COVID-19 in solid organ transplant: A multi-center cohort study

Background

The COVID-19 pandemic has led to significant reductions in transplantation, motivated in part by concerns of disproportionately more severe disease among solid organ transplant (SOT) recipients. However, clinical features, outcomes, and predictors of mortality in SOT recipients are not well-described.

Methods

We performed a multi-center cohort study of SOT recipients with laboratory-confirmed COVID-19. Data were collected using standardized intake and 28-day follow-up electronic case report forms. Multivariable logistic regression was used to identify risk factors for the primary endpoint, 28-day mortality, among hospitalized patients.

Results

Four hundred eighty-two SOT recipients from >50 transplant centers were included: 318 (66%) kidney or kidney/pancreas, 73 (15.1%) liver, 57 (11.8%) heart, and 30 (6.2%) lung. Median age was 58 (IQR 46-57), median time post-transplant was 5 years (IQR 2-10), 61% were male, and 92% had ≥1 underlying comorbidity. Among those hospitalized (376 [78%]), 117 (31%) required mechanical ventilation, and 77 (20.5%) died by 28 days after diagnosis. Specific underlying comorbidities (age >65 [aOR 3.0, 95%CI 1.7-5.5, p<0.001], congestive heart failure [aOR 3.2, 95%CI 1.4-7.0, p=0.004], chronic lung disease [aOR 2.5, 95%CI 1.2-5.2, p=0.018], obesity [aOR 1.9, 95% CI 1.0-3.4, p=0.039]) and presenting findings (lymphopenia [aOR 1.9, 95%CI 1.1-3.5, p=0.033], abnormal chest imaging [aOR 2.9, 95%CI 1.1-7.5, p=0.027]) were independently associated with mortality. Multiple measures of immunosuppression intensity were not associated with mortality.

Conclusions

Mortality among SOT recipients hospitalized for COVID-19 was 20.5%. Age and underlying comorbidities rather than immunosuppression intensity-related measures were major drivers of mortality.

Risk Factors for Cytomegalovirus Viremia following Liver Transplantation With a Seropositive Donor and Seronegative Recipient Receiving Antiviral Therapy

BACKGROUND

The risk factors for development of viremia in high-risk donor cytomegalovirus (CMV)-seropositive and recipient CMV-seronegative (D+R-) transplant recipients are incompletely defined.

METHODS

The study population comprised patients in the preemptive therapy (PET) arm of a randomized, controlled trial of PET versus prophylaxis using valganciclovir in D+R- liver transplant recipients. Weekly surveillance monitoring for viremia for 100 days was performed using a sensitive CMV-DNA polymerase chain reaction assays. Risk factors for viremia and time to onset (≤4 vs >4 weeks) of viremia were examined using logistic regression models.

RESULTS

Viremia developed in 84% (79/94) of recipients and older donor age was the only independent factor associated with viremia (odds ratio, 2.20 for each quartile increase in donor age; 95% confidence interval [CI], 1.07-4.52; P = .031). Recipients who developed early-onset viremia (within 4 weeks) also had significantly older donors than those with later-onset viremia (difference in age 10.1 years; 95% CI, 2-19; P = .03).

CONCLUSIONS

Older donor age was an independent predictor of viremia and earlier-onset of viremia in D+R- liver transplant recipients. Future studies should assess the mechanistic links underlying this novel association.

CLINICAL TRIAL REGISTRATION

NCT01552369.

Circulating exosomes with lung self-antigens as a biomarker for chronic lung allograft dysfunction: A retrospective analysis

BACKGROUND

Exosomes isolated from plasma of lung transplant recipients (LTxRs) with bronchiolitis obliterans syndrome (BOS) contain human leukocyte antigens and lung self-antigens (SAgs), K-alpha 1 tubulin (Kα1T) and collagen type V (Col-V). The aim was to determine the use of circulating exosomes with lung SAgs as a biomarker for BOS.

METHODS

Circulating exosomes were isolated retrospectively from plasma from LTxRs at diagnosis of BOS and at 6 and 12 months before the diagnosis (n = 41) and from stable time-matched controls (n = 30) at 2 transplant centers by ultracentrifugation. Exosomes were validated using Nanosight, and lung SAgs (Kα1T and Col-V) were detected by immunoblot and semiquantitated using ImageJ software.

RESULTS

Circulating exosomes from BOS and stable LTxRs demonstrated 61- to 181-nm vesicles with markers Alix and CD9. Exosomes from LTxRs with BOS (n = 21) showed increased levels of lung SAgs compared with stable (n = 10). A validation study using 2 separate cohorts of LTxRs with BOS and stable time-matched controls from 2 centers also demonstrated significantly increased lung SAgs-containing exosomes at 6 and 12 months before BOS.

CONCLUSIONS

Circulating exosomes isolated from LTxRs with BOS demonstrated increased levels of lung SAgs (Kα1T and Col-V) 12 months before the diagnosis (100% specificity and 90% sensitivity), indicating that circulating exosomes with lung SAgs can be used as a non-invasive biomarker for identifying LTxRs at risk for BOS.

Earliest cases of coronavirus disease 2019 (COVID-19) identified in solid organ transplant recipients in the United States

With the rapidly expanding pandemic of SARS-CoV-2, there is concern that solid organ transplant recipients will be particularly vulnerable to infection and may experience a more severe clinical course. We report four cases of COVID-19 in solid organ transplant recipients including recipients of kidney, liver, lung, and heart transplants. We describe each patient's medical history including transplantation history, their clinical presentation and workup, and their course from diagnosis to either hospital discharge or to improvement in symptoms. These reports demonstrate a range of symptoms, clinical severity, and disease course in solid organ transplant recipients with COVID-19, including two hospitalized patients and two patients managed entirely in the outpatient setting.

Use of SARS-CoV-2-infected deceased organ donors: Should we always "just say no?"

In the context of a rapidly evolving pandemic, multiple organizations have released guidelines stating that all organs from potential deceased donors with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection should be deferred, including from otherwise medically eligible donors found to have mild or asymptomatic SARS-CoV-2 discovered on routine donor screening. In this article, we critically examine the available data on the risk of transmission of SARS-CoV-2 through organ transplantation. The isolation of SARS-CoV-2 from nonlung clinical specimens, the detection of SARS-CoV-2 in autopsy specimens, previous experience with the related coronaviruses SARS-CoV and MERS-CoV, and the vast experience with other common RNA respiratory viruses are all addressed. Taken together, these data provide little evidence to suggest the presence of intact transmissible SARS-CoV in organs that can potentially be transplanted, specifically liver and heart. Other considerations including ethical, financial, societal, and logistical concerns are also addressed. We conclude that, for selected patients with high waitlist mortality, transplant programs should consider accepting heart or liver transplants from deceased donors with SARS-CoV-2 infection.

