Hepatitis B Virus Reactivation in Non-Liver Solid Organ Transplantation: Incidence and Risk Analysis.

INTRODUCTION: Hepatitis B virus reactivation (HBVr) can occur in solid organ transplant (SOT) recipients with previously inactive hepatitis B virus (HBV) infection. Previous studies have reported that HBVr is generally less than 10% in nonliver SOT recipients with past HBV infection. METHODS: We conducted a retrospective study from January 2018 to August 2023 at Mayo Clinic sites in Arizona, Florida, and Minnesota. We examined the antiviral prophylaxis strategy used and the characteristics of HBVr in hepatitis B core antibody-positive (HBcAb +) nonliver SOT adult recipients. Past HBV infection was defined as HBcAb + / hepatitis B surface antigen (HBsAg) -. Chronic HBV infection was defined as HBcAb + / HBsAg +. RESULTS: A total of 180 nonliver SOT recipients were identified during the study period. Indefinite antiviral prophylaxis was utilized in 77 recipients, and none developed HBVr after transplantation. In 103 recipients without antiviral prophylaxis, the incidence of HBVr was 12% (12/97) and 33% (2/6) in those with past HBV infection and chronic HBV infection. The incidence of HBVr in patients with past HBV infection is 16% (8/50), 15% (3/20), and 5% (1/22) in kidney, heart, and lungs, respectively. HBVr was more frequent in those who received alemtuzumab. Among 14 recipients with HBVr, none had HBV-associated liver failure or death. CONCLUSIONS: Our study observed a higher rate of HBVr (12%) in nonliver SOT recipients with past HBV infection compared to the previous studies. Further studies are needed to identify predictors of HBVr in nonliver SOT recipients and optimize antiviral prophylaxis guidance.

Risk factors and outcomes of Pneumocystis pneumonia in solid organ transplant recipients: Impact of posttransplant lymphoproliferative disorder.

BACKGROUND: Pneumocystis jirovecii pneumonia (PJP) is a potentially fatal infection afflicting the immunocompromised population, including solid organ transplant (SOT) recipients. Several risk factors have been described; however, little is known regarding the risk of PJP in SOT recipients with posttransplant lymphoproliferative disorder (PTLD). METHODS: We performed a nested case-control study of SOT recipients diagnosed with PJP from 2000 to 2020. PJP was defined as positive microscopy or polymerase chain reaction testing with compatible symptoms and radiographic findings. Control patients were matched 2:1 by year of first transplant, first transplanted organ, transplant center, and sex. Multivariable conditional logistic regression was performed to test associations with PJP and Cox regression analyzed post-PJP outcomes. RESULTS: Sixty-seven PJP cases were matched to 134 controls. The most common transplant was kidney (55.2%). Fourteen patients had a history of PTLD, 12 of whom developed PJP. After adjusting for age, acute rejection, cytomegalovirus infection, PJP prophylaxis, and lymphopenia (lymphocyte count < .5 × 109 /L), PTLD was independently associated with PJP (OR 14.0, 95% CI 1.7-114.5; p = .014). Lymphopenia was also a significant association (OR 8.2, 95% CI 3.2-20.7; p < .001). PJP was associated with mortality within 90 days of diagnosis (p < .001), but not after 90 days (p = .317). PJP was also associated with 90-day death-censored renal allograft loss (p = .026). CONCLUSIONS: PTLD is independently associated with PJP after adjustment for recognized risk factors. This is likely influenced by PTLD-directed chemotherapy, particularly rituximab-containing regimens. PJP is associated with early mortality, but this effect is not persistent after 90 days. PJP prophylaxis should be considered in SOT recipients with PTLD.

Synovitis due to Histoplasma capsulatum: a case series and literature review.

Musculoskeletal manifestations of Histoplasma capsulatum infection are uncommon but can mimic inflammatory arthritis. Early diagnosis of this complication is of critical importance in the era of potent immunosuppression for rheumatologic diseases. We conducted a retrospective chart review for patients with histoplasmosis and tenosynovitis, synovitis, or arthritis, diagnosed and treated at our institution between January 1, 2000, and December 31, 2019. We also reviewed the relevant literature. Four patients with biopsy-proven, culture-proven histoplasma tenosynovitis were identified at our institution. All four patients had wrist or hand involvement in an asymmetric pattern, and one patient had lower extremity involvement as well. Two patients were not immunocompromised at baseline. One patient underwent a lengthy evaluation and received immunosuppression for 4 years without improvement prior to the diagnosis of histoplasmosis. Histoplasma serologic tests varied among patients with localized infection. Pathologic findings revealed non-caseating granulomatous inflammation. Three patients recovered after 6-12 months of antifungal treatment. One patient still had recurrent infection despite 20 months of treatment. Histoplasma tenosynovitis and synovitis are rare causes of inflammatory arthritis. Infectious causes should be considered and carefully evaluated when patients present with asymmetric oligoarthritis. Early recognition is crucial for successful treatment, especially in patients with concomitant rheumatologic diseases receiving immunosuppressive treatment.

