A high prevalence of cytomegalovirus antigenaemia in patients with moderate to severe chronic plaque psoriasis: an association with systemic tumour necrosis factor alpha overexpression

A study on tumor necrosis factor-α single nucleotide polymorphisms and psoriasis vulgaris in Vietnam

This study aims to evaluate the association between tumor necrosis factor-a (TNF-α) single nucleotide polymorphisms and psoriasis vulgaris. This cross-sectional study involved 140 Vietnamese patients of Kinh ethnicity diagnosed with psoriasis vulgaris. The diagnosis of psoriasis vulgaris was based on clinical signs and symptoms. We used Sanger sequencing to analyze two single nucleotide polymorphisms (SNPs), rs1799964 and rs1799724. Data were analyzed by SPSS 25. SNP rs1799964 has the highest rate of TT genotype at 62.1%, more than double the heterozygous TC genotype at 30%, CC genotype has the lowest rate at 7.9%. CC genotype of SNP rs1799724 accounted for 90%, and no homozygous genotype TT was detected. No statistically significant association was found between both SNPs and clinical features (p >0.05). The Psoriasis Area and Severity Index (PASI) was significantly lower in patients with variant alleles (P =0.021). Our data show a significant negative association between SNP variant alleles and the disease's severity. Studies with larger sample sizes and more biochemical indices may help identify reliably predictive markers for these SNPs.

Immunocompromised Patients with Therapy-Refractory Chronic Skin Diseases Show Reactivation of Latent Epstein‒Barr Virus and Cytomegalovirus Infection

Reactivation of latent Epstein‒Barr virus (EBV) and/or Cytomegalovirus (CMV) infection is a dreaded complication in immunocompromised patients receiving hematopoietic stem cell transplantation. Evidence is sparse on whether subclinical reactivation of viral infection may also be of clinical relevance in dermatological patients. We screened patients (N = 206) suffering from chronic skin diseases for subclinical reactivation of EBV and CMV infection. We found that immunocompromised patients with therapy-refractory chronic skin diseases showed higher rates of subclinical reactivation of CMV and EBV infection (6.7% vs. 0% for EBV and 16.7% vs. 5.6% for CMV) and a higher prevalence of virus-specific DNA in skin tissue (30.8% vs. 0% for EBV and 21.4% vs. 0% for CMV) than nonimmunocompromised patients with chronic skin diseases. T cells isolated from lesional skin exhibited up to 14-fold increased proliferation with production of T helper type 1 and T helper type 17 cytokines on stimulation with viral proteins, providing evidence for possible aggravation of the underlying skin diseases by viral infection. Improvement of skin lesions in patients with reactivation of CMV infection (n = 4) was observed on antiviral treatment. Our data suggest that subclinical reactivation of EBV and/or CMV infection is an under-recognized condition in the dermatological patient population with chronic skin diseases.

Pre-transplant CD200 and CD200R1 concentrations are associated with post-transplant events in kidney transplant recipients

CD200 is an immunoglobulin superfamily membrane protein that binds to a myeloid cell-specific receptor and induces inhibitory signaling. The aim of this study was to investigate the role of CD200 and its receptor (CD200R1) on kidney transplant (KTx) outcome. In a collective of 125 kidney recipients (University hospital, Heidelberg, Germany), CD200 and CD200R1 concentrations were evaluated immediately before transplantation. Recipient baseline and clinical characteristics and KTx outcome, including acute rejection (AR), acute tubular necrosis, delayed graft function, cytomegalovirus (CMV) and human polyomaviridae (BK) virus infections, and graft loss were evaluated during the first post-transplant year. The association of CD200 and CD200R1 concentrations and CD200R1/CD200 ratios with the outcome of KTx was investigated for the first time in a clinical setting in a prospective cohort. There was a positive association between pre-transplant CD200R1 concentrations and CMV (re)activation (P = .041). Also, increased CD200R1 concentration was associated with a longer duration of CMV infection (P = .049). Both the frequency of AR and levels of creatinine (3 and 6 months after KTx) were significantly higher in patients with an increased CD200R1/CD200 ratio (median: 126 vs 78, P = .008). Increased pre-transplant CD200R1/CD200 ratios predict immunocompetence and risk of AR, whereas high CD200R1 concentrations predict immunosuppression and high risk of severe CMV (re)activation after KTx.

Sirolimus treatment for cirrhosis or hepatocellular carcinoma patients accompanied by psoriasis after liver transplantation: A single center experience

There is currently no consensus on the most suitable therapeutic approach for psoriasis (PS) co-existing with posthepatic cirrhosis (PCs) and hepatocellular carcinoma (HCC) following liver transplantation (LT). The present study provides an analysis of the therapeutic experience of such patients. Five LT recipients (two with PC and three with HCC) with accompanying PS were included. The induction program consisted of methylprednisolone plus basiliximab treatment. The initial postoperative treatment scheme consisted of tacrolimus (FK506) plus mycophenolate mofetil (MMF) and hormone; the latter was withdrawn 1 week after LT. The patients with PC had been using FK506 with or without a postoperative MMF program; the patients with HCC and recurrence of PS had been switched to a sirolimus (SRL)-based replacement therapy. Furthermore, all patients received anti-hepatitis B virus (HBV) therapy. The patients were followed up after 8.3±1.5 years. There was a positive correlation between HBV-DNA copy numbers, and psoriatic area and severity index (PASI) scores (r=0.97; P=0.006). The PASI scores were decreased significantly at 6 months following surgery compared with pre-transplantation (P<0.05). The patients who had received the FK506-based treatment experienced PS recurrence two years post-transplantation. The PASI scores increased significantly (P<0.05) and then declined gradually, maintaining a stable level (P<0.05) by 1 year after switching to the SRL-based treatment. The patients who had received the SRL-based treatment exhibited no recurrence of PS. The results of the present study suggest that SRL therapy provides a promising novel treatment method for patients with PS following LT that may be superior to tacrolimus treatment. When co-existing HBV is present pre-transplantation, regular injection of human hepatitis B immunoglobulin should be used to prevent the HBV from relapsing or aggravating the PS.