Detection of SARS-CoV-2 by bronchoscopy after negative nasopharyngeal testing: Stay vigilant for COVID-19

PURPOSE

Real-time polymerase chain reaction (RT-PCR) detection of severe acute respiratory syndrome coronavirus (SARS-CoV-2) is required for diagnosis of coronavirus disease 2019 (COVID-19). Sensitivity of RT-PCR nasopharyngeal (NP) testing is presumed to be high, but there is no gold standard against which this has been determined. The objective was to determine whether lower respiratory tract infection (LRTI), detected in bronchoalveolar lavage fluid (BALF), occurs in the absence of upper respiratory tract infection with clinical testing of both specimen types.

METHODS

Between March 26, 2020 and April 17, 2020 at the University of Washington Medical Center all patients with BALF specimens clinically tested for SARS-CoV-2 were identified. We assessed the proportion of patients with positive RT-PCR for SARS-CoV-2 in BALF after negative NP testing. We describe 3 cases with positive testing in BALF.

RESULTS

Among 16 patients with BALF samples, 3 cases (19%) had SARS-CoV-2 detected in BALF. In Case 1, negative NP testing occurred early in the infection and respiratory symptoms may have been missed due to neurologic injury. In Case 2, outpatient diagnosis was aspiration pneumonia, but clinical suspicion remained high for COVID-19 at hospitalization based on epidemiological and clinical features. All 3 cases involved older adults (age >65 years), one of whom was immunosuppressed in the setting of lung transplantation (Case 3).

CONCLUSIONS

These data demonstrate that SARS-CoV-2 LRTI occurs in the presence of negative NP testing. NP testing may underestimate the prevalence of COVID-19 and has implications for spread of SARS-CoV2 in the community and healthcare setting.

Prospective Assessment of Cytomegalovirus Immunity in High-Risk Donor-Seropositive/Recipient-Seronegative Liver Transplant Recipients Receiving Either Preemptive Therapy or Antiviral Prophylaxis

The differential impact of preemptive therapy (PET) and antiviral prophylaxis (AP) on development of cytomegalovirus (CMV)-specific neutralizing antibody (nAb) and T-cell responses have not previously been directly compared in high-risk donor-seropositive/recipient-seronegative (D+R-) organ transplant recipients. We prospectively assessed T-cell and nAb responses 3 months after transplantation in cohorts of high-risk D+R- liver transplant recipients who received either PET (n = 15) or AP (n = 25) and a control group of CMV-seropositive transplant recipients (R+) (AP; n = 24). CMV phosphoprotein 65 (pp65)- and immediate early protein 1-specific multifunctional T-cell responses were determined by means of intracellular cytokine staining and nAbs against BADrUL131-Y4 CMV in adult retinal pigment epithelial cell line-19 human epithelial cells; nAbs were detected in 8 of 12 (67%) in the PET group, none of 17 in the AP group, and 20 of 22 (91%) in the R+ group. Multifunctional CD8 and CD4 T-cell responses to pp65 were generally similar between PET and R+ groups, and lower for the AP group; multifunctional CD4 responses were similar across all groups. Among D+R- liver transplant recipients, PET was associated with the development of greater nAb and multifunctional CD8 T-cell responses compared with AP, providing a potential mechanism to explain the relative protection against late-onset disease with PET. Future studies are needed to define specific immune parameters predictive of late-onset CMV disease with AP.

Effect of Preemptive Therapy vs Antiviral Prophylaxis on Cytomegalovirus Disease in Seronegative Liver Transplant Recipients With Seropositive Donors: A Randomized Clinical Trial

IMPORTANCE

Despite the use of a cytomegalovirus (CMV) prevention strategy of antiviral prophylaxis for high-risk CMV-seronegative liver transplant recipients with seropositive donors, high rates of delayed-onset postprophylaxis CMV disease occur. An alternate approach, preemptive therapy (initiation of antiviral therapy for early asymptomatic CMV viremia detected by surveillance testing), has not previously been directly compared with antiviral prophylaxis in these patients.

OBJECTIVE

To compare preemptive therapy with antiviral prophylaxis in CMV-seronegative liver transplant recipients with seropositive donors for the prevention of CMV disease.

DESIGN, SETTING, AND PARTICIPANTS

Randomized clinical trial of preemptive therapy vs antiviral prophylaxis in 205 CMV-seronegative liver transplant recipients with seropositive donors aged older than 18 years. The trial was conducted at 6 academic transplant centers in the United States between October 2012 and June 2017, with last follow-up in June 2018.

INTERVENTIONS

Patients were randomized 1:1 to receive either preemptive therapy (valganciclovir, 900 mg, twice daily until 2 consecutive negative tests a week apart) for viremia detected by weekly plasma CMV polymerase chain reaction for 100 days (n = 100) or valganciclovir, 900 mg, daily for 100 days as antiviral prophylaxis (n = 105).

MAIN OUTCOMES AND MEASURES

The primary outcome was incidence of CMV disease by 12 months, defined as CMV syndrome (CMV viremia and clinical or laboratory findings) or end-organ disease. Secondary outcomes included acute allograft rejection, opportunistic infections, graft and patient survival, and neutropenia.

RESULTS

Among 205 patients who were randomized (mean age, 55 years; 62 women [30%]), all 205 (100%) completed the trial. The incidence of CMV disease was significantly lower with preemptive therapy than antiviral prophylaxis (9% [9/100] vs 19% [20/105]; difference, 10% [95% CI, 0.5% to 19.6%]; P = .04]). The incidence of allograft rejection (28% vs 25%; difference, 3% [95% CI, -9% to 15%]), opportunistic infections (25% vs 27%; difference, 2% [95% CI, -14% to 10%]), graft loss (2% vs 2%; difference, <1% [95% CI, -4% to 4%]), and neutropenia (13% vs 10%; difference, 3% [95% CI, -5% to 12%]) did not differ significantly for the preemptive therapy vs antiviral prophylaxis group, respectively. All-cause mortality at last follow-up was 15% in the preemptive therapy vs 19% in the antiviral prophylaxis group (difference, 4% [95% CI, -14% to 6%]; P = .46).

CONCLUSIONS AND RELEVANCE

Among CMV-seronegative liver transplant recipients with seropositive donors, the use of preemptive therapy, compared with antiviral prophylaxis, resulted in a lower incidence of CMV disease over 12 months. Further research is needed to replicate these findings and assess long-term outcomes.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT01552369.

Current Understanding of Cytomegalovirus Reactivation in Critical Illness

Cytomegalovirus (CMV) reactivation has been described in adults with critical illness caused by diverse etiologies, especially severe sepsis, and observational studies have linked CMV reactivation with worse clinical outcomes in this setting. In this study, we review observational clinical data linking development of CMV reactivation with worse outcomes in patients in the intensive care unit, discuss potential biologically plausible mechanisms for a causal association, and summarize results of initial interventional trials that examined the effects of CMV prevention. These data, taken together, highlight the need for a randomized, placebo-controlled efficacy trial (1) to definitively determine whether prevention of CMV reactivation improves clinical outcomes of patients with critical illness and (2) to define the underlying mechanism(s).

