Donor Cytomegalovirus Transmission Patterns in Solid Organ Transplant Recipients With Primary Infection.

BACKGROUND: The epidemiology of single versus multiple cytomegalovirus (CMV) strain transmission from donor (D+) to seronegative solid organ transplant (SOT) recipients (R-) is uncertain, as is whether "relapsing" recipient infection represents changing strain predominance when multiple strains are transmitted. Here we characterized CMV strain transmission patterns in D+/R- SOT recipients. METHODS: We studied pairs or groups of D+/R- SOT recipients who received organs from a common donor (group A) and recipients who experienced ≥2 waves of CMV DNAemia (group B). CMV in plasma was characterized by genotype-specific real-time PCR for genes gB and gH. RESULTS: Single concordant genotypes were identified in 12 of 18 recipient pairs/group sharing a common donor (group A); at least 6 of 18 (33%) donors transmitted > 1 strain. A single CMV strain was detected in 14 of 15 recipients in group B; only 1 recipient had coinfection. A shift in CMV strain predominance occurred after the first posttransplant year in at least 4 recipients with coinfection. CONCLUSIONS: Using a common donor approach, we confirmed that multiple CMV strain transmission from donors to R- SOT recipients is not uncommon. D+/R- SOT recipients with CMV coinfection can undergo changes in strain predominance in late waves of CMV DNAemia.

Cytomegalovirus transmission in mismatched solid organ transplant recipients: Are factors other than anti-viral prophylaxis at play?

Although antiviral prophylaxis has reduced cytomegalovirus (CMV) DNAemia and disease in seronegative solid organ transplant (SOT) recipients (R-) receiving seropositive donor organs (D+), its impact on CMV transmission is uncertain. Transmission, defined as CMV antigenemia/CMV DNAemia and/or seroconversion by year 2, and associated demographic risk factors were studied retrospectively in 428 D+/R- and 429 D-/R- patients receiving a SOT at our center. The cumulative transmission incidence was higher for lung (90.5%) and liver recipients (85.1%) than heart (72.7%), kidney (63.9%), and pancreas (56.2%) recipients (p < .001) and was significantly lower in living (50.1%) versus deceased donor (77.4%, p < .001) kidney recipients despite identical antiviral prophylaxis. In multivariate analysis, only allograft type predicted transmission risk (HR [CI] lung 1.609 [1.159, 2.234] and liver 1.644 [1.209, 2.234] vs kidney). For 53 D+ donating to >1 R- with adequate follow-up, 43 transmitted to all, three transmitted to none, and seven transmitted inconsistently with lungs and livers always transmitting but donor-matched heart, kidney or kidney-pancreas allografts sometimes not. Kidney pairs transmitted concordantly. CMV transmission risk is allograft-specific and unchanged despite antiviral prophylaxis. Tracking transmission and defining donor factors associated with transmission escape may provide novel opportunities for more targeted CMV prevention and improve outcome analysis in antiviral and vaccine trials.

Transfusion-transmitted and community-acquired cytomegalovirus infection in seronegative solid organ transplant recipients receiving seronegative donor organs.

Solid organ transplant (SOT) recipients who are cytomegalovirus (CMV) seronegative (R-) and receive seronegative donor (D-) organs have a small but currently unquantified risk of both transfusion-transmitted CMV (TT-CMV) and community-acquired CMV (CA-CMV). We retrospectively studied the incidence and clinical symptoms of TT-CMV (infection <1 year posttransplant) and CA-CMV (infection >1 year posttransplant) in a cohort of D-/R- adult and pediatric SOT recipients receiving leukoreduced blood products not screened for CMV seronegativity transplanted at our center between 2000 and 2011. CMV infection was defined as IgG seroconversion or detectable CMV antigenemia/DNAemia. Among 536 consecutive D-/R- recipients, 398 (81.8%) had adequate follow-up, and 231 (58%) received cellular blood products (total: 1626 red blood cell units, 470 platelet units) 30 days pretransplant to 90 days posttransplant. We observed no confirmed TT-CMV cases, but 14 CA-CMV cases (64% symptomatic) were seen. The estimated incidence rate of CA-CMV was higher in children (3.0/100 patient years) than adults (0.46/100 patient years, incident rate ratio of 6.52). The absence of TT-CMV over 11 years suggests neither seronegative blood products nor CMV DNA blood donor screening would provide significant incremental safety when blood is already leukoreduced. D-/R- SOT recipients, particularly children, have a significantly higher and ongoing risk of CA-CMV.

