Detection of cytomegalovirus in upper gastrointestinal biopsies from heart transplant recipients: comparison of light microscopy, immunocytochemistry, in situ hybridisation, and nested PCR

The Impact of Human Herpesviruses in Clinical Practice of Inflammatory Bowel Disease in the Era of COVID-19

Human herpesviruses (HHVs): herpes simplex virus (HSV) types 1 (HSV-1) and 2 (HSV-2), varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), HHV-6, HHV-7, and HHV-8, are known to be part of a family of DNA viruses that cause several diseases in humans. In clinical practice of inflammatory bowel disease (IBD), the complication of CMV enterocolitis, which is caused by CMV reactivation under disruption of intestinal barrier function, inflammation, or strong immunosuppressive therapy, is well known to affect the prognosis of disease. However, the relationship between other HHVs and IBD remains unclear. In the transplantation field, reactivation of other viruses, such as HHV-6, could cause colitis under immunosuppressed condition. Recent research revealed that combined infection of some HHVs could be a risk factor for colectomy in patients with ulcerative colitis. This suggests that it would be important to clarify HHV behavior in the treatment for patients with IBD, especially in those under immunosuppressive therapies. Looking at the relationship with recently emerged novel coronaviruses (SARS-CoV-2), there are reports describe that SARS-CoV-2 might induce reactivation of HSV-1, EBV, VZV (herpes zoster), and HHV-6/7. If SARS-CoV-2 infection becomes common, vigilance against HHV reactivation may become more crucial. In this review, we discuss the impact of HHVs in clinical practice of inflammatory bowel diseases, especially during the SARS-CoV-2 pandemic.

Analysis of gastrointestinal virus infection in immunocompromised hosts by multiplex virus PCR assay

Regarding viral infection of intestinal mucosa, there have been only a few studies on limited diseases, targeting a few herpes family viruses. In this study, we analyzed 12 kinds of DNA viruses including 8 species of herpes family viruses in the gastrointestinal mucosa of patients with hematologic malignancies, inflammatory bowel diseases, collagen diseases, or other miscellaneous forms of gastroenteritis using the multiplex virus PCR assay, which we recently developed. The virus PCR assay yielded positive results in 63 of 102 patients; Epstein-Barr virus (EBV) was the most frequently detected, followed by cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, parvovirus B19, and herpes simplex virus type 1. The frequencies of viral detection in the 4 diseases were similar involving these 6 viruses. Regarding CMV colitis, the multiplex virus PCR assay was superior to the immunohistopathologic method in detecting CMV. All viruses were more efficiently detected in the mucosa than in the blood in individual patients. These results suggest that CMV, EBV, and HHV-6 were commonly detected in the gastrointestinal mucosa of patients with these 4 diseases, and our multiplex virus PCR assay was useful for the early diagnosis of gastrointestinal virus infection, especially CMV colitis.

Mucosal Biopsy After Bone Marrow Transplantation

Gastrointestinal mucosal biopsies in the hematopoietic stem cell transplantation setting are challenging because histologic features of graft-versus-host disease (GVHD), which is treated by increasing immunosuppression, overlap with those of other conditions, such as infection, which can get worse with GVHD treatment. More than one condition can occur at the same time. It is important to understand the histologic features of GVHD, drug toxicity, infection, and clinical factors surrounding patients, including timing of biopsy in relation to transplantation, medication history, and laboratory data. Rendering a correct diagnosis and generating a pathology report with standard language that can direct clinical management ensure proper management.

Development of a vivo rabbit ligated intestinal Loop Model for HCMV infection

BACKGROUND

Human Cytomegalovirus (HCMV) infections can be found throughout the body, especially in epithelial tissue. Animal model was established by inoculation of HCMV (strain AD-169) or coinoculation with Hepatitis E virus (HEV) into the ligated sacculus rotundus and vermiform appendix in living rabbits. The specimens were collected from animals sacrificed 1 and a half hours after infection.

RESULTS

The virus was found to be capable of reproducing in these specimens through RT-PCR and Western-blot. Severe inflammation damage was found in HCMV-infected tissue. The viral protein could be detected in high amounts in the mucosal epithelium and lamina propria by immunohistochemistry and immunofluorescense. Moreover, there are strong positive signals in lymphocytes, macrophages, and lymphoid follicles. Quantitative statistics indicate that lymphocytes among epithlium cells increased significantly in viral infection groups.

