Immune Monitoring-Guided Versus Fixed Duration of Antiviral Prophylaxis Against Cytomegalovirus in Solid-Organ Transplant Recipients: A Multicenter, Randomized Clinical Trial.

BACKGROUND: The use of assays detecting cytomegalovirus (CMV)-specific T cell-mediated immunity may individualize the duration of antiviral prophylaxis after transplantation. METHODS: In this randomized trial, kidney and liver transplant recipients from 6 centers in Switzerland were enrolled if they were CMV-seronegative with seropositive donors or CMV-seropositive receiving antithymocyte globulins. Patients were randomized to a duration of antiviral prophylaxis based on immune monitoring (intervention) or a fixed duration (control). Patients in the control group were planned to receive 180 days (CMV-seronegative) or 90 days (CMV-seropositive) of valganciclovir. Patients were assessed monthly with a CMV ELISpot assay (T-Track CMV); prophylaxis in the intervention group was stopped if the assay was positive. The co-primary outcomes were the proportion of patients with clinically significant CMV infection and reduction in days of prophylaxis. Between-group differences were adjusted for CMV serostatus. RESULTS: Overall, 193 patients were randomized (92 in the immune-monitoring group and 101 in the control group), of whom 185 had evaluation of the primary outcome (87 and 98 patients). CMV infection occurred in 26 of 87 (adjusted percentage, 30.9%) in the immune-monitoring group and in 32 of 98 (adjusted percentage, 31.1%) in the control group (adjusted risk difference, -0.1; 95% confidence interval [CI], -13.0% to 12.7%; P = .064). The duration of prophylaxis was shorter in the immune-monitoring group (adjusted difference, -26.0 days; 95%, CI, -41.1 to -10.8 days; P < .001). CONCLUSIONS: Immune monitoring resulted in a significant reduction of antiviral prophylaxis, but we were unable to establish noninferiority of this approach on the co-primary outcome of CMV infection. CLINICAL TRIALS REGISTRATION: NCT02538172.

Differences Between Infectious Disease Events in First Liver Transplant Versus Retransplantation in the Swiss Transplant Cohort Study.

Retransplantation after graft failure is increasingly performed, and inferior graft survival, patient survival, and quality of life has been reported. The role of infectious disease (ID) events in this less favorable outcome is unknown. We analyzed ID events after first liver transplantation (FLTpx) and retransplantation (reLTpx) in the Swiss Transplant Cohort Study. Clinical factors were compared after FLTpx and reLTpx, and survival analysis was applied to compare the time to ID events after FLTpx and after reLTpx, adjusted for age, sex, Model for End-Stage Liver Disease score, donor type, liver transplant type (whole versus split liver), and duration of transplant surgery. In total, 60 patients were included (65.0% male, median age of 56 years). Overall, 343 ID events were observed: 204 (59.5%) after the FLTpx and 139 (40.5%) after reLTpx. Bacterial infections were most frequent (193/343, 56.3%), followed by viral (43/343, 12.5%) and fungal (28/343, 8.2%) infections, with less infections by Candida spp. but more by Aspergillus spp. after reLTpx (P = 0.01). The most frequent infection site was bloodstream infection (86, 21.3%), followed by liver and biliary tract (83, 20.5%) and intraabdominal (63, 15.6%) infections. After reLTpx, more respiratory tract and surgical site infections were observed (P < 0.001). The time to first infection was shorter after FLTpx (adjusted hazard ratio [HR], 0.5; 95%-confidence interval [CI], 0.3-1.0; P = 0.04). Reduced hazards for ID events after reLTpx were also observed when modelling recurrent events (adjusted HR, 0.5; CI, 0.3-0.8; P = 0.003). The number of infections was comparable after FLTpx and reLTpx; however, differences regarding infection sites and fungal species were observed. Hazards were reduced for infection after reLTpx.

Herpes simplex encephalitis in adult patients with MASP-2 deficiency.

