Interferon-gamma administration after abdominal surgery rescues antigen-specific helper T cell immune reactivity.

Antigen-induced activation of T cells is determined by many factors. Among these factors are (i) the number of T-cell receptors (TCRs) triggered by TCR ligands on antigen-presenting cells (APCs), and (ii) the intrinsic cellular threshold for activation. T-cell receptor triggering is optimized by adhesion molecules that form the interaction site between T cells and APCs, i.e. the immunological synapse. In addition, signals through co-stimulatory molecules lower the intrinsic T-cell activation threshold. Immunosuppressive agents and traumatic events such as major operative procedures change physiological T-cell responses. Depressed immune functions after surgery are presumed to render patients more susceptible to pathogens. Interferon-gamma (IFNgamma) is a type II homodimeric cytokine with multiple immunostimulatory properties. Several studies have been performed to assess the effects of IFNgamma treatment in patients in need of increased immune reactivity. However, until now, the effect of IFNgamma on human antigen specific CD4(pos) T-cell reactivity after surgically-induced immunosuppression has not been reported. Therefore, a comparative trial of recombinant human (rh) IFNgamma versus placebo in patients after abdominal surgery was initiated. Antigen-specific helper T cell immune reactivity was assessed by antigen-induced cytokine production, intracellular cytokine staining and flow cytometry. A single dose of rhIFNgamma rescued down-modulation of antigen-specific CD4(pos) T-cell reactivity, concomitant with an up-regulation of TCR-ligands on antigen-presenting cells. Selected patients may benefit from the immunostimulatory properties of rhIFNgamma administration in vivo.

Molecular diagnosis of visceral herpes zoster.

Patients with disseminated herpes zoster may present with severe abdominal pain that results from visceral involvement of varicella-zoster-virus infection. In the absence of cutaneous eruptions of herpes zoster, visceral herpes zoster is extremely difficult to diagnose. This diagnostic difficulty has the potential to cause devastating delays in treatment. We report a case series of four patients with visceral herpes zoster in whom large concentrations of DNA from varicella zoster virus were detectable in blood by PCR before signs of infection appeared on the skin, thus enabling early diagnosis and treatment.

Elevation of systemic markers related to cardiovascular diseases in the peripheral blood of periodontitis patients.

BACKGROUND: Periodontitis is a common, often undiagnosed, chronic infection of the supporting tissues of the teeth, epidemiologically associated with cardiovascular diseases. Since C-reactive protein (CRP) and other systemic markers of inflammation have been identified as risk factors for cardiovascular diseases, we investigated whether these factors were elevated in periodontitis. METHODS: Consecutive adult patients with periodontitis (localized n = 53; generalized n = 54), and healthy controls (n = 43), all without any other medical disorder, were recruited and peripheral blood samples were taken. RESULTS: Patients with generalized periodontitis and localized periodontitis had higher median CRP levels than controls (1.45 and 1.30 versus 0.90 mg/L, respectively, P = 0.030); 52% of generalized periodontitis patients and 36% of the localized periodontitis patients were sero-positive for interleukin-6 (IL-6), compared to 26% of controls (P= 0.008). Plasma IL-6 levels were higher in periodontitis patients than in controls (P = 0.015). Leukocytes were also elevated in generalized periodontitis (7.0 x 10(9)/L) compared to localized periodontitis and controls (6.0 and 5.8 x 10(9)/L, respectively, P= 0.002); this finding was primarily explained by higher numbers of neutrophils in periodontitis (P= 0.001). IL-6 and CRP correlated with each other, and both CRP and IL-6 levels correlated with neutrophils. The current findings for periodontitis were controlled for other known factors associated with cardiovascular diseases, including age, education, body mass index, smoking, hypertension, cholesterol, and sero-positivity for CMV, Chlamydia pneumoniae, and Helicobacter pylori. CONCLUSIONS: Periodontitis results in higher systemic levels of CRP, IL-6, and neutrophils. These elevated inflammatory factors may increase inflammatory activity in atherosclerotic lesions, potentially increasing the risk for cardiac or cerebrovascular events.

A survey of liver pathology in needle biopsies from HBsAg and anti-HBe positive individuals.