IL-23 plasma level is strongly associated with CMV status and reactivation of CMV in renal transplant recipients

Background

Cytomegalovirus seropositivity is an independent risk factor for atherosclerosis in patients with ESRD. Donor CMV seropositivity is associated with higher graft loss. Dendritic cells, macrophages and Th17 lymphocytes are defined as producers of IL-23. IL-23 is thought to be involved in the promotion of Th17 cell polarization. Latent CMV-induced Th17 might be involved in the pathogenesis of CMV infection in patients with ESRD. We aimed to evaluate associations of Th17-dependent cytokines with ESRD, CMV status and post-transplant outcome in kidney transplantation.

Results

IL-21 plasma levels were similar in patients and healthy controls (p = 0.47), whereas IL-9 (p = 0.02) and IL-23 (p < 0.0001) levels were significantly higher in ESRD patients. CMV-seronegative (p = 0.002) and –seropositive (p < 0.001) patients had significantly higher IL-23 plasma levels than controls. CMV-seropositive patients showed excessively higher IL-23 (p < 0.001) plasma levels than CMV-seronegative patients. Patients with post-transplant CMV reactivation had higher IL-23 plasma levels than patients without CMV reactivation (p = 0.025).

Conclusions

Our results indicate that latent CMV induces IL-23. IL-23 might be an inflammatory mediator of latent CMV infection in patients with ESRD and predisposes patients for post-transplant CMV reactivation.

Infliximab Does Not Worsen Outcomes During Flare-ups Associated with Cytomegalovirus Infection in Patients with Ulcerative Colitis

BACKGROUND

Immunosuppressive therapies used for treating ulcerative colitis are known to favor chronic and latent viral diseases. This study aimed at evaluating prospectively the association between colonic cytomegalovirus (CMV) reactivation and anti-tumor necrosis factor (TNF) monoclonal antibodies (mabs) by comparison to azathioprine (AZA) in a series of flare-ups occurring in consecutive ulcerative colitis patients.

METHODS

A total of 109 flare-ups were recorded in 73 patients receiving a maintenance therapy by anti-TNF mabs (n = 69) or AZA (n = 40). The CMV DNA load in colonic tissue was determined by reverse transcription polymerase chain reaction on a pair of biopsies.

RESULTS

The number of CMV reactivation was of 35% and 38% in patients receiving anti-TNF mabs and AZA, respectively. The median of CMV DNA load was 378 [10-29,800] and 8300 [10-3,25,000] copies/mg of tissue in patients treated by anti-TNF mabs and AZA, respectively (P = 0.11 by Mann-Whitney U test). In a subgroup of 45 patients under anti-TNF mabs requiring an optimized treatment by infliximab, clinical remission (partial Mayo score <3) was not significantly impacted by the presence of CMV reactivation at the time of flare-up (P = 0.52). Twenty of these patients underwent a second colonic biopsy 8 weeks after the initiation of flare-up therapy; except for 3 patients, the colonic CMV DNA load was stable or decreased.

CONCLUSIONS

Patients under anti-TNF maintenance therapy are not at higher risk of CMV reactivation in case of flare-up. No reciprocal adverse influence was observed between anti-TNF mabs and CMV infection, suggesting that these drugs must be considered for treating flare-ups associated to CMV reactivation.

Current characteristics and outcome of cytomegalovirus infections after kidney transplantation

INTRODUCTION

The clinical course of cytomegalovirus (CMV) infections in the current era is poorly described. We characterized the symptoms and outcome of all CMV infections in a large cohort of kidney transplant recipients. Among 1129 kidney transplant recipients transplanted between 2004 and 2011 in Charité Universitätsmedizin Berlin and Helsinki University Hospital, 297 patients with CMV infection were characterized.

RESULTS

CMV disease occurred in 217/1129 patients (19.2%), and CMV infection in 297/1129 (26.3%). Gastrointestinal symptoms were recorded in 58% and fever in 47% patients with primary CMV disease, compared to 46% and 27% patients with symptomatic CMV reactivation, whereas leukopenia or thrombocytopenia were seen in only 17-28% patients, and malaise in 9-10%. Tissue-invasive CMV gastroenteritis was confirmed in 11% and CMV pneumonia in only 1% of patients with CMV disease. Only 1 patient died because of CMV infection (mortality 0.3%). Virus-related factors or the use of secondary prophylaxis did not predict the risk of recurrence, which occurred in 33% patients.