We report here two cases of Herpes simplex virus encephalitis (HSE) in adult patients with very rare, previously uncharacterized, non synonymous heterozygous G634R and R203W substitution in mannan-binding lectin serine protease 2 (MASP2), a gene encoding a key protease of the lectin pathway of the complement system. None of the 2 patients had variants in genes involved in the TLR3-interferon signaling pathway. Both MASP2 variants induced functional defects in vitro, including a reduced (R203W) or abolished (G634R) protein secretion, a lost capability to cleave MASP-2 precursor into its active form (G634R) and an in vivo reduced antiviral activity (G634R). In a murine model of HSE, animals deficient in mannose binding lectins (MBL, the main pattern recognition molecule associated with MASP-2) had a decreased survival rate and an increased brain burden of HSV-1 compared to WT C57BL/6J mice. Altogether, these data suggest that MASP-2 deficiency can increase susceptibility to adult HSE.

Burden and Timeline of Infectious Diseases in the First Year After Solid Organ Transplantation in the Swiss Transplant Cohort Study.

BACKGROUND: The burden and timeline of posttransplant infections are not comprehensively documented in the current era of immunosuppression and prophylaxis. METHODS: In this prospective study nested within the Swiss Transplant Cohort Study (STCS), all clinically relevant infections were identified by transplant-infectious diseases physicians in persons receiving solid organ transplant (SOT) between May 2008 and December 2014 with ≥12 months of follow-up. RESULTS: Among 3541 SOT recipients, 2761 (1612 kidney, 577 liver, 286 lung, 213 heart, and 73 kidney-pancreas) had ≥12 months of follow-up; 1520 patients (55%) suffered 3520 infections during the first year posttransplantation. Burden and timelines of clinically relevant infections differed between transplantations. Bacteria were responsible for 2202 infections (63%) prevailing throughout the year, with a predominance of Enterobacteriaceae (54%) as urinary pathogens in heart, lung, and kidney transplant recipients, and as digestive tract pathogens in liver transplant recipients. Enterococcus spp (20%) occurred as urinary tract pathogens in kidney transplant recipients and as digestive tract pathogens in liver transplant recipients, and Pseudomonas aeruginosa (9%) in lung transplant recipients. Among 1039 viral infections, herpesviruses predominated (51%) in kidney, liver, and heart transplant recipients. Among 263 fungal infections, Candida spp (60%) prevailed as digestive tract pathogens in liver transplant recipients. Opportunistic pathogens, including Aspergillus fumigatus (1.4%) and cytomegalovirus (6%), were rare, scattering over 12 months across all SOT recipients. CONCLUSIONS: In the current era of immunosuppression and prophylaxis, SOT recipients experience a high burden of infections throughout the first year posttransplantation, with rare opportunistic pathogens and a predominance of bacteria.

A VP1 mutation acquired during an enterovirus 71 disseminated infection confers heparan sulfate binding ability and modulates ex vivo tropism.

Enterovirus 71 (EV71) causes hand, foot and mouth disease, a mild and self-limited illness that is sometimes associated with severe neurological complications. EV71 neurotropic determinants remain ill-defined to date. We previously identified a mutation in the VP1 capsid protein (L97R) that was acquired over the course of a disseminated infection in an immunocompromised host. The mutation was absent in the respiratory tract but was present in the gut (as a mixed population) and in blood and cerebrospinal fluid (as a dominant species). In this study, we demonstrated that this mutation does not alter the dependence of EV71 on the human scavenger receptor class B2 (SCARB2), while it enables the virus to bind to the heparan sulfate (HS) attachment receptor and modifies viral tropism in cell lines and in respiratory, intestinal and neural tissues. Variants with VP197L or VP197R were able to replicate to high levels in intestinal and neural tissues and, to a lesser extent, in respiratory tissues, but their preferred entry site (from the luminal or basal tissue side) differed in respiratory and intestinal tissues and correlated with HS expression levels. These data account for the viral populations sequenced from the patient's respiratory and intestinal samples and suggest that improved dissemination, resulting from an acquired ability to bind HS, rather than specific neurotropism determinants, enabled the virus to reach and infect the central nervous system. Finally, we showed that iota-carrageenan, a highly sulfated polysaccharide, efficiently blocks the replication of HS-dependent variants in cells and 2D neural cultures. Overall, the results of this study emphasize the importance of HS binding in EV71 pathogenesis and open new avenues for the development of antiviral molecules that may prevent this virus's dissemination.

