Human cytomegalovirus and Epstein-Barr virus infection in inflammatory bowel disease: Need for mucosal viral load measurement

AIM: To evaluate the best diagnostic technique and risk factors of the human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) infection in inflammatory bowel disease (IBD).

METHODS: A cohort of 40 IBD patients (17 refractory) and 40 controls underwent peripheral blood and endoscopic colonic mucosal sample harvest. Viral infection was assessed by quantitative real-time polymerase chain reaction and immunohistochemistry, and correlations with clinical and endoscopic indexes of activity, and risk factors were investigated.

RESULTS: All refractory patients carried detectable levels of HCMV and/or EBV mucosal load as compared to 13/23 (56.5%) non-refractory and 13/40 (32.5%) controls. The median DNA value was significantly higher in refractory (HCMV 286 and EBV 5.440 copies/10⁵ cells) than in non-refractory (HCMV 0 and EBV 6 copies/10⁵ cells; P < 0.05 and < 0.001) IBD patients and controls (HCMV and EBV 0 copies/10⁵ cells; P < 0.001 for both). Refractory patients showed DNA peak values ≥ 10³ copies/10⁵ cells in diseased mucosa in comparison to non-diseased mucosa (P < 0.0121 for HCMV and < 0.0004 for EBV), while non-refractory patients and controls invariably displayed levels below this threshold, thus allowing us to differentiate viral colitis from mucosal infection. Moreover, the mucosal load positively correlated with the values found in the peripheral blood, whilst no correlation with the number of positive cells at immunohistochemistry was found. Steroid use was identified as a significant risk factor for both HCMV (P = 0.018) and EBV (P = 0.002) colitis. Finally, a course of specific antiviral therapy with ganciclovir was successful in all refractory patients with HCMV colitis, whilst refractory patients with EBV colitis did not show any improvement despite steroid tapering and discontinuation of the other medications.

CONCLUSION: Viral colitis appeared to contribute to mucosal lesions in refractory IBD, and its correct diagnosis and management require quantitative real-time polymerase chain reaction assay of mucosal specimens.

Angiocentric and intravascular lymphomas

Under the generic diagnosis of angiocentric and intravascular lymphomas are included several subtypes of lymphomas histopathologically characterized either by the predominantly endovascular-endoluminal presence of neoplastic lymphocytes of B-T or NK/T cell origin, or by a pathologic process centered around a blood vessels secondarily infiltrated and invaded by the spreading infiltrate. This group of lymphoproliferative disorders is heterogeneous regarding phenotype, but they share common features that are multiorgan involvement, worse prognosis, and, frequently Ebstein-Barr virus (EBV) genomic integration. At onset, some of these rare lymphomas, e.g. intravascular large cell lymphoma or lymphomatoid granulomatosis (Liebow dieases), are misdiagnosed as inflammatory diseases. The actual treatments of these disorders are based upon chemotherapy and/or chemotherapy plus bone marrow transplantation with variable results. Therapeutic approaches for EBV related angiocentric and intravascular lymphomas, similarly to those employed for other viral induced lymphoproliferative disease would comprise the employment of chemotherapy together with drugs able to interfere with viral infection. Such an approach has been used in rare cases of EBV-positive diffuse large B-cell lymphoma of the elderly, a lymphoproliferative disorders which development is linked to immunosuppression due to senescence. The present review will focus on intravascular and angiocentric lymphomas providing histopathologic, immunophenotypical and molecular data useful to overcome to a specific diagnosis and to differentiate them from other lymphoproliferative disorders showing a secondary vascular engulfment and infiltration and some vasculitides showing overlapping histopathologic features.

Immune-mediated neuropathy with Epstein-Barr virus-positive T-cell lymphoproliferative disease

A 47-year-old man with Epstein-Barr virus (EBV)-positive T/NK- cell lymphoproliferative disease (EBV-T/NK-LPD) developed acute-onset weakness. A nerve conduction study showed a conduction block in both the proximal and most distal segments. Although the patient's neuropathy transiently responded to intravenous immunoglobulin, it was progressive for at least 25 days until the start of prednisolone (PSL) administration, after which it remarkably improved. The neuropathy further improved after allogeneic bone marrow transplantation (BMT). The present patient's clinical course is not consistent with that of typical Guillain-Barré syndrome. This case suggests that EBV-T/NK-LPD can cause progressive immune-mediated neuropathy as a result of chronic EBV antigen presentation and can be treated with PSL and BMT.