Outcomes of bebtelovimab and sotrovimab treatment of solid organ transplant recipients with mild-to-moderate coronavirus disease 2019 during the Omicron epoch.

BACKGROUND: Solid organ transplant recipients (SOTRs) are at high-risk for severe infection from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Anti-spike monoclonal antibodies are currently utilized under emergency use authorization to prevent hospitalization in high-risk individuals with coronavirus disease 2019 (COVID-19), including SOTRs. However, clinical data for bebtelovimab, the sole currently available anti-spike monoclonal antibody for COVID-19, is limited. METHODS: We conducted a retrospective cohort study of adult SOTRs diagnosed with mild-to-moderate COVID-19 from January 2022 through May 2022 who received either bebtelovimab or sotrovimab. The primary outcome was COVID-19-related hospitalization within 30 days of COVID-19 diagnosis. Data were analyzed with Fisher's exact test. RESULTS: Among 361 SOTRs, 92 (25.5%) received bebtelovimab and 269 (74.5%) received sotrovimab. The most common organ transplant was a kidney (42.4%). SOTRs who received bebtelovimab had a higher proportion who had received a booster SARS-CoV-2 vaccine dose and had received their last vaccination dose more recently. Eleven (3.0%) SOTRs were hospitalized, and rates of hospitalization were similar between monoclonal antibody groups (3.3% versus 3.0%; p > .99). Three patients required admission to an intensive care unit, all of who received sotrovimab. Four (1.1%) patients died within 30 days of COVID-19 diagnosis, two from each group. CONCLUSIONS: SOTRs with mild-to-moderate COVID-19 who received bebtelovimab had similar rates of COVID-19-related hospitalization as those who received sotrovimab. While differences in vaccination rates and viral subvariants could act as confounders, bebtelovimab appears to be of similar effectiveness as sotrovimab.

Epidemiology, risk factors, and association of antifungal prophylaxis on early invasive fungal infection in heart transplant recipients.

BACKGROUND: Invasive fungal infection (IFI) in heart transplant recipients is associated with poor outcomes. Estimated risk of 1-year IFI in heart transplant recipients is 3.4-8.6% with risk factors inconsistently identified in previous studies. The role of antifungal prophylaxis is unclear. The transplant program at Mayo Clinic provides 6 months of universal azole prophylaxis for those heart transplant recipients in Arizona. We sought to define risk factors for 1-year IFI and determine the effect of antifungal prophylaxis. METHODS: We conducted a retrospective cohort study of patients undergoing heart transplantation at Mayo Clinic from January 2000 to March 2019. We analyzed demographics, details of transplant hospitalization, antifungal prophylaxis, and fungal infection. Multivariable Cox analyses were performed to identify risk factors of 1-year IFI and impact of IFI on posttransplant mortality. RESULTS: A total of 966 heart transplant recipients were identified with a median age of 56 years (IQR 47, 62). A total of 444 patients received antifungal prophylaxis. Over 1-year follow-up, 62 patients developed IFI with a cumulative incidence of 6.4%. In multivariable analysis, factors associated with IFI were renal replacement therapy (RRT) (HR 3.24, 95% CI 1.65-6.39), allograft rejection (HR 2.33, 95% CI 1.25-4.34), and antifungal prophylaxis (HR 0.32, 95% CI 0.11-0.96). RRT was also associated with invasive mold infection (HR 3.00, 95% CI 1.29-6.97). CONCLUSIONS: RRT and allograft rejection after transplantation are associated with 1-year IFI, and RRT is also associated with invasive mold infection. Antifungal prophylaxis appears to be protective and further study is needed in the heart transplant population.

Establishing best practices in measles, mumps, and rubella serologic screening for kidney transplant candidates.