Vitamin D deficiency is common in kidney transplant recipients, but is not associated with infections after transplantation.

The relevance of vitamin D for infections after kidney transplantation is poorly defined. 25-OH vitamin D (25-OHD) levels of 135 kidney transplant recipients, enrolled in the Swiss Transplant Cohort Study, were determined peri-transplant and 6 months post-transplant. Logistic regression was used to address the associations of 25-OHD and overall infections and bacterial infections, respectively. For the first 6 months post-transplant, 25-OHD peri-transplant, and for the second period (after 6 to 30 months post-transplant), 25-OHD at 6 months post-transplant was considered. Vitamin D deficiency was common peri-transplant and remained highly prevalent 6 months after transplantation despite frequent supplementation. Median 25-OHD levels increased from 12.0 ng/mL (IQR 5.3-19.5) peri-transplant to 16.5 ng/mL (IQR 10.6-22.6) 6 months post-transplant (P = .005). We did not detect a significant association between 25-OHD and overall infections (adjusted odds ratio (aOR) 1.05, 95% confidence interval (95%CI) 0.44-2.51; aOR 0.67, 95%CI 0.31-1.43) or bacterial infections (aOR 0.79, 95%CI 0.32-1.96; aOR 0.79, 95%CI 0.35-1.75) for the first and second period. To conclude, at both time points, vitamin D deficiency was observed in more than 50% of kidney recipients, albeit an increase in 25-OHD in the longitudinal course was observed. No significant association between 25-OHD and infections was detected.

Vitamin D status and risk of infections after liver transplantation in the Swiss Transplant Cohort Study.

Increasing evidence indicates a role of vitamin D in the immune system affecting response to infections. We aimed to characterize the role of vitamin D status, i.e. deficiency [25-OH vitamin D (25-OHD) <50 nmol/l] and no deficiency (25-OHD ≥50 nmol/l) in incident infections after liver transplantation. In 135 liver transplant recipients, blood samples drawn at time of liver transplantation and 6 months afterwards were used to determine 25-OHD levels. Incident infections episodes were prospectively collected within the Swiss Transplant Cohort Study database. Poisson regression was applied to address associations between vitamin D status and incident infections. Vitamin D deficiency was common at time of transplantation and 6 months afterwards without a significant change in median 25-OHD levels. In univariable analyses, vitamin D deficiency was a risk factor for incident infections in the first 6 months post-transplant incidence rate ratio (IRR 1.52, 95% CI 1.08-2.15, P = 0.018) and for bacterial infections occurring after 6 up to 30 months post-transplant (IRR 2.29, 95% CI 1.06-4.94, P = 0.034). These associations were not detectable in multivariable analysis with adjustment for multiple confounders. Efforts to optimize vitamin D supplementation in liver transplant recipients are needed. Our data question the role of vitamin D deficiency in incident infections.

Burden of severe RSV disease among immunocompromised children and adults: a 10 year retrospective study.

BACKGROUND: Respiratory syncytial virus (RSV) is associated with significant mortality rates amongst hematopoietic stem cell transplant (HSCT) recipients, with less known about other immunocompromised patients. METHODS: Ten-year retrospective cohort study of immunocompromised patients presenting with RSV disease documented at University Hospitals of Lausanne and Geneva. Severe RSV-related outcomes referred to RSV documented respiratory conditions requiring hospital admission, presenting as lower respiratory tract infection (LRTI) or pneumonia. We used multivariable logistic regression to assess clinical and laboratory correlates of severe RSV disease. RESULTS: From 239 RSV-positive immunocompromised in and out-patients 175 were adults and 64 children of whom 111 (47.8%) presented with LRTI, which resulted in a 38% (89/239) admission rate to hospital. While immunocompromised children were more likely to be admitted to hospital compared to adults (75% vs 62.9%, p = 0.090), inpatients admitted to the intensive care unit (17/19) or those who died (11/11) were mainly adults. From multivariable analyses, adults with solid tumors (OR 5.2; 95% CI: 1.4-20.9 P = 0.015) or those requiring chronic immunosuppressive treatments mainly for rheumatologic conditions (OR 4.1; 95% CI: 1.1-16.0; P = 0.034) were significantly more likely to be admitted to hospital compared to hematopoietic stem cell (HSCT) recipients. Bacterial co-infection was significantly and consistently associated with viral LRTI and pneumonia. CONCLUSIONS: From our findings, RSV-related disease results in a significant burden among adults requiring chronic immunosuppressive treatments for rheumatological conditions and those with solid tumors. As such, systematic screening for respiratory viruses, should be extended to other immunocompromised populations than HSCT recipients.