Prognostic value and clinical implication of serum ferritin levels following allogeneic hematopoietic cell transplantation

Little research has been done on changes in serum ferritin (s-ferritin) levels and clinical implications following allogeneic hematopoietic cell transplantation (HCT). We retrospectively evaluated the correlation of s-ferritin levels after HCT with survival in 203 patients. The s-ferritin level was significantly elevated, with 75% of the patients showing peak levels 90 days after HCT. The level was >10,000 ng/ml in a total of 43% of the patients, a finding that was associated with febrile neutropenia or infection. The s-ferritin level at day 30 and at 1 year after HCT was significantly associated with prognosis. However, this statistically significant relationship was lost after adjusting for acute-phase reactants. We conclude that hyperferritinemia is very common and the degree of influence of a red blood cell transfusion will vary depending on the phase after HCT. A prospective study is needed to determine if iron load in and of itself contributes to a worse prognosis after HCT.

[Hemophagocytic syndrome associated with Epstein-Barr virus. Presentation of a case and treatment in the Resuscitation Unit]

We report the case of a 17 year old male patient, who was admitted to the Resuscitation Unit with the diagnosis of hemophagocytic syndrome, associated with infection by Epstein-Barr virus with unfavorable outcome. Hemophagocytic syndrome is a pathological immune activation syndrome due to the production/uncontrolled modulation of some cytokines. Its clinical signs and symptoms, defined by consensus criteria HLH-2004, are not pathognomonic, and often appear sequentially, thus suspicion should be followed by aggressive supportive therapy combined with early specific treatment of the triggering factor, as it is the only way to improve survival in patients with multiple organic failure as a result.

Systemic Epstein-Barr virus positive T-cell lymphoproliferative disease of childhood with hemophagocytic syndrome

Epstein-Barr virus (EBV) associated lymphoproliferative disease (LPD) are commonly derived from B-cells, however, it is becoming more and more apparently that EBV can also infect T-lymphocytes. Systemic EBV positive T-cell LPD of childhood is rare and characterized by an extremely aggressive course and poor prognosis. Here, we report a 22-year-old female of systemic EBV positive TLPD with acute EBV infection and review the clinical features of this disorder. A 22-year-old previously healthy female without immunocompromised status presented with persisting coach and fever resistant to conventional therapies. Physical examination showed hemorrhage and hepatosplenomegaly. Laboratory examinations revealed severe pancytopenia, disseminated intra-vascular coagulopathy (DIC), and anti-EBV-IgM positivity. Peripheral blood smears and bone marrow investigation identified a number of atypical lymphocytes. Flow cytometry (FCM) did not show any significant evidence of leukemia or lymphoma. The lymph node biopsy showed apparent infiltration of lymphocytes, which expressed CD2+, CD3+, CD7+ and TIA1+. There was no CD20+ or CD56+ cells. EBV early RNA (EBER) was positive. Cytogenetic analysis showed a normal karyotype. T-cell receptor (TCR) gene rearrangement revealed a polyclonal pattern. The patient received prednisolone and IVIG therapy with a transient good condition, and then died of multiorgan failure one week after diagnosis.

[Early diagnosis and comprehensive treatments of post-transplantation lymphoproliferative disorder after pediatric liver transplantation]

OBJECTIVE

To summarize the clinical characteristics, early diagnosis, comprehensive treatment and prognosis of 6 cases of children with post-transplantation lymphoproliferative disorder (PTLD) after liver transplantation.

METHOD

Data of 6 cases with PTLD seen between January 2011 and December 2013 were retrospectively analyzed. The anti-rejection drug dose adjustments, the effect of rituximab, antiviral therapy and comprehensive treatment program after surgery were explored.

