Tissue-invasive Disease Research Articles

Outcomes of transplant recipients treated with cidofovir for resistant or refractory cytomegalovirus infection.

Treatment of ganciclovir-resistant (GCV-R)/refractory cytomegalovirus (CMV) infections in blood/marrow transplant (BMT) and solid organ transplant (SOT) recipients remains suboptimal. Cidofovir (CDV), a nucleotide analogue with anti-CMV activity, is nephrotoxic and oculotoxic. We retrospectively evaluated the outcomes of SOT and BMT patients with GCV-R/refractory CMV treated with CDV between 1/1/2008 and 12/31/2017. baseline demographics, CMV serostatus, clinical and virologic presentations and outcomes, UL97 and UL54 genotype mutations, drug toxicities, and cause of death. Descriptive statistics were used. 16 patients received CDV for treatment of CMV: six BMT and 10 SOT. Seven (47%) of the patients had high-risk donor/recipient serostatus: six (60%) SOT were D+/R-; one (16.7%) BMT was D-/R+. Median time to CMV DNAemia was 131days post-transplant (IQR, 37.5-230.3). Proven tissue invasive disease was present in three patients (18.8%). Twelve (75%) had genotype testing; 10 (83.3%) of those had antiviral resistance mutations. While on CDV, six (37.5%) developed nephrotoxicity, and four (25%) developed uveitis (two had both uveitis and nephrotoxicity). Eight (50%) had failure to clear CMV DNAemia despite CDV treatment. Eight (50%) of the patients died; median time to death, after initiation of CDV, was 33.5days [IQR22-988]. In the absence of good therapeutic alternatives, CDV is used in GCV-R/refractory CMV infection. However, it is associated with a substantial risk of toxicity and failure to clear CMV DNAemia, highlighting the need for development of newer and less toxic therapies. The high mortality in this group of patients underscores the severity of illness in this population.

S2842 A Story of Small Bowel Ulcers and Multi-Organ Failure

INTRODUCTION: In tissue-invasive CMV, the most predominant GI presentation is CMV colitis. The incidence and clinical presentation of CMV enteritis however is much more rare and less understood. CASE DESCRIPTION/METHODS: A 70-year old male with hypertension and atrial flutter presented to the hospital with fevers, dyspnea and weight loss. He was found to have a pulmonary embolism and was discharged on Xarelto. He was then readmitted for abdominal pain. CT abdomen showed severe wall thickening in the distal duodenum and first portion of the jejunum. He developed abdominal distension, bright red blood per rectum and a diffuse rash, which was attributed to vasculitis. Repeat CT abdomen showed severe thickening of the mid jejunum, ileum and descending colitis. EGD showed multiple large non-bleeding duodenal and proximal jejunal ulcers with skip areas showing normal appearing small bowel. Similar findings were seen in the terminal ileum. Patchy mild inflammation was found in the ascending colon. Biopsies were consistent with CMV enteritis. He developed an acute abdomen. In the OR he was found to have a perforated ileum. Given poor prognosis post-operatively, he was transitioned to comfort care. DISCUSSION: For tissue invasive CMV, CMV colitis is the most predominant GI presentation while small bowel involvement is the most rare. Patients with CMV enteritis can present with anorexia, abdominal pain, obstruction, perforation or hemorrhage. Diagnosis is made with tissue biopsy as serum CMV PCR has a low positive predictive value for tissue-invasive disease. CMV infects the vascular endothelial cells, leading to ischemia and ulceration. Biopsies should therefore target the ulcer base to include these cells. Endoscopically, CMV infection may appear as inflammation, shallow or deep ulcers or pseudo-tumor formation. Histology shows diffuse ulcerations with necrosis and Cowdry inclusion bodies. Evaluation for immunosuppressive conditions is important as tissue-invasive CMV is almost exclusively in immunocompromised patients. There is a lack of data on treatment but extrapolation from CMV colitis suggests the use of Ganciclovir. When clinical suspicion is high, PCR testing for quicker results in order to start therapy is recommended. Given the devastating consequences of a delay in diagnosis, it is important to keep CMV enteritis in the differential despite its rarity.Figure 1.: CT Angiography of small intestine with wall thickening.Figure 2.: Endoscopy showing ulceration in the small bowel.Figure 3.: Pathology A: small bowel mucosa with ulcer; B: rare CMV inclusion identified in granulation tissue on the H&E stain; C: CMV positive cells highlighted by a CMV immunostain.

P1775CMV VIREMIA IN KIDNEY TRANSPLANT RECIPIENTS RECEIVING BASILIXIMAB OR LOW DOSE ANTI THYMOCYTE GLOBULIN INDUCTION WITHOUT VALGANCICLOVIR PROPHYLAXIS- SINGLE CENTRE EXPERIENCE IN INDIA