Clinical significance of post-prophylaxis cytomegalovirus infection in lung transplant recipients.

Cytomegalovirus (CMV) disease has been associated with the development of chronic lung allograft dysfunction (CLAD) after transplantation. However, the relevance of CMV replication occurring after the discontinuation of antiviral prophylaxis on the development of CLAD has not been fully established. Patients who underwent lung transplantation during 2004-2014 were included. All patients received antiviral prophylaxis for 3-6 months, followed by monitoring of CMV replication during the first year post-transplantation (preemptive therapy). Risk factors for the development of CLAD were assessed by Cox models. A linear regression model with an interaction coefficient between time and CMV infection was used to evaluate the influence of CMV infection on the evolution of FEV1 . Overall, 69 patients were included, 30/69 (43%) patients developed at least 1 episode of significant CMV infection, and 8/69 (11.5%) patients developed CMV disease. After a median follow-up of 3.67 years, 25/69 (36%) patients developed CLAD and 14/69 (20%) patients died. In the univariate Cox analysis, significant CMV infection (HR 1.177, P = .698), CMV disease (HR 1.001, P = .998), and duration of CMV replication (HR 1.004, P = .758) were not associated with CLAD. Only bacterial pneumonia tended to be associated with CLAD in the multivariate model (HR 2.579, P = .062). We did not observe a significant interaction between CMV replication and evolution FEV1 (interaction coefficient 0.006, CI 95% [-0.084 to 0.096], P = .890). In this cohort of lung transplant recipients receiving antiviral prophylaxis and monitored by preemptive therapy post-prophylaxis, CMV infection did not have impact on long-term allograft lung function.

Role of bi-weekly serum galactomannan screening for the diagnosis of invasive aspergillosis in haematological cancer patients.

Invasive aspergillosis (IA) is a life-threatening infection affecting haematological cancer patients with chemotherapy-induced neutropenia. The diagnosis of IA often relies on the detection of galactomannan (GM) in serum or bronchoalveolar lavage fluid (BAL). Bi-weekly serum GM screening has been proposed for a pre-emptive therapeutic approach of IA in patients not receiving mold-active prophylaxis. We have analysed all IA cases among patients with haematological malignancies and prolonged chemotherapy-induced neutropenia (>14 days) in our institution over a 10-year period (2007-2017). Serum GM was measured twice weekly and mold-active prophylaxis was not routinely administered. Thirty IA cases were observed and a positive serum GM was the first indicator of IA in 10 (33%) of them, which represents a need of approximately 500 GM tests for the detection of a single IA case. In the other 20 (67%) cases, suggestive chest CT lesion was the first sign of IA and bronchoscopy was required in 15 (50%) cases with negative serum GM for establishing the diagnosis of probable/proven IA. A positive serum GM was associated with a worse prognosis (57% 12-week survival vs 100% among serum GM-negative patients, P = .006), irrespective of the timing of GM positivity compared to CT. We concluded that bi-weekly serum GM screening demonstrated limited benefit in this population.

Human MicroRNA Responses Predict Cytomegalovirus Replication Following Solid Organ Transplantation.