CONCLUSION

In conclusion, CMV disease remains a common problem after kidney transplantation. Gastrointestinal symptoms were common, especially in patients with primary CMV infection, whereas bone marrow suppression, hepatopathy, or malaise were seen less frequently.

Markers of systemic inflammation in psoriasis: a systematic review and meta-analysis

Studies investigating systemic inflammation in psoriasis use different serum markers and report discrepant results. We set out to determine whether systemic inflammation is elevated in patients with psoriasis compared with healthy controls, and to measure the extent of this elevation, by summarizing available data on serum inflammatory markers. PubMed, Embase and Web of Science were searched from inception to March 2011. We included studies comparing the serum inflammatory markers interleukin (IL)-1β, IL-6, IL-10, C-reactive protein (CRP), intracellular adhesion molecule (ICAM)-1, E-selectin and tumour necrosis factor (TNF)-α in patients with psoriasis and healthy controls. Differences in serum marker levels between patients and controls were pooled as standardized mean differences (SMDs; Cohen's d) using a random-effects model. Seventy-eight studies were eligible. Of the 7852 individuals included, 3085 had (severe plaque) psoriasis. The pooled SMDs were higher in patients with psoriasis than in healthy controls for IL-6 [d = 1·32, 95% confidence interval (CI) 0·83-1·81], CRP (d = 1·83, 95% CI 0·76-2·90), TNF-α (d = 1·32, 95% CI 0·86-1·79), E-selectin (d = 1·78, 95% CI 1·32-2·25) and ICAM-1 (d = 1·77, 95% CI 1·15-2·39). The SMD between cases and controls for IL-1β and IL-10 was not significant. Age had a significant effect on the SMD for IL-6 and TNF-α. For IL-6 the effect size was higher for plaque psoriasis studies (d = 1·98). The effect size was not influenced by the Psoriasis Area and Severity Index, measurement method or quality assessment. The pooled analyses suggest modest but significantly elevated levels of the proinflammatory cytokines in the serum of patients with psoriasis with predominantly severe disease. To what extent this modest increment is clinically relevant could be investigated in a synthesis of all studies measuring inflammation before and after antipsoriatic therapy.

Dendritic cell biology in human cytomegalovirus infection and the clinical consequences for host immunity and pathology

Human cytomegalovirus (HCMV), a member of the herpesvirus family, establishes life-long persistence and latency after primary infection and can be reactivated later in life. In immunosuppressed patients, it is an important pathogen that can cause severe disease. HCMV is also thought to play a causative role in inflammatory diseases and cancer. The virus can infect different immune cells, including dendritic cells (DCs) and can take advantage of host immune functions to avoid immune recognition. These characteristics have sparked major interest in understanding HCMV and its interaction with immune cells and their relevance to disease pathogenesis. In this review, we focus on the complex host-pathogen relationship between HCMV and DCs, including the persistence of the virus in these cells, their function in the immune response to HCMV infection and the potential clinical consequences of HCMV infection in DCs.

Strong association of phenylalanine and tryptophan metabolites with activated cytomegalovirus infection in kidney transplant recipients

Infection-induced inflammation triggers catabolism of proteins and amino acids. Phenylalanine and tryptophan are 2 amino acids related to infections that regulate immune responses. Polyomavirus BK (BKV) and cytomegalovirus (CMV) are important pathogens after kidney transplantation. We investigated the clinical relevance of phenylalanine, tryptophan, and tryptophan metabolites (kynurenine and quinolinic acid) plasma levels in kidney transplant recipients with active CMV (BKV(-)CMV(+), n = 12) or BK virus infection (BKV(+)CMV(-), n = 37). Recipients without active viral infections (CMV(-)BKV(-), n = 28) and CMV(-)BKV(-) healthy individuals (HCs, n = 50) served as controls. In contrast to BKV infection, activated CMV infection is tightly linked to increased phenylalanine and tryptophan metabolite plasma levels (p ≤ 0.002). The association of phenylalanine (cutoff 50 μmol/L) with CMV infection demonstrates high sensitivity (100%) and specificity (94%). By contrast, kynurenine (p = 0.029) and quinolinic acid (p = 0.003) values reflect the severity of CMV infection. In this early proof-of-concept trial, evidence indicates that activated CMV infection is strongly associated with increased phenylalanine as well as kynurenine and quinolinic acid plasma levels. Moreover, tryptophan metabolite levels correlate with disease severity. Measurement of these amino acids is an inexpensive and fast method expected to complete conventional diagnostic assays.

Cytomegalovirus-induced immunopathology and its clinical consequences

Human cytomegalovirus (CMV) is a ubiquitous DNA virus that causes severe disease in patients with immature or impaired immune systems. During active infection, CMV modulates host immunity, and CMV-infected patients often develop signs of immune dysfunction, such as immunosuppression and autoimmune phenomena. Furthermore, active viral infection has been observed in several autoimmune diseases, and case reports have linked primary CMV infection and the onset of autoimmune disorders. In addition, CMV infection promotes allograft rejection and graft-versus-host disease in solid organ and bone marrow transplant recipients, respectively, further implicating CMV in the genesis and maintenance of immunopathological phenomena. The mechanisms by which CMV could induce inhibition of host defense, inflammation, and autoimmunity are discussed, as is the treatment of virus-induced immunopathology with antivirals.