Optimizing immunity against vaccine-preventable diseases improves outcomes in kidney transplant (KT) patients (Arora et al, World J Transplant, 2019, 9:1; Sester et al, Transplant Rev, 2008, 22:274; Fishman, N Engl J Med, 2007, 357:2601). The American Society for Transplantation (AST) Clinical Practice Guidelines advises that serologic screening for measles, mumps, and rubella (MMR) be conducted for all KT candidates, since live-attenuated vaccines are contraindicated post-transplantation (Malinis et al, Clin Transplant, 2019, 33:e13548). Our team at Mayo Clinic Florida (MCF) conducted a quality improvement (QI) initiative to establish a best MMR screening and immunizations clinical practice in KT candidates using a Plan-Do-Study-Act (PDSA) model. By retrospective chart review of all KT candidates evaluated at our institution from January 1, 2016 to December 31, 2017, baseline data determining the rate of MMR serologic screening was established. PDSA cycles were implemented to adopt protocol-driven testing for MMR serologies, immunization documentation, and vaccination in cases of seronegativity to any of the three MMR viruses in all pre-KT candidates. Two PDSA cycles were completed in 4 months. The study population totaled 447 patients (baseline n = 283, PDSA 1 n = 61, PDSA 2 n = 103). Baseline data showed that 83% (n = 235) of pre-KT candidates received infectious disease consultation (IDC). Complete MMR (all three viruses) serological screening in KT candidates improved from baseline 3.9%-87.4% post-PDSA cycle 2 (P < .001). Necessary immunizations per AST guidelines were ordered in only 41.1% (n = 23) of the control cohort vs 100% (n = 12) and 96.9% (n = 31) of PDSA cycles 1 and 2, respectively (P < .001). The data reflect significant practice improvements in MMR screening and immunization rates among KT candidates by using protocol-driven orders combined with our pre-existing IDCs.

Serologic screening and infectious disease consultation (IDC): Indicated in heart, lung, liver (HLL) solid organ transplants (SOT) for measles, mumps, rubella, and varicella.

BACKGROUND: Solid organ transplant (SOT) recipients are a special group of patients who require comprehensive evaluation for preventable infectious diseases before transplantation. The main aim of our study was to investigate the number of heart, lung, and liver (HLL) transplant recipients who were evaluated for their immune status against measles, mumps, rubella (MMR), and varicella (VZV). As a secondary aim, we investigated whether pre-transplant infectious disease consultation (IDC) improves vaccination rates. METHODS: This study was an institution-based retrospective analysis of HLL transplant recipients born in or after 1957 and evaluated at Mayo Clinic, FL Transplant Center between January 1st, 2016 and December 31st, 2017. Data collection was obtained from electronic medical records. The vaccination rates were compared by univariate analysis based on IDC and no ID consultation (NIDC). RESULTS: One hundred and eighty-seven (77%) of a total 242 patients received an IDC pre-transplantation. Varicella IgG levels were screened in all 187 IDC candidates. Among the 187 IDC patients, mumps, measles, and rubella IgG serologies were performed in 9 (5%), 21 (11%), and 51 (27%), respectively. Among all 242 patients, vaccines given included 2 (0.8%) MMR, 10 (4.1%) varicella and 85 (35.12%) Zostavax. Univariate analysis revealed that Zostavax was given to 76 (40.6%) pre-transplant IDC patients and only in 9 (16.7%) NIDC patients (P < .001). CONCLUSIONS: Despite the relatively high IDC rate, patients' screened numbers for MMR IgG levels were low. Results pointed out the need for MMR protocol-driven serologic screening as well as for VZV and IDC prior to transplantation to increase vaccination rates.

Editorial: The Risky Business of Fungal Infections in Patients with Cirrhosis.

Hospitalized patients with cirrhosis have a high rate of mortality. In the report by Bajaj et al., the negative impact of fungal infections (FI) on outcomes in a large US cohort of hospitalized cirrhotics is highlighted. Risk factors for FI are identified. Increasing awareness of FI along with the application of new diagnostic tools in species identification will provide the opportunity to improve patient outcomes.

The epidemiology and outcomes of invasive Candida infections among organ transplant recipients in the United States: results of the Transplant-Associated Infection Surveillance Network (TRANSNET).