Impact of donor and recipient cytomegalovirus serology on long-term survival of heart transplant recipients.

BACKGROUND: Some studies have shown that pre-transplant cytomegalovirus (CMV) serostatus is associated with heart transplant patient survival while others have not. We analyzed the relationship between pre-transplant donor/recipient CMV serostatus and long-term mortality in a retrospective cohort of heart transplant recipients at our center. METHODS: Adult (Age >17 years) heart recipients transplanted between July 1985-December 2015 were analyzed. Variables included age, sex, pre-transplant donor (D)/recipient (R) serostatus [D-/R-, D-/R+, D+/R+, D+/R-], CMV infection within 2 years of transplant and transplant eras divided by changes in CMV prevention strategies: Era 1 (Pre-ganciclovir, July 1985-April 1998), Era 2 (Oral ganciclovir, May 1998-December 2004), Era 3 (Valganciclovir, January 2005-December 2015). Survival analysis and Cox regression were performed at 10 years. RESULTS: A total of 620 heart transplants were included in our analysis; 20% were CMV mismatched pre-transplant. Thirty-eight percent of patients were infected with CMV within the first two post-transplant years. Survival analysis showed D/R CMV serostatus did not significantly impact survival of heart recipients at 10 years (P = 0.11). Survival was significantly different across eras for D-/R+, D+/R+, and D+/R+ (P = 0.043) but not D-/R- patients (P = 0.8). Cox regression revealed that patients transplanted in the valganciclovir era have an estimated 29% reduced risk of death (P = 0.047) compared to patients transplanted in the pre-ganciclovir era after controlling for age at transplantation, D/R CMV serostatus and CMV infection. CONCLUSION: Our review of the impact of CMV managed differently across eras suggests in heart transplantation there is no influence of D/R CMV serostatus on 10 year survival.

High incidence of clinically significant cytomegalovirus infection in CMV D+/R+ lung transplant recipients receiving 3 months of antiviral prophylaxis.

BACKGROUND: Universal antiviral prophylaxis is the preferred preventive strategy for lung transplant recipients (LTRs) at risk of CMV infection. We compared the risk of CMV infection between CMV D+/R + and D-/R + LTRs after 3 months of prophylaxis. METHODS: This was a retrospective review of CMV R + LTRs transplanted between 2005 and 2013. Patients dying before completing 3 months, or receiving >180 days of prophylaxis were excluded. The primary outcome was proportion of LTRs who developed CMV infection and clinically significant CMV infection defined as CMV infection leading to preemptive therapy or CMV disease. RESULTS: We analyzed 90 D+/R + and 72 D-/R + with a median follow up of 730 days. CMV infection and disease was more common in D+/R + compared to D-/R+ (CMV infection 66% vs 40%; P = 0.001; CMV disease 13% vs 4% P = 0.045). Fifty-nine patients developed at least one episode of clinically significant CMV infection (41/90 [46%] D+/R + and 18/72 [25%] D-/R + P=0.007) with recurrence occurring in 29 LTRs (49% of patients with previous CMV infection), of which 22 (76%) were CMV D+/R+. Thirty percent had side effects related to CMV therapy. CONCLUSION: Three months prophylaxis in D+/R + LTRs was associated with high rates of clinically significant CMV infection and recurrences.

Epstein-Barr virus associated smooth muscle tumors in solid organ transplant recipients: Incidence over 31 years at a single institution and review of the literature.

