A Retrospective, Observational Study of 12 Cases of Expanded-Access Customized Phage Therapy: Production, Characteristics, and Clinical Outcomes.

BACKGROUND: Antimicrobial resistance (AMR) is undermining modern medicine, a problem compounded by bacterial adaptation to antibiotic pressures. Phages are viruses that infect bacteria. Their diversity and evolvability offer the prospect of their use as a therapeutic solution. Reported are outcomes of customized phage therapy for patients with difficult-to-treat antimicrobial resistant infections. METHODS: We retrospectively assessed 12 cases of customized phage therapy from a phage production center. Phages were screened, purified, sequenced, characterized, and Food and Drug Administration-approved via the IND (investigational new drug) compassionate-care route. Outcomes were assessed as favorable or unfavorable by microbiologic and clinical standards. Infections were device-related or systemic. Other experiences such as time to treatment, antibiotic synergy, and immune responses were recorded. RESULTS: Fifty requests for phage therapy were received. Customized phages were generated for 12 patients. After treatment, 42% (5/12) of cases showed bacterial eradication and 58% (7/12) showed clinical improvement, with two-thirds of all cases (66%) showing favorable responses. No major adverse reactions were observed. Antibiotic-phage synergy in vitro was observed in most cases. Immunological neutralization of phages was reported in 5 cases. Several cases were complicated by secondary infections. Complete characterization of the phages (morphology, genomics, and activity) and their production (methods, sterility, and endotoxin tests) are reported. CONCLUSIONS: Customized phage production and therapy was safe and yielded favorable clinical or microbiological outcomes in two-thirds of cases. A center or pipeline dedicated to tailoring the phages against a patient's specific AMR bacterial infection may be a viable option where standard treatment has failed.

Successful restoration of protective immunity against measles, mumps, and rubella following MMR vaccination in adult hematopoietic cell transplant recipients.

BACKGROUND: The optimal number of doses as well as the role for measurement of postvaccination titers after measles, mumps, rubella (MMR) vaccination in adult hematopoietic cell transplantation (HCT) recipients remains unknown. METHODS: In the present study, we assessed humoral immunity against measles, mumps and rubella before and after MMR vaccination in 187 adults who received at least one dose of the MMR vaccine after HCT. RESULTS: Among those with baseline titers, posttransplant prevaccination seroprotection rates were 56%, 30%, and 54% for measles, mumps, and rubella, respectively; and significantly lower in allogeneic versus autologous HCT recipients for measles (39% vs. 80%, p = .0001), mumps (22% vs. 41%; p = .02) and rubella (48% vs. 62%, p = .12). Among those who were seronegative at baseline, seroconversion rates after one dose of MMR were 69%, 56%, and 97% for measles, mumps, and rubella, respectively. Seronegative patients after one dose of MMR (i.e., nonresponders) seroconverted for measles and mumps after a second MMR vaccine dose. CONCLUSION: Our findings demonstrate successful restoration of protective immunity against measles, mumps, and rubella after vaccination in adult HCT recipients; one dose of MMR elicited protective titers in the majority of patients, and a second vaccine dose was immunogenic in nonresponders.

Early administration of SARS-CoV-2 monoclonal antibody reduces the risk of mortality in hematologic malignancy and hematopoietic cell transplant patients with COVID-19.