BACKGROUND: Invasive candidiasis (IC) is a common cause of mortality in solid organ transplant recipients (OTRs), but knowledge of epidemiology in this population is limited. METHOD: The present analysis describes data from 15 US centers that prospectively identified IC from nearly 17 000 OTRs. Analyses were undertaken to determine predictors of infection and mortality. RESULTS: A total of 639 cases of IC were identified. The most common species was Candida albicans (46.3%), followed by Candida glabrata (24.4%) and Candida parapsilosis (8.1%). In 68 cases >1 species was identified. The most common infection site was bloodstream (44%), followed by intra-abdominal (14%). The most frequently affected allograft groups were liver (41.1%) and kidney (35.3%). All-cause mortality at 90 days was 26.5% for all species and was highest for Candida tropicalis (44%) and C. parapsilosis (35.2%). Non-white race and female gender were more commonly associated with non-albicans species. A high rate of breakthrough IC was seen in patients receiving antifungal prophylaxis (39%). Factors associated with mortality include organ dysfunction, lung transplant, and treatment with a polyene antifungal. The only modifiable factor identified was choice of antifungal drug class based upon infecting Candida species. CONCLUSION: These data highlight the common and distinct features of IC in OTRs.

First report of Nocardia beijingensis infection in an immunocompetent host in the United States.

Here we describe the first reported case of Nocardia beijingensis infection in the United States, made rarer by its presence in an immunocompetent patient.

Stability in the cumulative incidence, severity and mortality of 101 cases of invasive mucormycosis in high-risk patients from 1995 to 2011: a comparison of eras immediately before and after the availability of voriconazole and echinocandin-amphotericin combination therapies.

As invasive mucormycosis (IM) numbers rise, clinicians suspect prior voriconazole worsens IM incidence and severity, and believe combination anti-fungal therapy improves IM survival. To compare the cumulative incidence (CI), severity and mortality of IM in eras immediately before and after the commercial availability of voriconazole all IM cases from 1995 to 2011 were analysed across four risk-groups (hematologic/oncologic malignancy (H/O), stem cell transplantation (SCT), solid organ transplantation (SOT) and other), and two eras, E1 (1995-2003) and E2, (2004-2011). Of 101 IM cases, (79 proven, 22 probable): 30 were in E1 (3.3/year) and 71 in E2 (8.9/year). Between eras, the proportion with H/O or SCT rose from 47% to 73%, while 'other' dropped from 33% to 11% (P = 0.036). Between eras, the CI of IM did not significantly increase in SCT (P = 0.27) or SOT (P = 0.30), and patterns of anatomic location (P = 0.122) and surgical debridement (P = 0.200) were similar. Significantly more patients received amphotericin-echinocandin combination therapy in E2 (31% vs. 5%, P = 0.01); however, 90-day survival did not improve (54% vs. 59%, P = 0.67). Since 2003, the rise of IM reflects increasing numbers at risk, not prior use of voriconazole. Frequent combination of anti-fungal therapy has not improved survival.

The Cascade of Care in Management of Solid Organ Transplant Candidates With Latent Tuberculosis Infection.

Background: Solid organ transplant (SOT) candidates should be screened and treated for latent tuberculosis infection (LTBI) to prevent tuberculosis (TB) reactivation after transplantation. We aimed to assess the steps from positive QuantiFERON (QFT) through LTBI treatment (cascade of care) in the SOT population. Methods: We conducted a retrospective study of SOT recipients older than 18 y with a positive QFT during pretransplant evaluation at the Mayo Clinic from January 2010 to June 2023. We analyzed each cascade step to determine associated drop-out factors for LTBI management. Results: Of 629 patients who had positive QFT results, 587 (93%) were evaluated by an infectious disease (ID) specialist, 478 (76%) were recommended to start LTBI treatment, 473 (75%) initiated LTBI treatment, and 457 (73%) completed LTBI treatment. LTBI treatment was not recommended in 109 patients evaluated by infectious disease, most of whom had previously received either LTBI (n = 72) or TB (n = 14) treatment. LTBI treatment was initiated before or after transplantation for 45% and 55% of patients, respectively. Isoniazid monotherapy was the most common regimen (92%), and adverse events were rare (7%). Seven patients developed active TB infection posttransplantation under various circumstances (3 without LTBI treatment, 1 during LTBI treatment, and 3 after completing LTBI treatment). Conclusions: Our findings demonstrate the variability of LTBI management in SOT recipients with positive QFT. When recommended, most patients completed LTBI treatment successfully. Nonetheless, active TB was noted regardless of whether patients received LTBI treatment. This study highlights the importance of optimizing LTBI management in this population.

Disseminated Monkeypox Infection in a Kidney Transplant Recipient: A Case Report.

