A single-center review of pre-exposure prophylaxis with tixagevimab-cilgavimab in solid organ transplant recipients.

BACKGROUND: Coronavirus disease 2019 (COVID-19) continues to negatively impact solid organ transplant recipients (SOTr). Data on the use of tixagevimab-cilgavimab (tix-cil) in vaccinated SOTr during circulation of Omicron and its subvariants are limited. Therefore, this single-center review was conducted to evaluate tix-cil efficacy in multiple organ transplant groups during a study period where Omicron B.1.1.529, BA.2.12.1, and BA.5 predominated. METHODS: In this single-center retrospective study, we evaluated the incidence of COVID-19 infection in adult SOTr who did or did not receive pre-exposure prophylaxis (PrEP) with tix-cil. SOTr were included if they were at least 18 years of age and met emergency use authorization criteria for tix-cil use. The primary outcome analyzed was the incidence of COVID-19 infection. RESULTS: Ninety SOTr met inclusion criteria and comprised of two groups, tix-cil PrEP (n = 45) and no tix-cil PrEP (n = 45). Of SOTr who received tix-cil PrEP, three (6.7%) developed COVID-19 infection, compared to eight (17.8%) in the no tix-cil PrEP group (p = .20). Of the 11 SOTr diagnosed with COVID-19, 15 (82.2%) were fully vaccinated against COVID-19 prior to transplantation. Moreover, 18.2% and 81.8% of the COVID-19 cases observed were asymptomatic and mild-to-moderate, respectively. DISCUSSION: Our study results, which included months when BA.5 was in increased circulation, suggest no significant difference in COVID-19 infection with or without use of tix-cil PrEP in our solid organ transplant groups. As the COVID-19 pandemic continues to evolve, clinical utility of tix-cil should be evaluated against new, emerging strains.

A multicenter evaluation of hepatitis B reactivation with and without antiviral prophylaxis after kidney transplantation.

BACKGROUND: Hepatitis B virus (HBV) reactivation in hepatitis B surface antigen (HBsAg)-negative and hepatitis B core antibody (anti-HBc)-positive kidney transplant recipients ranges between 1.4% and 9.6%. Limited evidence is available regarding routine antiviral prophylaxis and identifiable risk factors for HBV reactivation in this population. METHODS: In this multicenter retrospective study, we evaluated the prevalence of HBV reactivation in HBsAg-negative anti-HBc-positive kidney transplant recipients who did or did not receive antiviral prophylaxis. The primary outcome assessed the prevalence of HBV reactivation, defined as a positive HBV DNA by PCR of any viral load at or above the minimal detection level. The principal safety outcomes assessed 1-year graft survival, 1-year all-cause mortality, biopsy-proven acute rejection, and antibody-mediated rejection. RESULTS: One hundred and sixty-one patients met inclusion criteria and comprised two groups, antiviral prophylaxis (n = 14) and no antiviral prophylaxis (n = 147). Of patients who did not receive prophylaxis, only five (3.4%) experienced HBV reactivation, whereas one (7.1%) patient in the prophylaxis group experienced reactivation over a median follow-up of 1103 days (p = .43). Furthermore, there were no differences with respect to all secondary outcomes. Statistical analysis demonstrated delayed graft function to be a significant factor associated with HBV reactivation. CONCLUSION: These study results suggest that the prevalence of HBV reactivation in HBsAg-negative anti-HBc-positive kidney transplant recipients is low, regardless of antiviral prophylaxis. Furthermore, there were no significant graft-related outcomes among those that did experience reactivation.

Safety and efficacy of direct-acting oral anticoagulants versus warfarin in kidney transplant recipients: a retrospective single-center cohort study.