AIMS: To use laboratory data and liver biopsies, prospectively obtained from hepatitis B surface antigen (HBsAg) and anti hepatitis B e antigen (anti-HBe) positive patients, for the assessment of: (1) the relation between biopsy length/number of portal tracts and sampling error; (2) the relation between the severity of piecemeal necrosis and the new grading terminology (minimal, mild, moderate, and severe chronic hepatitis); and (3) liver pathology, which has not been studied in patients with this specific serological profile. METHODS: The study group (n = 174) included 104 patients with normal aminotransferase concentrations and no cases with clinically apparent cirrhosis. The specimen length and number of portal tracts were measured at light microscopy examination. Sampling error analysis was related to the discrepancies between aminotransferase concentrations versus histological grade. Detailed histological scorings were undertaken by the reference pathologist and compared with laboratory and hepatitis B virus (HBV) DNA precore sequence data. RESULTS: Sampling error seemed to be a constant feature, even for biopsies > or = 20 mm, but increased dramatically in biopsies < 5 mm long and/or containing less than four portal tracts. Between 25% and 30% of biopsies, graded as "mild" or "moderate" activity showed features of moderate and severe piecemeal necrosis, respectively. Ten per cent of the patients with normal aminotransferase values had stage III-IV hepatic fibrosis, and 20% had piecemeal necrosis. Only cytoplasmic, not nuclear, core antigen expression was a strong predictor of high hepatitis B viraemia. There was no association between precore stop codon mutations, grade/stage of liver disease, and hepatitis B core antigen (HBcAg) expression. CONCLUSIONS: The specimen available for light microscopical examination should be > 5 mm long and should contain more than four portal tracts. In addition, the new grading terminology might give the clinician an inappropriately mild impression of the severity of piecemeal necrosis. Furthermore, even in the presence of normal aminotransferase concentrations, considerable liver pathology can be found in 10-20% of HBsAg and anti-HBe positive individuals; such pathology is not associated with the occurrence of precore stop codon mutations.

Quantitation of varicella-zoster virus DNA in whole blood, plasma, and serum by PCR and electrochemiluminescence.

We describe a highly sensitive assay for quantitation of varicella-zoster virus (VZV) DNA in blood, involving PCR amplification, solution hybridization with Tris-(2, 2'-bipyridine)-ruthenium(II) chelate-labeled probes, and measurement by electrochemiluminescence (ECL). Extraction and amplification efficiencies were monitored by the inclusion of internal control (IC) DNA, mimicking the VZV target, in the DNA extraction. Viral DNA load was calculated from the ratio of VZV and IC ECL signals. The lower limit of sensitivity was 20 VZV DNA copies/ml of plasma or serum and 80 copies/ml of whole blood. In reconstruction experiments, expected and calculated VZV DNA loads were in excellent accordance. Blood specimens from 42 VZV-infected patients were tested for the presence of VZV DNA and showed detection rates of 86% in patients with varicella and 81% in patients with herpes zoster. In specimens obtained during the first week after onset of the rash, detection rates were 100 and 89%, respectively. Viral DNA was detected in all immunocompromised patients with herpes zoster, emphasizing the risk of disseminated disease in this patient group. VZV DNA load was similar in patients with varicella and multidermatomal herpes zoster and lower in patients with unidermatomal zoster. Despite the cell-associated nature of the virus, VZV DNA was detected in serum and plasma at high copy numbers, and at similar frequencies compared to whole-blood specimens. Quantitation of VZV DNA in blood is of potential importance for diagnosis and clinical management of VZV-infected patients. Plasma and serum provide convenient matrices for this purpose.

Development of virus-specific CD4(+) T cells during primary cytomegalovirus infection.

Although virus-specific CD4(+) T cells have been characterized extensively in latently infected individuals, it is unclear how these protective T-cell responses develop during primary virus infection in humans. Here, we analyzed the kinetics and characteristics of cytomegalovirus-specific (CMV-specific) CD4(+) T cells in the course of primary CMV infection in kidney transplant recipients. Our data reveal that, as the first sign of specific immunity, circulating CMV-specific CD4(+) T cells become detectable with a median of 7 days after first appearance of CMV-DNA in peripheral blood. These cells produce the T helper 1 type (Th1) cytokines IFNgamma and TNFalpha, but not the T helper 2 type (Th2) cytokine IL4. In primary CMV infection, the vast majority of these circulating virus-specific T cells have features of recently activated naive T cells in that they coexpress CD45RA and CD45R0 and appear to be in the cell cycle. In contrast, in people who have recovered from CMV infection earlier in life, virus-specific T cells do not cycle and express surface markers characteristic of memory T cells. After the initial rise, circulating virus-specific CD4(+) T cells decline rapidly. During this phase, a strong rise in IgM and IgG anti-CMV antibody titers occurs, concomitant with the reduction of CMV-DNA in the circulation.