Background: Homo sapiens mature micro-ribonucleic acid (miRNA)-200b-3p and 200c-3p are predicted to bind to 3' untranslated region of mRNA encoding human cytomegalovirus (HCMV) immediate early protein 2 (IE2). We hypothesized that expression of these miRNAs pretransplant could predict HCMV replication after solid organ transplantation (SOT). Methods: A total of 272 SOT recipients were HCMV-seropositive pretransplant and were managed using preemptive therapy. Pretransplant peripheral blood mononuclear cells were stimulated with HCMV followed by collection of RNA 1 day poststimulation. The miRNAs were quantified using real-time reverse transcription-polymerase chain reaction. Human foreskin fibroblasts were transfected with 200b-3p and 200c-3p and infected with HCMV 1 hour post-transfection. Protein was collected at 3 days postinfection (dpi) and 7 dpi underwent immunoblotting for IE2. Results: Medians of 200b-3p and 200c-3p were significantly lower in recipients with HCMV replication (n = 144) (361.6 vs 552.6, P = .035; 3586.8 vs 12986.8 copies/µL, P = .03, respectively). Multivariate regression revealed that 200b-3p ≥100 copies/µL (odds ratio [OR]: 0.53; P = .02), was associated with less HCMV replication. Transfection with 200b-3p resulted in 2.7- and 2.5-fold decreased IE2 at 3 dpi and 7 dpi, respectively, compared to mock cells. Conclusions: MicroRNAs may play a biologically relevant role in controlling HCMV replication post-transplant.

Polymorphisms in the lectin pathway of complement activation influence the incidence of acute rejection and graft outcome after kidney transplantation.

There are conflicting data on the role of the lectin pathway of complement activation and its recognition molecules in acute rejection and outcome after transplantation. To help resolve this we analyzed polymorphisms and serum levels of lectin pathway components in 710 consecutive kidney transplant recipients enrolled in the nationwide Swiss Transplant Cohort Study, together with all biopsy-proven rejection episodes and 1-year graft and patient survival. Functional mannose-binding lectin (MBL) levels were determined in serum samples, and previously described MBL2, ficolin 2, and MBL-associated serine protease 2 polymorphisms were genotyped. Low MBL serum levels and deficient MBL2 diplotypes were associated with a higher incidence of acute cellular rejection during the first year, in particular in recipients of deceased-donor kidneys. This association remained significant (hazard ratio 1.75, 95% confidence interval 1.18-2.60) in a Cox regression model after adjustment for relevant covariates. In contrast, there was no significant association with rates of antibody-mediated rejection, patient death, early graft dysfunction or loss. Thus, results in a prospective multicenter contemporary cohort suggest that MBL2 polymorphisms result in low MBL serum levels and are associated with acute cellular rejection after kidney transplantation. Since MBL deficiency is a relatively frequent trait in the normal population, our findings may lead to individual risk stratification and customized immunosuppression.

Ventricular assist devices as bridge to heart transplantation: impact on post-transplant infections.

BACKGROUND: Ventricular assist devices (VAD) are valuable options for patients with heart failure awaiting cardiac transplantation. We assessed the impact of pre-transplant VAD implantation on the incidence of post-transplant infections in a nationwide cohort of heart transplant recipients. METHODS: Heart transplant recipients included in the Swiss Transplant Cohort Study between May 2008 and December 2012 were analyzed. Cumulative incidence curves were used to calculate the incidence of bacterial or Candida infections (primary endpoint) and of other infections (secondary endpoint) after transplant. Cox regression models treating death as a competing risk were used to identify risk factors for the development of infection after transplant. RESULTS: Overall, 119 patients were included in the study, 35 with a VAD and 84 without VAD. Cumulative incidences of post-transplant bacterial or Candida infections were 37.7 % in VAD patients and 40.4 % in non-VAD patients. In multivariate analysis, the use of cotrimoxazole prophylaxis was the only variable associated with bacterial/Candida infections after transplant (HR 0.29 [95 % CI 0.15-0.57], p < 0.001), but presence of a VAD was not (HR 0.94, [95 % CI 0.38-2.32], p = 0.89, for continuous-flow devices, and HR 0.45 [0.15 - 1.34], p = 0.15, for other devices). Risk for post-transplant viral and all fungal infections was not increased in patients with VAD. One-year survival was 82.9 % (29/35) in the VAD group and 82.1 % (69/84) in the non-VAD group. All 6 patients in the VAD group that died after transplant had a history of pre-transplant VAD infection. CONCLUSION: In this nationwide cohort of heart transplant recipients, the presence of VAD at the time of transplant had no influence on the development of post-transplant infections.