RESULT

(1) The diagnosis of PTLD was confirmed by histologic findings. Six cases of PTLD including 3 males and 3 females were diagnosed as congenital biliary atresia and underwent split liver transplantation. The occurrence rate of PTLD was 2.9%. (2) The median time to the development of PTLD was less than 6 months. The initial symptom of PTLD in all patients was fever and clinical manifestations of PTLD were non-specific, depending on the involving organs. Five cases of PTLD developed gastrointestinal symptoms, including diarrhea, abdominal pain, and abdominal distension. One case developed respiratory symptoms, including cough and tachypnea. Three cases had lymph node involvement. In 2 cases pathophysiology involved polymorphic lymphocyte proliferation and in 4 cases B lymphocyte proliferation. (3) Two cases died, in whom EBV DNA was not detected and were diagnosed as PTLD by surgical pathology before death. Four survived cases had high EBV-DNA load and then were diagnosed as PTLD by biopsy pathology. (4) Of the 6 cases of PTLD, 2 cases died and 4 cases survived. The overall mortality was 33%. The dead cases were only treated with laparotomy because of intestinal obstruction or perforation and the survived cases were treated with tacrolimus at reduced doses or discontinuation and rituximab. In 2 cases antiviral therapy (acyclovir) was continued, including 1 cases of intestinal obstruction treated with surgical repair. All the survived patients were followed up for 4 months to 1 year and no evidence has been found.

CONCLUSION

EBV infection is the high risk factor for PTLD after liver transplantation. Close clinical surveillance of EBV DNA for pediatric liver transplantation was important for the early diagnosis of PTLD. Reducing doses of immunosuppressive agents and rituximab is the initial therapy for PTLD. A reduction in the dose of tacrolimus is suggested. Operation therapy can also play a role in the management of local complications.

[Unresolved problems and the prospects for research in area of the multiple sclerosis: virologic, immunologic and therapeutic aspects]

Multiple sclerosis--important and unsolved problem of modern neurology. Despite a great deal of publications, in the modern theory of multiple sclerosis there remain many unresolved problems, without solving of which no further advances in the diagnosis and treatment can be possible. The present work elucidates blind spots in pathogenesis of the disease to indicate the most perspective directions of research, the results of which would allow the optimization of existing diagnostic and therapeutic algorithms. Microbial triggers, immunopathological mechanisms, association with immunodeficiencies, efficacy of the immunotherapy and side effects of the immunosuppressants as well as additional antimicrobial treatment are discussed.

Spectrum of Epstein-Barr virus-associated T-cell lymphoproliferative disorder in adolescents and young adults in Taiwan

Epstein-Barr Virus (EBV) is a herpesvirus usually infecting B-cells but may occasionally infect T- or natural killer (NK)-cells. EBV-associated T- or NK-cell lymphoproliferations represent a continuous spectrum of diseases ranging from asymptomatic infection, infectious mononucleosis (IM), to clonal and malignant lymphoproliferations including systemic EBV-positive T/NK-cell lymphoproliferative disease (EBV-T/NK-LPD) of childhood and hydroa-vacciniforme-like lymphoma of the skin. The clonal diseases are more prevalent in East Asia and exhibit overlapping clinical and pathological features with chronic active EBV infection. Here we report our experience on 10 cases of EBV-associated T-cell lymphoproliferation from Taiwan including five males and five females with a median age of 18 years old (range, 15-28). The most common clinical symptoms were fever, neck mass and hepatosplenomegaly. Eight of these patients showed elevated lactate dehydrogenase level and half of the patients had cytopenia. All patients had either elevated EBV antibody titers or increased serum EBV DNA levels. Five cases were clinically IM-like with polyclonal (3 cases) or clonal (2 cases) T-cell lymphoproliferation. Two patients each had chronic active EBV infection (CAEBV) and hemophagocytic lymphohistiocytosis (HLH). One patient had both CAEBV and HLH. One of the HLH patients with marrow infiltration by intra-sinusoidal large atypical lymphocytes experienced a fulminant course. In a median follow-up time of 21.5 months, seven patients were free of disease, one was alive with disease, and two died of disease in 31 and 3 months, respectively, despite chemotherapy. We confirmed a wide clinicopathological range of EVB-associated T-cell lymphoproliferation in Taiwan. Furthermore, monomorphic LPD and the single case with fulminant course as defined by Ohshima et al (Pathol Int 2018) as categories A3 and B, respectively, died of disease despite chemotherapy. Our report, the largest series in the recent decade from Taiwan, adds to the understanding of these rare diseases with variable clinical and histopathological presentations.

Posttransplant lymphoproliferative disorder after liver and kidney transplant

OBJECTIVES

We evaluated posttransplant lymphoproliferative disorder after solid-organ transplant.