Measles in a Dutch hospital introduced by an immuno-compromised infant from Indonesia infected with a new virus genotype.

A fatal measles case in an immunocompromised Indonesian child was associated with nosocomial transmission to health care workers. The virus isolated proved to represent a new genotype within clade G.

Hepatitis B and C virus co-infection and the risk for hepatotoxicity of highly active antiretroviral therapy in HIV-1 infection.

OBJECTIVE: To investigate the risk of hepatotoxicity after initiation of protease inhibitor-containing highly active antiretroviral therapy (HAART) for HIV-1 infected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) co-infection. DESIGN: Retrospective study with 394 HIV-1-infected patients initiating HAART at a single university clinic. METHODS: Liver enzyme elevation (LEE) was defined as alanine aminotransferase or aspartate aminotransferase at least five times the upper limit of normal and an absolute increase of > 100 U/l. Relative risks for time to LEE were estimated using Cox proportional hazards models. RESULTS: Of 394 patients 7% were hepatitis B surface antigen (HBsAg)-positive and 14% were anti-HCV-positive. Patients with chronic hepatitis had a higher risk for LEE compared with patients without co-infection: 37% versus 12% respectively. After adjustment for higher baseline transaminases, the presence of HBsAg or anti-HCV remained associated with an increased risk of LEE - relative risk 2.78 (95% confidence interval, 1.50-5.16) and 2.46 (95% confidence interval, 1.43-4.24) respectively. In patients with LEE, transaminases declined whether HAART was continued or modified. Of patients with chronic HBV infection 38% lost HBeAg or developed anti-HBe after initiation of HAART, and one seroconverted from HBsAg-positive to anti-HBs-positive. However, there was no clear relationship with LEE. CONCLUSIONS: HIV-1-infected patients co-infected with HBV or HCV were at considerably higher risk of developing LEE when HAART was initiated compared with patients without co-infection, but it is usually not necessary to modify antiretroviral therapy.

Kawasaki disease: a maturational defect in immune responsiveness.

Kawasaki disease (KD), an acute febrile disease in children of unknown etiology, is characterized by a vasculitis that may result in coronary artery aneurysms (CAAs). In new patients with KD, a selective and prolonged T cell unresponsiveness to activation via the T cell antigen receptor CD3 was observed, whereas proliferation to other stimuli was intact. This "split T cell anergy" delineated KD from other pediatric infections and autoimmune diseases and correlated with CAA formation (P<.001). A transient immune dysfunction was also suggested by an incomplete responsiveness to measles-mumps-rubella (MMR) vaccination in patients with KD versus controls (P<.0001; odds ratio, 15.6; 95% confidence interval, 4.8-51.1), which was overcome by revaccination(s). The reduced responsiveness to MMR in patients with KD suggests a subtle and predetermining immune dysfunction. An inherent immaturity to clear certain antigens may be an important cause that precipitates KD and the immune dysregulation during acute disease.

Influence of highly active antiretroviral therapy on the development of CMV disease in HIV positive patients at high risk for CMV disease.

