 day before HSV-1 corneal infection caused an acceleration of both stromal inflammation and periocular skin disease, and rendered mice uniformly susceptible to lethal encephalitis. Treatment with either mAb beginning 6 days after HSV-1 corneal infection did not significantly affect the clinical course of herpetic disease. Our findings suggest that LFA-1 may play a role in the early phase of corneal stromal inflammation following HSV-1 corneal infection. Both LFA-1 and ICAM-1 appear to be important for protection of the skin from HSV-1 infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Viral glycoproteins in herpesviridae granulomas

Granulomatous reactions after varicella zoster virus (VZV) and herpes simplex virus (HSV) infections are rare, and their pathogenesis remains unclear. We studied by immunohistochemistry and in situ hybridization early granulomatous reactions after VZV and HSV infections. In the five cases studied, the VZV glycoproteins gp I and gp II were present in cells abutted to altered vessels, but the corresponding genome sequences were disclosed in similar locations in only one of these cases. In an immunocompromised patient with diffuse HSV eruption, HSV I antigens were present in cells of the reticular dermis, while viral nucleic acids were not evident. Immunophenotyping of the granulomas showed strong Mac 387 and CD68 positive labelings of macrophages/monocytes, without any involvement of Factor XIIIa-positive cells. These findings suggest that the major viral envelope glycoproteins, rather than complete viral particles could trigger granuloma formation following HSV and VZV skin infections.

Changes in epidermal Langerhans cells, gamma delta T cells and CD4 T cells after intradermal infection with recombinant vaccinia virus expressing cytokine genes

Langerhans cells (LC) play a critical role in cutaneous immunity, and whereas Thy-1+ dendritic epidermal cells (Thy-1+ dEC) are also present in murine epidermis, their role remains unknown. Antigens and cytokines influence the number of LC found in the epidermis. However, there has been no investigation into the effects of particular cytokines during resolution of a viral infection. In order to study this we infected mice subcutaneously with vaccinia virus (VV) constructs containing the genes encoding TNF-alpha, IL-6 or IFN-gamma and the density of LC, THY-1+ dEC and CD4+ cells was determined. In this system the cytokines were produced locally at the site of viral replication. Cell densities were examined at day 1, while the response was being initiated, and at day 5 as the infection was being resolved. Infection with VV, like exposure to other antigens, decreased the density of epidermal LC at day 1, and they remained depressed at day 5. Production of TNF-alpha during VV growth did not influence this response by LC, whereas IFN-gamma and IL-6 both increased the number of epidermal Ia+ LC at day 1 but then caused a reduction at day 5. Thy-1+ dEC were not affected by VV infection at any time-point examined, nor did any cytokine influence the density of these cells at day 1. However, by day 5 IFN-gamma and IL-6, but not TNF-alpha, decreased the number of Thy-1+ dEC.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of apoptosis-mediating Fas antigen in human skin and effects of anti-Fas monoclonal antibody on human epidermal keratinocyte and squamous cell carcinoma cell lines

Fast antigen is a cell surface protein that mediates apoptosis. Using immunohistological, flow cytometry and electron microscopic analyses, we investigated the expression of Fas antigen on various skin tissues, and on cultured SV40-transformed human epidermal keratinocyte cell line KJD and human skin squamous cell carcinoma cell line HSC. The Fas antigen was widely distributed in skin components such as the keratinocytes in the lower portion of the epidermis, epidermal dendritic cells, endothelial cells, fibroblasts, apocrine glands, eccrine sweat glands, sebaceous glands, some normal melanocytes and infiltrating lymphoid cells. It was also strongly expressed on the keratinocytes of lichenoid eruptions seen in lupus erythematosus and lichen planus, and on the spongiotic or acanthotic epidermis seen in chronic eczema, adult T-cell leukaemia/lymphoma (ATLL) and atopic dermatitis. Its expression was closely correlated with lymphoid infiltrating cells and it was strongly expressed in lymphoid neoplastic cells, particularly ATLL cells, and fibroblasts seen in dermatofibroma. However, the antigen was not detected on basal cell epithelioma cells, some malignant melanomas or any junctional naevi. The cell lines KJD and HSC strongly expressed the Fas antigen, and crosslinking of the Fas antigen by an anti-Fas monoclonal antibody induced apoptosis of these cell lines. These results indicate that the apoptosis-mediating Fas antigen may play an important role in normal skin turnover and cell differentiation, in immune regulation of skin tumours, and in the pathogenesis of various skin diseases.