Monitoring of Cytomegalovirus (CMV)-Specific Cell-Mediated Immunity in Heart Transplant Recipients: Clinical Utility of the QuantiFERON-CMV Assay for Management of Posttransplant CMV Infection.

The clinical utility of the QuantiFERON-CMV (QFN-CMV) assay in heart transplant recipients was assessed. Forty-four cytomegalovirus (CMV)-seropositive patients were enrolled: 17 received antiviral prophylaxis, and 27 were managed preemptively. CMV-DNAemia monitoring was performed by the use of a quantitative real-time PCR assay. The QFN-CMV assay was retrospectively performed on blood samples collected at five posttransplant time points. A higher proportion of patients with an indeterminate QFN-CMV result after the suspension of prophylaxis than of patients who showed a global T-cell responsiveness developed CMV infection (P = 0.036). Patients who reconstituted a CMV-specific response following the first CMV-DNAemia-positive result (42.9%) showed a median CMV-DNAemia peak 1 log of magnitude lower than that seen with patients with indeterminate results, and all controlled viral replication spontaneously. The 25% of patients with an indeterminate result developed CMV disease. In the preemptive strategy group, no differences in the development of subsequent infection, magnitude of viral load, and viral control were observed on the basis of QFN-CMV measurements performed before and after the first CMV-DNAemia-positive result. Considering both CMV prevention strategies, viral relapse was associated with the failure to reconstitute CMV-specific cell-mediated immunity (CMI) after the resolution of the first episode of CMV infection (P = 0.032). QFN-CMV measurements can be a useful tool for identifying patients (i) at higher risk of developing infection after discontinuing antiviral prophylaxis, (ii) with late CMV infection who would benefit from appropriate antiviral interventions, and (iii) at higher risk of viral relapses. QFN-CMV measurements taken within 1 month posttransplantation (early period) are not revealing.

Infectious meningitis/encephalitis: evaluation of a rapid and fully automated multiplex PCR in the microbiological diagnostic workup.

Infectious diseases of the central nervous system (CNS) such as meningitis/encephalitis (ME) require rapid identification of causative pathogens for effective treatment. This study evaluated the analytical performance and clinical utility of a fully automated multiplex PCR test to improve the microbiological diagnostic workup of ME. Seventy-seven cerebrospinal fluid (CSF) samples from 77 patients with suspected ME were studied. The samples were tested by FilmArray™ (FA) ME Panel test and the results were compared with those obtained using conventional microbiological procedures (CMP). Furthermore, the assay's validity was evaluated testing 5 pooled CSF samples positive for different pathogens. The data showed a good concordance (90.9%) between the FA ME panel test and CMP results. Discrepant results were observed in CSF samples with low viral load (5/77) and in samples of patients (2/77) undergoing antimicrobial therapy for fungal infection. The ability of the FA ME panel test to correctly detect the target pathogens was confirmed. Faster microbiological diagnosis was obtained by the FA ME test in comparison to CMP for both bacterial and viral analytes (P<0.001). Implementation of microbiological diagnostic workup with FA ME panel test may improve the management of patients with suspected CNS infection.

Salivary glands and human congenital cytomegalovirus infection: What happens in early fetal life?

Salivary glands are a site of human cytomegalovirus (CMV) replication, latency, and persistence. Prolonged secretion of virus in saliva for months following a primary infection contribute to horizontal transmission. In order to better understand the early effects of CMV on salivary glands and the mechanisms of viral persistent replication, submandibular glands of six CMV congenitally infected fetuses at 21 weeks gestation were studied. Three fetuses at the same gestational age from CMV-seronegative women were compared as negative controls. Tissue viral load and the type of inflammatory infiltrate were evaluated. Moreover, development and branching of salivary glands, the number of myoepithelial cells, cellular proliferation, and expression of secretory proteins of the saliva (Gross Cystic Disease Fluid Protein-15 and lysozyme) were studied. A low viral load and rare CMV-positive cells associated with T CD8 cytotoxic lymphocytes were observed. Branching was impaired with a decrease in terminal acinar structures, the number of myoepithelial cells, and cellular proliferation were reduced. In addition, a compromised secretion of defense proteins involved in the oral humoral immunity was observed. These findings suggest that CMV may affect salivary glands, impairing structure development and secretion of defense proteins, probably responsible for the prolonged viral shedding in saliva. J. Med. Virol. 89:318-323, 2017. © 2016 Wiley Periodicals, Inc.

Infectious agents after liver transplant: etiology, timeline and patients' cell-mediated immunity responses.