Monkeypox is a rapidly spreading infection worldwide and is a public health concern, especially with newly reported fatality cases. The characteristics and disease course of monkeypox infection in transplant recipients remain elusive because no case reports have been published detailing its clinical presentation and outcome in this population. We report a case of a kidney transplant recipient who developed end-stage renal disease secondary to HIV-associated nephropathy and manifested monkeypox infection after kidney transplantation. The patient had severe clinical manifestations, including disseminated vesicular skin rash, diffuse mucosal involvement, urine retention, proctitis, and bowel obstruction. We also highlight several clinical considerations regarding the use of tecovirimat, a novel antiviral therapy with activity against orthopoxviruses that has been used in the United States to treat monkeypox infection.

Disseminated mycobacterial infections after tumor necrosis factor inhibitor use, revealing inborn errors of immunity.

Tumor necrosis factor-a inhibitors can be associated with increased risk of infections, particularly reactivation of latent tuberculosis or nontuberculous mycobacterium (NTM). However, because disseminated NTM is rare, inborn errors of immunity should be considered. We present three patients with disseminated NTM after tumor necrosis factor-a inhibitor use who were found to have inborn errors of immunity.

Outcomes of B-Cell-Depleted Patients With Coronavirus Disease 2019 Treated With Antispike Monoclonal Antibodies.

Antispike monoclonal antibody treatment of 180 B-cell-depleted patients with mild-to-moderate coronavirus disease 2019 (COVID-19) resulted in good outcomes overall, with only 12.2% progressing to severe disease, 9.4% requiring hospitalization, 0.6% requiring mechanical ventilation, no deaths within 30 days, and 1.8% developing persistent COVID-19. Antispike monoclonal antibodies appear effective in this immunocompromised population.

Invasive non-Aspergillus mold infections in transplant recipients, United States, 2001-2006.

Recent reports describe increasing incidence of non-Aspergillus mold infections in hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients. To investigate the epidemiology of infections with Mucorales, Fusarium spp., and Scedosporium spp. molds, we analyzed data from the Transplant-Associated Infection Surveillance Network, 23 transplant centers that conducted prospective surveillance for invasive fungal infections during 2001-2006. We identified 169 infections (105 Mucorales, 37 Fusarium spp., and 27 Scedosporium spp.) in 169 patients; 124 (73.4%) were in HCT recipients, and 45 (26.6%) were in SOT recipients. The crude 90-day mortality rate was 56.6%. The 12-month mucormycosis cumulative incidence was 0.29% for HCT and 0.07% for SOT. Mucormycosis incidence among HCT recipients varied widely, from 0.08% to 0.69%, with higher incidence in cohorts receiving transplants during 2003 and 2004. Non-Aspergillus mold infections continue to be associated with high mortality rates. The incidence of mucormycosis in HCT recipients increased substantially during the surveillance period.

Comparison of in vitro susceptibility characteristics of Candida species from cases of invasive candidiasis in solid organ and stem cell transplant recipients: Transplant-Associated Infections Surveillance Network (TRANSNET), 2001 to 2006.

Invasive fungal infections (IFI) are a major cause of morbidity and mortality among both solid organ transplant (SOT) and hematopoietic stem cell transplant (HSCT) recipients. Candida is the most common cause of IFI in SOT recipients and the second most common cause of IFI in HSCT recipients. We determined susceptibilities to fluconazole, voriconazole, itraconazole, posaconazole, amphotericin B, and caspofungin for 383 invasive Candida sp. isolates from SOT and HSCT recipients enrolled in the Transplant-Associated Infection Surveillance Network and correlated these results to clinical data. Fluconazole resistance in C. albicans, C. tropicalis, and C. parapsilosis isolates was low (1%), but the high percentage of C. glabrata and C. krusei isolates within this group of patients increased the overall percentage of fluconazole resistance to 16%. Voriconazole resistance was 3% overall but was 8% among C. glabrata isolates. On multivariable analysis, among HSCT recipients fluconazole nonsusceptibility was independently associated with C. glabrata, non-Hodgkin's lymphoma, cytomegalovirus (CMV) antigenemia, diabetes active at the time of the IFI, and any prior amphotericin B use; among SOT recipients, fluconazole nonsusceptibility was independently associated with any fluconazole use in the 3 months prior to the IFI, C. glabrata, ganciclovir use in the 3 months prior to the IFI, diabetes acquired since the transplant, and gender.