Impact of valganciclovir prophylaxis duration on cytomegalovirus disease in high-risk donor seropositive/recipient seronegative heart transplant recipients

BACKGROUND

Few data support use of 6 over 3 months of antiviral prophylaxis for cytomegalovirus (CMV) disease prevention in donor seropositive/recipient seronegative (D+R-) heart transplant recipients (HTR).

METHODS

We retrospectively assessed CMV disease and outcomes in 310 adult HTR between July 5, 2005, and December 30, 2016, at our center. Valganciclovir (VGCV) prophylaxis was given for 3-6 months in the D+R- group. Multivariable models evaluated risk factors for CMV disease in patients who received 3 vs 6 months (±1 month) of prophylaxis, with investigation of inverse probability weighting to correct for confounding variables.

RESULTS

The incidence of CMV disease among all patients and the D+R- group was 8.7% (27/310) and 26.5% (22/83), respectively, and included syndrome in 22.2% (6/27) and end-organ involvement in 77.8% (21/27). In a multivariable model, 6 vs 3 months of antiviral prophylaxis was not associated with reduced risk for CMV disease (OR 2.28 [95% CI 0.66, 7.91], P = .19). CMV disease in D+R- HTR was associated with higher rates of hospitalization (87.5% [14/16] vs 6.3% [1/16], P < .001) and for a longer duration than in matched D+R- controls without disease.

CONCLUSIONS

Cytomegalovirus disease remains a major cause of morbidity in D+R- HTR. In contrast to documented benefit in D+R- lung and kidney recipients, VGCV duration of 6 months was not associated with a lower incidence of CMV disease in D+R- HTR compared to 3-month duration and should be reconsidered in this patient population.

Respiratory viral infection in lung transplantation induces exosomes that trigger chronic rejection

BACKGROUND

Respiratory viral infections can increase the risk of chronic lung allograft dysfunction after lung transplantation, but the mechanisms are unknown. In this study, we determined whether symptomatic respiratory viral infections after lung transplantation induce circulating exosomes that contain lung-associated self-antigens and assessed whether these exosomes activate immune responses to self-antigens.

METHODS

Serum samples were collected from lung transplant recipients with symptomatic lower- and upper-tract respiratory viral infections and from non-symptomatic stable recipients. Exosomes were isolated via ultracentrifugation; purity was determined using sucrose cushion; and presence of lung self-antigens, 20S proteasome, and viral antigens for rhinovirus, coronavirus, and respiratory syncytial virus were determined using immunoblot. Mice were immunized with circulating exosomes from each group and resulting differential immune responses and lung histology were analyzed.

RESULTS

Exosomes containing self-antigens, 20S proteasome, and viral antigens were detected at significantly higher levels (p < 0.05) in serum of recipients with symptomatic respiratory viral infections (n = 35) as compared with stable controls (n = 32). Mice immunized with exosomes from recipients with respiratory viral infections developed immune responses to self-antigens, fibrosis, small airway occlusion, and significant cellular infiltration; mice immunized with exosomes from controls did not (p < 0.05).

CONCLUSIONS

Circulating exosomes isolated from lung transplant recipients diagnosed with respiratory viral infections contained lung self-antigens, viral antigens, and 20S proteasome and elicited immune responses to lung self-antigens that resulted in development of chronic lung allograft dysfunction in immunized mice.

Cytokine Profiles and Severity of Influenza Infection in Transplant Recipients

Influenza is responsible for significant morbidity after transplantation. We evaluated T-helper 1/T-helper 2 (Th2) cytokines and interleukin (IL) 10 levels during influenza infection in the posttransplant setting. Serum samples from 277 transplant recipients were analyzed at influenza diagnosis and 28 days later for interferon gamma (IFN-γ), IL-4, IL-13, and IL-10. IL-13 levels were associated with protection against pneumonia and intensive care unit (ICU) admission, whereas the IFN-γ/IL-13 ratio and IL-10 levels were associated with an increased risk of pneumonia and ICU admission. This association was independent of viral load. A skewing of immune responses toward Th2 in transplant patients appears to confer protection from severe influenza infection, independent of viral load.

Trillions and Trillions: Herpes Simplex Virus-1 Hepatitis in an Immunocompetent Adult

We describe a case of acute liver failure and myopericarditis due to herpes simplex virus-1 (HSV-1) in an immunocompetent adult. We estimate that, at the height of viremia, the patient contained a quantity of HSV-1 virions approaching that of human cells. The patient recovered with acyclovir that was dose-adjusted for neurotoxicity and developed a vigorous anti-HSV-1 T-cell response.

2668. Β Lactam and Other Antibiotic Allergies in Patients Undergoing Solid-Organ and Hematopoietic Cell Transplantation

Background

Patients with reported β-lactam antibiotic allergies (BLA) are more likely to receive broad-spectrum antibiotics and experience adverse outcomes. There are limited data on the burden of β-lactam and other antibiotic allergies among solid-organ transplant (SOT) and hematopoietic cell transplant (HCT) recipients.

Methods

We reviewed records of first-time adult SOT or allogeneic HCT recipients from January 1, 2013 to December 31, 2017 to characterize allergy labels at the time of transplant. Days of hospitalization and inpatient antibiotic use for pre-specified antimicrobials were collected for the first 100 days post-transplant, and incidence rate ratios (IRR) comparing BLA to non-BLA group were calculated using negative binomial models adjusted for transplant type, age, and diagnosis of cystic fibrosis as appropriate. If the adjusted estimates were significantly different for SOT and HCT recipients, separate models were presented.

Results

Among 2153 SOT (65%) and HCT (35%) recipients, 634 (29%) reported any antibiotic allergy and 347 (16%) reported BLAs (Figure 1). Of 634 patients with allergy labels, the most common were penicillins (40%), sulfa (29%), and cephalosporins (17%); 31% reported allergies to ≥2 classes of antibiotics. The most commonly reported reaction to β-lactams was rash (42%), followed by unknown (18%) and hives (17%). In a multivariable model (Table 1), patients with reported BLAs had significantly higher use of vancomycin (IRR 1.35 [95% CI 1.13, 1.60], P < 0.001) and significantly lower use of ampicillin-sulbactam (IRR 0.13 [0.05, 0.39], P < 0.001) and piperacillin–tazobactam (IRR 0.39 [0.25, 0.62], P < 0.001) compared with those without BLAs. For some antibiotics, the effect of BLA varied by SOT/HCT (Table 2). No significant differences in Clostridioides difficile infection or inpatient days were noted.

Conclusion

Transplant recipients have a high burden of reported antibiotic allergies, in particular BLAs. A BLA label was significantly associated with altered antibiotic prescribing in the early post-transplant period. Pre-transplant allergy evaluation may be helpful in directing antibiotic use following transplant as part of a comprehensive antibiotic stewardship program.

Disclosures

All authors: No reported disclosures.