Abstract Background and Aims CMV is a major cause of morbidity in transplant recipients and manifests as tissue invasive disease or CMV viral syndrome. Controversy exists regarding best method for CMV prevention. Therefore, we intended to evaluate incidence of CMV viremia and symptomatic CMV infection in adult KTR with basiliximab or antithymocyte globulin (ATG) induction without the use of valganciclovir prophylaxis. This study will help developing a protocol for management of CMV infection/disease in Indian patients since there is no such data amongst Indians. Method A prospective, open-label, single centre study. Patients were monitored for CMV DNA-PCR twice a week for month 1 post-transplant, once a week in month2, and then every 2 weeks in month 3, and then once a month from month 4 to 6. Results We included 17 patients with low-dose ATG induction (group1) and 20 patients with Basiliximab induction (group2). Mean recipient age was 42.9 and 45.9 yr in group 1 and 2 whereas mean donor age was 50.6 and 51.6 yr respectively. Male recipients were 76.4% (13/17) and 65% (13/20) in group 1 and 2 respectively; male donors were 11.7% (2/17) and 20% (4/20) respectively (not signficant). Average HLA mismatches were 3.4/6 and 3.7/6 (not significant). In group1 average transfusions per patient were 6units (vs 1.7units in group2) and 65% pts in group1 had >3 units transfusion (p<0.05). Mean follow-up was 12.7 and 20.7 months respectively. Incidence of acute rejection was 5.8% (1/17) and 10% (2/20) in group 1 and 2 respectively. (not significant). Incidence of CMV viremia requiring valganciclovir therapy was 11.6% (2/17) and 10% (2/20) in group 1 and 2 respectively. (not significant). No patient developed CMV disease. Mean serum creatinine was 1.1 and 1.09 mg/dL at 1 month and 1.2 and 1.14 mg/dL at 3 months (not significant) Conclusion The incidence of CMV viremia is low and not significantly different in patients receiving basiliximab or low dose ATG induction in living donor kidney transplants on tacrolimus based immunosuppression. In our study patients in ATG group had significantly more transfusions vs basiliximab group and hence were more sensitised. Still the incidence of acute rejection remained low in both these groups (5.8% and 10%). Hence universal prophylaxis with valganciclovir may not be required in all the patients with basiliximab and low dose ATG induction especially in developing countries where cost of therapy is borne by the patients.

P1667ANALYSIS OF RISK FACTORS FOR CMV DISEASE IN KIDNEY TRANSPLANT PATIENTS - SINGLE CENTER STUDY

Abstract Background and Aims Cytomegalovirus (CMV) disease and infection negatively influence outcome of kidney transplantation. The aim of this retrospective study was to analyze risk factors for CMV disease and its influence on kidney graft function and survival. Method 1050 patients underwent kidney transplantation from January 2014 to December 2018 and received calcineurin inhibitor, mycophenolate mofetil and steroid-based immunosuppression. Recipients with PRA>20% received rATG while others had received basiliximab as induction. 825 out of 1050 patients (78.6%) received CMV prophylaxis (D+/R-, n=173; R+, n=652). Patients were followed up to 71 months /median 38 months/. Results CMV tissue invasive disease occurred in 49 out of 1050 patients (4.7%), while CMV infection in 87 patients (8.3%). CMV disease, but not CMV infection, had significant negative influence on graft survival at 5 years post transplantation (p=0.0029). Patients with CMV disease had significantly worse graft function at 4 years post transplantation (p<0.0001). CMV disease occurred in 31 out of 173 patients (17.9%) in D+/R- group vs. 18 out of 652 patients (2.8%) in R+ group. Incidence of CMV infection was 30/173 patients (17.3%) in D+/R- group vs. 57/652 patients (8.7%) with induction therapy. Shortening of CMV prophylaxis was found in 82 patients (9.9%). Leukopenia (≤ 2.0 x 109/L) was observed in 97 (11.7%) patients from those who received CMV prophylaxis, Its shortening significantly increased risk for both CMV infection (20,7% vs. 7.2%, p<0,0001) and CMV disease (8,5% vs. 4,2%, p=0,04). Among most significant risk factors for CMV disease in univariable analysis were CMV mismatch (OR 11, 95% CI: 5,9-20,4; p<0,0001), delayed graft function (OR 2,8, 95% CI: 1,6-5,1; p<0,0001, cadaveric donor (OR 6, 95% CI: 1,5-25,1; p=0,00013) and shortening of CMV prophylaxis (OR 2.1, 95% CI: 0,91-4,86; p=0,08). Multivariable analysis revealed as independent significant predictors of CMV disease DGF (OR 2,29, 95% CI: 1,2-4,3; p=0,01) and CMV mismatch (OR 10,8, 95% CI: 5,7-20,6; p<0.0001) in a model adjusted for type of donor, prophylaxis shortening and leukopenia. Conclusion CMV mismatch is the main independent predictor of CMV disease after kidney transplantation in multivariable analysis.

Clinical "real-world" experience with letermovir for prevention of cytomegalovirus infection in allogeneic hematopoietic cell transplant recipients.

Letermovir was approved in 2017 for prevention of cytomegalovirus (CMV) infection in seropositive (R+) allogeneic hematopoietic cell transplantation (HCT) patients. Post-marketing data with this new agent are scarce. We compared the incidence of both CMV reactivation (any viremia) and clinically significant CMV infection (CS-CMVi; CMV DNAemia leading to preemptive treatment or presence of CMV tissue invasive disease) at days +100 and +200 post-HCT in 25 adult allogeneic HCT patients who received letermovir prophylaxis (until day 100) and a historical control group of 106 CMV R+ allogeneic HCT recipients who underwent CMV preemptive therapy. CMV reactivation within 100days post-HCT was lower in the letermovir group vs control group (20% vs 72% respectively, P<.001). The 100-day cumulative incidence of CS-CMVi was significantly lower in the letermovir group vs control group (4% vs 59% respectively, P<.001). Significantly reduced incidence of CMV reactivation and CS-CMVi was also observed at 200days in the letermovir group. No difference in mortality was observed between the two groups. This study confirms the efficacy of letermovir in preventing CMV reactivation in CMV R+ allogeneic HCT recipients in first 100days post-HCT and suggests sustained efficacy after discontinuation of prophylaxis.