MATERIALS AND METHODS

All 2224 solid-organ transplant recipients who underwent transplant between 1985 and 2013 were included. Clinicopathological findings were examined, and all patients with posttransplant lymphoproliferative disorder were reclassified to World Health Organization 2008 lymphoma classification.

RESULTS

Only 27 of 2224 patients developed posttransplant lymphoproliferative disorder. The incidence of posttransplant lymphoproliferative disorder was 3.3-fold higher in children than in adults. The mean interval between transplant and diagnosis of posttransplant lymphoproliferative disorder was 65 months. Patients with tacrolimus were associated with a shorter posttransplant lymphoproliferative disorder development time compared with cyclosporine patients. Epstein-Barr virus-encoded small RNA positive showed shorter time for development of posttransplant lymphoproliferative disorder compared with Epstein-Barr virus-encoded small RNA negative patients. The risk of developing posttransplant lymphoproliferative disorder within the first year of transplant was higher in patients under tacrolimus protocol compared with patients under cyclosporine. Of 27 patients, 4 showed early lesion and 23 patients showed monomorphic posttransplant lymphoproliferative disorder. The development of T-cell monomorphic posttransplant lymphoproliferative disorder was significantly late compared with patients with B-cell monomorphic posttransplant lymphoproliferative disorder. Eight patients died at 38 ± 50 months after posttransplant lymphoproliferative disorder diagnosis. Four patients with early type posttransplant lymphoproliferative disorder were alive, and 3 of 4 patients with T-cell monomorphic posttransplant lymphoproliferative disorder died shortly after diagnosis. Five of 19 patients with B-cell monomorphic posttransplant lymphoproliferative disorder died at a mean 29 ± 18 months. A significant difference was found between the histologic types regarding patient survival. A significant difference was found between the Epstein-Barr virus-encoded small RNA positive and Epstein-Barr virus-encoded small RNA negative patients regarding mean survival time.

CONCLUSIONS

To decrease the incidence of posttransplant lymphoproliferative disorder, risk factors should be evaluated and new approaches must be derived for prophylaxis, diagnosis, and treatment.

[Clinical case. Chronic gastritis associated with Helicobacter pylori and Epstein-Barr virus]

The article describes a clinical case of chronic gastritis associated with Helicobacter pylori infection and Epstein-Barr virus. The authors draw attention to the peculiarities of dyspepsia syndrome, on the characteristics of this disease in the endoscopic and morphological study.

Epstein-Barr virus as a paradigm in nasopharyngeal cancer: from lab to clinic

Nasopharyngeal carcinoma (NPC) of the undifferentiated subtype remains endemic in southern China, with a peak incidence in this region approaching 30 cases per 100,000 population per year. Despite advances in chemotherapy and radiation delivery techniques in localized disease, distant metastasis is still common and NPC remains the seventh leading cause of cancer death in the region. There is great need for early diagnosis, developing novel therapies, and identifying patients with localized disease at higher risk of future recurrence or metastasis to appropriately tailor their treatment and improve outcomes. Knowledge of the integral involvement of Epstein-Barr virus (EBV) in the pathogenesis of undifferentiated NPC has been of seminal importance in developing strategies to optimize disease management. The close association with EBV is being evaluated in multiple settings including screening of at-risk populations, disease prognostication, development of targeted therapies, optimizing adjuvant treatment, and early recurrence detection. These translational studies are likely to have an enormous effect on management of undifferentiated NPC and significantly improve the landscape of the disease in years to come.

EBV associated lymphomas in 2008 WHO classification

Epstein-Barr virus (EBV) is a ubiquitous γ-herpes virus that asymptomatically infects more than 90% of the world's population. The exact mechanism of EBV in oncogenesis is an area of active debate. However, EBV has been implicated in the pathogenesis of several kinds of lymphomas and lymphoproliferative disorders, including B-, T- and NK-cell derived. Subsequent studies have proven that the EBV gene expression product plays an activating and/or promoting role on lymphomagenesis, and paves the way for novel cellular therapies of EBV-associated lymphomas. This review concentrates on the pathology, morphology, treatment and prognosis of EBV-associated lymphomas in the 2008 WHO classification of tumors of hematopoietic and lymphoma tissues.