BACKGROUND: Data on severe acute respiratory distress syndrome coronavirus 2 monoclonal antibody (SARS-CoV-2-specific mAb) use in hematologic malignancy and hematopoietic cell transplantation (HM/HCT) patients are limited. Here, we describe our experience with the use of casirivimab-imdevimab or bamlanivimab for the treatment of coronavirus disease 2019 (COVID-19) in HM/HCT patients. METHODS: This was a retrospective chart review at the University of Miami Hospital and Sylvester Comprehensive Cancer Center for HM/HCT patients with COVID-19 who received casirivimab-imdevimab or bamlanivimab from November 21, 2020, to September 30, 2021. Outcomes measured were mortality, hospital admission, and infusion reaction to SARS-CoV-2-specific mAbs. RESULTS: We identified 59 HM/HCT patients with mild to moderate COVID-19 who received casirivimab-imdevimab or bamlanivimab. Median age was 57 years (interquartile range [IQR]: 45-65). Among the 59 patients, 25 (42%) received cellular therapy: 14 (24%) had undergone allogeneic HCT, nine (15%) autologous HCT, and two (3%) received chimeric antigen receptor T-cell therapy. The median time from COVID-19 symptom onset to SARS-CoV-2-specific mAb administration was 4 (IQR: 3-6) days. Forty-six (78%) patients received SARS-CoV-2-specific mAbs as outpatients and 13 (22%) patients received SARS-CoV-2-specific mAbs during hospitalization. Among patients who received SARS-CoV-2-specific mAbs as outpatients, only four (9%) visited the emergency department at days 10, 11, 15, and 35 after SARS-CoV-2-specific mAb administration. None of these four patients required hospital admission. Among the hospitalized patients, five (38%) were admitted to the hospital with neutropenic fever, four (31%) were already hospitalized for transplantation and cellular therapy, three (23%) were admitted for monitoring of COVID-19 symptoms, and one (8%) was admitted with acute kidney injury. Three hospitalized patients (23%) died at 14, 35, and 59 days after SARS-CoV-2-specific mAb administration; two of these three deaths were attributed to COVID-19 infection. One patient developed an immediate infusion reaction to bamlanivimab, and no infusion reactions were reported to casirivimab-imdevimab use. CONCLUSION: During the alpha and delta variant surges, early administration of bamlanivimab or casirivimab-imdevimab prevented hospitalization and death when given in the outpatient setting. Among patients who received mAbs at or after hospital admission, the risk of COVID-19 disease progression and death remains significant. Larger studies of the use of mAb therapy to treat COVID-19 in this population are needed.

Breakthrough invasive fungal infections on isavuconazole prophylaxis in hematologic malignancy & hematopoietic stem cell transplant patients.

BACKGROUND: Isavuconazole (ISA) is a newer antifungal used in patients with history of hematologic malignancies and hematopoietic transplant and cellular therapies (HM/TCT). Although it has a more favorable side-effect profile, breakthrough invasive fungal infections (bIFIs) while on ISA have been reported. METHODS: In this single-center retrospective study evaluating HM/TCT patients who received prophylactic ISA for ≥7 days, we evaluated the incidence and potential risk factors for bIFIs. RESULTS: We evaluated 106 patients who received prophylactic ISA. The patients were predominantly male (60.4%) with median age of 65 (range: 21-91) years. Acute myeloid leukemia (48/106, 45.3%) was the most common HM, with majority having relapsed and/or refractory disease (43/106, 40.6%) or receiving ongoing therapy (38/106, 35.8%). Nineteen patients (17.9%) developed bIFIs-nine proven [Fusarium (3), Candida (2), Mucorales plus Aspergillus (2), Mucorales (1), Colletotrichum (1)], four probable invasive pulmonary Aspergillus, and six possible infections. Twelve patients were neutropenic for a median of 28 (8-253) days prior to bIFI diagnosis. ISA levels checked within 7 days of bIFI diagnosis (median: 3.65 µg/mL) were comparable to industry-sponsored clinical trials. All-cause mortality among the bIFI cases was 47.4% (9/19).We also noted clinically significant cytomegalovirus co-infection in 5.3% (1/19). On univariate analysis, there were no significant differences in baseline comorbidities and potential risk factors between the two groups. CONCLUSION: ISA prophylaxis was associated with a significant cumulative incidence of bIFIs. Despite the appealing side-effect and drug-interaction profile of ISA, clinicians must be vigilant about the potential risk for bIFIs.

National Landscape of Human Immunodeficiency Virus-Positive Deceased Organ Donors in the United States.