Colitis por citomegalovirus en trasplante renal: presentación de 2 casos

Cytomegalovirus infection is a latent risk among immunocompromised kidney transplant recipients and is associated with increased risk of allograft failure and death. CMV infection can manifest as active infection or as CMV disease (divided in CMV syndrome and CMV tissue-invasive disease). We present two cases of tissue invasive CMV disease, presenting within 7 months after kidney transplantation. Both cases were D+/R-, received lymphocyte-depleting agents and mycophenolate, and both received CMV prophylaxis according to General Practice Guidelines. CMV disease criteria included detectable viral replication in blood, classical endoscopic findings and histopathological confirmation. We emphasize the need of categorical identification of CMV infection risk factors among kidney transplantation recipients, specially CMV donor/recipient serostatus and immunosuppressive medication. Although clinical practice guidelines suggest 1 to 3 months CMV prophylaxis in high-risk cases, extended prophylaxis and immunosuppressive medication adjustment should be considered.

Impact of Human HLA-E and NKG2C Variants and of HCMV Ul40 Genotype Populations on HCMV Replication in Lung Transplant Recipients

Human Cytomegalovirus (HCMV) is an important viral pathogen in lung-transplant recipients (LTRs), which may cause tissue-invasive disease. The risk for HCMV-replication depends on HCMV-specific immune responses, which may limit viral spread after lung-transplantation. NKG2C+ Natural-Killer (NK-) cells limit HCMV replication, even under immunosuppressive therapy. NK-cell activation can be mediated by the NKG2C receptor, which binds to HLA-E molecules on the surface of HCMV-infected cells, and these are stabilized by an HCMV-encoded UL40 peptide. NKG2C, HLA-E and UL40 occur naturally as different variants. We investigated whether these variants differently influence the individual NK-cell response and have impact on the extent of HCMV-replication after lung transplantation. We included 137 lung transplant recipients (LTRs), who received the transplant between 2013 and 2016 at the Medical University of Vienna and who had either no or low HCMV replication (N=69) or developed high level viremia (>1000 copies HCMV DNA/ml plasma, N=68) post-transplantation. We assessed donor and recipient NKG2Cwt/del and HLA-E*0101/0103 variants as well as the UL40 peptide variants of the infecting HCMV strains. We further investigated UL40 kinetics by NGS and UL40 dependent NK-cell cytotoxicity and proliferation. In total, we detected 18 different UL40 peptides in low- and high viremic LTRs. Specific UL40 peptide variants were differently distributed in the blood of LTRs and the VMAPRTLIL variant occurred more frequently in highly viremic patients, while the VMTPRTLIL variant was detectable preferably in patients with low viremia (p=0.004). This difference was not associated with altered cytotoxicity, but with differences in the proliferation of NK-cells (p=0.002). In homozygous HLA-E recipients, UL40 strains seem to emerge over time towards low affinity. In addition, recipient encoded NKG2Cwt/del and donor encoded heterozygous HLA-E*0101/0103 variants were associated with development of high-level viremia in the follow-up (p=0.01 and p=0.007, respectively). The present data provide evidence that the NKG2C/UL40/HLA-E axis and variations thereof have a substantial impact on the patients' individual NK-cell response and on the development of high-level viremia post-transplantation.

Dissection of the HCMV-Specific Antibody Responses in Lung-Transplant Recipients

Human Cytomegalovirus (HCMV) is an important viral pathogen in lung-transplant recipients (LTRs), which may cause generalized infection and tissue-invasive disease. The risk for HCMV-replication depends on the donor (D) and recipient (R) serostatus as well as on HCMV-specific immune responses such as HCMV-specific antibodies (AB) and NK-cells, which may limit viral spread after lung-transplantation. In this study we analyzed the glycoprotein B (gB) and pentameric complex (PC)-specific AB-responses as well as the antibodies' neutralizing and NK-cell activating effector functions following lung transplantation. 35 R+, 26 D+/R- LTRs, who received a lung transplant between 2013 and 2016 at the Medical University of Vienna and 134 non-transplanted control individuals were included in the study. From each transplanted patient, follow-up plasma samples were collected in a three-month interval in a one (R+) or two (D+/R-) year period post-transplantation. PC-specific as well as gB-specific IgG titers were determined by ELISA. 50% neutralizing titers were determined with epithelial cells, fibroblasts and the laboratory strain TB40E-BAC4. The NK-cell response was determined using NK92-CD16a cells in a serum-dependent focal expansion and a CD107 cytotoxicity assay. The R+ LTRs reached a higher level of gB- but not of PC-specific IgG-titers in the first year post-transplantation compared to healthy seropositive individuals (IgG1 one year post-transplantation gB: p<0.0001, PC=ns, Dunetts-Test). Functional analysis of gB-specific ABs exhibited a significantly better NK-cell activation in the LTRs than in healthy controls at all time points investigated (p<0.0001, Dunetts-Test). In contrast, PC-specific ABs showed only low level NK-cell activation and their neutralization capacity was comparable with that of healthy controls until one year post-transplantation (p=ns, Dunetts-Test). In 23/26 D+R- patients neutralizing ABs against PC developed during antiviral prophylaxis in the first year post-transplantation, independent from the occurrence of viremia, although only low level gB-titers and a weak NK-cell activation were observed, compared to R+ LTRs. From the present data it appears that R+ patients with pre-existing HCMV-specific ABs show a high level of NK-cell activation by gB-specific ABs.