INTRODUCTION: Epstein-Barr virus (EBV) associated smooth muscle tumors (EBV-SMT) are a rare complication of solid organ transplantation (SOT). Incidence data related to this EBV-SMT are limited. EBV DNA is universally present in these tumors. How these cells get infected with EBV, whether this is a result of primary EBV infection vs reactivation, and how persistent active EBV infection post-transplant influences EBV-SMT pathogenesis remains unknown. METHODS: Among 5006 SOT recipients (474 pediatric, 4532 adult) receiving SOT at our center between Jan 1984 and Dec 2015, three cases of post-transplant EBV-SMT were identified. RESULTS: All cases were pediatric heart transplants who were EBV seronegative prior to transplant, and experienced primary EBV infection with persistently elevated EBV viral loads, despite antiviral therapy. Two are deceased at 3.2 and 0.9 years post-diagnosis, while one remains alive 6.2 years post diagnosis. The overall local incidence of post-transplant EBV-SMT at our institution was 0.7 (95% CI, 0.2-1.7) per 1000 patient years, and 2.6 (95% CI, 0.6-6.7) per 1000 patient years in pediatric heart transplants. A literature review identified 36 pediatric and 51 adult cases of post-transplant EBV-SMT. CONCLUSIONS: We hypothesize that pre-transplant EBV seronegativity, followed by primary EBV infection and persistently high EBV viral loads, represents a unique risk factor for post-transplant EBV-SMT. Pediatric heart transplant recipients were found to be disproportionately affected by post-transplant EBV-SMT at our institution.

Impact of donor and recipient cytomegalovirus serology on long-term survival of lung transplant recipients.

BACKGROUND: Pre-transplant cytomegalovirus (CMV) serostatus has been associated with lung transplant patient survival. We retrospectively analyzed the relationship between pre-transplant donor/recipient CMV serostatus and long-term mortality in a cohort of lung transplant recipients at our center. METHOD: Adult (Age >17 years) lung recipients transplanted between July 1985-December 2015 were analyzed. Variables included age, sex, pre-transplant donor (D)/recipient (R) serostatus [D-/R-, D-/R+, D+/R+, D+/R-], CMV infection within 2 years of transplant and transplant eras divided by changes in CMV prevention strategies: Era 1 (pre-ganciclovir, July 1985-April 1998), Era 2 (oral ganciclovir, May 1998-December 2004), Era 3 (valganciclovir, January 2005-December 2015). Survival analysis and Cox regression were performed at 10 years. RESULTS: A total of 652 lung recipients were analyzed. Twenty percent were CMV mismatched pre-transplant and 45% had CMV infection within 2 years post-transplant. Survival at 10 years appeared worse in D+ transplants (P = 0.027). D-/R- lungs did not have significantly different survival across eras (P = 0.76), but survival of D-/R+, D+/R+, D+/R- lungs improved (P < 0.001). Cox regression revealed that transplantation in the valganciclovir era reduced risk of death in lung transplants by an estimated 52% (P < 0.001) compared to transplantation in the pre-ganciclovir era after controlling for age at transplant, D/R CMV serostatus and CMV infection. Age at transplant and CMV infection were also significant predictors of mortality in lung transplants (P < 0.001 and 0.033 respectively). CONCLUSION: Our review of the impact of CMV managed differently across eras suggests in lung transplantation there is no independent influence of D/R CMV serostatus on 10-year survival.

Assignment of cytomegalovirus infection status in infants awaiting solid organ transplant: Viral detection methods as adjuncts to serology.

Assignment of CMV infection status in infants awaiting SOT is challenging as passive maternal antibody can lead to false-positive serology. Since 2000, our protocol has recommended sending throat and urine samples for CMV viral detection, culture, or NAAT, for CMV-seropositive infants <18 months awaiting SOT. We reviewed pretransplant CMV serology for 152 infants and, for CMV seropositives, examined relationships between CMV IgG OD values, age, and CMV viral detection to explore time to clearance of maternal CMV IgG and evaluate viral detection in assignment of pretransplant CMV infection status. The proportion of CMV-seropositive infants decreased from 52% in infants 0-6 months of age to 28% in those 12-18 months. Among CMV-seropositive infants, median OD was significantly higher in the 6- to 12- and 12- to 18-month groups compared to the 0- to 6-month group. Distribution of OD by age group suggested that maternal antibody cleared before 12 months. Of 59 eligible CMV-seropositive infants, 49 (83%) had CMV viral detection studies and 18 of 49 (36.7%) had detectable CMV: 9 of 30 (30.0%) infants 0-6 months, 7 of 15 (46.7%) infants 6-12 months, and 2 of 4 (50.0%) infants 12-18 months. CMV viral detection studies are useful to confirm positive CMV infection status in CMV-seropositive infants awaiting SOT. Maternal CMV IgG likely clears before 12 months.