BACKGROUND: Organ transplantation from donors with human immunodeficiency virus (HIV) to recipients with HIV (HIV D+/R+) presents risks of donor-derived infections. Understanding clinical, immunologic, and virologic characteristics of HIV-positive donors is critical for safety. METHODS: We performed a prospective study of donors with HIV-positive and HIV false-positive (FP) test results within the HIV Organ Policy Equity (HOPE) Act in Action studies of HIV D+/R+ transplantation (ClinicalTrials.gov NCT02602262, NCT03500315, and NCT03734393). We compared clinical characteristics in HIV-positive versus FP donors. We measured CD4 T cells, HIV viral load (VL), drug resistance mutations (DRMs), coreceptor tropism, and serum antiretroviral therapy (ART) detection, using mass spectrometry in HIV-positive donors. RESULTS: Between March 2016 and March 2020, 92 donors (58 HIV positive, 34 FP), representing 98.9% of all US HOPE donors during this period, donated 177 organs (131 kidneys and 46 livers). Each year the number of donors increased. The prevalence of hepatitis B (16% vs 0%), syphilis (16% vs 0%), and cytomegalovirus (CMV; 91% vs 58%) was higher in HIV-positive versus FP donors; the prevalences of hepatitis C viremia were similar (2% vs 6%). Most HIV-positive donors (71%) had a known HIV diagnosis, of whom 90% were prescribed ART and 68% had a VL <400 copies/mL. The median CD4 T-cell count (interquartile range) was 194/µL (77-331/µL), and the median CD4 T-cell percentage was 27.0% (16.8%-36.1%). Major HIV DRMs were detected in 42%, including nonnucleoside reverse-transcriptase inhibitors (33%), integrase strand transfer inhibitors (4%), and multiclass (13%). Serum ART was detected in 46% and matched ART by history. CONCLUSION: The use of HIV-positive donor organs is increasing. HIV DRMs are common, yet resistance that would compromise integrase strand transfer inhibitor-based regimens is rare, which is reassuring regarding safety.

Successful Treatment of Disseminated Disease Due to Highly Resistant Aspergillus calidoustus with a Novel Antifungal Therapy.

Invasive aspergillosis is the most common invasive mold infection following a hematopoietic cell transplant. Widespread use of antifungal prophylaxis has led to the increasing incidence of cryptic Aspergillus species. Aspergillus calidoustus is one of those emerging species and is notorious for multidrug resistance to antifungals. Here, we report a case of disseminated A. calidoustus infection in a hematopoietic stem cell transplant recipient who was successfully treated with combination therapy that included a novel antifungal.

Viral kinetics and outcomes of adenovirus viremia following allogeneic hematopoietic cell transplantation.

BACKGROUND: Adenovirus (AdV) is a serious infection following hematopoietic cell transplantation (HCT). Little is known about AdV viral kinetics and optimal threshold for initiation of pre-emptive therapy. METHODS: Single-center retrospective study of 16 consecutive adult HCT recipients with detectable AdV identified over a 5-year period. RESULTS: Median time to AdV reactivation after HCT was 176 days (IQR 86-408). Nine patients received cidofovir, although 14/16 had no tissue-invasive disease. Among treated patients, median duration of viremia was shorter when initiating treatment at viral loads < 10,000 copies/ml (28 vs. 52 days). All-cause mortality in this cohort was 44%. All six patients (five of which were untreated) with peak viral loads < 10,000 copies/ml survived; whereas only 30% (3/10) of patients with peak viral loads greater than this threshold survived, despite most (n = 8; 80%) of them receiving cidofovir (P = .01). Three-month survival following diagnosis of AdV viremia was significantly lower with peak viremia > 10,000 copies/ml (100 vs. 17%; P = .005). CONCLUSION: AdV is associated with high all-cause mortality, especially for viremia > 10,000 copies/ml. Delaying therapy until viremia reaches AdV levels ≥10,000 copies/ml was associated with more protracted infection and poor outcomes. Larger studies are needed.

Kidney transplantation during coronavirus 2019 pandemic at a large hospital in Miami.

