Cytomegalovirus infection as a common complication following liver transplantation

Intensive Care of Pulmonary Complications Following Liver Transplantation

Chronic liver disease has been associated with pulmonary dysfunction both before and after liver transplantation. Post-liver transplantation pulmonary complications can affect both morbidity and mortality often necessitating intensive care during the immediate postoperative period. The major pulmonary complications include pneumonia, pleural effusions, pulmonary edema, and atelectasis. Poor clinical outcomes have been known to be associated with age, severity of liver dysfunction, and preexisting lung disease as well as perioperative events related to fluid balance, particularly transfusion and fluid volumes. Delineating each and every one of these pulmonary complications and their associated risk factors becomes paramount in guiding specific therapeutic strategies.

A meta-analysis of complications following deceased donor liver transplant

BACKGROUND

Liver transplantation is a complex surgery associated with high rates of postoperative complications. While national outcomes data are available, national rates of most complications are unknown.

DATA SOURCES

A systematic review of the literature reporting rates of postoperative complications between 2002 and 2012 was performed. A cohort of 29,227 deceased donor liver transplant recipients from 74 studies was used to calculate pooled incidences for 17 major postoperative complications.

CONCLUSIONS

This is the first comprehensive review of postoperative complications after liver transplantation and can serve as a guide for transplant and nontransplant clinicians. Efforts to collect national data on complications, such as through the National Surgical Quality Improvement Program, would improve the ability to provide patients with informed consent, serve as a tool for individual center performance monitoring, and provide a central source against which to measure interventions aimed at improving patient care.

Effect of maintenance immunosuppressive drugs on virus pathobiology: evidence and potential mechanisms

Recent evidence suggesting a potential anti-CMV effect of mTORis is of great interest to the transplant community. However, the concept of an immunosuppressant with antiviral properties is not new, with many accounts of the antiviral properties of several agents over the years. Despite these reports, to date, there has been little effort to collate the evidence into a fuller picture. This manuscript was developed to gather the evidence of antiviral activity of the agents that comprise a typical immunosuppressive regimen against viruses that commonly reactivate following transplant (HHV1 and 2, VZV, EBV, CMV and HHV6, 7, and 8, HCV, HBV, BKV, HIV, HPV, and parvovirus). Appropriate immunosuppressive regimens posttransplant that avoid acute rejection while reducing risk of viral reactivation are also reviewed. The existing literature was disparate in nature, although indicating a possible stimulatory effect of tacrolimus on BKV, potentiation of viral reactivation by steroids, and a potential advantage of mammalian target of rapamycin (mTOR) inhibition in several viral infections, including BKV, HPV, and several herpesviruses.

Resistance to combined ganciclovir and foscarnet therapy in a liver transplant recipient with possible dual-strain cytomegalovirus coinfection

We present a case report of a cytomegalovirus (CMV)-seronegative, 58-year-old male who received a CMV-seropositive donor liver transplant without CMV prophylaxis. On postoperative day 30, the patient developed primary CMV disease that responded to ganciclovir. On postoperative day 114, however, he was diagnosed with recurrent CMV infection. Despite aggressive, combined antiviral treatment with ganciclovir and foscarnet and reduction of immunosuppression, viral clearance was never achieved. Serum samples were collected throughout the infectious process for viral DNA analysis. Portions of the UL97 and UL54 genes were amplified and compared to the AD169 wild-type strain. Sequencing studies revealed the presence of mutations in viral isolates obtained after clinical resistance was observed. These mutations were not present in samples obtained during the primary CMV infection. Our findings suggest the presence of coinfection with at least 2 different strains of CMV rather than induction of mutations after ganciclovir therapy.

Autopsy-proven causes of death in lungs of patients immunocompromised by secondary interstitial pneumonia

PURPOSE

To present the more frequent associations found in autopsies of immunocompromised patients who developed secondary interstitial pneumonia as well as the risk of death (odds ratio) in having specific secondary interstitial pneumonia according to the cause of immunocompromise.

METHOD

From January 1994 to March 2004, 17,000 autopsies were performed at Hospital das Clínicas, São Paulo University Medical School. After examining the pathology report review, we selected 558 of these autopsies (3.28%) from patients aged 15 years or more with primary underlying diseases who developed radiologically diffuse infiltrates of the lung during their hospital course and died after secondary interstitial pneumonia (bronchopneumonia, lobar pneumonia, interstitial pneumonia, diffuse alveolar damage, pulmonary recurrence of underlying disease, drug-induced lung disease, cardiogenic pulmonary edema, or pulmonary embolism). Histology slides were reviewed by experienced pathologists to confirm or not the presence of secondary interstitial pneumonia. Statistical analysis included the Fisher exact test to verify any association between histopathology and the cause of immunocompromise; a logistic regression was used to predict the risk of death for specific histological findings for each of the independent variables in the model.

RESULTS

Secondary interstitial pneumonia was histologically represented by diffuse interstitial pneumonitis ranging from mild nonspecific findings (n = 213) to a pattern of diffuse alveolar damage (n = 273). The principal causes of immunocompromise in patients with diffuse alveolar damage were sepsis (136 cases), neoplasia (113 cases), diabetes mellitus (37 cases), and transplantation (48 cases). A high risk of death by pulmonary edema was found for patients with carcinoma of colon. Similarly, in patients with lung cancer or cachexia, A high risk of death by bronchopneumonia (OR = 3.6; OR = 2.6, respectively) was found. Pulmonary thromboembolism was associated with an appreciable risk of death (OR = 2.4) in patients with arterial hypertension. The risk of death was also high in patients presenting hepatic cancer (OR = 2.5) or steroid therapy (OR = 2.4) who developed pulmonary hemorrhage as the histological pattern of secondary interstitial pneumonia . The risk of death by lung metastasis was also elevated (OR = 1.6) for patients that were immunosuppressed after radiotherapy.