Determination of the Biological Form of Human Cytomegalovirus DNA in the Plasma of Solid-Organ Transplant Recipients.

Background: Whether cytomegalovirus (CMV) DNA exists in plasma as virion-associated or free DNA is uncertain. Methods: An assay combining DNase I digestion and CMV quantitative polymerase chain reaction (DNase-CMV-qPCR) was developed to differentiate free naked DNA from virion DNA. One hundred three frozen and 10 fresh CMV DNA-positive plasma samples from solid-organ transplant recipients (SOTRs) were tested. Three sets of paired qPCR (P-qPCR) assays with amplicons of variable length were used to study CMV DNA fragmentation in 20 SOTR plasma samples, viral stocks (Towne, Merlin, AD169) and the first World Health Organization (WHO) international standard (IS) for CMV DNA. Results: In all plasma samples, 98.8%-100% of CMV DNA was free DNA; this was the only form in 93 of 103 (90.3%) frozen and all 10 fresh samples tested using DNase-CMV-qPCR. Low levels of virion CMV DNA were found in 10 of 103 (9.7%) samples with higher total DNA load. Cytomegalovirus DNA results were highly reproducible for 3 CMV virus stocks and WHO IS (P > .80), tested by three sets of paired q-PCR. However, for the 20 SOTR plasma samples, the smaller amplicon assay result was 2.6-fold, 3.4-fold, and 6.5-fold higher than the longer amplicion result (P < .001). Conclusions: Cytomegalovirus DNA in SOTR plasma is almost exclusively free DNA, highly fragmented, and not virion associated.

Tumor Infiltrating Lymphocytes Predict Survival in Solid Organ Transplant Recipients With Monomorphic Post-transplant Lymphoproliferative Disorders.

INTRODUCTION: The tumor microenvironment (TME) in post-transplant lymphoproliferative disorders (PTLDs) remains unexplored. Tumor infiltrating lymphocytes (TILs) are prognostic in other lymphomas. We assessed the prognostic impact of TILs in monomorphic B-cell PTLD. METHODS: TIL density (CD3+ cells/mm2) was determined by CD3 immunohistochemistry in archived diagnostic biopsies from patients diagnosed with monomorphic B-cell PTLD. RESULTS: Amongst monomorphic PTLDs (N = 107), low TIL-count was associated with inferior 2-year progression-free survival (PFS) (41% versus 86%, P = .003) and 2-year overall survival (OS) (52% versus 93%, P = .003) by Kaplan-Meier analysis. Low TIL-count was significant on Cox univariate regression for inferior PFS (HR 4.5, 95% CI 2.0-9.9, P < .001) and OS (HR 4.6, 95% CI 1.8-11.8, P < .001). Multivariate analysis with clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) and TIL-count showed significance for PFS (HR 3.3, 95% CI 1.3-8.3, P = .010) and a non-significant trend for OS (HR 2.6, 95% CI 0.9-7.3, P = .064). A composite score including TILs and clinical variables (age ≥60 years, high LDH, stage III/IV, CNS involvement) effectively stratified monomorphic PTLD patients by PFS and OS (2-year OS: low-risk 93%, intermediate-risk 61%, high-risk 23%, P < .001). CONCLUSIONS: The TME and TILs are prognostically relevant in monomorphic PTLD. Prognostic models including measures of the TME may improve risk stratification for patients with monomorphic PTLDs.

Using blood donors and solid organ transplant donors and recipients to estimate the seroprevalence of cytomegalovirus and Epstein-Barr virus in Canada: A cross-sectional study.