BACKGROUND: Coronavirus 2019 (COVID-19) pandemic has resulted in more than 350 000 deaths worldwide. The number of kidney transplants has declined during the pandemic. We describe our deceased donor kidney transplantation (DDKT) experience during the pandemic. METHODS: A retrospective study was conducted to evaluate the safety of DDKT during the COVID-19 pandemic. Multiple preventive measures were implemented. Adult patients that underwent DDKT from 3/1/20 to 4/30/20 were included. COVID-19 clinical manifestations from donors and recipients, and post-transplant outcomes (COVID-19 infections, readmissions, allograft rejection, and mortality) were obtained. The kidney transplant (KT) recipients were followed until 5/31/20. RESULTS: Seventy-six patients received kidneys from 57 donors. Fever, dyspnea, and cough were reported in 1, 2, and 1 donor, respectively. Thirty-eight (66.6%) donors were tested for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2) prior to donation (mainly by nasopharyngeal or bronchoalveolar lavage polymerase chain reaction [PCR]) and 36 (47.3%) KT recipients were tested at the time of DDKT by nasopharyngeal PCR; all of these were negative. Our recipients were followed for a median of 63 (range: 33-91) days. A total of 42 (55.3%) recipients were tested post-transplant for SARS-CoV2 by nasopharyngeal PCR including 12 patients that became symptomatic; all tests were negative except for one that was inconclusive, but it was repeated and came back negative. Forty (52.6%) KT recipients were readmitted, and 7 (9.2%) had biopsy-proven rejection during the follow-up. None of the KT recipients transplanted during this period died. CONCLUSIONS: Our cohort demonstrated that DDKT can be safely performed during the COVID-19 pandemic when preventive measures are implemented.

Antimicrobial resistance and recurrent bacterial urinary tract infections in hospitalized patients following kidney transplantation: A single-center experience.

PURPOSE: The burden of urinary tract infections (UTIs) and risk factors for developing infections with multidrug resistant organisms (MDROs) post-kidney transplantation (KT) are poorly understood. METHODS: Single-center retrospective cohort study (January 2015-December 2017) evaluating first and recurrent episodes of bacteriuria and subsequent analysis of episodes caused by MDROs up to 6 months post-KT. Donor and recipient variables were reviewed. RESULTS: A total of 743 adults underwent single KT during the study period, and 106 patients were hospitalized with bacteriuria. 45% were asymptomatic in their first episode. 73.6% had a single episode, and 26.4% had 2 or more episodes. A total of 28 patients had recurrent episodes; 64.3% had an MDRO on the first episode and 78.6% on the second episode. Escherichia coli was the most common organism isolated, 88.5% were resistant to trimethoprim-sulfamethoxazole (TMP-SMX), 9.3% were extended-spectrum beta-lactamase (ESBL) producers, and 38.1% were MDROs. Body mass index ≥30 was significantly associated with the presence of MDROs in both univariate and multivariate analyses (RR 1.37, 95% CI 1.01-1.88; OR 3.26, CI 1.29-8.25). A total of 12 donors had bacteremia or bacteriuria and 6 (50%) with E coli. A total of 10 KT recipients received antibiotic prophylaxis to prevent donor-derived infections. CONCLUSIONS: Our results suggest that a significant proportion of patients develop recurrent bacteriuria post-transplantation; of those, more than half caused by MDROs. There is a possible association between obesity and MDROs in KT recipients that merits further investigation. With the global crisis in antimicrobial resistance, innovative strategies are needed to prevent and treat UTIs in KT patients.

Successful Treatment of Invasive Fungal Infection Due to Highly Resistant Aspergillus calidoustus in an Allogeneic Hematopoietic Cell Transplant Recipient.