[Latest update on immunotherapy of Epstein-Barr virus-associated post-transplantation lymphoproliferative disease]

Epstein-Barr virus (EBV)-associated post-transplantation lymphoproliferative disease (EBV-PTLD) is a potentially life-threatening complication after hematopoietic stem cell transplantation or solid organ transplantation. In the last decade, the survival of patients with EBV-PTLD has been significantly improved by immunotherapeutic interventions among high-risk patients. The immunotherapeutic interventions for EBV-PTLD include reduction in immunosuppression, CD20 monoclonal antibodies (rituximab) as monotherapy or in combination with chemotherapy, and adoptive immunotherapy with EBV-specific T cells. This paper reviews the latest update on the high-risk factors, clinical manifestations and immunotherapy of EBV-PTLD.

Differences in gastric carcinoma microenvironment stratify according to EBV infection intensity: implications for possible immune adjuvant therapy

Epstein-Barr virus (EBV) is associated with roughly 10% of gastric carcinomas worldwide (EBVaGC). Although previous investigations provide a strong link between EBV and gastric carcinomas, these studies were performed using selected EBV gene probes. Using a cohort of gastric carcinoma RNA-seq data sets from The Cancer Genome Atlas (TCGA), we performed a quantitative and global assessment of EBV gene expression in gastric carcinomas and assessed EBV associated cellular pathway alterations. EBV transcripts were detected in 17% of samples but these samples varied significantly in EBV coverage depth. In four samples with the highest EBV coverage (hiEBVaGC – high EBV associated gastric carcinoma), transcripts from the BamHI A region comprised the majority of EBV reads. Expression of LMP2, and to a lesser extent, LMP1 were also observed as was evidence of abortive lytic replication. Analysis of cellular gene expression indicated significant immune cell infiltration and a predominant IFNG response in samples expressing high levels of EBV transcripts relative to samples expressing low or no EBV transcripts. Despite the apparent immune cell infiltration, high levels of the cytotoxic T-cell (CTL) and natural killer (NK) cell inhibitor, IDO1, was observed in the hiEBVaGCs samples suggesting an active tolerance inducing pathway in this subgroup. These results were confirmed in a separate cohort of 21 Vietnamese gastric carcinoma samples using qRT-PCR and on tissue samples using in situ hybridization and immunohistochemistry. Lastly, a panel of tumor suppressors and candidate oncogenes were expressed at lower levels in hiEBVaGC versus EBV-low and EBV-negative gastric cancers suggesting the direct regulation of tumor pathways by EBV.

Epstein-Barr virus (EBV) is detected in roughly 10% of gastric carcinoma (GC) cases worldwide. Despite a strong link between EBV and gastric carcinoma, the contribution of EBV to the tumor environment in EBV associated gastric carcinoma is unclear. We performed a global assessment of EBV and host cell gene expression in gastric carcinoma tumors from 71 patients to link EBV genes (and expression intensities) to cell and microenvironmental changes. In addition to the finding that EBV is associated with down-regulated tumor regulatory genes, this study revealed that samples with high levels of EBV gene expression (hiEBVaGCs) displayed elevated immune cell infiltration with high interferon-gamma (IFNG) expression compared to samples with low or no EBV gene expression. Despite this evidence of increased immune posturing, hiEBVaGC samples also showed elevated expression of the potent immune cell inhibitor, IDO1. This finding may partly explain the persistence of these virus associated tumors in the face of local immune cell concentration. Importantly, the small molecule IDO inhibitor, 1MT (1-methyl Tryptophan), has been shown to reverse the tolerance inducing effects of IDO1 in other tumors. We propose that stratification of gastric carcinomas into EBV-negative, EBV-low and EBV-high may provide indicator value for the use of IDO1 inhibitors as adjuvant therapies against hiEBVaGCs.