Extending cytomegalovirus prophylaxis in high-risk (D+/R-) lung transplant recipients from 6 to 9 months reduces cytomegalovirus disease: A retrospective study.

Cytomegalovirus (CMV)-seronegative recipients receiving a seropositive allograft (D+/R-) are at a high risk of developing CMV disease. Our program increased the duration of CMV prophylaxis from 6 to 9months in May 2013. Here, we present the impact on the incidence of CMV infection, disease, side effects, rejection, and other factors. Retrospective cohort of 241 CMV (D+/R-) patients transplanted between January 1, 2008, and December 31, 2017. Blood CMV testing was done according to protocol. All patients received ganciclovir/valganciclovir as prophylaxis. We compared the incidence and timing of CMV infection and disease up to 6months after cessation of prophylaxis between patients who received 9months (May 2013 onwards) and a historical control group who received 6months of prophylaxis (prior to May 2013). CMV infection was defined as detectable CMV viremia in the absence of symptoms. CMV disease was defined as CMV syndrome or tissue-invasive disease. Side effects of prophylaxis and CMV resistance were recorded. A total of 116 patients were included in the 6-month group and 125 in the 9-month group. The extended 9-month CMV prophylaxis delayed the onset of CMV infection (median time to CMV infection after lung transplantation 295 vs 353days, P<.01) but did not significantly reduce the incidence of CMV infection (65% vs 64%, P=.06, log-rank). The 9-month prophylaxis delayed the onset and decreased the incidence of CMV disease from 50% in the 6-month group to 42% (P=.02 log-rank). There was no difference in the rate of adverse effects (leukopenia in 32% in both groups, P=.53) or development of CMV resistance between the two groups (4 cases in both groups, P=.92). There were no significant differences in overall survival or the rate of chronic lung allograft dysfunction between the groups. Extending duration of CMV prophylaxis from 6 to 9months resulted in a delayed and decreased incidence of CMV disease in our lung transplant population. The absolute risk reduction achieved by extended CMV prophylaxis was 8%. The incidence of CMV infection, and ganciclovir resistance and side effects were similar between the two groups. Our results suggest that extending CMV prophylaxis in the highest risk CMV D+/R- group is effective in reducing CMV disease.

Cytomegalovirus in Adult Allogeneic Blood and Marrow Transplant Patients Before or Around the Period of Neutrophil Recovery: A Single-Center, Retrospective, Descriptive Study.

BackgroundFew reports exist on pre-engraftment cytomegalovirus (CMV) DNAemia in allogeneic blood or marrow transplant (allo BMT) recipients. We describe this clinical entity, its management, and the potential effect of 3 different quantitative CMV deoxyribonucleic acid (DNA) tests used during the 6-year study period. MethodsWe performed a retrospective, single-center study of allo BMT recipients from 2010 to 2015 who developed CMV DNAemia before neutrophil recovery (absolute neutrophil count [ANC] <1000 cells/mm3, “pre-engraftment CMV”) or who became neutropenic concomitant with detectable CMV DNA (“peri-engraftment CMV”). Clinical data were collected from the electronic medical record.ResultsAmong 1151 adult allo BMT patients, 73 developed CMV DNAemia before engraftment or while neutropenic after initial engraftment. Most patients were eventually treated (valganciclovir or ganciclovir, N = 68; foscarnet, N = 1); 4 were not treated. First CMV detection occurred at median day +12 (range, 0–48), but treatment was not started until median day +33 (range, 4–105) at median ANC of 760 cells/mm3. Six patients had peak viral loads >5000 IU/mL; none had tissue-invasive disease. One developed ganciclovir resistance. No significant differences were observed upon stratification by quantitative CMV DNA test. ConclusionsCytomegalovirus DNA was detected in 6.3% of pre- and peri-engraftment allo-HSCT patients. Ganciclovir derivatives were commonly used for treatment despite risk of neutropenia. Treatment was typically deferred until CMV DNA and ANC rose. With rare exceptions, this treatment strategy did not appear to have adverse clinical consequences with respect to acute CMV. Different CMV DNA quantification tests used performed similarly from a clinical perspective despite different analytical performance characteristics.

Clinical "Real-World" Experience with Letermovir for Prevention of Cytomegalovirus Infection in Allogeneic Hematopoietic Cell Transplant Recipients

<h3>Introduction</h3> Cytomegalovirus (CMV) is the most common opportunistic infection following hematopoietic cell transplantation (HCT). Letermovir was approved in 2017 by the Food and Drug Administration (FDA) for prevention of CMV infection in allogeneic HCT patients. Letermovir was shown to be safe and effective in the phase 3 trial but published post-marketing data with this new agent is scarce. <h3>Objectives</h3> To describe our "real-world" clinical experience with letermovir. <h3>Methods</h3> Twenty-five CMV positive (R+) allogeneic HCT recipients transplanted between March 2018 and January 2019 who received letermovir prophylaxis (until day 100) were included in the treatment group. A historical group of 106 CMV R+ allogeneic HCT recipients transplanted between September 2012 and June 2016 who underwent CMV preemptive therapy served as control group. We compared the incidence of both CMV reactivation (any viremia) and clinically significant CMV infection (CS-CMVi; defined as any detectable CMV DNAemia leading to preemptive treatment or presence of CMV tissue invasive disease) between initiation of letermovir and days +100 and +200 post-HCT. <h3>Results</h3> CMV reactivation within 100 days post-HCT was lower in the letermovir group vs. control group (20% vs. 72% respectively, P<0.001) [Figure 1]. The 100-day cumulative incidence of CS-CMVi was significantly lower in the letermovir group vs. control group (4% vs. 59% respectively, P<0.001) [Figure 2] with no tissue invasive disease in the former. Significantly reduced incidence of CMV reactivation and CS-CMVi were also observed at 200 days in the letermovir group. No difference in mortality was observed between the two groups (20% vs. 21% respectively, P 0.79) in the first 100 days post-HCT. <h3>Conclusion</h3> This study confirms the efficacy of letermovir in preventing CMV reactivation in CMV R+ allogeneic HCT recipients in first 100 days post-HCT and suggests sustained efficacy after discontinuation of prophylaxis. Further studies are needed to investigate the role of letermovir use beyond 100 days post-HCT.