Invasive aspergillosis (IA) is the most common invasive fungal infection following a hematopoietic cell transplant, with emerging cryptic species exhibiting resistance to commonly used antifungals such as azoles. These species have been increasingly found after the introduction of anti-mold prophylaxis. We report a case of a 56-year-old female with primary myelofibrosis whose allogeneic hematopoietic cell transplant was complicated by disseminated fungal infection (skin, lung) due to Aspergillus calidoustus, a cryptic specie. Treatment of Aspergillus species remains challenging as these cryptic species are usually resistant to azoles including voriconazole which is the first line of treatment of IA. Infection was successfully treated with surgical excision and combination antifungal therapy based on in vitro susceptibility and synergy testing. Therapy included isavuconazole, a drug that has been shown to be non-inferior to voriconazole in the treatment of invasive mold infections.

A Randomized, Placebo-controlled Trial of Fidaxomicin for Prophylaxis of Clostridium difficile-associated Diarrhea in Adults Undergoing Hematopoietic Stem Cell Transplantation.

Background: Clostridium difficile-associated diarrhea (CDAD) is common during hematopoietic stem-cell transplantation (HSCT) and is associated with increased morbidity and mortality. We evaluated fidaxomicin for prevention of CDAD in HSCT patients. Methods: In this double-blind study, subjects undergoing HSCT with fluoroquinolone prophylaxis stratified by transplant type (autologous/allogeneic) were randomized to once-daily oral fidaxomicin (200 mg) or a matching placebo. Dosing began within 2 days of starting conditioning or fluoroquinolone prophylaxis and continued until 7 days after neutrophil engraftment or completion of fluoroquinolone prophylaxis/clinically-indicated antimicrobials for up to 40 days. The primary endpoint was CDAD incidence through 30 days after study medication. The primary endpoint analysis counted confirmed CDAD, receipt of CDAD-effective medications (for any indication), and missing CDAD assessment (for any reason, including death) as failures; this composite analysis is referred to as "prophylaxis failure" to distinguish from the pre-specified sensitivity analysis, which counted only confirmed CDAD (by toxin immunoassay or nucleic acid amplification test) as failure. Results: Of 611 subjects enrolled, 600 were treated and analyzed. Prophylaxis failure was similar in fidaxomicin and placebo recipients (28.6% vs 30.8%; difference 2.2% [-5.1, 9.5], P = .278). However, most failures were due to non-CDAD events. Confirmed CDAD was lower in fidaxomicin vs placebo recipients (4.3% vs 10.7%; difference 6.4% [2.2, 10.6], P = .0014). Drug-related adverse events occurred in 15.0% of fidaxomicin recipients and 20.0% of placebo recipients. Conclusions: While no difference was demonstrated between arms in the primary analysis, results of the sensitivity analysis demonstrated that fidaxomicin significantly reduced the incidence of CDAD in HSCT recipients. Clinical Trials Registration: NCT01691248.

How Clean Is the Linen at My Hospital? The Mucorales on Unclean Linen Discovery Study of Large United States Transplant and Cancer Centers.

Mucormycosis outbreaks have been linked to contaminated linen. We performed fungal cultures on freshly-laundered linens at 15 transplant and cancer hospitals. At 33% of hospitals, the linens were visibly unclean. At 20%, Mucorales were recovered from >10% of linens. Studies are needed to understand the clinical significance of our findings.

Tissue and blood protozoa including toxoplasmosis, Chagas disease, leishmaniasis, Babesia, Acanthamoeba, Balamuthia, and Naegleria in solid organ transplant recipients- Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of tissue and blood protozoal infections in the pre- and post-transplant period. Significant new developments in the field have made it necessary to divide the previous single guideline published in 2013 into two sections, with the intestinal parasites separated from this guideline devoted to tissue and blood protozoa. The current update reflects the increased focus on donor screening and risk-based recipient monitoring for parasitic infections. Increased donor testing has led to new recommendations for recipient management of Toxoplasma gondii and Trypanosoma cruzi. Molecular diagnostics have impacted the field, with access to rapid diagnostic testing for malaria and polymerase chain reaction testing for Leishmania. Changes in Babesia treatment regimens in the immunocompromised host are outlined. The risk of donor transmission of free-living amebae infection is reviewed. Changing immigration patterns and the expansion of transplant medicine in developing countries has contributed to the recognition of parasitic infections as an important threat to transplant outcomes. Medications such as benznidazole and miltefosine are now available to US prescribers as access to treatment of tissue and blood protozoa is increasingly prioritized.