Background: Cytomegalovirus (CMV) and Epstein-Barr virus (EBV) infections are common, causing significant morbidity in pregnancy (congenital CMV) and transplant recipients (CMV, EBV). Canadian prevalence data are needed to model disease burden and develop strategies for future vaccines. We estimated prevalence using screening data from blood donors and solid organ transplant (SOT) donors and recipients. Methods: We retrospectively analyzed CMV and EBV serology from Alberta SOT donors (n = 3,016) and recipients (n = 4,614) (1984-2013) and Canadian Blood Services blood donors (n = 1,253,350) (2005-2014), studying associations with age, sex, organ, year, and geographic region. Results: CMV seroprevalence rises gradually with age. By age 70, CMV seropositivity ranged from 67% (blood donors) to 73% (SOT recipients). Significant proportions of women of child-bearing age were CMV-seronegative (organ donors, 44%; SOT recipients, 43%; blood donors, 61%). Blood donor CMV seroprevalence decreased from 48% in Western Canada to 30% in Eastern Canada. Women were more likely to be CMV-seropositive (ORs = 1.58, 1.45, and 1.11 for organ donors, SOT recipients, and blood donors, respectively) and EBV-seropositive (ORs = 1.87 and 1.46 for organ donors and SOT recipients, respectively). EBV prevalence rises rapidly, and by age 17-29 years, 81% of SOT recipients and 90% of organ donors were seropositive. Conclusions: Canada has relatively low and perhaps decreasing age-specific EBV and CMV prevalence, making Canadians vulnerable to primary infection-associated morbidity and suggesting benefit from future vaccines. Collection and analysis of routine serology screening data are useful for observing trends.

Historique: Les infections à cytomégalovirus (CMV) et au virus d'Epstein­Barr (EBV) sont courantes et responsables d'une morbidité importante pendant la grossesse (infection congénitale à CMV) et les receveurs d'organes (CMV, EBV). Il faut colliger des données de prévalence au Canada pour en modéliser le fardeau et établir des stratégies en vue de futurs vaccins. Les chercheurs en ont évalué la prévalence à l'aide des données de dépistage des donneurs de sang et des donneurs d'organes pleins. Méthodologie: Les auteurs ont procédé à l'analyse rétrospective de la sérologie du CMV et de l'EBV des donneurs (n = 3 016) et des receveurs (n = 4 614) d'organes pleins de l'Alberta entre 1984 et 2013 et des donneurs de sang de la Société canadienne du sang de 2005 à 2014 (n = 1 253 350) et étudié les associations avec l'âge, le sexe, l'organe, l'année et la région géographique. Résultats: Le statut sérologique pour le CMV augmente graduellement avec l'âge. À l'âge 70 ans, la séropositivité au CMV se situait entre 67 % (donneurs de sang) et 73 % (receveurs d'organes pleins). Des proportions importantes de femmes en âge de procréer étaient séronégatives au CMV (donneuses d'organes, 44 %; receveuses d'organes pleins, 43 %; donneuses de sang, 61 %). La séroprévalence du CMV chez les donneurs de sang passait de 48 % dans l'Ouest canadien à 30 % dans les Maritimes. Les femmes étaient plus susceptibles d'être séropositives au CMV (RC = 1,58, 1,45, et 1,11 pour les donneuses d'organes, les receveuses d'organes pleins et les donneuses de sang, respectivement) et à l'EBV (RC = 1,87 et 1,46 pour les donneuses d'organes et les receveuses d'organes pleins, respectivement). La prévalence de l'EBV augmente rapidement: entre l'âge de 17 et 29 ans, 81 % des receveurs d'organes pleins et 90 % des donneurs d'organes étaient séropositifs. Conclusions: Le Canada présente une prévalence relativement faible ­ et peut-être même à la baisse ­ d'EBV et de CMV liée à l'âge, ce qui rend les Canadiens vulnérables aux morbidités associées à la primo-infection et laissent croire au caractère avantageux de futurs vaccins. Il est utile d'amasser et d'analyser des données de dépistage pour observer les tendances.

Classic Hodgkin lymphoma post-transplant lymphoproliferative disorders (PTLD) are often preceded by discordant PTLD subtypes.

