Identification of bacterial infections and clinical manifestation associated with cytomegalovirus in liver transplantation patients

INTRODUCTION

Liver transplantation has become the most effective therapy for the treatment of patients with end-stage liver disease. With new immunosuppressive agents the incidence of acute rejection has been significantly reduced, but infection has become a serious problem.

OBJECTIVE

Our objective was to correlate cytomegalovirus (CMV) positivity of antigenemia and polymerase chain reaction (PCR) with clinical manifestations and bacterial infections among patients undergoing liver transplantation.

METHODS

This prospective study included patients monitored for 6 months for early detection of CMV infection. Sample collections were performed at the time of surgery and weekly until the second month followed by fortnightly in the third month, and monthly in the fourth to sixth month. CMV infection was defined by positive antigenemia (>3 cells) or 2 positive PCR tests associated or not with clinical symptoms. The methodology for the diagnosis of bacterial infection was through biochemical tests and the automated VITEK/bioMérieux (identification and antibiogram) using samples of urine and blood cultures. Chi-square test was used for dicotomic variables with significant differences when P < .05.

RESULTS

Sixteen patients (32%) had CMV infections, including 13 (81%) with concomitant infections. Thirty-four patients (68%) did not have CMV infections and 8 of these (24%) had bacterial infection. There was a high correlation with bacterial infections among CMV-positive patients.

CONCLUSION

Bacterial infections after liver transplantation were associated with CMV infection.

Correlation of cytomegalovirus and human herpesvirus 7 with CD3+ and CD3+ CD4+ cells in chronic periodontitis patients

BACKGROUND AND OBJECTIVE

Human chronic periodontitis is an inflammatory process characterized by dense accumulation of immune cells in the periodontal tissue. The periodontitis can lead to loss of teeth in the patient and the pathogenesis of this disease is not completely known. This study tested the hypothesis that chronic periodontitis-affected sites can harbor betaherpesviruses and that viruses are linked to a profile of the inflammatory infiltrate.

MATERIAL AND METHODS

Biopsies of periodontal tissue were taken from periodontitis-affected patients and from healthy subjects. Immunohistochemistry was performed to count CD19(+) B cells, CD3(+) total T cells, T-CD4(+) and T-CD8(+) cell subsets, and PCR was performed to detect cytomegalovirus and human herpesvirus 6 and 7 in the samples. One slide of each sample was stained with Giemsa for histopathological examination and to evaluate the quality of the cellular infiltrate.

RESULTS

As expected, tissues collected from healthy subjects presented no significant level of inflammatory infiltration and were therefore excluded from immunostaining procedures. Results showed that CD19(+) B cells were in higher number than CD3(+) T cells in the periodontitis-affected tissue, but this was not statistically significant. The T-CD4(+) lymphocyte subset was significantly higher than the T-CD8(+) lymphocyte subset (p = 0.004) in the samples. Cytomegalovirus and human herpesvirus 7 were found at periodontitis-affected sites, but not in tissue collected from healthy subjects (p = 0.04 and p = 0.04, respectively). Human herpesvirus 6 was rarely detected. We found a correlation between cytomegalovirus and lower CD19(+) /CD3(+) ratios (ratio < 0.9, p = 0.003) and between human herpesvirus 7 and lower CD19(+) /CD3(+) ratios (ratio < 0.9, p = 0.003) and higher CD4(+) /CD8(+) ratios (ratio > 1.1, p = 0.002).

CONCLUSION

This study shows that cytomegalovirus and human herpesvirus 7 can be present at periodontitis-affected sites but are uncommon at healthy periodontal sites. Moreover, our data suggest that cytomegalovirus can be related to an inflammatory infiltrate with predominance of CD3(+) T cells, whereas human herpesvirus 7 can be associated with an infiltrate with predominance of T-CD4(+) cells. However, further studies are necessary to support this hypothesis. Herpesviruses could play a role in human chronic periodontitis by modulation of the T cell response.

Detection and monitoring of human herpesvirus 7 in adult liver transplant patients: impact on clinical course and association with cytomegalovirus

We herein have described HCMV and HHV-7 detection during the follow-up of 29 adult liver recipients in our transplant unit. For basic immunosuppression, the patients received cyclosporine and symptomatic HCMV infection was treated with gancyclovir. The most prevalent etiology for liver transplantation was hepatitis C or alcohol abuse (45% of patients). The laboratory monitoring to 180 days after transplantation was performed by nested-polymerase chain reaction to HCMV or HHV-7. HCMV DNA was detected in 19/29 of patients (65.5%) and HHV-7 DNA, in 14/29 of patients (48.2%). The time-related appearance of HHV-7 and HCMV DNA differed significantly (P = .02); their detection was considered independent (P = .2). The results showed that few patients remained free of HHV-7 or HCMV after liver transplantation, indicating that most patients were actively infected with more then one virus sequentially and not concurrently. Graft dysfunction, fever, gastrointestinal system abnormalities, and interstitial pneumonitis dominated the clinical pictures. Thirteen of 29 patients (44.8%) developed symptomatic HCMV active infections. The relationship between the detection of HCMV DNA, and HCMV disease development was significant (P = .0004). In HCMV-free patients, no symptoms or significant laboratory findings were linked with HHV-7. However, HHV-7 was frequently detected sequentially after HCMV, and an interaction of HCMV and/or HHV-6 to increase their pathogenic effects could not be excluded. Further studies should be performed including HHV-6 to evaluate the relationship, among beta herpesviruses.