Intestinal parasites including Cryptosporidium, Cyclospora, Giardia, and Microsporidia, Entamoeba histolytica, Strongyloides, Schistosomiasis, and Echinococcus: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice.

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of intestinal parasites in the pre- and post-transplant period. Intestinal parasites are prevalent in the developing regions of the world. With increasing travel to and from endemic regions, changing immigration patterns, and the expansion of transplant medicine in developing countries, they are increasingly recognized as a source of morbidity and mortality in solid-organ transplant recipients. Parasitic infections may be acquired from the donor allograft, from reactivation, or from de novo acquisition post-transplantation. Gastrointestinal multiplex assays have been developed; some of the panels include testing for Cryptosporidium, Cyclospora, Entamoeba histolytica, and Giardia, and the performance is comparable to conventional methods. A polymerase chain reaction test, not yet widely available, has also been developed to detect Strongyloides in stool samples. New recommendations have been developed to minimize the risk of Strongyloides donor-derived events. Deceased donors with epidemiological risk factors should be screened for Strongyloides and recipients treated if positive as soon as the results are available. New therapeutic agents and studies addressing the optimal treatment regimen for solid-organ transplant recipients are unmet needs.

Implementation of a Strongyloides screening strategy in solid organ transplant donors and recipients.

BACKGROUND: Strongyloides stercoralis infects 100 million people worldwide. Mortality rates in hyperinfection syndrome exceed 50%. Donor-derived Strongyloides infection has occurred after heart, kidney, kidney-pancreas and liver transplantation; yet, only 10% of the US organ procurement organizations currently screen donors for strongyloidiasis. METHODS: We report a fatal case of donor-derived disseminated Strongyloides infection in a liver transplant recipient. Following this case, we implemented universal screening and treatment of donors and recipients. We reviewed our local epidemiology and outcomes after protocol implementation. RESULTS: From a total of 355 deceased donors accepted at our center between January 2016, and March 2018, 14 (3.9%) had positive Strongyloides serology. Except for the index case, all other recipients of Strongyloides antibody-positive donors within that period (including 10 kidneys, 3 livers, one combined liver/kidney, and one kidney/pancreas from eight seropositive donors) received post-transplant prophylaxis with ivermectin, and to date are alive and doing well without signs of infection. Between October 2015, and September 2016, a total of 441 deceased donor solid organ transplants were performed at our center. 220 of these recipients had pretransplant Strongyloides serology available, and 23 of them were seropositive (10.5%). Within the first two years after the implementation of universal screening and treatment of donors and recipients, we had no cases of Strongyloides reactivation in our center. CONCLUSIONS: Implementation of a Strongyloides screening and treatment protocol in our center was an effective strategy to prevent both recipient- and donor-derived strongyloidiasis. Transplant centers should consider implementation of Strongyloides preventive strategies.

Clinical outcomes in HIV+/HCV+ coinfected kidney transplant recipients in the pre- and post-direct-acting antiviral therapy eras: 10-Year single center experience.