The 'indirect' effects of cytomegalovirus infection

Cytomegalovirus (CMV) remains the most important infection in the immunocompromized host even in the era of effective therapy. CMV is usually acquired early in life and can be transmitted by contact with infected body fluids. In the immunocompetent population, primary infection is almost always of little clinical consequence. However, CMV infection in immunocompromized patients, especially those naive to CMV exposure, can cause tissue invasive disease, severe symptoms and/or death. However, beyond these direct effects, increasing in vitro evidence is accumulating that suggests CMV has many other effects on the host's immune response which may explain some of the detrimental consequences for the immunosuppressed patient, and may also be partially responsible for a variety of conditions in immunocompetent individuals. In its latent state, CMV employs several mechanisms to evade detection by the host's immune system. The virus also employs other methods to take advantage of activation of the immune system and replicate in sites of inflammation. This review focuses on the immunosuppressive and inflammatory mechanisms that have been attributed to CMV and will relate them to some of the clinical sequellae that have been associated with the indirect effects of CMV infection.

HCMV infection of PDCs deviates the NK cell response into cytokine-producing cells unable to perform cytotoxicity

Plasmacytoid dendritic cells (PDCs) are thought to induce natural killer (NK) cell CD69 expression, cytotoxicity, and cytokine secretion. Since human cytomegalovirus (HCMV) interferes with multiple functions of infected cells, we investigated whether the HCMV infection of PDCs affects NK cell activation. Human PDCs infected with HCMV strain VR1814 at multiplicity of infection (MOI) 10 or stimulated with control CpG-A were cocultured with human NK cells in an autologous system. As expected, CpG-stimulation of PDCs increased expression of the NK cell activation marker CD69, enhanced cytotoxicity and stimulated secretion of tumor necrosis factor (TNF)-alpha and IFN-alpha, but not IFN-gamma, and induced NK cell migration. In contrast, incubation with HCMV-infected PDCs induced CD69 expression, migration and elevated production of both TNF-alpha and IFN-gamma by NK cells, but these cells did not exhibit enhanced cytotoxicity. Also, HCMV-infected PDCs were unable to induce increased intracellular perforin levels. Thus, HCMV infection of PDCs induce NK cells to increase CD69 expression and produce inflammatory cytokines, but infected PDCs are unable to induce NK cell cytotoxicity. This NK cell phenotype with impaired killing abilities, but enhanced production of inflammatory cytokines may instead facilitate reactivation and replication of HCMV. This data indicate that HCMV can target PDCs through novel dual strategies that may result in evasion of the innate immune response at the same time as facilitating virus reactivation and replication early in the infection, through enhanced inflammation.

A high prevalence of parvovirus B19 DNA in patients with psoriasis

Psoriasis is a common inflammatory skin disease. Infectious models are considered to be of pathophysiological importance in psoriasis. The immunological profile of stable psoriasis plaques suggests that viral antigens may be important. Human parvovirus B19 (PVB19) is a single-stranded DNA virus that causes various clinical symptoms. Several case reports have suggested associations between PVB19 infection and various chronic autoimmune and dermatologic diseases. There has so far been no information regarding the role of PVB19 in psoriasis, except psoriatic arthritis. In this report, to investigate the role of PVB19 in psoriasis, we analyzed PVB19 DNA of peripheral blood from psoriatic patients (n = 47) in comparison with blood donors (n = 20). We also determined the presence of anti-PVB19 IgG and IgM antibodies by using enzyme-linked immunosorbent assay (ELISA). We found that the presence of PVB19 DNA in patients with psoriasis (38%) was significantly higher than in controls (0%, P < 0.01). Anti-PVB19 IgG antibodies were detected in 79% of the cases while only 6% had anti-PVB19 IgM antibodies. PVB19 DNA presence was associated with seropositivity for anti-PVB19 IgG (P < 0.05) but not with IgM antibodies, indicating subclinical activation of latent infection. No correlation was found between the presence of PVB19 DNA and a patient's age, sex, type of psoriasis, or psoriasis area and severity index. The data demonstrated a statistically significant association between psoriasis and PVB19. Therefore, we suggest that PVB19 infection may be of pathophysiological importance in psoriasis.

Does cytomegalovirus play a causative role in the development of various inflammatory diseases and cancer?

Human cytomegalovirus (HCMV) is a herpes virus that infects and is carried by 70-100% of the world's population. During its evolution, this virus has developed mechanisms that allow it to survive in an immunocompetent host. For many years, HCMV was not considered to be a major human pathogen, as it appeared to cause only rare cases of HCMV inclusion disease in neonates. However, HCMV is poorly adapted for survival in the immunosuppressed host and has emerged as an important human pathogen in AIDS patients and in patients undergoing immunosuppressive therapy following organ or bone marrow transplantation. HCMV-mediated disease in such patients has highlighted the possible role of this virus in the development of other diseases, in particular inflammatory diseases such as vascular diseases, autoimmune diseases and, more recently, with certain forms of cancers. Current research is focused on determining whether HCMV plays a causative role in these diseases or is merely an epiphenomenon of inflammation. Inflammation plays a central role in the pathogenesis of HCMV. This virus has developed a number of mechanisms that enable it to hide from the cells of the immune system and, at the same time, reactivation of a latent infection requires immune activation. Numerous products of the HCMV genome are devoted to control central functions of the innate and adaptive immune responses. By influencing the regulation of various cellular processes including the cell cycle, apoptosis and migration as well as tumour invasiveness and angiogenesis, HCMV may participate in disease development. Thus, the various drugs now available for treatment of HCMV disease (e.g. ganciclovir, acyclovir and foscarnet), may also prove to be useful in the treatment of other, more widespread diseases.