2307. Risk factors for Cytomegalovirus (CMV) reactivation and Association with Clinical Outcomes in Critically Ill Adults with Sepsis: A Pooled Analysis of Prospective Studies

Background

CMV reactivation in seropositive, non-immunosuppressed adults with sepsis has been associated with worse clinical outcomes. To inform rational design of interventional trials determining whether CMV prevention improves outcomes, it is critical to identify the independence and strength of the association of CMV reactivation measures with clinically-relevant endpoints. Identification of patient factors associated with CMV reactivation would allow for optimization of the study population.

Methods

We performed a secondary pooled analysis of two prospective cohorts with sepsis: an observational cohort of ICU patients (n = 40) and the placebo cohort from a randomized, double-blind trial of ganciclovir to prevent CMV reactivation in acute critical illness (n = 66). Personnel blinded to the PCR results assessed clinical variables; CMV DNAemia was measured by quantitative plasma PCR twice weekly. Multivariable modeling using logistic and linear methods was used to examine the associations of CMV with clinical outcomes and between baseline patient factors and measures of CMV reactivation (adjusted for age, race, gender, transfusion status, study cohort, and APACHE score).

Results

CMV reactivation occurred at any level in 38/106 (36%), at >100 IU/mL in 25/106 (24%), and at >1,000 IU/mL in 14/106 (13%). In a multivariate model, CMV reactivation at any level, >100 IU/mL, or >1,000 IU/mL was associated with fewer days alive and not requiring ventilation: mean difference of −3.5 days ([95% CI −7.0, 0], P = 0.057), −5.1 days ([−8.9, −1.2], P = 0.012), and −6.1 days ([−10.9, −1.2], P = 0.016), respectively. Multiple measures of CMV reactivation were associated with other clinically-relevant outcomes, even after adjustment for baseline factors (Table 1). The association of APACHE score with CMV reactivation measures was inconsistent and with small effect size. We did not identify other patient variables associated with subsequent CMV reactivation.

Conclusion

CMV reactivation in seropositive adults with sepsis is independently and quantitatively associated with clinically-important outcomes, including death or continued hospitalization by day 28, ventilator-, ICU-, and hospital-free days. These effect sizes provide key data to inform design parameters of future interventional trials.

Disclosures

All authors: No reported disclosures.

A prospective multicenter observational study of cell-mediated immunity as a predictor for cytomegalovirus infection in kidney transplant recipients

T cell immunity is essential for the control of cytomegalovirus (CMV) infection after transplantation. We evaluated a CMV-specific peptide-based enzyme-linked immunosorbent spot (ELISPOT) assay to determine whether assay results could predict subsequent CMV events. Adult kidney transplant recipients at 43 centers underwent ELISPOT testing to enumerate interferon gamma (IFN-γ) binding spot-forming units (sfu) after stimulation of cells with an overlapping peptide pool of CMV phosphoprotein 65 (pp65) and immediate early-1 (IE-1) protein at the end of antiviral prophylaxis (EOP) and various time points thereafter. The primary outcome was a CMV event in the first posttransplant year. In 583 kidney transplant recipients (260 seropositive donor [D+]/seronegative recipient [R-] and 277 R+), CMV events occurred in 44 of 368 eligible patients (11.8%) at a median of 227 days (range 92-360) posttransplant. A cutoff value of >40 sfu/2.5 × 10⁵  cells for either IE-1 or pp65 was derived as a threshold for positivity, with a negative predictive value of >97% for CMV events. CMV events were significantly lower in assay positive vs assay negative patients (3.0% vs 19.5%, P < .0001 for pp65). Time to CMV event post-EOP was significantly greater in those with sfu >40 at EOP (P < .0001). In this large, multicenter trial of kidney transplant recipients, we show that an assessment of CMV-specific immunity using a novel ELISPOT assay is able to predict protection from CMV infection.

Humoral response to natural influenza infection in solid organ transplant recipients

The humoral immune response of transplant recipients to influenza vaccination has been studied in detail. In contrast, the hemagglutinin inhibiting (HI) antibody response evoked by natural influenza infection and its impact on viral kinetics is unknown. In this prospective, multicenter, cohort study of natural influenza infection in transplant recipients, we measured HI antibody titers at presentation and 4 weeks later. Serial nasopharyngeal viral loads were determined using a quantitative influenza A polymerase chain reaction (PCR). We analyzed 196 transplant recipients with influenza infection. In the cohort of organ transplant patients with influenza A (n = 116), seropositivity rates for strain-specific antibodies were 44.0% (95% confidence interval [CI] 31.5-53.2%) at diagnosis and 64.7% (95% CI 55.4-72.9%) 4 weeks postinfection. Seroconversion was observed in 32.8% (95% CI 24.7-41.9%) of the cases. Lung transplant recipients were more likely to seroconvert (P = .002) and vaccine recipients were less likely to seroconvert (P = .024). A subset of patients (n = 30) who were unresponsive to prior vaccination were also unresponsive to natural infection. There was no correlation between viral kinetics and antibody response. This study provides novel data on the seroresponse to influenza infection in transplant patients and its relationship to a number of parameters including a prior vaccination status, virologic measures, and clinical variables.

Varicella zoster virus in solid organ transplantation: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the American Society of Transplantation Infectious Diseases Community of Practice review the diagnosis, prevention, and management of varicella zoster virus (VZV) in the pre- and post-transplant period. Primary varicella is an uncommon complication post-solid-organ transplant (SOT), except among pediatric transplant patients and those seronegative for VZV. As the majority of SOT recipients are seropositive for VZV, herpes zoster (HZ) occurs frequently following SOT, particularly among recipients who are older (≥65 years of age) and those receiving more intensive immunosuppression. Transplant providers should aware of the increased risk for HZ-related complications such as dissemination, organ-specific involvement, and post-herpetic neuralgia. Treatment for localized zoster is primarily given as oral regimens, but those with more complicated presentations or those at risk for dissemination should be treated initially with IV therapy. Available antiviral prophylaxis regimens and vaccination strategies for varicella and HZ among these immunosuppressed patients remain a mainstay for prevention in the pre-and post-transplant periods. Finally, we discuss important approaches to addressing post-exposure prophylaxis and infection control practices for those SOT patients with documented VZV infections.

Transplant tourism complicated by life-threatening New Delhi metallo-β-lactamase-1 infection

Transplant tourism, which is the practice of traveling to other countries for transplant, continues to be a major problem worldwide. We describe a patient who traveled to Pakistan and underwent commercial kidney transplant. He developed life-threatening infections from New Delhi metallo-β-lactamase-1-producing Enterobacter cloacae and Rhizopus oryzae, resulting in a necrotizing kidney allograft infection and subsequent external iliac artery rupture. He survived after a prolonged course of nonstandardized antimicrobial therapy, including a combination of aztreonam and ceftazidime-avibactam, and aggressive surgical debridement with allograft nephrectomy. The early timing of infection with these unusual organisms localized to the allograft suggests contamination and substandard care at the time of transplant. This case highlights the challenges of caring for these infections and serves as a cautionary tale for the potential complications of commercial transplant tourism.