A Phase 3 Active-Controlled Study of Maribavir (MBV) for the Treatment (Tx) of Transplant Recipients with Refractory/Resistant (RR) Cytomegalovirus (CMV): Study Design

Introduction In transplant recipients, CMV infection RR to prior antiviral Tx is associated with significant morbidity and mortality. Existing antivirals are not approved for RR CMV infection and are limited by their toxicities. A prior Phase 2 dose-ranging study of MBV for RR CMV (67% of patients [pts] achieved undetectable CMV DNA within 6 wks) motivated initiation of a Phase 3 trial with the concept of an investigator-assigned (IA) Tx comparator arm. Objective To assess the efficacy and safety of MBV compared with IA anti-CMV therapies in HSCT/SOT recipients with RR CMV infection. Methods In this Phase 3, randomized, open-label, multicenter, active-controlled study (NCT02931539), HSCT/SOT recipients (≥12 years old) with RR CMV infection are randomized 2:1 to MBV (400 mg BID) or IA Tx (ganciclovir [GCV], valganciclovir [VGC], foscarnet [FSC], cidofovir [CDV]) for 8 wks. Pts in the IA Tx group discontinuing Tx early (lack of response and/or intolerance; investigator discretion) are assessed Wks 3–7 to enter MBV rescue arm. Pts are followed for 12 wks after the 8-wk Tx period. Inclusion criteria include: documented CMV infection with screening value ≥2730 IU/mL / ≥910 IU/mL (whole blood / plasma) in 2 consecutive tests ≥1 day apart; current refractory CMV infection: documented failure to achieve >1 log10 decrease in CMV DNA after ≥14 days of the same anti-CMV Tx. Pts with ≥1 genetic mutation associated with GCV/VGC, FSC or CDV resistance must also meet refractory criteria. Pts with tissue invasive CMV disease with CNS involvement including the retina, eg CMV retinitis, are excluded. A central specialty laboratory quantifies plasma CMV DNA (COBAS ‘AmpliPrep/TaqMan' CMV test). The primary efficacy endpoint is confirmed CMV viremia clearance (defined as plasma CMV DNA concentrations Results Planned enrollment is 351 pts across ∼140 sites (North America, Europe, Asia Pacific). Study start, Dec 2016; completion ∼Sep 2020. Conclusions The comparator arm of this Phase 3 study is valid for evaluating efficacy and safety of MBV for RR CMV compared with available anti-CMV Tx, whilst allowing for personalized Tx for pts in the comparator group.

CMV Viral Load Kinetics as Surrogate Endpoints for Antiviral Prophylaxis Trials

<h3>Introduction</h3> The paradigm for preventing clinically significant cytomegalovirus (CMV) infection and CMV disease after hematopoietic cell transplantation (HCT) has shifted from preemptive treatment to antiviral prophylaxis with the approval of letermovir. Previously, our group validated the use of quantitative CMV DNA viral load as a surrogate endpoint for tissue-invasive CMV disease (ASBMT 2018) in the <i>pre-emptive treatment setting</i>. <h3>Objectives</h3> To address whether CMV viral load kinetics could serve as valid surrogate endpoints for CMV disease in the <i>prophylactic setting</i>, we performed CMV viral load testing of frozen serum samples collected during a placebo-controlled randomized trial of ganciclovir (GCV) given at engraftment (Goodrich et al. Ann Intern Med 1993). Because this study pre-dated the approval of ganciclovir, CMV disease occurred in an extremely high proportion of patients, allowing us to link viral load kinetics with CMV disease, which would not be possible in the modern treatment environment. <h3>Methods</h3> We calculated each patient's CMV viral load kinetics (mean, peak, maximum change, percentage of positive viral loads) from samples collected during the first five weeks after randomization and analyzed their value as surrogates for CMV disease by 24 weeks after randomization. First, we tested each marker for fulfillment of the Prentice criteria for valid surrogate endpoints using multivariable logistic regression, including quantifying the degree to which each marker captured the effect of ganciclovir on CMV disease. Secondly, to determine the ability of the viral load markers to predict CMV disease, we developed a ‘SuperLearner' machine learning model and quantified prediction accuracy by cross-validated area under the receiver-operator characteristic curves (cv-AUCs). <h3>Results</h3> Mean, peak, change, and percentage of positive viral loads were significantly higher in the placebo group than in the ganciclovir group. See viral loads by group in Fig 1. Percentage of positive viral load satisfied Prentice criteria as a valid surrogate endpoint for CMV disease by week 24 after randomization (Fig 2). All kinetics explained greater than 80% of ganciclovir's reduction in CMV disease (mean: 86%, peak: 83%, maximum change: 95%, percent positive: 94%). We found that a SuperLearner model that included all four viral load kinetics, CMV donor serostatus, acute graft-versus-host disease, and baseline viral load predicted CMV disease with 91% cv-AUC in the placebo group, 78% in the ganciclovir group, and 82% in the combined groups (Fig 3). <h3>Conclusion</h3> We have shown for the first time in a clinical endpoint-rich, placebo-controlled antiviral prophylaxis trial that CMV viral load kinetics fulfill the Prentice criteria as valid surrogate endpoints and have high predictive value for CMV disease after HCT.