Increased Levels of Tumor Necrosis Factor α Are Associated with an Increased Risk of Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation

Tumor necrosis factor-alpha (TNF) has been implicated in the reactivation of cytomegalovirus (CMV) at a cellular level. We therefore hypothesized that increased posttransplantation TNF levels may be associated with the development of CMV antigenemia (CMV-Ag). We studied 134 patients undergoing allogeneic hematopoietic stem cell transplantation. After excluding CMV-negative donor and recipient pairs, 94 patients were evaluable. By cluster analysis, 2 groups were designated by TNF levels obtained between days 4 and 7 after transplantation: 58 patients had low levels (median, 0 pg/mL; range, 0-5.5 pg/mL), and 36 patients had high levels (median, 43.75 pg/mL; range, 7.5-1756 pg/mL). To determine the independent effect of TNF on the development of CMV-Ag and acute graft-versus-host disease and on survival, Kaplan-Meier and Cox models stratified by TNF patient groups were evaluated. High TNF levels were associated with a more rapid onset of CMV-Ag (P < .001) and with the occurrence of the composite end point of CMV-Ag or death (P < .001). Factors independently associated with CMV-Ag in multivariate analysis were a high TNF level (hazard ratio [HR], 2.57; P = .003) and acute graft-versus-host disease (as a time-dependent covariate; HR, 2.30; P = .010). Factors independently associated with the composite end point of CNV-Ag or death were a high TNF level (HR, 2.42; P < .001) and patient age (per year; HR, 1.93; P = .017). In conclusion, a high posttransplantation TNF level is significantly associated with the risk for developing CMV infection. Early detection of high levels of TNF may be used to identify patients at high risk for developing CMV-Ag.

Amplification of autoimmune disease by infection

Reports of infection with certain chronic persistent microbes (herpesviruses or Chlamydiae) in human autoimmune diseases are consistent with the hypothesis that these microbes are reactivated in the setting of immunodeficiency and often target the site of autoimmune inflammation. New experimental animal models demonstrate the principle. A herpesvirus or Chlamydia species can be used to infect mice with induced transient autoimmune diseases. This results in increased disease severity and even relapse. The evidence suggests that the organisms are specifically imported to the inflammatory sites and cause further tissue destruction, especially when the host is immunosuppressed. We review the evidence for the amplification of autoimmune inflammatory disease by microbial infection, which may be a general mechanism applicable to many human diseases. We suggest that patients with autoimmune disorders receiving immunosuppressing drugs should benefit from preventive antiviral therapy.

Biology of tumor necrosis factor-alpha- implications for psoriasis

Numerous recent investigations have pointed to a key role of the proinflammatory, pleiotropic cytokine tumor necrosis factor-alpha (TNF-alpha) in host defense and inflammatory processes. TNF overexpression has been found in lesional skin and in the circulation of psoriatic patients, and it was suggested that TNF-alpha is crucial in this and other immune diseases. Several approaches to inhibit TNF-alpha activity have been developed. These include three different neutralizing antibodies to TNF-alpha as well as three different soluble TNF-alpha receptors with characteristic properties designed to bind the 17-KDa soluble trimeric TNF-alpha and the 26-KDa membrane-bound form of TNF-alpha. Clinical trials have demonstrated significant antipsoriatic effects, and it is likely that blocking TNF-alpha will become an important therapeutic option. The data available from these trials contribute to further understanding of the disease by demonstrating the major role of TNF-alpha. An in-depth understanding of the regulation of TNF gene expression, protein production, receptor expression, and signaling pathways may lead to further, potentially important novel therapeutic strategies and antipsoriatic active small molecules, suitable for oral application in the future. Here we review the current knowledge of TNF biology, the approaches to inhibit TNF activity, and their clinical and immunological effects in psoriasis. In addition, the host-defense effects and chronic TNF-blocking activity are discussed.

Human cytomegalovirus inhibits cytokine-induced macrophage differentiation

Human cytomegalovirus (HCMV) infection in immunocompromised patients is associated with impaired immunological function. Blood monocytes, which differentiate into macrophage effector cells, are of central importance for immune reactivity. Here, we demonstrate that HCMV transiently blocks cytokine-induced differentiation of monocytes into functionally active phagocytic macrophages. In HCMV-treated cultures, the cells had classical macrophage markers but lacked the classical morphological appearance of macrophages and had impairments in migration and phagocytosis. Even at very low multiplicities of infection, macrophage differentiation was almost completely inhibited. The inhibition appeared to be mediated by a soluble factor released upon viral treatment of monocytes. Human immunodeficiency virus or measles virus had no such effects. These findings suggest that HCMV impairs immune function by blocking certain aspects of cytokine-induced differentiation of monocytes and demonstrate an efficient pathway for this virus to evade immune recognition that may have clinical implications for the generalized immunosuppression often observed in HCMV-infected patients.