BACKGROUND: Previous studies have demonstrated inferior patient and graft survival following kidney transplant (KT) in HIV+/HCV+ coinfected patients compared to HIV+/HCV- recipients. However, these studies were conducted prior to the availability of direct-acting antiviral (DAA) agents and data in the modern era are lacking. METHODS: Single center retrospective study of HIV+/HCV+ coinfected KT recipients (2007-2017). Outcomes were assessed for the pre-DAA and post-DAA (ie, after December 2013) eras including 1-year patient survival, death-censored graft survival, and acute rejection; and serious infections (defined as infections requiring admission to the intensive care unit during initial transplant hospitalization or re-admission to the hospital after discharge) within the first 6 months post-transplant. RESULTS: A total of 13 consecutive HIV+/HCV+ recipients were identified. Median time of post-transplant follow-up was 722 days. Seven patients were transplanted in the DAA era; five of them had anti-HCV Ab+ donors, with two donors being HCV NAT positive; all received DAA therapy, six of them post-transplant (median time from KT to DAA: 83 days; IQR, 54-300). All the patients in the pre-DAA era were on a protease inhibitor-containing ART regimen. One-year patient and death-censored graft survivals were 83% and 67%, respectively, for the patients transplanted in the pre-DAA era, and 100% for both outcomes in the subgroup of patients transplanted in the post-DAA era (P > 0.05). Compared to patients in the post-DAA era, those in the pre-DAA era had higher incidence of serious infections (0 vs 67%; P = 0.02). Acute rejection exclusively occurred in the pre-DAA group (n = 1; 17%). CONCLUSIONS: Outcomes of HIV+/HCV+ KT recipients, including HIV-/HCV+ to HIV+/HCV+ transplants, in the DAA era were excellent in this small cohort. Larger studies are needed.

Use of maintenance therapy and incidence of recurrent Cytomegalovirus DNAemia among allogeneic hematopoietic cell transplant recipients.

BACKGROUND: Cytomegalovirus (CMV) infection is the most common infection following hematopoietic cell transplantation (HCT). Preemptive antiviral therapy is highly effective at halting viral replication and preventing CMV disease; however, recurrence rates after clearance of CMV DNAemia are high (50-70%). Current treatment guidelines recommend maintenance therapy after initial clearance. Yet, the effectiveness of this intervention to prevent recurrence is not well defined. OBJECTIVES: We aimed to assess the impact of maintenance therapy on the probability of recurrent CMV in allogeneic HCT recipients with early CMV reactivation. STUDY DESIGN: Sixty-six patients with an initial episode of early CMV reactivation who achieved viral clearance in response to preemptive therapy were included. We compared the incidence of recurrent CMV DNAemia in patients who received maintenance therapy vs those who underwent early discontinuation of antiviral therapy. RESULTS: Recurrence occurred in 47/64 (73%) patients, including 11/14 (79%) patients without maintenance therapy and 36/50 (72%) of patients who received maintenance therapy (P = 0.74). The propensity score adjusted risk ratio for the effect of maintenance therapy on recurrence was 0.89 (95% CI 0.64-1.25; P = 0.41). In a time to event analysis using the unweighted cohort, the 90-day probability of CMV recurrence was similar between patient groups independent of maintenance therapy administration (54% vs 64% for maintenance vs non-maintenance groups, respectively; log-rank P = 0.37). CONCLUSION: These data suggest that maintenance antiviral therapy does not reduce the incidence of CMV recurrence while off therapy and is of limited value in HCT recipients who have successfully eradicated CMV DNAemia in response to preemptive therapy. Larger studies in this area are needed.

Bloodstream infection caused by enteric organisms during the first 6 months after intestinal transplant.

BACKGROUND: Data on bloodstream infection (BSI) due to enteric organisms are scarce. METHODS: This retrospective study (1/2009-5/2017) was aimed to evaluate the incidence of BSI episodes due to enteric organisms during the first 6 months after intestinal transplant (ITx). Differences between the first (2009-2012) and second period (2013-2017) were evaluated as they differed from each other in the perioperative fungal prophylaxis and immunosuppressive regimen. RESULTS: Fifty-five adult patients were analyzed. Twenty-eight (51%) patients developed a total of 51 episodes of BSI. Mean time from transplant to BSI was 85.5 ± 58.8 days. The most common organisms were Klebsiella pneumoniae (33%), Enterococcus spp (31%), and Candida spp (18%). Twenty-three (45%) were multidrug resistant. The most common sources were gut translocation (35%), central line infection (20%), and intra-abdominal abscess (14%). Biopsy-proven rejection was associated with 16 (31%) of the BSI episodes. Patients during the first period were more likely to develop BSI (79% vs 41%, P = 0.03). There were more episodes of rejection associated with BSI in the first period (45% vs 14%, P = 0.03). The rate of reoperation into the abdominal cavity within 2 weeks after ITx was higher and the transplant hospital stay was longer among those who developed BSI (P = 0.04 for both). CONCLUSIONS: Half of our patients developed BSI (typically during the first 3 months). Gut translocation was the most common source of BSI. Patients with rejection and/or enteritis should be monitored closely for BSI.

