A.M. Sampaio

Simultaneous monitoring of CMV and human herpesvirus 6 infections and diseases in liver transplant patients: one-year follow-up

OBJECTIVE: The aim of this study was to simultaneously monitoring cytomegalovirus and human herpesvirus 6 active infections using nested-polymerase chain reaction and, together with clinical findings, follow the clinical status of patients undergoing liver transplant. INTRODUCTION: The human β-herpesviruses, including cytomegalovirus and human herpesvirus 6, are ubiquitous among human populations. Active infections of human herpesvirus 6 and cytomegalovirus are common after liver transplantation, possibly induced and facilitated by allograft rejection and immunosuppressive therapy. Both viruses affect the success of the transplant procedure. METHODS: Thirty patients submitted to liver transplant at the Liver Transplant Unit, at the Gastro Center, State University of Campinas, SP, Brazil, were studied prospectively from six months to one year, nested-polymerase chain reaction for cytomegalovirus and human herpesvirus 6 DNA detections. Two or more consecutive positive nested-polymerase chain reaction were considered indicative of active infection. RESULTS: Active infection by cytomegalovirus was detected in 13/30 (43.3%) patients, median time to first cytomegalovirus detection was 29 days after transplantation (range: 0-99 days). Active infection by human herpesvirus 6 was detected in 12/30 (40%) patients, median time to first human herpesvirus 6 detection was 23.5 days after transplantation (range: 0-273 days). The time-related appearance of each virus was not statistically different (p = 0.49). Rejection of the transplanted liver was observed in 16.7% (5/30) of the patients. The present analysis showed that human herpesvirus 6 and/or cytomegalovirus active infections were frequent in liver transplant recipients at our center. CONCLUSIONS: Few patients remain free of betaherpesviruses after liver transplantation. Most patients presenting active infection with more than one virus were infected sequentially and not concurrently. Nested-polymerase chain reaction can be considered of limited value for clinically monitoring cytomegalovirus and human herpesvirus 6.

Human herpesvirus 6 in donor biopsies associated with the incidence of clinical cytomegalovirus disease and hepatitis C virus recurrence.

BACKGROUND Reactivation of cytomegalovirus (CMV) and human herpesvirus 6 (HHV-6), as well as the recurrence of hepatitis C virus (HCV), occurs in the post liver transplantation period. However, their correlations remain questionable. The objectives of this study were to analyze the presence of CMV DNA and HHV-6 DNA in pre-transplant and post-transplant liver graft biopsies and to determine any correlations with CMV disease and HCV recurrence. METHODS Forty-one liver transplant recipients were followed up in the post-transplant period. The presence of CMV DNA and HHV-6 DNA was detected by nested PCR. RESULTS Four patients (4/41, 9.8%) were positive for CMV DNA in pre-transplant biopsies and three of them remained positive after transplantation; 11 patients became positive in the post-transplant biopsies (p=0.06). Fifteen (15/41, 36.6%) patients were positive for HHV-6 DNA in pre-transplant biopsies and 11 of these remained positive after transplantation. Another 11 patients became positive after the surgery (p=0.05). CMV disease occurred in 17 recipients; 10 of these 17 (58.8%) patients were positive for HHV-6 DNA in pre-transplant biopsies and they continued positive after transplantation (p=0.0128). Twenty-eight patients were transplanted due to hepatitis C; 12 of these patients had recurrence of the virus, and HHV-6 was positive in nine of the 12 (75%) patients (p=0.049). CONCLUSIONS Recipients with HHV-6 DNA in pre-transplant graft biopsies remained positive post transplantation, showing a possible risk for post-transplant allograft loss because there was an association between HHV-6 and recurrent HCV and CMV disease.

Cytomegalovirus, Human Herpesvirus-6, and Human Herpesvirus-7 in Adult Liver Transplant Recipients: Diagnosis Based on Antigenemia

Human herpesvirus (HHV)-6, HHV-7, and cytomegalovirus (CMV) that remain latent after primary infection can be reactivated during immunosuppression following organ transplantation in liver transplant recipients. The aim of this study was to monitor active infections for HHV-6, HHV-7, and CMV among adult liver transplantation recipients using antigenemia detected by an immunoperoxidase staining. Twenty-eight adult liver transplant patients were monitored using antigenemia in blood samples obtained at the time of transplantation, as well as weekly in the first month and once a month for 6 months. Of these patients, 28.5% showed positive CMV antigenemia; 39.2%, HHV-6 antigenemia; and 14.2%, HHV-7 antigenemia. The detection of the three viruses was considered to be independent of one another (P>.05). The results described above showed that few patients remain free of beta herpesviruses after liver transplantation. Most patients were infected sequentially and not concurrently. Antigenemia has been considered useful to detect active HHV-6 and HHV-7 infections. Antigenemia can be more efficiently interpreted when compared with polymerase chain reaction results, although other studies are necessary to establish the reference of HHV-6 and HHV-7 antigenemia.