Despite the increased use, comparative safety and efficacy of direct-acting oral anticoagulants (DOACs) against warfarin have not been well studied in kidney transplant recipients. In this single-center retrospective study, we evaluated 197 adult kidney transplant recipients on DOAC or warfarin between January 1, 2011, and June 30, 2018. The primary outcome was incidence of major bleeding defined as a hemoglobin decrease ≥2 g/dl, blood transfusion ≥2 units, or symptomatic bleeding in a critical area or organ. Patients were initiated on anticoagulation therapy at a median of 6.5 years post-transplant and followed for a median of 12.3 months. The rates of major bleeding were 7.2% per year with DOACs vs. 11.4% per year with warfarin (Mantel-Cox P = 0.15). No difference was found in composite bleeding, clinically relevant nonmajor bleeding, or thromboembolic events between the groups. There was a lower incidence of major bleeding with apixaban compared to all other anticoagulants (6.7% vs. 19.0%, P = 0.027). After controlling for potential confounders, DOAC use was not associated with an increased risk of major bleeding (HR 0.73, 95% CI 0.27-1.95). Further research is warranted to definitively determine whether DOACs are effective and safe alternatives to warfarin for anticoagulation in kidney transplant recipients.

The incidence of fungal infections in pancreas transplant recipients in the absence of systemic antifungal prophylaxis.

BACKGROUND: There is a lack of high-level evidence identifying meaningful outcomes and the place in therapy for systemic perioperative antifungal prophylaxis (ppx) in pancreas transplant recipients. As our program does not routinely utilize systemic perioperative antifungal ppx in pancreas transplant recipients, we assessed the incidence of post-transplant infectious complications. METHODS: This was a single-center, retrospective cohort study of consecutive adult pancreas transplant recipients between 01/2016 and 04/2018 to describe the incidence of fungal infections. Patients with a history of previous simultaneous pancreas-kidney (SPK) transplant, HIV, or unexplained use of antifungal ppx after transplantation were excluded. The primary outcome was the incidence of fungal infections within 3 months after transplantation. RESULTS: After screening 60 patients, 56 met inclusion criteria. Within 3 months post-transplantation, two (3.6%) patients had a positive fungal culture requiring systemic antifungal treatment. The sources for infection in both cases were intra-abdominal fluid cultures, positive for Candida albicans. Both patients were treated with fluconazole. Allograft-related outcomes included a 6-month pancreas graft survival of 91.1% and pancreas transplant rejection incidence of 10.7%. CONCLUSION: In this single-center experience, pancreas transplant recipients not receiving systemic antifungal ppx had similar infectious and graft-related outcomes to what is reported in literature.

Rational use of rasburicase for the treatment and management of tumor lysis syndrome.

Purpose There is a lack of high-level evidence identifying meaningful outcomes and the optimal place in therapy of rasburicase in patients with, or at high risk for tumor lysis syndrome. The primary objective of this study was to evaluate and characterize outcomes resulting from an institution-specific guideline emphasizing supportive care, xanthine oxidase inhibitors, and lower doses of rasburicase. Methods In this retrospective chart review, we compared conservative rasburicase dosing, in accordance with newly developed UMHS tumor lysis syndrome guidelines, with aggressive rasburicase in adult patients (≥ 18 years of age) with hematological or solid tumor malignancies, and a uric acid level between 8 and 15 mg/dL. The primary efficacy outcome assessed the difference in the proportion of patients achieving a uric acid level <8 mg/dL within 48 h using a one-sided noninferiority test. The principle safety outcomes analyzed included incidence of acute kidney injury and hemodialysis requirement. Results One hundred sixty-one patients met inclusion criteria and were included in the study. Within 48 h of an elevated uric acid level, treatment was successful in 97.03% of patients in the conservative group, as compared with 98.33% in the aggressive group (difference, 1.3 percentage points; 95% confidence interval [CI], -3.33 to 5.93). Furthermore, there was no difference in the proportion of patients requiring hemodialysis (2.97% vs. 10.0%, p-value 0.079), or incidence of acute kidney injury (4.0% vs. 12.5%, p-value 1.00) between the treatment group and control group, respectively. Conclusions Conservative rasburicase use was noninferior to aggressive rasburicase use in patients with or at high risk for tumor lysis syndrome.