Disseminated cryptococcosis in a patient with newly diagnosed HTLV-1 infection.

Infection by human T-lymphotropic virus 1 (HTLV-1) is often seen as the cause of chronic infection or lymphoproliferative disorders, but many clinicians do not recognise its association with severe immunosuppression. We report the case of a woman in her 70s from the Caribbean who sought care at the emergency department for weakness, fatigue and weight loss. Further work-up showed atypical lymphocytosis with floral lymphocytes and smudge cells in the peripheral blood smear and hypercalcaemia. Chest CT demonstrated a moderate right pleural effusion. Results of HIV testing were negative, and screening and confirmatory tests for HTLV-1 were positive. Empiric antibiotic therapy was administered, and the patient was discharged home. Five days later, she was readmitted with shortness of breath and severe abdominal pain. A disseminated infection with Cryptococcus neoformans was diagnosed. Despite aggressive intravenous antifungal therapy, the patient died on day 7 of hospitalisation.

Serologic screening and infectious diseases consultation in renal transplant candidates for measles, mumps, rubella and varicella.

Background. Renal transplant recipients are at increased risk for developing complications of vaccine-preventable diseases. They benefit from a comprehensive pre-transplant evaluation when they might safely receive live vaccines. The primary aim of our study was to investigate the number of renal transplant recipients who were evaluated for serologic status against measles, mumps, rubella (MMR), and varicella. Secondarily, we investigated if pre-transplant Infectious Diseases consultation (IDC) improved vaccination rates.Methods. We retrospectively analyzed 282 kidney-alone and kidney-plus adult transplant recipients who were born in or after 1957. Patients were evaluated at Mayo Clinic, Florida Transplant Center between January 2015 and December 2017. Serologic status evaluation and vaccination rates were compared in two groups created based on IDC and no ID consultation (NIDC).Results. 235 (83%) of a total 282 patients received an IDC pre-transplantation. Varicella IgG levels were screened in all 235 IDC candidates. Among the IDC patients, mumps, measles and rubella IgG serologies were performed in 7 (3%), 143 (61%) and 144 (61%), respectively. Among 44 patients seronegative for any of MMR, 24 (55%) were vaccinated. Ten (66%) of 15 varicella seronegative patients were vaccinated. Zostavax was not given to 18% of IDC patients. Zostavax and MMR were administered more frequently in the IDC group compared to NIDC (p < .001 and p = 0.0016, respectively).Conclusion. Although the majority of patients had IDC, the screening rate for MMR serologies was lower than varicella. A protocol-driven serologic screening similar to the one for VZV is required for MMR. Pre-transplant IDC increases vaccination rates.

Monoclonal Antibody Therapy for COVID-19 in Solid Organ Transplant Recipients.

BACKGROUND: Bamlanivimab and casirivimab-imdevimab are authorized for emergency use treatment of mild to moderate coronavirus disease 2019 (COVID-19) in patients at high risk for developing severe disease or hospitalization. Their safety and efficacy have not been specifically evaluated in solid organ transplant recipients. METHODS: We retrospectively reviewed solid organ transplant recipients who received monoclonal antibody infusion for COVID-19 at Mayo Clinic sites through January 23, 2021. Outcomes included emergency department visit, hospitalization, mortality, and allograft rejection. RESULTS: Seventy-three patients were treated, most commonly with bamlanivimab (75.3%). The median age was 59 years, 63% were male, and the median Charlson comorbidity index was 5. Transplant type included 41 kidney (56.2%), 13 liver (17.8%), 11 heart (15.1%), 4 kidney-pancreas (5.5%), 2 lung (2.7%), 1 heart-liver, and 1 pancreas. Eleven (15.1%) patients had an emergency department visit within 28 days of infusion, including 9 (12.3%) who were hospitalized for a median of 4 days. One patient required intensive care unit admission for a nonrespiratory complication. No patients required mechanical ventilation, died, or experienced rejection. Ten adverse events occurred, with 1 seeking medical evaluation. Hypertension was associated with hospital admission (P < .05), while other baseline characteristics were similar. The median time from symptom onset to antibody administration was 4 days in nonhospitalized patients compared with 6 days among hospitalized patients (P < .05). CONCLUSIONS: Monoclonal antibody treatment has favorable outcomes with minimal adverse effects in solid organ transplant recipients with mild to moderate COVID-19. Earlier administration of monoclonal antibody therapy appears to be more efficacious.