Cytomegalovirus immunoglobulin G titers do not predict reactivation risk in immunocompetent hosts

Cytomegalovirus (CMV) reactivation occurs in roughly one-third of immunocompetent patients during critical illness, and is associated with worse outcomes. These outcomes have prompted consideration of early antiviral prophylaxis, but two-third of patients would receive unnecessary treatment. Tissue viral load has been associated with risk of reactivation in murine models, and recent work has suggested a relationship between immune responses to CMV and underlying viral load. We, therefore, sought to confirm the hypothesis that serum CMV-specific immunoglobulin G (IgG) correlates with tissue viral load, and might be used to predict the risk of reactivation during critical illness. We confirm that there is a good correlation between tissue viral load and serum CMV-specific IgG after laboratory infection of inbred mice. Further, we show that naturally infected outbred hosts have variable tissue viral DNA loads that do not correlate well with serum IgG. Perhaps as a consequence, CMV-specific IgG was not predictive of reactivation events in immunocompetent humans. When reactivation did occur, those with the lowest IgG levels had longer durations of reactivation, but IgG quartiles were not associated with differing peak DNAemia. Together our data suggest that CMV-specific IgG titers diverge from tissue viral loads in outbred immunocompetent hosts, and their importance for the control of reactivation events remains unclear.

LB21. Preemptive Therapy (PET) vs. Prophylaxis for Prevention of Cytomegalovirus (CMV) Disease in High-Risk Donor Seropositive/Recipient Seronegative (D+R−) Liver Transplant Recipients (LTR): A NIH-Sponsored, Randomized, Controlled, Multicenter Trial

Background

Current guidelines preferentially recommend valganciclovir (VGCV) prophylaxis over PET in most D+R− organ transplant populations, but adequately powered direct comparative clinical trials are lacking.

Methods

D+R− LTR were randomly assigned (1:1, stratified by site and T-cell depleting induction) to receive either PET (weekly plasma CMV DNAemia at central laboratory for 100 days, with VGCV 900 mg bid for DNAemia at any level, until two consecutive negative weekly tests) or prophy (VGCV 900 mg qd for 100 days). The primary outcome was CMV disease by 12 months as adjudicated by an independent, blinded, endpoint committee in ITT population. Secondary outcomes were opportunistic infections (OIs) (invasive fungal and bacterial), neutropenia (ANC < 1000/µL), acute rejection, graft loss, and mortality assessed at12 months.

Results

From October 2012 to June 2017, 205 patients were randomized at six centers; 100 to PET, 105 to prophy. The incidence of CMV disease was 9% (9/100) in PET and 19% (20/105) in prophy (P = 0.039) with majority of difference due to post-prophylaxis disease: 6% in PET vs. 17% in prophy (P = 0.027). CMV disease included syndrome in 55% (16/29) and end-organ in 45% (13/29), with similar proportions in two groups. Secondary outcomes were not different for PET and prophy groups: OIs (19% vs. 21%), neutropenia (34% vs.. 28%), acute rejection (27% vs. 27%), graft loss (2% vs. 2%), and mortality (10% vs. 6%), respectively, P > 0.05 for all comparisons. Mortality at last follow-up (median 3.2 years) was not different for PET vs. prophy (14% vs. 18%, P = 0.43).

Conclusions

PET significantly reduced the incidence of CMV disease compared with prophy in D+R- LTR, and was associated with similar other clinical outcomes. Current guidelines should be revised to recommend PET over prophylaxis in this setting, and similar trials conducted in other D+R− transplant populations. (Funded by NIAID; ClinicalTrials.gov# NCT01552369.)

Disclosures

D. Winston, Merck: Investigator, Research support. Chimerix: Investigator, Research support. Shire: Investigator, Research support. Gilead: Investigator, Research support. Oxford Immunotech: Investigator, Research support. G. M. Lyon III, Shire: Investigator, institutional research support. Hookipa: Investigator, institutional research support. Merck: Investigator, institutional research support. F. P. Silveira, Shire: contracted clinical research, site investigator. A. P. Limaye, Merk: Consultant and Investigator, Consulting fee and Research grant. Astellas Pharma Inc.: Consultant and Investigator, Consulting fee. Helocyte Inc.: Consultant, Consulting fee.

Are we underestimating the quality of aviremic hepatitis C-positive kidneys? Time to reconsider

Kidney Donor Risk Index (KDRI) introduced in 2009 included hepatitis C serologic but not viremic status of the donors. With nucleic acid amplification testing (NAT) now being mandatory, further evaluation of these donors is possible. We conducted a retrospective matched case-control analysis of adult deceased donor kidney transplants performed between December 5, 2014 to December 31, 2016 with the KDRI score and hepatitis C virus antibody (HCV Ab) and NAT testing status obtained from the United Network for Organ Sharing database. The 205 aviremic HCV Ab+ NAT - kidney transplants were compared to KDRI matched control kidneys that were HCV Ab-NAT-. The aviremic HCV kidneys were recovered from donors who were significantly younger, more likely to be white, and less likely to have hypertension and diabetes. The majority of the recipients of the aviremic HCV kidneys when compared to matched controls were HCV positive: 90.2% vs 4.3%. The recipients were significantly older, were on dialysis for a shorter time, and were transplanted sooner. The graft survival of aviremic HCV kidneys was similar (P < .08). If the HCV status of the aviremic kidneys was assumed to be negative, 122 more kidneys could have been allocated to patients with estimated posttransplant survival <20. Seven kidneys would no longer have Kidney Donor Profile Index >85%. Further policies might consider these findings to appropriately allocate these kidneys.

Donor-derived hepatitis C in the era of increasing intravenous drug use: A report of the Disease Transmission Advisory Committee

The opioid epidemic has resulted in a potential increase in donors in the testing window period for hepatitis C virus (HCV). We analyzed HCV reports to the Disease Transmission Advisory Committee (DTAC) between 2008 and 2016 to estimate the risk of HCV transmission. In 15 of 95 (16%) reports, at least one recipient developed proven/probable donor-derived HCV resulting in 32 infected recipients. Seven transmissions occurred during the nucleic acid testing (NAT) window period; four occurred during serological window period. The other four transmission occurred due to human error (3) and false-negative serology (1). All seronegative-exposed liver and lung recipients contracted HCV; 18/21 (86%) kidney and 3/4 (75%) heart recipients developed HCV. Four transmitting donors died of intravenous drug overdose, three in 2016 and one in 2012. Among donors with a history of intravenous drug use (IVDU), drug intoxication as a mechanism of death, or increased risk status, and negative screening HCV testing, the risk of transmission to a recipient was about 1 in 1000. The overall risk of transmitting HCV from NAT-negative donors with IVDU is low and consistent with modeling data. This information may be helpful to clinicians counseling potential recipients offered these organs.