Epstein-Barr Virus (EBV)-associated gastric carcinoma

The ubiquitous Epstein-Barr virus (EBV) is associated with several human tumors, which include lymphoid and epithelial malignancies. It is known that EBV persistently infects the memory B cell pool of healthy individuals by activating growth and survival signaling pathways that can contribute to B cell lymphomagenesis. Although the monoclonal proliferation of EBV-infected cells can be observed in epithelial tumors, such as nasopharyngeal carcinoma and EBV-associated gastric carcinoma, the precise role of EBV in the carcinogenic progress is not fully understood. This review features characteristics and current understanding of EBV-associated gastric carcinoma. EBV-associated gastric carcinoma comprises almost 10% of all gastric carcinoma cases and expresses restricted EBV latent genes (Latency I). Firstly, definition, epidemiology, and clinical features are discussed. Then, the route of infection and carcinogenic role of viral genes are presented. Of particular interest, the association with frequent genomic CpG methylation and role of miRNA for carcinogenesis are topically discussed. Finally, the possibility of therapies targeting EBV-associated gastric carcinoma is proposed.

Posttransplant lymphoproliferative disease after lung transplantation

Posttransplant lymphoproliferative disease (PTLD) after lung transplantation occurs due to immunosuppressant therapy which limits antiviral host immunity and permits Epstein-Barr viral (EBV) replication and transformation of B cells. Mechanistically, EBV survives due to latency, escape from cytotoxic T cell responses, and downregulation of host immunity to EBV. Clinical presentation of EBV may occur within the lung allograft early posttransplantation or later onset which is more likely to be disseminated. Improvements in monitoring through EBV viral load have provided a means of earlier detection; yet, sensitivity and specificity of EBV load monitoring after lung transplantation may require further optimization. Once PTLD develops, staging and tissue diagnosis are essential to appropriate histopathological classification, prognosis, and guidance for therapy. The overall paradigm to treat PTLD has evolved over the past several years and depends upon assessment of risk such as EBV-naïve status, clinical presentation, and stage and sites of disease. In general, clinical practice involves reduction in immunosuppression, anti-CD20 biologic therapy, and/or use of plasma cell inhibition, followed by chemotherapy for refractory PTLD. This paper focuses upon the immunobiology of EBV and PTLD, as well as the clinical presentation, diagnosis, prognosis, and emerging treatments for PTLD after lung transplantation.

The management of upper respiratory tract infections

Upper respiratory tract infections (URTIs), generally termed colds, sore throats and coughs, are common presentations in primary care. This article discusses the clinical picture, management, significant differential diagnosis, and specifically, when antibiotics may be required for an URTI.

[Cycloferon in complex therapy management of chronic laryngitis]

The clinical course of various forms of chronic laryngitis, including contact granulomas not only persistant and relapsing, but also inclined to oncologic pathology due to hyperplastic changes in the larynx resulting in malignization was described. Inhibition of the leukocyte interferon-synthesizing activity was observed in more than 88.1% of the subjects. Pathogenic viruses were isolated from 48.2% of the patients, EBV and mycoplasma prevailing. High direct correlation between chronic laryngitis and Herpes viruses was shown. The presence of three-component virus associations in the larynx mucosa was likely indicative of the bening process malignancy. The use of the interferon inductor cycloferon in the complex surgical and medicamentous management of chronic laryngitis was shown valid. The rate of the relapses lowered to 1.7 episodes a year.

EBV and posttransplantation lymphoproliferative disease: what to do?

This review summarizes the available evidence and outlines our approach to the prophylaxis and management of posttransplantation lymphoproliferative disorder (PTLD) in adult solid organ transplantation recipients. We attempt to reduce immunosuppression as tolerated in every patient with suspected PTLD in close cooperation with their transplantation physician. There is no evidence to guide the decision when to initiate further treatment; we usually wait no longer than 4 weeks and always initiate further therapy unless there is a complete or at least good partial remission. If clinical and histological findings indicate rapidly progressive disease, we initiate additional therapy significantly earlier. CD20-positive PTLD accounts for approximately 75% of PTLD cases. Outside of clinical trials, we currently regard sequential therapy with rituximab and CHOP (cyclophosphamide, hydroxydaunorubicin, vincristine, prednisone/prednisolone) chemotherapy as standard evidence-based treatment for CD20-positive PTLD unresponsive to immunosuppression. We also discuss our approach to the rare instance of adults with PTLD associated with primary EBV infection, localized (stage I) disease, rare PTLD subtypes, and refractory/relapsed disease based on the available retrospective data and our own experience. In addition to immunotherapy and chemotherapy, this includes local therapy approaches such as surgery and radiotherapy in stage I disease, plasmacytoma-like PTLD, and primary CNS PTLD. We also provide our view on the current indications for the use of allogeneic cytotoxic T cells, even though this treatment modality is so far unavailable in our clinical practice.