CONCLUSION

Patients with secondary immunosuppression who developed secondary interstitial pneumonia during treatment in hospital should be evaluated to avoid death by diffuse alveolar damage, pulmonary edema, bronchopneumonia, lung hemorrhage, pulmonary thromboembolism, or lung metastasis. The high-risk patients are those immunosuppressed by hematologic disease; those under steroid treatment; or those with colon or hepatic carcinoma, cachexia, or arterial hypertension.

Postoperative Severe Pneumonia in Adult Liver Transplant Recipients

Severe pneumonia in adult liver transplantation (OLT) recipients is a dangerous condition with significant morbidity and mortality. To analyze the risk factors for postoperative severe pneumonia in OLT patients, we collected data from 132 consecutive adult patients who underwent OLT between February 1999 and April 2004. According to the American Thoracic Society consensus statement, episodes of severe pneumonia were observed in 24 patients (18.2%). We retrospectively reviewed the etiology diagnosis, treatment, and prognosis of the 24 recipients. Bacteria were responsible for 95.8% of these episodes (23 of 24), fungi for 16.7% (4 of 24) and viruses for 4.4% (1 of 24). Twenty-six percent of the bacterial pneumonias were due to Streptococcus alpha hemolyticus. The mortality rate was 37.5% (9 of 24) for patients with severe pneumonia versus 7.4% (8 of 108, P = .004) for patients without pneumonia. Two cases with hepatorenal syndrome died, and three patients with coinfection by bacteria and fungi died. Acute rejection episodes occurred in 15 patients, four of whom died. Mechanical ventilation and tracheotomy were required in 13 cases (54%). Six who experienced prolonged intubation died. Sputum and pleural fluid cultures helped to establish a diagnosis in 91.7% (22 of 24) of cases. Twenty cases (83%) underwent reduction in the immunosuppressive regimen. Patient age, intraoperative transfusion requirements, extubation time, and hospital stay were fatal predictors of prognoses. We concluded that early detection of the responsible pathogen; timely and specific diagnosis; reduction in the immunosuppressive regimen; appropriate treatment with reliable, effective techniques; and implementation of sensitive culture-based antibiotics was an effective strategy to treat severe adult pneumonia in liver transplantation recipients.

The Impact of Pretransplant Cytomegalovirus Infection on Acute Renal Allograft Rejection

BACKGROUND

The role of cytomegalovirus (CMV) infection in renal allograft rejection remains controversial; moreover, there are few studies on pretransplant infections. This study sought to investigate whether pretransplant CMV infections had negative effects on acute rejection episodes (ARE) and to evaluate the effect of preemptive treatment.

METHODS

This retrospective single-center study of 416 transplant recipients from October 1, 2000 to September 1, 2003 had CMV infections diagnosed by CMV antigenemia tests. The incidences of ARE were compared between CMV-infected and noninfected groups. Risk factors for ARE were analyzed. Based on preemptive treatment, pretransplant CMV-infected recipients were divided into ganciclovir-treated and nontreated groups and the incidence of ARE was compared between the two groups.

RESULTS

One hundred eighty four recipients had CMV infections pretransplant; the infection rate was 44.2%. Fifty five recipients had ARE among the pretransplant CMV-positive group, which was significantly higher than that in the noninfected group (29.9% vs 19.5%, P = .014). But the rejection subgroups and renal function recovery had no significant differences. While the presence of pretransplant infection was an independent predictor of ARE (RR = 1.807), severity showed no significant impact on ARE. Among 184 pretransplant CMV infection recipients, the incidences of ARE were 14.3% and 18.0% in ganciclovir-treated versus nontreated patients, respectively (P = .650).

CONCLUSIONS

Pretransplant CMV-positive recipients were at greater risk of ARE. Pretransplant CMV infection was an independent risk factor for ARE. Preemptive antiviral treatment did not show protective effects against ARE related to CMV infection-mediated immunological injuries.

Diarrhea in liver transplant recipients: etiology and management

Diarrhea is common after liver transplantation (LT). The true incidence of diarrhea in liver transplant recipients is unknown but possibly ranges from 10% to 43% based on a few published studies in other solid organ and bone marrow transplantation. Infectious etiologies, including cytomegalovirus (CMV), Clostridium difficile, and occasional atypical intestinal infections, are the most common causes. Diarrhea is also a frequent side effect of immunosuppressive medications. To variable extents, mycophenolate mofetil (MMF), cyclosporine A (CSA), tacrolimus, and sirolimus are all known to be associated with diarrhea. Rarely, graft-versus-host disease (GVHD), lymphoproliferative disorder, de novo inflammatory bowel disease (IBD), or colon cancer may present as diarrhea. Flare-up of preexisting IBD is also not uncommon after LT. However, the cause of acute diarrhea remains unidentified in 1 of 3 patients. This review summarizes the literature and provides recommendations on the management of acute diarrhea after LT. Although our focus is on LT, the etiology and management recommendations apply to most transplant recipients.

Cytomegalovirus and chronic allograft rejection in liver transplantation

Cytomegalovirus (CMV) remains one of the most frequent viral infections and the most common cause of death after liver transplantation (LT). Chronic allograft liver rejection remains the major obstacle to long-term allograft survival and CMV infection is one of the suggested risk factors for chronic allograft rejection. The precise relationship between cytomegalovirus and chronic rejection remains uncertain. This review addresses the morbidity of cytomegalovirus infection and the risk factors associated with it, the relationship between cytomegalovirus and chronic allograft liver rejection and the potential mechanisms of it.