Infections continue to be one of the leading causes of morbidity and mortality in liver transplant recipients. We retrospectively reviewed the symptomatic infectious episodes that occurred during the first year post-transplant to determine time of onset, causative pathogens and cell-mediated immunity response patterns. Ninety-eight of the 202 (48.5%) recipients enrolled developed at least one infectious episode. The total number of infectious episodes was 135: 77 (57.1%) bacterial, 45 (33.3%) viral and 13 (9.6%) fungal. The most frequently isolated bacteria were Escherichia coli (21 isolates) and Klebsiella pneumoniae (19 isolates). Overall, extended-spectrum beta lactamase-producing and methicillin-resistant organisms were responsible for 29 (29/77; 37.7%) infectious episodes. Members of the herpes virus group, in particular cytomegalovirus (34/45 viral infections, 75.5%), were detected. Candida species (9 isolates) followed by Aspergillus species (4 isolates) were isolated. The majority of infections (63%) occurred during the early post-transplant phase (<1 month), whereas only 8/135 episodes (5.9%) were detected after the sixth month (late phase). Significantly lower median ImmuKnow® intracellular ATP values in patients who developed bacterial and fungal infections compared to infection-free patients were observed (P < 0.0001 and P = 0.0016, respectively), whereas patients who developed a viral infection had a median intracellular ATP level not statistically different compared to uninfected patients (P = 0.4). Our findings confirm that bacteria are responsible for the majority of symptomatic infections and occur more frequently during the first month post-transplant. The ImmuKnow® measurements can be a useful tool for identifying patients at high risk of developing infection, particularly of fungal and bacterial etiology.

Clinical evaluation of the new Roche platform of serological and molecular cytomegalovirus-specific assays in the diagnosis and prognosis of congenital cytomegalovirus infection.

Clinical evaluation of the Elecsys® CMV IgM, IgG, IgG Avidity and COBAS AmpliPrep/COBAS TaqMan CMV (COBAS CMV) assays (Roche Diagnostics AG) in the diagnosis and prognosis of congenital CMV infection was performed. In this study, 150 preselected clinical samples (50 primary infection sera, 50 amniotic fluid [AF] and 50 newborn urine) were processed using Roche serological/molecular CMV-specific tests. Results were compared with those obtained by routine assays (comparator assays). The Elecsys® CMV IgM and IgG assays showed a perfect agreement (100%) with the comparator assays. Using the combination of the Elecsys® CMV IgM and IgG Avidity assays results, a primary infection was identified in 100% of cases. Inappropriate avidity CMV IgG values in two samples with very low IgG values (<6 AU/mL) were observed. COBAS CMV assay showed an agreement equal to 98% and 100% with comparator assays by processing AF and urine samples, respectively. Among AF with quantitative results, Lin's concordance correlation was 0.933 and comparator-COBAS CMV assays gave CMV-DNA loads differing by <0.5 log10 DNA. Finally, higher CMV-DNA levels in AF samples were associated with a symptomatic outcome (p=0.003). The Roche CMV-specific assays compared well with the comparator assays, thus providing to be suitable for clinical use.

Successful management of EBV-PTLD in allogeneic bone marrow transplant recipient by virological-immunological monitoring of EBV infection, prompt diagnosis and early treatment.

Epstein-Barr virus-related post-transplant lymphoproliferative disorder (EBV-PTLD) is an uncommon, but frequently fatal, complication after allogeneic hematopoietic stem cell transplant. Prospective post-transplant virological and immunological monitoring allowed to successfully manage a patient who developed both polymorphic and monomorphic, "diffuse large B-cell lymphoma like", as an EBV-PTLD, 65days after allogeneic bone marrow transplant. Early detection of significant increase in EBV DNA level in patient's peripheral blood (peak of viral load equal to 119,039copies/mL whole blood, +56day after transplant) led to administration of pre-emptive anti-CD20 monoclonal antibody (rituximab) and close clinical monitoring. After one week, physical exam revealed laterocervical adenopathy. Histopathologic features, immunohistochemical characterization and in situ hybridization study allowed to establish a diagnosis of EBV-related PTLD. Immunological monitoring showed no EBV-specific T-cell responses during EBV replication, thus potentially explaining the occurrence of high EBV load with subsequent PTLD development. A total of four doses of anti-CD20 monoclonal antibody were administered and at the end of the treatment, EBV infection was cleared and imaging technique showed complete disease remission. In conclusion, the early use of anti-CD20 monoclonal antibody proved to be a safe and effective treatment strategy for EBV-PTLD. Moreover, combined virological-immunological monitoring of EBV infection may more accurately assess patients at higher risk for EBV-PTLD.