Molecular diagnosis and management of viral infections in hematopoietic stem cell transplant recipients

Viral infections after allogeneic hematopoietic stem cell transplantation (HSCT) are important complications associated with high morbidity and mortality. In this setting, reactivations of persisting latent viral pathogens from donor and/or recipient cells play a central role whereas the sterile environment of transplant units renders new infections less likely. The viruses currently regarded as most relevant in the HSCT setting include particularly the herpes virus family--specifically cytomegalovirus (CMV), Epstein-Barr virus (EBV), and human herpesvirus 6 (HHV-6)--as well as human adenoviruses (AdVs) and the polyoma virus BK (BKV). Timely detection and monitoring of virus copy numbers are prerequisites for successful preemptive treatment approaches. Pre- and post-transplant surveillance by sensitive and quantitative molecular methods has therefore become an essential part of the diagnostic routine. In this review, we discuss diagnostic aspects and the clinical management of the most important viral infections in HSCT recipients, with a focus on pediatric patients.

Effects of intensified conditioning on Epstein-Barr virus and cytomegalovirus infections in allogeneic hematopoietic stem cell transplantation for hematological malignancies

BACKGROUND

Intensified conditioning regimens (increasing the intensity of standard myeloablative conditioning) for hematological malignancies in allogeneic hematopoietic stem cell transplantation (allo-HSCT) could reduce the relapse rate of the underlying disease, but it might simultaneously increase the transplant-related mortality including the mortality of infections. To explore whether intensified conditioning affected Epstein-Barr virus (EBV) and cytomegalovirus (CMV) infections, 185 patients undergoing allo-HSCT were enrolled.

METHODS

A total of 104 cases received standard and 81 intensified conditioning. Cyclosporine A (CsA) withdrawal and/or donor lymphocyte infusion (DLI) were conducted in high-risk patients. The EBV-DNA and CMV-DNA levels of blood were monitored regularly by quantitative real-time polymerase chain reaction (RQ-PCR) and immune reconstitution of recipients were analyzed by flow cytometry.

RESULTS

The 3-year cumulative incidence of EBV viremia, EBV-associated diseases and mortality of EBV-associated diseases were 25.3% ± 4.6%, 10.5% ± 3.4% and 0.0% ± 0.0% in the standard group, compared with 45.6% ± 6.5%, 26.0% ±5.3% and 7.3% ± 3.1% in the intensified group (P = 0.002, P = 0.002, P = 0.008). The 3-year cumulative incidence of CMV viremia and CMV-associated diseases, mortality of CMV-associated diseases and incidence of bacterial and fungal infections were similar between the two groups (P = 0.855, P = 0.581, P = 0.933, P = 0.142, P = 0.182, respectively). Multivariate analysis showed that intensified conditioning was one of the risk factors for EBV viremia and EBV-associated diseases (P = 0.037, P = 0.037), but it had no effects on CMV infections. The percentage of CD4+ T cells and CD4+/CD8+ ratio at 3 months post-transplantation were lower in the intensified group (P = 0.032, P = 0.022). The 3-year OS and DFS in the standard group were 62.2% ± 5.8% and 60.6% ± 5.6%, compared with 51.6% ± 6.2% and 51.1% ± 5.9% in the intensified group (P = 0.029, P = 0.063).

CONCLUSIONS

Intensified conditioning represents a promising approach for high-risk hematological malignancies, although it affects early immune reconstitution of recipients and increases the incidence and mortality of EBV infections.

Monitoring and managing viral infections in pediatric renal transplant recipients

Viral infections remain a significant cause of morbidity and mortality following renal transplantation. The pediatric cohort is at high risk of developing virus-related complications due to immunological naiveté and the increased alloreactivity risk that requires maintaining a heavily immunosuppressive environment. Although cytomegalovirus is the most common opportunistic pathogen seen in transplant recipients, numerous other viruses may affect clinical outcome. Recent technological advances and novel antiviral therapy have allowed implementation of viral and immunological monitoring protocols and adoption of prophylactic or preemptive treatment approaches in high-risk groups. These strategies have led to improved viral infection management in the immunocompromised host, with significant impact on outcome. We review the major viral infections seen following kidney transplantation and discuss strategies for preventing and managing these pathogens.