Subclinical activation of latent cytomegalovirus (CMV) infection and anti-CMV immune response in patients with atopic dermatitis

BACKGROUND

Microbiological infections are considered to be of pathophysiological importance in atopic dermatitis (AD). As yet, no information is available regarding cytomegalovirus (CMV) infection in this disease. This, however, is of interest because of the high prevalence of latent infections in the general population, the frequent reactivation in inflammatory diseases, and the immunomodulating capacity of CMV.

OBJECTIVES

To investigate the prevalence of latent CMV infection, the frequency of active CMV infection, and the immune response to CMV in patients with moderate to severe AD. Methods To detect active infection we analysed CMV antigen expression by peripheral blood mononuclear cells (PBMC) from 27 patients with moderate to severe AD in comparison with 53 healthy volunteers. We used three monoclonal antibodies recognizing different CMV-encoded antigens and immunocytological staining (alkaline phosphatase-antialkaline phosphatase technique).

RESULTS

Patients with AD had a higher mean frequency of CMV-positive PBMC: 2.25 per 10 000 vs. 0.74 per 10 000 in controls (P = 0.001) as well as a higher incidence of CMV antigenaemia: 29.6% vs. 7.5% (P < 0.01). Seropositivity for anti-CMV IgG antibodies indicated subclinical activation of latent infection. Remarkably, a clearance of CMV antigenaemia was observed during anti-eczematous treatment. Significantly higher plasma levels of tumour necrosis factor-alpha, which is involved in CMV reactivation, and interleukin-12, which is crucial for an antiviral cellular immune response, were observed in AD patients in comparison with healthy volunteers. Furthermore, a significantly enhanced frequency of circulating activated HLA-DR+ T cells especially in CMV-seropositive AD patients (19.3% vs. 13.5% in seronegative AD patients vs. 10.2% in controls) suggested that the active CMV infection triggers a cellular immune response. This was also supported by a high frequency of CMV-specific interferon-gamma-producing T cells in CMV-seropositive patients with AD.

CONCLUSIONS

Our data suggest that active, subclinical CMV infection is more frequent in patients with moderate to severe AD and may have immunopathophysiological relevance.

NF-kappaB--a potential therapeutic target for inhibition of human cytomegalovirus (re)activation?

From clinical studies the proinflammatory cytokine TNFalpha was proposed to play a key role in human cytomegalovirus (HCMV) reactivation from latency. In vitro experiments confirmed that TNFalpha stimulates the activity of the HCMV IE1/2 enhancer/promoter, which controls immediate early protein IE1 and IE2 gene expression via activation of the transcription factor NF-kappaB and its binding to putative binding sites in the IE1/2 enhancer. NF-kappaB was also proposed to be involved in IE1-mediated autostimulation of this promoter. The IE1/2 enhancer of HCMV contains four putative NF-kappaB binding sites which differ in their distance to the transcription start site as well as in their sequence. Construction and testing of a series of promoter mutants demonstrated that NF-kappaB is essential for both TNFalpha and IE1 stimulation. Furthermore, we were able to show that although all four NF-kappaB sites bind NF-kappaB with similar affinity in vitro, the contribution to TNFalpha and IE1 stimulation differs in correlation with the distance to the transcription start site and the sequence. Site 1 and 3 play the most dominant role and site 2 an intermediate, while site 4, which is conserved in sequence but far distant from the transcription start site, had no influence on NF-kappaB-mediated regulation of the IE1/2 promoter. Specific inhibition of NF-kappaB signalling by co-expression of a dominant-negative IkappaB variant reduced TNFalpha stimulation of the IE1/2 enhancer/promoter by up to 80%. From this data, inhibitors of NF-kappaB activation are suggested to be an alternative therapeutical strategy to interfere with HCMV (re)activation in undifferentiated monocyte/granulocyte progenitor cells in patients with a high risk of inflammation-related HCMV (re)activation.

Proteasome Inhibitors: A Novel Tool to Suppress Human Cytomegalovirus Replication and Virus-Induced Immune Modulation

Recently, we like others, demonstrated that systemic inflammation is the most important mechanism involved in (re)activation of human cytomegalovirus (HCMV) in both immunocompromised and immunocompetent patients. By in vitro studies the eukaryotic transcription factor NF-κB could be identified as the key mediator of TNF-α- and IE1-dependent stimulation of the HCMV IE1/2 enhancer/promoter activity, which is crucial for initiation of viral gene expression during reactivation from latency as well as productive infection. The enzymatic proteasome complex plays a central role in regulating intracellular processes, including the activation of NF-κB. As present antiviral strategies target mainly late events in HCMV replication (DNA replication, virus assembly) that do not completely prevent virus mediated immunopathogenesis, we wondered whether proteasome inhibitors might be a novel tool for targeting the interaction between inflammation and HCMV (re)activation. Here, proteasome inhibitors like MG132, PSI, II and III (MG262) have been shown to block both TNF-α-associated up-regulation of the HCMV IE1/2 enhancer/promoter in monocytic cells in an in vitro transient transfection system and HCMV replication in permissive human embryonal lung fibroblasts. Importantly, ganciclovir-resistant HCMV strains are sensitive to proteasome inhibitors. The effect of proteasome inhibitors on HCMV replication was found to be specific as replication of other herpes viruses, like HSV-1 and HSV-2, under identical experimental conditions was not influenced. Inhibition of HCMV replication correlated with a delayed and significantly reduced expression of IE proteins, particularly of the IE2 protein, suggesting that MG132 blocks HCMV replication at an immediate early stage of infection. Early and late protein synthesis as shown exemplary for the pp52 (DNA-binding protein) and p68 (structural protein) protein production and viral DNA synthesis were also inhibited. Suppression of HCMV replication could be correlated with an increased cytosolic accumulation of IκB as well as a reduced NF-κB binding activity in nuclear extracts of MG132-treated cells, which mainly regards NF-κB p50. MG132 also reduced the immune modulatory activity of the virus by abrogating virus-induced up-regulation of cellular ICAM-1. These data suggest that short-term therapy with proteasome inhibitors might be an alternative strategy to prevent (re)activation, replication and immune modulatory activity of HCMV in patients with systemic inflammation.