Nontuberculous mycobacteria in solid organ transplant.

PURPOSE OF REVIEW: Nontuberculous mycobacteria (NTM) are emerging pathogens of concern especially in solid organ transplant candidates and recipients. This review aims to address diagnostic challenges, new and emerging treatment options, and infection prevention. RECENT FINDINGS: The incidence of NTM infections in transplant candidates and recipients is rising. The infection prevalence of these environmental pathogens varies geographically by species with a coastal predominance. Although existing guidelines from the American Thoracic Society, Infectious Diseases Society of America, and British Thoracic Society provide recommendations for diagnosis and management, they do not fully address the subtle nuances and challenges faced in managing infections in immunocompromised transplant recipients. Evolving data on new therapeutic agents and their use in combination therapy will help individualize treatment regimens while limiting adverse effects and improving compliance. Use of combination ß-lactams, avibactam, tedizolid, clofazimine, bedaquiline, liposomal amikacin, and ciprofloxacin for commonly isolated species such as Mycobacterium abscessus and Mycobacterium avium complex have proven effective. SUMMARY: Further studies are needed to determine the incidence of NTM infection in a prospective, multicentric manner and evaluate the most promising synergistic treatment combinations in transplant recipients.

Impact of Cytomegalovirus Viral Load on Probability of Spontaneous Clearance and Response to Preemptive Therapy in Allogeneic Stem Cell Transplantation Recipients.

The optimal viral load threshold at which to initiate preemptive cytomegalovirus (CMV) therapy in hematopoietic cell transplantation (HCT) recipients remains to be defined. In an effort to address this question, we conducted a retrospective study of 174 allogeneic HCT recipients who underwent transplantation at a single center between August 2012 and April 2016. During this period, preemptive therapy was initiated at the discretion of the treating clinician. A total of 109 patients (63%) developed CMV viremia. The median time to reactivation was 17 days (interquartile range, IQR, 7-30 days) post-HCT. A peak viremia ≥150 IU/mL was strongly associated with a reduced probability of spontaneous clearance (relative risk, .16; 95% confidence interval, .1-.27), independent of established clinical risk factors, including CMV donor serostatus, exposure to antithymocyte globulin, and underlying lymphoid malignancy. The median time to clearance of viremia was significantly shorter in those who started therapy at CMV <350 IU/mL (19 days; IQR, 11-35 days) compared with those who started antiviral therapy at higher viremia thresholds (33 days; IQR, 21-42 days; P = .02). The occurrence of treatment-associated cytopenias was frequent but similar in patients who started preemptive therapy at CMV <350 IU/mL and those who started at CMV >350 IU/mL (44% versus 57%; P = .42). Unresolved CMV viremia by treatment day 35 was associated with increased risk of therapeutic failure (32% versus 0%; P = .001). Achieving eradication of CMV viremia by treatment day 35 was associated with a 74% reduction in 1-year nonrelapse mortality (NRM) (adjusted hazard ratio [HR], .26; 95% confidence interval [CI], .1-.8; P = .02), whereas therapeutic failure was associated with a significant increase in the probability of 1-year NRM (adjusted HR, 26; 95% CI, 8-87; P <.0001). We conclude that among allogeneic HCT patients, a peak CMV viremia ≥150 IU/mL is associated with a >80% reduction in the probability of spontaneous clearance independent of ATG administration, CMV donor serostatus, and lymphoid malignancy, and is a reasonable cutoff for preemptive therapy. Delaying initiation of therapy until a CMV value ≥350 IU/mL is associated with more protracted CMV viremia, and unresolved viremia by treatment day 35 is associated with a significant increase in NRM.