Revisiting cytomegalovirus serostatus and replication as risk factors for inferior long-term outcomes in the current era of renal transplantation.

Cytomegalovirus (CMV) serostatus and CMV replication are considered as risk factors for inferior graft and patient survival after renal transplantation, but long-term outcome data are limited. The aim of this retrospective single-centre study was to investigate the impact of CMV serostatus and CMV replication/disease on long-term outcomes in a well-defined cohort managed by a standardized CMV prevention/treatment protocol. We investigated 599 consecutive kidney transplantations having a CMV prevention protocol consisting of either prophylaxis (D+/R- and R+ with ATG induction) or screening/deferred therapy (R+ without ATG induction). Patients were grouped according to CMV serostatus [high risk (D+/R-): n = 122; intermediate risk (R+): n = 306; low risk (D-/R-): n = 171] and occurrence of CMV replication/disease (no CMV replication: n = 419; asymptomatic CMV replication: n = 110; CMV syndrome: n = 39; tissue-invasive CMV disease: n = 31). The median follow-up time was 6.5 years. Graft and patient survival were not different among the three CMV serostatus groups as well as the four CMV replication/disease groups (P ≥ 0.44). Eighty-seven patients died, 17 due to infections (21%), but none was attributable to CMV. The overall hospitalization incidence for CMV-related infection was 3% (17/599 patients). The incidence of clinical and (sub)clinical rejection was similar among the groups (P ≥ 0.17). In a multivariate Cox proportional hazard model, neither CMV serostatus, nor CMV replication, nor CMV disease were independent predictors for patient death or graft failure, respectively. This retrospective single-centre study suggests that the negative impact of CMV infection on long-term patient and allograft survival as well as on allograft rejection can be largely eliminated with current diagnostic/therapeutic management.

Influence of major histocompatibility complex class I chain-related gene A polymorphisms on cytomegalovirus disease after allogeneic hematopoietic cell transplantation

Objective/BackgroundCytomegalovirus (CMV) infection and disease are common infectious complications after allogeneic hematopoietic cell transplantation (alloHCT). Major histocompatibility complex (MHC) class I chain-related gene A (MICA) is a ligand of the natural killer (NKG2D) receptor on immune effector cells that helps mediate NK cell alloreactivity. We hypothesized that MICA polymorphisms may influence CMV infection and disease incidence after alloHCT. MethodsWe conducted a retrospective analysis of 423 adults at the Cleveland Clinic with hematologic malignancies treated with a matched related or unrelated donor alloHCT. CMV cases analyzed included a compositive of instances of viral copy replication above detection limits as well as any biopsy-proven tissue invasive disease episodes. Genotypes at the MICA-129 position have been categorized as weak (valine/valine; V/V), intermediate (methionine/valine; M/V), or strong (methionine/methionine; M/M) receptor affinity. ResultsIn multivariable analysis, V/V donor MICA-129 genotype was associated with CMV infection and disease (hazard ratio [HR] = 1.40; 95% confidence interval [CI], 1.00–1.96; p = .05), but not MICA mismatch (HR = 1.38; 95% CI, 0.83–2.29; p = .22). There was no association of acute or chronic GVHD with MICA donor–recipient mismatch (HR = 1.05; 95% 95% CI, 0.66–1.68; p = .83 and HR = 0.94; 95% CI, 0.51–1.76; p = .85, respectively) or V/V donor MICA-129 genotypes (HR = 1.02; 95% CI, 0.79–1.31; p = .89 and HR = 0.89; 95% CI, 0.65–1.22; p = .47, respectively). ConclusionThese findings suggest that the donor MICA-129 V/V genotype with weak NKG2D receptor binding affinity is associated with an increased risk of CMV infection and disease after alloHCT.

Virological and Immunological Monitoring of Human Cytomegalovirus (HCMV) Infection in Hematopoietic Stem Cell Transplantation Recipients (HSCTR)