Novel therapies for psoriasis

The T cell-driven immunopathogenesis of psoriasis has been well recognized since cyclosporine first revolutionized the treatment of psoriasis 20 years ago. Almost all investigative and clinical research subsequently, has concentrated on elucidating the specifics of antigen presentation, T cell interaction and the production of specific cytokines. The role of the keratinocyte, previously thought to be the primary target cell in psoriasis pathogenesis, has been relegated to a secondary role and the mechanism of action of systemic methotrexate in psoriasis has been challenged, the primary role of the T lymphocyte is now well known. While psoriasis has traditionally been treated "ab initio" with topical medications (corticosteroids, vitamin D(3), and retinoid derivatives), either singly, in combination, or with ultraviolet B (UVB) or psoralens and ultraviolet A (PUVA) therapy, the role of systemic medications has assumed greater prominence. Thus, three systemic medications currently are approved worldwide for the treatment of moderate to severe forms of psoriasis, namely cyclosporine, methotrexate and acitretin. The first two are likely to give significant clearing (greater than 75%) in the majority of cases, whereas acitretin is significantly less effective as monotherapy, but may approach methotrexate and cyclosporine in efficacy, if combined with PUVA or UVB phototherapy. The main limitations of these three drugs remain organ toxicity, especially hepatic toxicity with methotrexate, hypertension and nephrotoxicity with cyclosporine, and teratogenicity and mucocutaneous toxicity with acitretin. Thus, the need for more specific systemic therapy, targeting the T lymphocyte. This has become the major area of clinical research interest over the past 5 years, with the promise of longer-term disease control (improved remissions) and less organ toxicities. Currently, there are over 15 of these "biologic" drugs in various stages of development and clinical trials, either by the subcutaneous, intramuscular or intravenous route. The three main variables are the rapidity of onset, percentages of improvement and remission rates. Without exception, these new systemic agents appear to be remarkably free of systemic organ toxicities (liver, renal, bone-marrow, etc.), with adverse effects being limited to mild flu-like symptoms with the anticipated increase in infections (e.g., herpes simplex) being either equal to placebo or only marginally increased. Not all these agents under evaluation give clinical responses equal to methotrexate or cyclosporine (75% or greater clearing in 75% of cases). In addition, response rates may be slower with some therapies versus others. However, the need for intermittent administration even by the injectable route, longer remissions, lack of systemic organ toxicities and the potential for safer usage in females of child-bearing age, make a compelling argument for widespread acceptance by both patients and the dermatological community. Other modalities under clinical evaluation include vitamin D and retinoid drugs, topically and systemically, with effects on nuclear receptors, as well as more specific wavelengths (308 to 311 nm) of UVB phototherapy with application for more localized forms of psoriasis. For the 2 to 3% of the worldwide population of patients with psoriasis the future has never looked brighter.

CCAAT/enhancer-binding proteins alpha and beta negatively influence the capacity of tumor necrosis factor alpha to up-regulate the human cytomegalovirus IE1/2 enhancer/promoter by nuclear factor kappaB during monocyte differentiation

Recently we demonstrated that the ability of tumor necrosis factor alpha (TNFalpha) to stimulate the human cytomegalovirus (HCMV) IE1/2 enhancer/promoter activity in myeloid progenitor-like cells decreases when these cells differentiate into promonocytic cells. In addition, TNFalpha stimulation in the progenitor-like cell line HL-60 was shown to be mediated by nuclear factor kappaB (NF-kappaB) activation and its binding to the 18-base pair sequence motifs of the IE1/2 enhancer. We demonstrate here that the cell differentiation-dependent reduction of TNFalpha stimulation is not due to insufficient NF-kappaB activation but correlates with increased synthesis of the monocyte differentiation-associated factors CCAAT/enhancer-binding protein (C/EBP) alpha and beta. Overexpression of C/EBPalpha/beta in HL-60 cells, which normally produce only very small amounts of C/EBP, stimulated the basal activity of the promoter in the absence of NF-kappaB but suppressed the stimulatory effect of TNFalpha. A novel C/EBP-binding site was identified in the IE1/2 enhancer directly downstream of a NF-kappaB site. In order to understand the mechanisms of interaction, we used an IE1/2 promoter mutant that failed to bind C/EBP at this position and several constructs that contained exclusively NF-kappaB- and/or C/EBP-binding sites upstream of the minimal IE1/2 promoter. We could demonstrate that C/EBPalpha/beta interacts with NF-kappaB p65 and displays inhibitory activity even in the absence of direct DNA binding by forming p65-C/EBP-containing protein complexes bound to the NF-kappaB site. Moreover, C/EBP binding to the DNA adjacent to NF-kappaB supports the down-regulatory effect of C/EBPs possibly due to stabilization of a multimeric NF-kappaB-C/EBP complex. Our results show that cell differentiation factors may interfere with TNFalpha-induced human cytomegalovirus gene (re)activation.