CONCLUSIONS

The results showed that HCMV or HEV + HCMV can efficiently infect in rabbits by vivo ligated intestine loop inoculation. The present study successfully developed an infective model in vivo rabbit ligated intestinal Loop for HCMV pathogenesis study. This rabbit model can be helpful for understanding modulation of the gut immune system with HCMV infection.

Immunohistochemistry Improves the Detection of Adenovirus in Gastrointestinal Biopsy Specimens From Hematopoietic Stem Cell Transplant Recipients

OBJECTIVES

Gastrointestinal infections by cytomegalovirus (CMV) and adenovirus may complicate hematopoietic stem cell transplantation (HSCT). Although CMV and adenovirus produce recognizable cytopathic changes, these changes may be subtle or focal. The value of viral immunohistochemistry in detecting infection in HSCT recipients when cytopathic changes are not identified has not been demonstrated.

METHODS

H&E-stained sections from gastrointestinal biopsy specimens were reviewed by three pathologists. Cases were classified as negative, suspicious, or positive for CMV and/or adenovirus infection based on the presence or absence of viral inclusions. Viral immunohistochemistry was performed, and the results were compared with the interpretations of H&E-stained sections.

RESULTS

Four of 104 cases contained viral inclusions confirmed by immunohistochemistry: two were infected with CMV, and two were positive for adenovirus. All three reviewers correctly classified both immunopositive CMV cases on H&E evaluation. However, all reviewers missed the diagnosis of adenovirus on H&E assessment in one case.

CONCLUSIONS

In HSCT recipients, cytopathic changes of adenovirus may be easily missed in H&E-stained sections of gastrointestinal biopsy specimens. Thus, the routine use of adenovirus immunohistochemistry in all cases is recommended. Both cases of CMV infection were apparent on H&E evaluation, so the judicious use of immunohistochemical stains for CMV in selected cases may be considered.

Diagnosing cytomegalovirus in patients with inflammatory bowel disease--by immunohistochemistry or polymerase chain reaction?

Cytomegalovirus (CMV) reactivation is a common complication in patients with inflammatory bowel diseases (IBD), particularly in those with steroid-resistant ulcerative colitis. It is usually diagnosed by histopathologic and immunohistochemical examination of the colon biopsy. The introduction of quantitative, real-time polymerase chain reaction (qPCR) has been recommended to improve the sensitivity, but there is little consensus on how to use it. We compared the two methods in samples from resected bowel of patients with IBD. Twelve patients with IBD who had undergone bowel resection were analysed for CMV, using qPCR and immunohistochemistry. In all cases, tissue samples from the base and the edge of ulcers and from uninvolved mucosa were obtained. The highest densities of CMV-positive cells were found in samples from the base of ulcers (immunohistochemistry 0-0.47 positive cells/mm(2); qPCR 10-3809 viral copies/mg) or the edge of ulcers (immunohistochemistry 0.06-0.32 positive cells/mm(2); qPCR 35-1049 viral copies/mg). In samples of uninvolved mucosa, immunohistochemistry was negative, whereas qPCR was either negative or showed very low values (0-3 viral copies/mg). We conclude that both immunohistochemistry and qPCR can be successfully used for diagnosing CMV reactivation in patients with IBD. The base and the edge of ulcers are the optimal sites for endoscopic biopsies. The density of CMV-positive cells was low and their distribution within the colon uneven. It therefore seems that the number of sampled biopsies and/or the number of investigated levels is more important that the choice of diagnostic method.

Update on cytomegalovirus infections of the gastrointestinal system in solid organ transplant recipients

Cytomegalovirus (CMV) infection of the gastrointestinal tract is the most common manifestation of tissue-invasive CMV disease, and is a significant cause of morbidity and mortality in the solid organ transplantation (SOT) recipient. In addition to the direct effects of the infection, its indirect effects on allograft function, risk for other opportunistic infections, and mortality are significant in this population. The most common clinical syndromes are esophagitis, colitis, and hepatitis; however, infection can occur anywhere in the gastrointestinal tract. Diagnosis is usually by histopathology or viral culture of tissue specimens; molecular assays also often have a role. Antivirals are the cornerstone of therapy for gastrointestinal tract CMV disease and complications such as recurrent infection and antiviral resistance are not uncommon. Prevention with antiviral prophylaxis or preemptive therapy is important. This review summarizes recent data regarding the clinical manifestations, diagnosis, treatment, and prevention of gastrointestinal tract CMV infection in the SOT population.