Monitoring and Detection of Cytomegalovirus in Liver Transplant Recipients

Cytomegalovirus (CMV) is a β-herpesvirus. CMV infections are a common complication contributing to morbidity and mortality after liver transplantation. Among organ transplant recipients, CMV can reactivate from latency during the first 6 months. This prospective study performed from February 2008 to December 2009 examined liver transplant recipients during the first 6 months. Two methods were performed to detect CMV infections: antigenemia (AGM) and nested (PCR). Ninety-four patients, including 72 men (76.6%) and 22 women (23.4%) underwent liver transplantation during this period. We analyzed 575 samples including 465 for AGM and PCR. Forty-three (9.25%) showed positive AGM as detected 2 to 179 days posttransplantation with a mean of 50 days and a median of 35 days, and 93/465 (20%) showed positive PCR at 0 to 186 days posttransplantation with a mean of 31 days and a median of 38 days. Among the 43 antigenemia patients, 38 samples were positive for up to 5 cells 18 of which were PCR-positive. Five samples were positive with more than 5 cells, including 3 that were PCR-positive. Only 4.51% had AGM and were PCR-positive in the same sample. Despite only 9.25% (43/465) showing AGM, the current study suggested the utility of routine monitoring to detect early CMV infection among liver transplantation patients seeking to reduce morbidity and mortality.

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.

Co-infection and Clinical Impact of Human Herpesvirus 5 and 6 in Liver Transplantation

BACKGROUND Human herpesvirus (HHV) 5 and 6 remain latent after primary infection and can be reactivated after immunosuppression for organ transplantation. An association between HHV-5 and HHV-6 has been reported in liver transplant patients. The coinfection is associated with clinical manifestations and graft dysfunction. OBJECTIVE The aim of this study was to monitor herpesviruses in liver transplant recipients to better understand issues involving coinfection with HHV-5/6 and correlations with acute cellular rejection episodes and bacterial infections. METHODS Forty-five adult liver transplant patients of median age 47 years (range, 18-66), gave blood samples and liver biopsies in the first 6 months after their surgeries. Viremia was detected with the use of nested PCR and antigenemia; the Banff classification was used to detect allograft rejection. RESULTS IgG positive for HHV-5 was observed in 94% of subjects whose main indication (67%) for transplantation was hepatitis C. Twenty-three (51.1%) displayed cytomeg virus (CMV) infections and 12 (26.7%) HHV-6 infection. There were 6 patients (13.3%) with HHV-5/6 coinfections. Eighteen of the 23 patients had CMV disease, showing a strong correlation between a positive test and CMV disease; 6 displayed an acute cellular rejection episode in the same period (χ(2) = 6.62; P < .03). Four out of 6 patients who displayed coinfections (HHV-5/6) had concomitant bacterial infections; 3/6 experienced graft rejection episodes. During follow-up, 1 patient had HHV-6 infection diagnosed as encephalitis followed by fever on the 24th day after surgery. The median 32 days for HHV-6 detection by nested PCR positivity was shorter than 38 days for HHV-5. CONCLUSIONS HHV-5/6-infected patients displayed more allograft rejection episodes, coinfections, and concomitant bacterial infections, besides an higher risk for CMV disease.

Detection of Cytomegalovirus and Human Herpesvirus-6 DNA in Liver Biopsy Specimens and Their Correlation With Rejection After Liver Transplantation

Cytomegalovirus (CMV) and human herpesvirus-6 (HHV-6) reactivation after transplantation put patients at an increased risk of graft rejection mainly among those who receive organs that are positive in their donor biopsies. The aim of this study was to investigate the presence of CMV and HHV-6 DNA in liver biopsy specimens from the donors and from their grafts for correlation with rejection after transplantation. We followed 41 liver transplantation patients whose samples were evaluated using nested-polymerase chain reactions (N-PCR). Twenty-one (51%) of the 41 studied patients experienced rejection; 4/21 (19%) were CMV positive in the donor biopsy specimens and remained positive; another 5 subjects became positive. The patients who received organs from donors with biopsies positive for CMV demonstrated a trend to develop graft rejection after transplantation (Fishers exact test [P = .0591] with significant results on univariate and multivariate analysis [P = .042]). Eight of the 21 who experienced rejection episodes were HHV-6 positive in the donor biopsy but there was no statistical significance CMV DNA diagnosed in liver donor biopsies remained positive posttransplantation in liver biopsy recipients; it was considered a tendency to develop acute cellular rejection after transplantation.

Cytomegalovirus Infection in Liver Transplantation

With the global evolution of organ transplantation in humans a new class of patients with special problems related to opportunistic infections after transplantation has appeared [1, 2 ].Some of these challenges infections with members of the herpesvirus family. Among these viruses, human cytomegalovirus (HCMV) often affects immunocompromised patients, HCMV can be reactivated by immunosuppression and cause significant morbidity and mortality [3,4]. In the postoperative period, HCMV infection can result in serious complica‐ tions in patients who received grafts by modulating the immune response [5]. However in immunocompetent individuals cytomegalovirus infection can be asymptomatic or cause symptoms similar to infectious mononucleosis syndrome, such as lymphadenopathy, fever, rash, malaise, arthralgia, hepatomegaly and splenomegaly [6].

Betaherpesviruses in Adult Liver Transplant Recipients

Liver transplantation similar to other allograft transplants requires the use of immunossupressive therapy to avoid graft rejection in the host. Immunossupressive drugs can also decrease the capacity of the host immune system to response against infectious agents which would not be a problem to immunocompetent persons. Many infectious agents such as bacteria, fungus, protozoa and viruses can cause serious complication in the post-transplant course (Blair & Shimon, 2005).