Human cytomegalovirus infections in nonimmunosuppressed critically ill patients

OBJECTIVE

To assess the occurrence of active human cytomegalovirus (HCMV) infection and HCMV disease and to evaluate potential risk factors in immunocompetent intensive care patients after major surgery or trauma.

DESIGN

A prospective clinical study.

SETTING

An anesthesiological intensive care unit (ICU) in a university hospital.

PATIENTS

Fifty-six anti-HCMV immunoglobulin G (IgG) seropositive patients without manifest immunodeficiency whose simplified acute physiology score (SAPS II) value rose to >or=41 points during their ICU stay.

INTERVENTIONS

Once a week, the patients were examined for active HCMV infection by polymerase chain reaction and by viral cultures from blood and lower respiratory tract secretions. Three times a week, detailed clinical examination for signs of HCMV disease was carried out.

MEASUREMENTS AND MAIN RESULTS

Twenty of the 56 ICU patients (35.6%) who met the study criteria of a SAPS II score >40 points and anti-HCMV IgG seropositivity developed an active HCMV infection as diagnosed by the detection of HCMV DNA in leukocytes, plasma, or respiratory tract secretions. In seven patients, the virus was isolated in the respiratory tract secretions. Severe HCMV disease appeared in two patients with pneumonia or encephalitis respectively. In patients with active HCMV infection, the mortality tended to be higher (55%) than in those without (36%); the duration of intensive care treatment of the survivors was significantly longer in the patients with active HCMV infection (median 30 vs. 23 days; p = .0375). Univariate testing for factors associated with active HCMV infection showed the importance of sepsis at admission (p = .011) and prolonged pretreatment on the ward or in an external ICU (p = .002); the relevance of underlying malignant disease was borderline (p = .059). Multiple regression analysis identified only sepsis to be independently associated with active HCMV infection (p = .02; odds ratio, 4.62).

CONCLUSIONS

Even in a group of ICU patients without manifest immunodeficit who were anti-HCMV IgG seropositive and had reached a SAPS II score of >or=41 points, active HCMV infection occurred frequently (35.6%). Septic patients were affected twice as often as the total study population. In 2 of the 20 cases, active HCMV infection progressed to severe HCMV disease. Proper diagnosis demands special clinical attention combined with extended virological examinations. Further studies in a larger patient group should evaluate the influence of HCMV on ICU mortality.

Interleukin-10 promoter polymorphism in psoriasis

Beneficial effects of interleukin-10 therapy and lower endogenous interleukin-10 formation compared with atopic dermatitis and cutaneous T cell lymphomas indicated that interleukin-10 is a key cytokine in psoriasis. The interleukin-10 promoter is highly polymorphic, with two informative microsatellites, interleukin-10.G and interleukin-10.R. In order to understand whether interleukin-10 itself is a predisposing gene for the psoriasis susceptibility we analyzed interleukin-10 promotor polymorphism in patients. The distribution of interleukin-10.G and interleukin10.R microsatellite alleles did not vary between patients (n = 78) and healthy controls (n = 80). In addition, when the psoriasis patients were stratified according to age of onset (younger than 40 y of age, or age 40 and older), no difference in allele distribution was observed; however, a clear differential distribution was revealed at the interleukin10.G locus when patients were stratified according to whether they had a positive family history of psoriasis (p = 0.04). This difference was due to an over-representation of the interleukin10.G13 allele in those patients with familial disease (40.4% vs 19.6%, Chi-square = 7.292, p = 0.007). The positive association of allele interleukin10.G13 with familial psoriasis was especially true when patients with an early onset (< 40 y of age) of the disease were compared with those patients with early onset against a nonfamilial background (39.6% vs 14.5%, Chi-square = 8.959, p = 0.003). Patients with age-of-onset of less than 40 were 4-fold [odds ratio = 3.85 (1.55--9.62)] more likely to have a psoriatic family background if they carried this interleukin10.G13 allele. These data suggest that the interleukin-10 locus contributes to the heritability of psoriasis susceptibility.

Human cytomegalovirus reactivation in bone-marrow-derived granulocyte/monocyte progenitor cells and mature monocytes

Monocyte/granulocyte progenitor cells of the bone marrow are a major site of human cytomegalovirus (HCMV) latency. The mechanisms of establishment and maintenance of HCMV latency are still unknown. Reactivation of the latent virus in bone-marrow-derived progenitor cells has been demonstrated in vitro and suggested to occur also in vivo. Clinical studies have shown that reactivation is a rather frequent event not only in immunosuppressed but also in nonimmunosuppressed patients and in healthy blood donors. At least three independent mechanisms of virus reactivation are discussed: systemic inflammation connected with strong tumor necrosis factor alpha release; application of cAMP-elevating drugs, and highly stressful events associated with increased plasma catecholamine levels.