Unintended Consequences in Use of Increased Risk Donor Kidneys in the New Kidney Allocation Era

BACKGROUND

The new kidney allocation system (KAS) intends to allocate the top 20% of kidneys to younger recipients with longer life expectancy. We hypothesized that the new KAS would lead to greater allocation of Public Health Service (PHS) increased-risk donor organs to younger recipients.

METHODS

Analyses of the Organ Procurement and Transplantation Network data of patients who underwent primary deceased kidney transplantation were performed in pre- and post-KAS periods.

RESULTS

The allocation of PHS increased-risk kidney allografts in various age groups changed significantly after implementation of the new KAS, with an increased proportion of younger individuals receiving increased-risk kidneys (7% vs 10% in age group 20-29 y and 13% vs 18% in age group 30-39 y before and after KAS, respectively; P < .0001). This trend was reversed in recipients 50-59 years old, with 31% in the pre-KAS period compared with 26% after KAS (P < .0001).

CONCLUSIONS

The new KAS resulted in a substantial increase in allocation of PHS increased-risk kidneys to candidates in younger age groups. Because increased-risk kidneys are generally underutilized, future efforts to optimize the utilization of these organs should target younger recipients and their providers.

Clinical characteristics and outcomes of late-onset BK virus nephropathy in kidney and kidney-pancreas transplant recipients

BACKGROUND

BK virus nephropathy (BKPyVAN) is a major complication in kidney transplant recipients (KTR) and typically occurs within 1 year of transplant. Guidelines vary in recommendations for BKPyV screening beyond 1 year. A systematic characterization of risk factors and outcomes of late-onset (>1 year) BKPyVAN has not previously been reported.

METHODS

We retrospectively compared characteristics and outcomes of early- (<1 year) and late-onset BKPyVAN (definitive [biopsy-confirmed] or presumptive [plasma BKPyV >10 000 copies/mL]) in a cohort of 671 KTR and simultaneous kidney-pancreas transplant (SPK) recipients between 2008 and 2013 at a single US transplant center. Proportions were compared using Chi-square or Fisher's exact test with P < .05 considered significant.

RESULTS

BKPyVAN was diagnosed in 96 (14.3%) patients (proven 16.7%, presumptive 83.3%): 79 (82.3%) early- and 17 (17.7%) late-onset. The proportion with late-onset BKPyVAN was significantly higher among SPK than KTR (4 of 7 [57.1%] vs 13 of 89 [14.6%], P = .017). Late-onset represented "de novo" infection (no BKPyV detection within the first year) in 14 (82.4%) and progression of earlier lower grade BKPyV reactivation in 3 (17.6%). Clinical outcomes were similar for early- and late-onset BKPyVAN (P > .05 all comparisons). In a pooled analysis of prior studies of BKPyVAN in SPK recipients, 62.9% (17 of 27) were late-onset.

CONCLUSION

A significant proportion of BKPyVAN is late-onset, especially among SPK recipients, and supports a longer duration of BKPyV monitoring for SPK recipients than recommended in some guidelines.

Willingness to Consider Increased-Risk Donors: A Single-Center Experience in Kidney Transplantation

Background

The number of Public Health Service increased-risk organ donors (PHS IRD) is growing, largely from an increase in intravenous drug use overdoses due to the current opioid epidemic.

Material/Methods

We conducted a retrospective case series review using our single-center data. We reviewed 82 PHS IRD kidney transplant offers between 2015 and 2017, 20 of which were declined. We reviewed outcomes of patients who declined vs. accepted PHS IRD offers. We studied the effect of education on these patients’ willingness to consider another PHS IRD.

Results

Twenty patients declined PHS IRD over a 2-year period. They waited on average 9 months for another transplant, and tended to be transplanted with a higher-KDPI kidney than the one originally offered. Patients who declined PHS IRD were more likely to be predialysis, women, and Asian American, and to require an interpreter. Ninety-two percent of patients who received education on PHS IRD after declining an offer stated that they would consider another PHS IRD offer in the future. Four of these patients received a PHS IRD transplant.

Conclusions

Our results suggest that education of patients may have a positive impact on patient attitudes toward PHS IRD.

Risk Factors and Outcomes of Ganciclovir-Resistant Cytomegalovirus Infection in Solid Organ Transplant Recipients

Background

Ganciclovir-resistant (ganR) cytomegalovirus (CMV) is an emerging and important problem in solid organ transplant (SOT) recipients. Only through direct comparison of ganR- and ganciclovir-sensitive (ganS) CMV infection can risk factors and outcomes attributable specifically to ganciclovir resistance appropriately be determined.

Methods

We performed a retrospective, case-control (1:3) study of SOT recipients with genotypically confirmed ganR-CMV (n = 37) and ganS-CMV infection (n = 109), matched by donor/recipient CMV serostatus, year and organ transplanted, and clinical manifestation. We used χ2 (categorical) and Mann-Whitney (continuous) tests to determine predisposing factors and morbidity attributable to resistance, and Kaplan-Meier plots to analyze survival differences.

Results

The rate of ganR-CMV was 1% (37/3467) overall and 4.1% (32/777) among CMV donor-positive, recipient-negative patients, and was stable over the study period. GanR-CMV was associated with increased prior exposure to ganciclovir (median, 153 vs 91 days, P < .001). Eighteen percent (3/17) of lung transplant recipients with ganR-CMV had received <6 weeks of prior ganciclovir (current guideline-recommended resistance testing threshold), and all non-lung recipients had received ≥90 days (median, 160 [range, 90-284 days]) prior to diagnosis of ganR-CMV. GanR-CMV was associated with higher mortality (11% vs 1%, P = .004), fewer days alive and nonhospitalized (73 vs 81, P = .039), and decreased renal function (42% vs 19%, P = .008) by 3 months after diagnosis.

Conclusions

GanR-CMV is associated with longer prior antiviral duration and higher attributable morbidity and mortality than ganS-CMV. Upcoming revised CMV guidelines should incorporate organ transplant-specific thresholds of prior drug exposure to guide rational ganR-CMV testing in SOT recipients. Improved strategies for prevention and treatment of ganR-CMV are warranted.

Expanding access to transplantation with hepatitis C-positive donors: A new perspective on an old issue

With the need for organs far exceeding supply, donors previously exposed to hepatitis B (HBV) and hepatitis C (HCV) viral infections should be considered for transplantation. Although many centers have protocols for transplanting organs from HBV core antibody-positive (HBcAb+) donors into select recipients, in the era of direct-acting antivirals (DAAs), a new focus should be placed on HCV-positive donors. The transmission rate from HCV antibody-positive (HCVAb+) nucleic acid testing negative (HCV NAT-) donors is expected to be very low, and we encourage use of such organs in HCV recipients provided a normal biopsy, appropriate counseling, and careful post-transplant monitoring. While transmission of HCV from HCV NAT+ donors is universal, the success of DAA in obtaining a sustained viral response in post-transplant recipients should make the use of these organs more appealing. We herein provide information to help guide the use of organs from HCV donors.