BACKGROUND/AIMS: In the pre-HAART era, HIV positive patients with CD4+ cell counts below 50 cells x10(6)/l, and those with detectable cytomegalovirus (CMV) DNA in their peripheral blood, were considered to be at high risk for the development of CMV disease. With the start of highly active antiretroviral therapy (HAART), a restoration of immune function occurred in these patients, and as a consequence patients became less vulnerable to CMV disease. Since it is not exactly known how HAART influences CMV viral load in peripheral blood and the incidence of CMV disease in high risk HIV positive patients a group of patients was followed before and after initiation of HAART. METHODS: 29 HIV positive patients, seen in the first 3 months of 1996 at the AIDS clinic of the Academic Medical Centre, at high risk for development of CMV disease (positive CMV DNA assay in blood and/or CD4+ cell count below 50 cells x10(6)/l), not receiving anti-CMV maintenance therapy, were included in a prospective cohort study. HAART was started in the second trimester of 1996. Patients were evaluated for the occurrence of CMV retinitis, or CMV disease elsewhere, comparing the incidence of CMV events before and after the start of HAART. Following the introduction of HAART, CD4+ cell counts and quantitative polymerase chain reaction (PCR) for CMV DNA in blood were monitored in all patients who remained alive and were not receiving anti-CMV maintenance therapy (n=22). Follow up was performed until August 1998; the mean follow up after the start of HAART was 14.9 months (range 8-22 months). RESULTS: In the pre-HAART period four patients developed CMV disease, and four died (without clinically manifest CMV disease). After the start of HAART no patient developed CMV disease or died. With HAART, the mean CD4+ cell counts increased from 34 cells x10(6)/l to 194 cells x10(6)/l at the end of follow up. CMV DNA could be detected in the blood of 11 patients. Quantification showed a decline in the amount of detectable DNA during follow up. At the last examination only one patient showed a positive PCR assay. This was the only patient with a CD4+ cell count remaining below 100 cells x10(6)/l. CONCLUSION: In HIV positive patients at high risk of CMV retinitis, either with a positive CMV PCR assay in blood and/or with CD4+ cell counts below 50 cell x10(6)/l, HAART causes a dramatic decrease in the occurrence of CMV disease. This decrease is paralleled by an increase in CD4+ cell count, and a decrease in the amount of CMV DNA in the blood, which was below detection levels in all patients with CD4+ cell counts above 100 cells x10(6)/l.

Comparison of PCR, culture, and serological tests for diagnosis of Mycoplasma pneumoniae respiratory tract infection in children.

For diagnosis of Mycoplasma pneumoniae infection we compared two rapid tests, PCR and the immunoglobulin M immunofluorescence assay (IgM IFA), with culture and the complement fixation test (CFT), in a prospective study among 92 children with respiratory tract infection and 74 controls. Based on positivity of culture and/or CFT as the diagnostic criterion, nine patients (10%) were diagnosed with M. pneumoniae infection. All patients positive by culture were also positive by PCR. In all controls cultures, PCRs, and serological assays were negative, except in one with a positive IgM IFA. The IgM IFA had a low positive predictive value of 50%. Only a combination of PCR (seven patients) and CFT (seven patients) allowed diagnosis of all cases.

Relation between laboratory test results and histological hepatitis activity in individuals positive for hepatitis B surface antigen and antibodies to hepatitis B e antigen.

BACKGROUND: Hepatitis B surface antigen (HBsAg) and antibodies to hepatitis B e antigen (anti-HBe) commonly coexist, and laboratory tests are often requested to assess histological hepatitis activity. An optimum panel of tests has not been found and the usefulness of hepatitis B virus (HBV) DNA assays in this context has not been established. We assessed various blood tests to find which best predicted hepatitis activity. METHODS: Routine plasma biochemical liver tests and serum HBV DNA (hybridisation and PCR assays) were assessed prospectively in 123 patients positive for HBsAg and anti-HBe. We scored histological hepatitis activity (hepatitis activity index) and determined whether chronic active hepatitis (chronic hepatitis with portal and periportal lesions) was present. We analysed the relation between laboratory data and the hepatitis activity index or risk of chronic active hepatitis by multiple regression and multiple logistic regression, respectively. FINDINGS: The analyses provided models for predicting either the hepatitis activity index or the risk of chronic active hepatitis. Aspartate aminotransferase was the most important test in the two models. The contribution of HBV DNA and other assays, especially alanine-aminotransferase activity, were of no practical importance. INTERPRETATION: Because screening by aspartate-aminotransferase activity could not be improved by the addition of other assays or HBV DNA, patients positive for HBsAg and anti-HBe could be screened for chronic active hepatitis with a single assay and counselling of patients can be improved if proper reference values are used.

Risk of developing CMV retinitis following non-ocular CMV end organ disease in AIDS patients.

AIM: To describe the risk of developing cytomegalovirus (CMV) retinitis after a first episode of extraocular CMV disease in AIDS patients. METHODS: A review of the clinical records of 20 AIDS patients, without CMV retinitis, with histologically confirmed extraocular CMV disease, was performed. The main outcome measures were occurrence of CMV retinitis, time to development of CMV retinitis, relation to maintenance therapy, and survival. RESULTS: A CMV retinitis was diagnosed in 17 of 20 (85%) patients with an immunohistologically confirmed diagnosis of extraocular CMV disease after a mean follow up of 6.4 months. Four patients received maintenance therapy. Three of them developed retinitis after a mean of 9.6 months (range 2-16 months). Sixteen did not receive maintenance and retinitis was diagnosed in 14 of them after a mean of 5.7 months (range 2-11 months). Mean survival was 9.9 months after the diagnosis of extraocular disease, and 4.5 months after the diagnosis of retinitis. In the four patients receiving maintenance therapy, mean survival was 11.5 months, and in the 16 other patients mean survival was 9.5 months. Patients did not receive protease inhibitors. CONCLUSION: In the preprotease inhibitor era extraocular CMV disease strongly predisposes to the subsequent development of CMV retinitis. Although maintenance therapy did not prevent the occurrence of retinitis, the time period between both events seems to lengthen considerably. In patients receiving maintenance survival is also longer.