Dosing of Enoxaparin in Renal Impairment.

OBJECTIVE: To review enoxaparin treatment dosing, pharmacokinetics, and clinical outcomes data in patients with renal impairment and to examine the current two-tiered dosing regimen approved by the Food and Drug Administration (FDA). DATA SOURCES: A literature search of PubMed (1990-2016) was performed using the search terms low-molecular-weight heparin, unfractionated heparin, bleeding, enoxaparin, renal impairment, pharmacokinetics, and hemodialysis. STUDY SELECTION AND DATA EXTRACTION: All studies assessing the pharmacokinetic properties of enoxaparin in patients with renal impairment were evaluated. In addition, all retrospective and prospective studies assessing the safety and efficacy of enoxaparin treatment in this population were evaluated. DATA SYNTHESIS: Five pharmacokinetic studies evaluated changes in the pharmacokinetics of enoxaparin in patients with renal impairment. In these studies, enoxaparin clearance was reduced by 17% to 44% in patients with mild and moderate renal impairment. Six retrospective studies evaluated the safety of enoxaparin in patients with renal impairment. In one study, patients with moderate renal impairment were at increased risk of bleeding when using the current FDA-approved two-tiered scheme (odds ratio, 4.7; 95% confidence interval, 1.7-13.0; P = 0.002). Another study demonstrated that individualized enoxaparin dosing, when compared to FDA-approved dosing, resulted in a decreased risk of bleeding. Two retrospective studies evaluated efficacy. One of these studies compared reduced-dose enoxaparin with unfractionated heparin; there was a trend toward lower incidences of thromboembolism and 30-day mortality with reduced-dose enoxaparin. Hospital length of stay also decreased with reduced-dosed enoxaparin. CONCLUSIONS: This paper highlights the differences in the pharmacokinetic properties and safety and efficacy outcomes in multiple degrees of renal impairment when using treatment-dose enoxaparin. Given the literature highlighted in this review, a more multitiered enoxaparin renal dosing strategy-perhaps shifting from the current two-tier approach to at least three or four tiers-should be considered.

Safety and Efficacy of Biologic Agents for the Management of Inflammatory Bowel Disease After Liver Transplantation.

Primary sclerosing cholangitis (PSC) frequently progresses to end-stage liver disease and cirrhosis, requiring liver transplantation. Approximately 70% of patients with PSC have concomitant inflammatory bowel disease (IBD) during their clinical course. After liver transplantation for PSC, corticosteroids and other high-intensity immunosuppressants are initiated to keep IBD in remission. Patients with IBD that is refractory to these agents may need to be managed with biologic therapies. Biologic agents, however, may further increase the risks for malignancy and infection due to their immunosuppressive effects. Thus, to gain a better understanding of the risks and benefits of these agents in this high-risk patient population, we performed a literature search of the PubMed database (2002-2017) to identify studies assessing the efficacy and safety of various biologic agents for the management of IBD in liver transplant recipients. No randomized controlled studies or retrospective comparative studies were identified; however, 15 case reports and case series were identified that met our inclusion criteria. From these case reports, we identified 67 patients who developed de novo or recurrent IBD after liver transplantation and received anti-tumor necrosis factor-α or anti-integrin therapy. Of the 13 published cases reporting clinical response or remission of IBD activity in liver transplant recipients (59 patients), clinical response or remission of IBD was reported in 38 (64.4%) of those patients. Adverse complications reported included cholangitis, oral candidiasis, Clostridium difficile colitis, bacterial pneumonia, cryptosporidiosis, Epstein-Barr virus-positive posttransplantation lymphoproliferative disease, and hepatotoxicity. Given the limited literature (case reports and case series) highlighted in this review, biologic agents such as tumor necrosis factor-α inhibitors and integrin inhibitors commonly used for moderate to severe IBD may be appropriate after liver transplantation; however, consideration of risk versus benefit should always occur in a patient-specific manner.