Increasing seroprevalence of Human herpesvirus 8 (HHV-8) with age confirms HHV-8 endemicity in Amazon Amerindians from Brazil

Human herpesvirus 8 (HHV-8) seroprevalences were determined in two isolated Amazon Amerindian tribes, according to age, gender and familial aggregation. Plasma and serum samples obtained from 982 Amazon Amerindians (664 Tiriyó and 318 Waiampi) were tested for antibodies against lytic and latent HHV-8 antigens by using ‘in-house’ immunofluorescence assays. Overall, HHV-8 seroprevalence was 56·8 % (57·4 % in the Tiriyó tribe and 55·7 % in the Waiampi tribe). Seroprevalence was independent of gender and increased linearly with age: it was 35·0 % among children aged 2–9 years, 51·4 % in adolescents (10–19 years), 72·9 % in adults and 82·3 % in adults aged >50 years. Interestingly, 44·4 % of children under 2 years of age were HHV-8-seropositive. No significant differences in seroprevalence between tribes and age groups were detected. It is concluded that HHV-8 is hyperendemic in Brazilian Amazon Amerindians, with vertical and horizontal transmission during childhood, familial transmission and sexual contact in adulthood contributing to this high prevalence in these isolated populations.

Early diagnosis of HIV-1: infected infants in Brazil using nested-PCR

The polymerase chain reaction (PCR) has been the most promising test for HIV-1 early diagnosis in infants suspected of perinatal transmission. The first and second reactions of the amplification in 41 infants (under 18 months old) suspected of HIV-1 perinatal infection, were standardized and carried out in the present study. The first and the second PCR were carried out with the sets of primers JA4-JA7, JA9-JA12, JA13-JA16, and JA17-JA20 for the first reaction of amplification (outer primers) and JA5-JA6, JA10-JA11, JA14-JA15, and JA18-JA19 for the second reaction of amplification (inner primers), resulting in amplification of 131, 341, 172, and 129 pb, respectively. From 41 patients analysed, 12 patients presented positive to HIV-1 infection by PCR. The gag, env (region 1), and pol regions presented a greater sensitivity. The first and the second reactions of the amplification were performed with the same concentration of MgCl2 for all sets of primers. The results agree with several studies that affirm that the PCR is the indicated method for HIV-1 early diagnosis in infants suspected of perinatal infection.

Lymphocyte subpopulations during cytomegalovirus disease in renal transplant recipients

We have determined the number of circulating T, B and natural killer cells in renal transplant recipients in order to detect changes during cytomegalovirus (CMV) infections. Serial blood samples were taken from 61 patients on standard triple immunosuppression therapy (cyclosporin A, azathioprine and prednisone). Using two-color flow cytometry analysis, the absolute number of CD3+, CD4+, CD8+, CD19+, CD3+HLA-DR+ and CD16+56+ cells was determined. Forty-eight patients (78.7%) developed active CMV infection, and all of them subsequently recovered. Twenty of the infected patients (32.8%) presented symptoms compatible with CMV disease during the infectious process. The number of lymphocytes and their main subpopulations were normal before the onset of CMV disease. During the disease there was a decrease followed by a significant increase (P<0.005) in the number of CD3+, CD4+, CD8+ and CD3+HLA-DR+ cells. No significant changes were observed in natural killer cells or B lymphocytes during the disease. We conclude, as observed in all viremic patients recovering from infection, that recovery is associated with an increase in the number of T cell subsets. The monitoring of different lymphocyte subsets along with antigenemia can be extremely useful in the detection of patients at high risk of developing CMV symptoms, allowing the early introduction of antiviral therapy or the reduction of immunosuppression therapy.

Characterization of bovine respiratory syncytial virus isolated in Brazil

This paper presents the first isolation of bovine respiratory syncytial virus in Brazil and its physicochemical, morphological and molecular characterization. The virus was isolated from 33 samples of nasotracheal secretions, successively inoculated into a Madin-Darby bovine kidney cell culture, which was characterized by physicochemical tests and morphological observation by electron microscopy. The Brazilian sample is an RNA pleomorphic, enveloped, thermolabile and non-hemagglutinating spicular virus. Reverse transcription, followed by nested polymerase chain reaction (nRT-PCR) assay was carried out using oligonucleotides B1, B2A, B3 and B4 for the fusion proteins (F) and B5A, B6A, B7A and B8 for the attachment protein (G). The nRT-PCR-F amplified a fragment of 481 bp corresponding to part of the gene that codes for protein F, whereas nRT-PCR-G amplified a fragment of 371 bp, in agreement with part of the G gene. The virus isolated from Brazilian samples in this study corresponded to the bovine respiratory syncytial virus, and RT-PCR proved to be useful for the diagnosis of bovine clinical samples.