Value of laboratory investigations in clinical suspicion of cytomegalovirus-induced upper gastrointestinal tract ulcerations in HIV-infected patients.

To assess the value of laboratory investigations for the diagnosis and treatment of cytomegalovirus-induced upper gastrointestinal tract ulcerations, the medical records and biopsy material from HIV-infected patients were reviewed retrospectively during a 12-month period. Clinical diagnosis of cytomegalovirus (CMV) ulceration, based on characteristic endoscopic appearance of extensive ulceration of the mid- to distal esophageal or gastric mucosa and responsiveness to anti-CMV therapy, was compared with laboratory investigations of biopsies. Laboratory procedures consisted of both histopathological examination of the biopsy specimens and viral culture. Twenty episodes in 12 HIV-infected patients could be evaluated. Clinical diagnosis of CMV ulceration appeared to be justified in 14 of 20 episodes (70%), which were confirmed by laboratory investigations. Of the remaining six episodes, which showed partial or no response to anti-CMV therapy, laboratory investigations were negative in two episodes and discrepant in four episodes (histopathology or viral culture positive). A good response to anti-CMV therapy was more frequent in patients whose biopsies proved positive by histopathological examination and/or viral culture than in patients with negative tests (82% versus 0%), which indicates the importance of both investigations. In conclusion, laboratory diagnosis of CMV-induced upper gastrointestinal tract ulcerations supported the diagnosis and decisions on treatment of CMV-induced upper gastrointestinal tract ulcerations.

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.

[Acyclovir-resistant herpes simplex virus infections in immunocompromised patients]. / Aciclovir-resistente herpes simplex-virusinfecties bij immuungecompromitteerde patiënten.

In order to determine the sensitivity of herpes simplex virus (HSV) isolates from immunocompromised patients treated with antiviral compounds, a retrospective study was carried out in the Clinical Virology Department of the University Medical Centre, Amsterdam. Virus isolates from four AIDS patients and one bone marrow transplant recipient were examined for their sensitivity for the antiviral compounds used by means of plaque reduction assay. In some of the virus isolates, from patients in whom resistance was assumed on clinical grounds, in vitro resistance of the HSV to acyclovir (ACV) could be demonstrated, both after oral and after parenteral administration. There was a clear correlation between the clinical course of the HSV infection and in vitro resistance. ACV resistant virus isolates were sensitive to foscarnet, both clinically and in vitro. In immunocompromised patients treated for some time with ACV for HSV infection, resistance should be considered at lack of results or progression of the lesion and when necessary be demonstrated in vitro. Alternative therapy then consists of intravenous foscarnet treatment.

Expression of HLA class I heavy chains and beta 2-microglobulin does not affect human cytomegalovirus infectivity.

Human cytomegalovirus (HCMV) purified from urine or tissue culture supernatant has been reported to contain beta 2-microglobulin (beta 2m), which forms the light chain of HLA class I molecules. It has been postulated that HCMV covered with beta 2m binds to HLA class I alpha-chains at the cell surface. In the present study we used transfected human and mouse cell lines expressing distinct allelic forms of HLA class I and beta 2m to determine whether HLA class I molecules could act as cellular receptors for HCMV. The susceptibility of cells to HCMV infection was estimated by calculating the percentage of cells expressing HCMV immediate early antigens. Although the results showed some variation between different transfected cell clones, no correlation was found between expression of HLA class I on the cell membrane and HCMV infection. Preincubation of HLA class I-positive cells with antibodies against HLA class I antigens inhibited HCMV infection after binding and adsorption of HCMV. Trypsin prevented HCMV infection of both class I-positive and class I-negative cells. We conclude that these results do not support the assumption that HLA class I molecules are functional receptors for HCMV.