Is Kidney Donor Profile Index (KDPI) Valid for Hepatitis C Aviremic Kidneys?

The Kidney Donor Risk Index (KDRI) and Kidney Donor Profile Index (KDPI) assist clinicians with the selection of deceased donor kidneys. This scoring system is based on 10 donor factors including Hepatitis C virus (HCV) status from serological or NAT testing. The donor HCV status (i.e., having either a positive hepatitis C antibody (Ab) or nucleic acid testing (NAT) result) increases the hazard ratio for graft failure by 1.27 and the KDPI by approximately 20%. Whether this increase in KDPI is a true reflection of graft quality for HCV seropositive but not viremic donors is unknown. Further investigations are needed to maximize the use of these organs.

Utilization of Organs From Donors According to Hepatitis C Antibody and Nucleic Acid Testing Status: Time for Change

Previous studies have grouped all donors positive for hepatitis C virus (HCV) antibody (Ab). Only recently has donor HCV nucleic acid testing (NAT) become routine, and the impact of Ab and NAT status on organ utilization is unknown. Using the United Network for Organ Sharing database, we identified 9290 donors from 2015 to 2016 for whom both HCV Ab and NAT data were available and compared organ utilization by HCV status. Overall, 93.8% of donors were Ab negative and NAT negative (Ab-NAT-), 0.15% were Ab negative and NAT positive, 1.8% were Ab positive and NAT negative (Ab+NAT-), and 4.2% were both Ab and NAT positive (Ab+NAT+). Ab-NAT- donors donated at the highest rate for all organs except livers, of which Ab+NAT- donors donated at a higher rate (81.2% vs 73.2%, p = 0.03). Livers were discarded for reasons related to abnormal biopsies in Ab+NAT+ donors, whereas kidneys from Ab- or NAT-positive donors were discarded for reasons related to HCV status. Using a propensity score-matched model, we estimated that using Ab+NAT- donors at the same rate as Ab-NAT- donors could result in 48 more kidney donors, 37 more heart donors, and 15 more lung donors annually. We urge the use of HCV Ab+NAT- donors for appropriately selected and consenting recipients.

Effect of Ganciclovir on IL-6 Levels Among Cytomegalovirus-Seropositive Adults With Critical Illness: A Randomized Clinical Trial

IMPORTANCE

The role of cytomegalovirus (CMV) reactivation in mediating adverse clinical outcomes in nonimmunosuppressed adults with critical illness is unknown.

OBJECTIVE

To determine whether ganciclovir prophylaxis reduces plasma interleukin 6 (IL-6) levels in CMV-seropositive adults who are critically ill.

DESIGN, SETTING, AND PARTICIPANTS

Double-blind, placebo-controlled, randomized clinical trial (conducted March 10, 2011-April 29, 2016) with a follow-up of 180 days (November 10, 2016) that included 160 CMV-seropositive adults with either sepsis or trauma and respiratory failure at 14 university intensive care units (ICUs) across the United States.

INTERVENTIONS

Patients were randomized (1:1) to receive either intravenous ganciclovir (5 mg/kg twice daily for 5 days), followed by either intravenous ganciclovir or oral valganciclovir once daily until hospital discharge (n = 84) or to receive matching placebo (n = 76).

MAIN OUTCOMES AND MEASURES

The primary outcome was change in IL-6 level from day 1 to 14. Secondary outcomes were incidence of CMV reactivation in plasma, mechanical ventilation days, incidence of secondary bacteremia or fungemia, ICU length of stay, mortality, and ventilator-free days (VFDs) at 28 days.

RESULTS

Among 160 randomized patients (mean age, 57 years; women, 43%), 156 patients received 1or more dose(s) of study medication, and 132 patients (85%) completed the study. The mean change in plasma IL-6 levels between groups was -0.79 log10 units (-2.06 to 0.48) in the ganciclovir group and -0.79 log10 units (-2.14 to 0.56) in the placebo group (point estimate of difference, 0 [95% CI, -0.3 to 0.3]; P > .99). Among secondary outcomes, CMV reactivation in plasma was significantly lower in the ganciclovir group (12% [10 of 84 patients] vs 39% [28 of 72 patients]); absolute risk difference, -27 (95% CI, -40 to -14), P < .001. The ganciclovir group had more median VFDs in both the intention-to-treat (ITT) group and in the prespecified sepsis subgroup (ITT group: 23 days in ganciclovir group vs 20 days in the placebo group, P = .05; sepsis subgroup, 23 days in the ganciclovir group vs 20 days in the placebo group, P = .03). There were no significant differences between the ganciclovir and placebo groups in duration of mechanical ventilation (5 days for the ganciclovir group vs 6 days for the placebo group, P = .16), incidence of secondary bacteremia or fungemia (15% for the ganciclovir group vs 15% for the placebo group, P = .67), ICU length of stay (8 days for the ganciclovir group vs 8 days for the placebo group, P = .76), or mortality (12% for the ganciclovir group vs 15% for the placebo group, P = .54).

CONCLUSIONS AND RELEVANCE

Among CMV-seropositive adults with critical illness due to sepsis or trauma, ganciclovir did not reduce IL-6 levels and the current study does not support routine clinical use of ganciclovir as a prophylactic agent in patients with sepsis. Additional research is necessary to determine the clinical efficacy and safety of CMV suppression in this setting.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01335932.

Changing landscape of hepatitis C virus-positive donors

With the introduction of the new highly effective antiviral therapies, there has been a dramatic increase in the use of the hepatitis C virus (HCV)-positive livers in HCV-positive recipients. In the majority of studies, HCV positivity was defined as a donor testing HCV Ab positive. In 2015, all Organ Procurement Organizations were mandated to perform and report HCV Nucleic Acid Amplification Testing (NAT) results on all deceased and living donors. Studies are not yet available on how organs are being utilized based on NAT status and whether NAT status affects recipient outcomes. Further studies are needed to maximize the use of these organs.

Variability in assessing for BK viremia: whole blood is not reliable and plasma is not above reproach - a retrospective analysis

Polyomavirus nephropathy (PVN) is a major complication of kidney transplantation. Most reports describe polyomavirus viremia either precedes or is detectable at the time of diagnosis of PVN. This association is the basis of current screening recommendations. We retrospectively reviewed the PCR results of blood and urine samples from 29 kidney transplant recipients with biopsy-proven PVN. Biopsies were performed for a rise in serum creatinine or persistent high-level BK viruria. All biopsies showed polyoma virus large T-antigen expression in tubular epithelium using immunohistochemistry. All had viruria preceding or at the time of biopsy (range, 5.2 × 10⁴ to >25 × 10⁶ BKV DNA copies/ml). Twenty (69%) had viremia ranging from 2.5 × 10³ to 4.3 × 10⁶ copies/ml at the time of the biopsy. Via blood BK PCR assay, nine (31%) had no BK viremia detected either preceding or at the time of the biopsy. In five recipients where sufficient specimen permitted, additional plasma BK assessment revealed positive detection of viremia. A comparative analysis of assays from two centres was performed with spiked samples. BK DNA may not be detected in the blood of some kidney transplant recipients with histologically confirmed PVN. This may reflect limitation of whole blood as opposed to plasma-based BK DNA assessment.