Classic Hodgkin lymphoma (CHL) is the rarest post-transplant lymphoproliferative disorder (PTLD) subtype. Few cases of patients with metachronous discordant PTLD episodes including CHL-PTLD have been reported, but the incidence of and risk factors for this phenomenon are unknown. Patients with CHL-PTLD were identified from an institutional PTLD database. Of 13 patients identified with CHL-PTLD six (46%) had antecedent non-CHL-PTLD: three had polymorphic PTLD, two monomorphic PTLD, and one nondestructive PTLD. Patients with prior metachronous non-CHL-PTLD were younger at transplant and had a longer latency time to CHL-PTLD post-transplant. The prevalence of EBV seronegativity at transplant was high in both groups, but prolonged high-level EBV DNAemia only occurred in some with metachronous non-CHL-PTLD. In conclusion, patients with CHL-PTLD have metachronous non-CHL-PTLD diagnoses with discordant histology more commonly than previously recognized. Primary EBV infection with chronically elevated EBV viral loads may represent unique risk factors for CHL-PTLD following an initial non-CHL-PTLD event.

The Changing Epidemiology of Posttransplant Lymphoproliferative Disorder in Adult Solid Organ Transplant Recipients Over 30 Years: A Single-center Experience.

BACKGROUND: Posttransplant lymphoproliferative disorders (PTLD) are a complication of solid organ transplantation (SOT) associated with Epstein-Barr virus (EBV). METHODS: We analyzed the incidence of and risk factors for PTLD among adult SOT recipients at our center over 30 years (1984-2013). We also compared PTLD incidence before and after a prevention strategy of EBV viral load monitoring in EBV serology mismatched patients was adapted in 2001 (ie, transplant era 1 [1983-2001] vs era 2 [2002-2013]). RESULTS: Among 4171 SOT patients, 109 developed PTLD. Cumulative incidence at 1, 10, and 20 years posttransplant was 0.95, 2.3, and 3.5 per 100 person-years, respectively. Beyond the first year peak of almost exclusively EBV-positive PTLD, a lower incidence of PTLD, predominantly EBV negative, persisted for 20 years. Thoracic transplant (hazard ratio [HR], 2.1; P = 0.007) and negative EBV serology (HR, 7.7; P < 0.001) were independent risk factors for PTLD on multivariate Cox regression analysis. EBV seronegativity significantly increased risk of early (HR, 18.5) and EBV-positive PTLD (HR, 14.2), as well as late (HR, 4.9) and EBV-negative PTLD (HR, 3.6) on univariate analyses. Risk of early PTLD was significantly reduced in the recent transplant era (0.8% era 2 vs 1.9% era 1 at 5 years, P = 0.002); this reduction was seen in recent era EBV seropositive (P = 0.035 at 5 years) but not seronegative recipients (P = 0.90 year 5), suggesting lack of impact of viral load monitoring. CONCLUSIONS: Adult SOT recipients face a prolonged risk of late PTLD, whereas risk of early PTLD may have declined in recent years.

Radiation Exposure from Diagnostic Imaging in a Cohort of Pediatric Transplant Recipients.

Recipients of solid organ transplants (SOT) have extensive diagnostic imaging (DI). The purpose of this study was to quantify this exposure. Children from northern Alberta with SOTs at Stollery Children's Hospital, Edmonton, Alberta January 1, 2006, to July 31, 2012, were included. Effective doses of radiation were estimated using published norms for DI performed post-transplant up to October 16, 2014. The 54 eligible children had 6215 DI studies (5628 plain films, 293 computerized tomography (CT) scans, 149 positron emission topography (PET) -CT scans, 47 nuclear medicine scans and 98 cardiac catheterizations). Children less than 5 years of age underwent more DI studies than did older children (median (IQR) 140 (66-210) vs 49 (19-105), p = 0.010). Children with post-transplant lymphoproliferative disorder (N = 8) had more CT scans (median (IQR) 13 (5.5-36) vs 1 (0-5), p<0.001) and PET-CT scans (median (IQR) 3.5 (1.5-8) vs 0 (0-0), p<0.001) than did other children. The estimated cumulative effective dose attributed to DI studies post-transplant was median (range) 78 (4.1-400) millisievert (mSv), and 19 of 54 children (35%; 95% confidence interval 24-49%) had a dose >100 mSv. In conclusion, a significant proportion of pediatric transplant recipients have sufficient radiation exposure post-transplant for DI to be at potential risk for radiation-induced malignancies.