Introduction HCMV infection is a significant viral complication in HSCTR, causing either a subclinical infection or a severe disease (systemic syndrome and localized tissue invasive disease (TID)). Pre-emptive therapy used for the management of HCMV infection and prevention of disease requires the monitoring of HCMV load in blood to start antiviral therapy after detection of a viral load threshold associated to the risk for HCMV severe infection and disease. In previous studies we observed that patients reconstituting both CD4+ and CD8+ HCMV-specific T cells are generally protected from HCMV disease. Thus, determination of specific T cells may discriminate patients lacking immunity and requiring stricter virological monitoring (negative T-cell response) from those early recovering T-cell immunity and thus not requiring antiviral interventions (positive T-cell response). Aims The aim of our work is to assess the possibility to manage HCMV infection by combined virological and immunological monitoring. The primary endpoint of this study is to compare the frequency of HCMV disease between two groups of HSCTR: in the first one, pre-emptive therapy was started according to combined virological/immunological methods; the second group consisted of an historical cohort of patients monitored with HCMV-DNA as the only guiding parameter for pre-emptive therapy. Methods We analyzed adult patients receiving allogeneic HSCT: the recipients, the donor or both had to be HCMV seropositive. Virological follow-up (HCMV-DNA determination in whole blood) was performed weekly for the first 3 months, then monthly during the first year. Immunological follow-up was performed at 1, 2, 3, 4, 6, 8, 10 and 12 months. Peripheral blood HCMV-specific T cells were determined by two assays: i) iCL (infected Cell Lysate)-ELISPOT, considering as "protective" immunity a blood count of specific T-cell ≥ 0.1/µL ii) iDC-CFC (infected Dendritic Cells-Cytokine Flow Cytometry), considering as "protective" immunity a blood count of CD4+ T-cell ≥ 1/µL and CD8+ T cells ≥ 3/µL. According to study, within the first 3 months following transplantation pre-emptive antiviral therapy was given to all patients presenting a viral load ≥30.000 copies/mL blood (severe infection). Beyond 3 months following transplantation, patients with negative T-cell response continued receiving a pre-emptive antiviral therapy as reported above. In patients with positive T-cell response confirmed by both assays ("protected" patients), antiviral therapy was deferred even if viral load would reach ≥30.000 copies/mL blood. Results We performed an analysis of 36 patients with a follow-up ≥4 months from HSCT (median follow-up 245 days, 120-397; see Table 1 for patients' characteristics). Among them, 32 HCMV-seropositive HSCTR developed HCMV infection whereas 4 HCMV-seronegative patient receiving HSCT from seropositive donors did not (nor developed specific immunity). Among the 32 HSCTR with HCMV reactivation, 13 (41%) resolved spontaneously HCMV reactivation, whereas 19 (59%) had a severe infection (11 [34%] controlled the infection after a single course of Valganciclovir therapy and the remaining 8 [25%] required multiple courses for relapsing episodes). Thirty days after HSCT, levels of total and HCMV-specific CD4+ and CD8+ T cells were significantly higher in the 13 patients spontaneously resolving the infection than in the 19 patients with severe infection. The two immunological assays were concordant in detecting time to protective immune reconstitution (median time: 177 vs 183 days for iDC and iCL-ELISPOT, respectively). HCMV-specific immune reconstitution was significantly delayed in patients with multiple infection episodes (median time: 250 days post-transplantation) vs patients with a single episode of severe infection (187 days) and patients with self-resolving infection (89 days). No patient developed HCMV severe infection after HCMV-specific immune reconstitution. Currently, no patient developed HCMV disease. Conclusion These results suggest that combined virological/immunological monitoring can be useful to identify patients not requiring strict virological controls and antiviral interventions. Disclosures No relevant conflicts of interest to declare.

1750. Epidemiology of Cytomegalovirus DNAemia in Pediatric Solid-Organ Transplant Patients

BackgroundDespite the widespread use of prevention strategies, CMV remains a common opportunistic infection in SOTR. Contemporary data regarding CMV in pediatric SOTR is limited. We sought to determine the frequency of and risk factors for CMV infection and disease in a large single-center cohort of pediatric SOTR.MethodsA retrospective cohort study of patients <22 yr of age who received lung, heart, liver, kidney, or multi-organ transplants at TCH between 2014 and 2018 was completed. Universal CMV prophylaxis was used based on risk status (Figure 1). Primary outcome was CMV DNAemia (plasma level ≥ 1,000 IU/mL). Associations with CMV DNAemia were measured using Fisher exact, Kruskal–Wallis, and multivariate logistic regression. Survival analysis and time to CMV infection were assessed using Kaplan–Meier plots.ResultsAmong 465 SOTR, 57 (12%) had CMV DNAemia ≥ 1,000 IU/mL; this included 9/52 (17%) lung, 22/155 (14%) liver, 16/125 (13%) heart, 1/9 (11%) multi-organ, and 9/124 (7%) kidney recipients. 6 (10%) SOTR had early-onset CMV reactivation while on antiviral prophylaxis. Post-prophylaxis, 48 (85%) SOTR had CMV reactivation and 3 (5%) had primary infection. Median time to DNAemia > 1,000 IU/mL was 366 days post-transplant for lung, 115 for liver, 185 for heart, and 290 for kidney (P = 0.04), reflecting differences in prophylaxis strategies. High-risk CMV status (D+/R- for heart, liver, kidney and D+ and/or R+ for lung) was associated with CMV DNAemia (P < 0.01, Figure 2). DNAemia was not associated with age at transplantation, type of organ, or induction immunosuppression. There was no difference in survival during the study follow-up period (1 – 5 years) for SOTR with vs. without DNAemia. Overall, 18/465 (4%) SOTR had CMV disease: 2 (4%) lung, 3 (2%) liver, 5 (4%) heart, 1 (11%) multi-organ, and 7 (6%) kidney recipients. 16 had CMV syndrome and 2 had tissue-invasive disease. Median (range) maximum viral loads were 35,768 IU/mL (3,239–4,807,992) for SOTR with vs. 2,605 IU/mL (1,000–112,000) for SOTR without CMV disease (P < 0.01)ConclusionThis large contemporary cohort of pediatric SOTR on universal prophylaxis demonstrates low overall rates of CMV DNAemia and CMV disease. High-risk CMV status remains associated with CMV DNAemia, suggesting that further interventions targeting this group may be warranted. DisclosuresFlor M. Munoz, MD, Biocryst: Grant/Research Support; CDC: Research Grant; Moderna: Other Financial or Material Support, Safety Monitoring Board Member/Chair; NIH: Research Grant; Novavax: Research Grant; UP to Date: Author and Editor - Royalties, Other Financial or Material Support.