Quantification of BK Virus Standards by Quantitative Real-Time PCR and Droplet Digital PCR Is Confounded by Multiple Virus Populations in the WHO BKV International Standard

BACKGROUND

The WHO recently released a BK virus (BKV) international standard. This study evaluated the WHO international standard and commercially available BKV standards by quantitative real-time PCR (qPCR) and droplet digital PCR (ddPCR).

METHODS

WHO, Exact Diagnostics, Acrometrix, and Zeptometrix BKV standards were tested by qPCR and ddPCR. Two preparations of NIST BKV clones were also tested. Nucleic acid was extracted with the Roche MP96 and MPLC, followed by quantification in duplicate. To resolve discrepancies, we sequenced the WHO and NIST materials.

RESULTS

Manufacturers' expected copies/mL were close to WHO IU/mL: linear regression of qPCR data revealed 1.12 Exact copies/IU, 0.76 Acrometrix copies/IU, and 0.70 Zeptometrix copies/IU. For ddPCR, similar concentrations were measured when either the VP1 region or the T region was targeted, and concentrations were almost 2-fold higher when both regions were targeted simultaneously. ddPCR results for the VP1 and T regions were similar for all commercial standards, but targeting the T region of the WHO standard led to a 4-fold lower result than the VP1 region. Next-generation sequencing revealed no primer or probe mismatches. However, large differences in coverage across the WHO standard and junctional reads were observed, indicating subpopulations of the WHO standard with deletions in the T region.

CONCLUSIONS

BKV standards showed concordance among providers, but the WHO standard contains subpopulations of viruses with various deletions in the T region. PCR results will vary depending on which region of the WHO standard is targeted.

The Pandemic H30 Subclone of Escherichia coli Sequence Type 131 Is Associated With Persistent Infections and Adverse Outcomes Independent From Its Multidrug Resistance and Associations With Compromised Hosts

BACKGROUND

The H30 subclone within Escherichia coli sequence type 131 (ST131-H30) has emerged rapidly to become the leading antibiotic-resistant E. coli strain. Hypervirulence, multidrug resistance, and opportunism have been proposed as explanations for its epidemic success.

METHODS

We assessed 1133 consecutive unique E. coli clinical isolates from 5 medical centers (2010-2011) for H30 genotype, which we compared with epidemiological and clinical data extracted from medical records by blinded reviewers. Using univariable and multivariable logistic regression analysis, we explored associations of H30 with underlying host characteristics, clinical presentations, management, and outcomes, adjusting for host characteristics.

RESULTS

The H30 (n = 107) isolates were associated with hosts who were older, male, locally and systemically compromised, and healthcare and antibiotic exposed. With multivariable adjustment for host factors, H30 lost its numerous significant univariable associations with initial clinical presentation, but remained strongly associated with clinical persistence (odds ratio [OR], 3.47; 95% confidence interval [CI], 1.89-6.37), microbiological persistence (OR, 4.46; 95% CI, 2.38-8.38), subsequent hospital admission (OR, 2.68; 95% CI, 1.35-5.33), and subsequent new infection (OR, 1.73; 95% CI, 1.01-3.00). These host-adjusted associations remained strong even with added adjustment for resistance to the initially prescribed antibiotics, and the adverse outcome associations (subsequent hospital admission, new infection) were independent of clinical and microbiological persistence.

CONCLUSIONS

In addition to targeting compromised hosts and resisting multiple antibiotics, H30 isolates may have an intrinsic ability to cause highly persistent infections and later adverse outcomes. The basis for these host- and resistance-independent associations is unclear, but they should be considered when managing patients with H30 infections.

Infection control strategies that successfully controlled an outbreak of Mycobacterium abscessus at a cystic fibrosis center

BACKGROUND

Mycobacterium abscessus infection in patients with cystic fibrosis (CF) can result in accelerated clinical decline and the potential for direct or indirect transmission between patients has been recently demonstrated. Data on the outcomes of M abscessus outbreaks and the efficacy of specific infection control procedures in patients with CF remain limited. This study provides follow-up from an outbreak of pulmonary M abscessus in our center, highlighting outcomes and strategies that appear to have prevented further spread of the organism.

METHODS

Data from our adult CF center (1989-2015) were analyzed, including chart reviews of all patients with positive mycobacterial sputum cultures, cultures from environment surfaces, and epidemiologic evaluation of infected patients. Following an M abscessus outbreak in 2009, infection control policies were intensified based on CF guidelines and surveillance data were collected and reviewed.

RESULTS

Five cases of M abscessus were involved in the outbreak; 3 patients died during follow-up. An environment search failed to reveal an intermediary source of transmission between patients. After implementation of infection control measures composed of staff/patient education, environment sterilization, and patient isolation, no new cases were detected.

CONCLUSIONS

Direct or indirect patient-to-patient transmission of M abscessus is a threat in the CF population. A multifaceted infection control strategy based on CF guidelines was effective in halting transmission in our center.

Symptomatic Respiratory Virus Infection and Chronic Lung Allograft Dysfunction

Background. Chronic lung allograft dysfunction (CLAD) is a major cause of allograft loss post-lung transplantation. Prior studies have examined the association between respiratory virus infection (RVI) and CLAD were limited by older diagnostic techniques, study design, and case numbers. We examined the association between symptomatic RVI and CLAD using modern diagnostic techniques in a large contemporary cohort of lung transplant recipients (LTRs).

Methods. We retrospectively assessed clinical variables including acute rejection, cytomegalovirus pneumonia, upper and lower RVI, and the primary endpoint of CLAD (determined by 2 independent reviewers) in 250 LTRs in a single university transplantation program. Univariate and multivariate Cox models were used to analyze the relationship between RVI and CLAD in a time-dependent manner, incorporating different periods of risk following RVI diagnosis.

Results. Fifty patients (20%) were diagnosed with CLAD at a median of 95 weeks post-transplantation, and 79 (32%) had 114 episodes of RVI. In multivariate analysis, rejection and RVI were independently associated with CLAD (adjusted hazard ratio [95% confidence interval]) 2.2 (1.2–3.9), P = .01 and 1.9 (1.1–3.5), P = .03, respectively. The association of RVI with CLAD was stronger the more proximate the RVI episode: 4.8 (1.9–11.6), P < .01; 3.4 (1.5–7.5), P < .01; and 2.4 (1.2–5.0), P = .02 in multivariate analysis for 3, 6, and 12 months following RVI, respectively.

Conclusions. Symptomatic RVI is independently associated with development of CLAD, with increased risk at shorter time periods following RVI. Prospective studies to characterize the virologic determinants of CLAD and define the underlying mechanisms are warranted.