Viral myocarditis: diagnosis, aetiology and management

Myocarditis is an inflammatory disease of the cardiac muscle caused by myocardial infiltration of immunocompetent cells following any kind of cardiac injury. Classic myocarditis mainly occurs as a result of the host's immune response against organisms that cause common infectious illnesses, as a manifestation of hypersensitivity or as a toxic reaction to drug therapy. Chronic inflammatory events may survive successful clearance of initial cardiotoxic agents, be triggered or amplified by autoimmunological processes, or develop in the context of systemic diseases. If the underlying infectious or immune-mediated causes of the disease are carefully defined by clinical and biopsy-based tools, specific immunosuppressive and antiviral treatment options may improve the prognosis of patients with acute and chronic disease.

Immunohistochemically proven cytomegalovirus end-organ disease in solid organ transplant patients: clinical features and usefulness of conventional diagnostic tests

We studied the main clinical features, outcome, and laboratory parameters in a group of solid organ transplant (SOT) patients with immunohistochemically proven cytomegalovirus (CMV) disease. Confirmed CMV cases were obtained through databases. Demographics, clinical data, transplantation type, immunosuppressive regimens, donor and recipient CMV serostatus, therapy, outcome and laboratory results, pp65 antigenemia, and qualitative polymerase chain reaction (PCR) for CMV were analyzed. From 1995 to 2004, 31 cases with complete medical records were identified. Disease appeared between 24 and 2538 days after transplantation but most cases presented in the first 100 days. Gastrointestinal CMV disease was the most frequent form (71%), while thrombocytopenia was present in 50% of cases, and leukopenia was less common (35.5%). CMV pp65 antigenemia was positive in 58% of patients, but its sensitivity increased to 71% if performed during the first 6 months. A qualitative CMV PCR technique gave similar results during this period (71.4%). Most patients were treated with intravenous ganciclovir (n=25; 80.6%). In 4 cases (19.4%), use of foscarnet alone or a sequential regimen with ganciclovir-foscarnet was deemed necessary. Surgical procedures were necessary in 5 patients (16%). The death rate reached 13%. CMV end-organ disease can be a life-threatening infection in SOT patients. Gastrointestinal disease was the most frequent end-organ disease. CMV antigen detection is best suited for the early period after transplantation.

High prevalence of viral genomes and multiple viral infections in the myocardium of adults with "idiopathic" left ventricular dysfunction

BACKGROUND

For a long time, enteroviruses have been considered to be the most common cause of acute viral myocarditis (MC), with possible transition from MC to dilated cardiomyopathy (DCM). Recent investigations have shown, however, that other viruses are also frequently encountered in MC patients, suggesting that persistence of various virus species may play a pathogenic role in the transition from MC to DCM. The purpose of this study was to screen endomyocardial biopsies (EMBs) from patients with "idiopathic" DCM for the presence of viral genomes by using polymerase chain reaction (PCR) to assess the frequency of cardiac viral infections that may be involved in the pathogenesis of the disease.

METHODS AND RESULTS

EMBs were obtained for PCR analysis from 245 consecutive patients (median left ventricular ejection fraction, 35.0%; range, 9% to 59%). PCR and reverse transcription-PCR were performed to detect the genomic sequences of enterovirus (EV), adenovirus (ADV), human cytomegalovirus (HCMV), herpes simplex virus, Epstein-Barr virus (EBV), human herpesvirus 6 (HHV-6), parvovirus B19 (PVB19), and influenza A and B viruses. Myocardial inflammation was assessed by histological and immunohistological analyses. Viral genomes could be amplified from EMBs of 165 (67.4%) of the 245 DCM patients: EV=23 (9.4%), ADV=4 (1.6%), PVB19=126 (51.4%), HHV-6=53 (21.6%), EBV=5 (2.0%), HCMV=2 (0.8%), including n=45 cases (27.3%) with multiple infections. Active or borderline myocarditis according to the Dallas classification did not exist in any case. Lymphocyte and macrophage infiltrates were not significantly different in virus-positive versus virus-negative patients.