Cytomegalovirus prevention strategies and the risk of BK polyomavirus viremia and nephropathy.

Polyomavirus BK (BKV) is the cause of polyomavirus-associated nephropathy resulting in premature graft loss. There are limited data regarding the role of cytomegalovirus (CMV) infection and its prevention in developing BKV viremia and PVAN. In a prospective study, we analyzed 207 consecutive renal transplant recipients previously enrolled in 2 randomized trials evaluating different CMV prevention regimens with routine screening for BKV and CMV. Of these, 59 received valganciclovir and 100 valacyclovir prophylaxis; 48 patients were managed by preemptive therapy. At 3years, the incidence of BKV viremia and PVAN was 28% and 5%, respectively. CMV DNAemia developed in 55% and CMV disease in 6%. Both BKV viremia (42% vs 23% vs 21%, P=.006) and PVAN (12% vs 2% vs 2%, P=.011) were increased in patients treated with valganciclovir prophylaxis compared to valacyclovir and preemptive therapy. Using multivariate Cox proportional hazard regression, valganciclovir prophylaxis was independent predictor of BKV viremia (hazard ratio [HR]=2.38, P=.002) and PVAN (HR=4.73, P=.026). In contrast, the risk of subsequent BKV viremia was lower in patients with antecedent CMV DNAemia (HR=0.50, P=.018). These data suggest valganciclovir prophylaxis may be associated with increased risk of BKV viremia and PVAN. CMV DNAemia did not represent a risk for BKV.

Reactivation of latent cytomegalovirus infection in patients with rheumatologic disease: a case-control study.

The disease burden, risk factors and clinical sequelae of CMV reactivation in patients with rheumatologic conditions is poorly understood. We have described a cohort with underlying rheumatic disease and CMV, and compared a subgroup with systemic lupus erythematosus (SLE) to controls to identify potential risk factors for CMV reactivation. Adults with rheumatic disease and CMV infection from 2000-2015 were identified. SLE cases were matched 3:1 with controls based on age, sex and year of admission, and compared. Fourteen patients were included (6 SLE, 4 rheumatoid arthritis, 2 sarcoidosis, 1 psoriatic arthritis, 1 microscopic polyangiitis). Seven had viremia alone, the remainder tissue-invasive disease. Thirteen received glucocorticoids prior to CMV reactivation. Fever was the most common symptom, and coinfections were seen in eight including four with bacteremia. Thirteen received antiviral therapy (median 33days), four died during hospitalization. Six patients with underlying SLE and CMV reactivation were compared to 18 SLE controls. Cases received more glucocorticoids prior to admission (median 36.5 vs. 2.5mg/day, p = 0.006), had longer hospitalizations (median 47 vs. 7days, p = 0.006) and more coinfections (67% vs. 17%, p = 0.04). There were no significant differences in symptoms at presentation. CMV reactivation occurs in patients with rheumatologic disease, can result in severe clinical sequelae, and is difficult to distinguish from a flare of the underlying disease. Patients with CMV received higher doses of glucocorticoids and developed more co-infections. CMV should be considered during the evaluation of a febrile illness in this complex patient population.

Clinical Correlation of Cytomegalovirus Infection With CMV-specific CD8+ T-cell Immune Competence Score and Lymphocyte Subsets in Solid Organ Transplant Recipients.

Control of cytomegalovirus (CMV) infection after solid organ transplantation (SOT) requires a functional immune system. We assessed the association between quantitation and function of CMV-specific CD8+ T cells and CMV infection in SOT recipients. During a 10-year period, selected kidney, heart, lung, pancreas, liver, and composite tissue recipients were tested for CMV-specific CD8+ T cells immune competence (CMV-CD8+), as measured by enumeration, interferon-gamma production, and CD107a/b degranulation. Quantitative and functional data were used to assemble T-cell immune competence (TIC) score. CMV infection was diagnosed by polymerase chain reaction in blood and other samples or histopathology. Of 130 patients tested, 59 had CMV infection or disease. The median onset to CMV infection was 10.5 months (interquartile range [IQR], 5.5-18.7). Gastrointestinal disease (28.8%), pneumonia (20.3%), and CMV syndrome (17%) were most common presentation. An impaired nonspecific or CMV-CD8+ TIC score was associated with tissue-invasive disease (hazard risk, 2.84, 95% confidence interval, 1.03-11.81; P = 0.04). Patients with impaired CMV-CD8+ TIC score had longer viremia duration (42.4 days vs 18.8 d; P < 0.001). Patients with impaired nonspecific or CMV-CD8+ TIC score had higher risk of relapse (68.8% vs 27.9%; hazard risk, 2.56; 95% confidence interval, 1.09-5.89; P = 0.03). Patients with CMV infection or disease had lower median absolute lymphocyte count (380 [IQR, 240-540] vs 940 [IQR, 551-1210] cells/mm; P < 0.0001) and CD4+ T cell count (29 cells/mm [IQR, 1.3-116.0] vs 325.5 cells/mm [IQR, 151.5-589.8]; P < 0.0001). Nonspecific and CMV-specific CD8+ T-cell function correlated with the course of CMV after SOT, and measuring these has the potential to assist in its clinical management.