CONCLUSIONS

Viral genomes were frequently detected in EMBs of patients with systolic left ventricular dysfunction. Our data suggest that myocardial persistence of various viruses, often presenting as multiple infections, may play a role in the pathogenesis of DCM far more frequently than suspected so far.

Cytomegalovirus infection and development of biliary complications after liver transplantation

BACKGROUND

Cytomegalovirus (CMV) infection is known to cause ulceration and mucosal hemorrhage in the gastrointestinal tract. Gastroduodenal and biliary complications were prospectively evaluated in 100 consecutive liver transplant patients in whom CMV was monitored during the first posttransplant year.

METHOD

Gastroduodenal biopsy specimens were taken from 36 patients by endoscopies and in 28 patients by endoscopic retrograde cholangiopancreatography, and bile duct specimens were taken from three patients who underwent surgical reconstruction because of biliary complication. CMV was demonstrated from blood by the pp65 antigenemia test and from frozen sections of tissue specimens by immunohistochemistry and in situ hybridization.

RESULTS

Symptomatic CMV infection, treated with ganciclovir, developed in 49 recipients: 13 (100%) of CMV seropositive donor (D+) seronegative recipient (R-) cases, 29 (45%) D+/R+ cases, and 7 (32%) D-/R+ cases. Duodenal ulcer developed in three and hemorrhagic gastritis in three recipients. CMV antigens were found from the gastroduodenal mucosa in 37 (69%) of the 54 studied recipients. The biliary complication rate was 24%. Preceding or concomitant CMV antigenemia was demonstrated in 75% of patients with a biliary complication (68% in CMV D+/R+ or D-/R+ and 100% in D+/R- recipients). The biliary complication rate was higher among recipients with CMV antigenemia, compared with recipients without (P<0.05). CMV antigenemia, CMV infection, or both in the duodenal mucosa was found in 96% of patients with a biliary complication. In two patients who underwent surgical reconstruction, CMV antigens and DNA were demonstrated in the bile ducts.

CONCLUSIONS

Liver transplant patients are at risk of developing biliary complications after CMV infection, especially those with primary CMV infection.

Disseminated cytomegalovirus disease in hosts without acquired immunodeficiency syndrome and without an organ transplant

We describe 7 histologically proven cases of cytomegalovirus disease in patients without human immunodeficiency virus and without organ transplants, all of whom had associated comorbid conditions. Therapy with ganciclovir generally resulted in a favorable outcome.

New strategies for prevention and therapy of cytomegalovirus infection and disease in solid-organ transplant recipients

In the past three decades since the inception of human organ transplantation, cytomegalovirus (CMV) has gained increasing clinical import because it is a common pathogen in the immunocompromised transplant recipient. Patients may suffer from severe manifestations of this infection along with the threat of potential fatality. Additionally, the dynamic evolution of immunosuppressive and antiviral agents has brought forth changes in the natural history of CMV infection and disease. Transplant physicians now face the daunting task of recognizing and managing the changing spectrum of CMV infection and its consequences in the organ recipient. For the microbiology laboratory, the emphasis has been geared toward the development of more sophisticated detection assays, including methods to detect emerging antiviral resistance. The discovery of novel antiviral chemotherapy is an important theme of clinical research. Investigations have also focused on preventative measures for CMV disease in the solid-organ transplant population. In all, while much has been achieved in the overall management of CMV infection, the current understanding of CMV pathogenesis and therapy still leaves much to be learned before success can be claimed.

Gastrointestinal infections in the immunocompromised host

Infectious diseases of the gastrointestinal tract continue to be an important source of morbidity and mortality. Viruses, bacteria, fungi, and protozoa that infect normal hosts also infect the gastrointestinal tract in immunocompromised hosts. Disease caused by these pathogens may be more severe and more difficult to treat in immunocompromised hosts. In addition, pathogens that rarely cause disease in normal hosts cause significant disease in immunosuppressed hosts. Diagnostic decisions need to take into account expected pathogens and response to therapy. Treatment decisions must be based on the findings of diagnostic procedures; expected pathogens; and recent data suggesting that highly active antiretroviral therapy, with its ability to reconstitute immune function, is an essential component of treatment. This review summarizes the most important developments made in the pathogenesis, clinical presentation, diagnosis, and treatment of gastrointestinal infections in immunocompromised hosts in the past year.