Search

Background: Solid organ transplant (SOT) recipients are at risk of complications from COVID‐19. Nirmatrelvir/ritonavir (Paxlovid) can reduce mortality from COVID‐19 but is contraindicated in patients receiving calcineurin inhibitors (CI), which depend on cytochrome p4503A (CY3PA). In this study, we aim to show the feasibility of nirmatrelvir/ritonavir administration to SOT recipients receiving CI with coordination of medication management and limited tacrolimus trough monitoring. Methods: We reviewed adult SOT recipients treated with nirmatrelvir/ritonavir from 4/14 to 11/1/2022 and assessed for changes in tacrolimus trough and serum creatinine after therapy. Results: Of 47 patients identified, 28 were receiving tacrolimus and had follow‐up laboratory testing. Patients had a mean age of 55 years, 17 (61%) received a kidney transplant and 23 (82%) received three or more doses of SARS‐CoV‐2 mRNA vaccine. Patients had mild‐moderate COVID‐19 and started nirmatrelvir/ritonavir within 5 days of symptom onset. Median baseline tacrolimus trough concentration was 5.6 ng/mL (Interquartile range 5.1–6.7), while median follow‐up tacrolimus trough concentration was 7.8 ng/mL (Interquartile range 5.7–11.5, p = 0.0017). Median baseline and follow‐up serum creatinine levels were 1.21 mg/dL (Interquartile range 1.02–1.39) and 1.21 mg/dL (interquartile range 1.02–1.44, p = 0.3162), respectively. One kidney recipient had a follow up creatinine level >1.5 times baseline. No patients were hospitalized or died from COVID‐19 in the follow up period. Conclusion: While administration of nirmatrelvir/ritonavir resulted in a significant increase in tacrolimus concentration, this did not result in significant nephrotoxicity. Early oral antiviral treatment in SOT recipients is feasible with medication management, even with limited tacrolimus trough monitoring. [ABSTRACT FROM AUTHOR]

Abstract: Tick‐borne infections in solid organ transplant recipients are an infrequent and difficult diagnostic challenge owing to multiple routes of acquisition and unusual presentations. A 67‐year‐old male recipient of a combined liver and kidney transplant presented with recurrent fevers following surgery. Standard microbiologic workup was non‐diagnostic. Shortness of breath, confusion, lethargy, and hypotension developed along with progressive anemia, requiring multiple blood transfusions. Workup suggested hemolysis and review of the peripheral smear was diagnostic for Babesia microti infection. Tick transmission, transmission via blood products, and/or the transplanted organ were all considered. More extensive questioning revealed a history of intermittent fevers for several months before transplantation. Testing of pre‐transplant blood was positive for B. microti antibodies, suggesting infection prior to transplantation. The delayed diagnosis of babesiosis in this patient highlights the need for a detailed exposure history prior to transplantation, as well as considering the potential for atypical presentations of tick‐borne infections in immune suppressed solid organ recipients. Furthermore, this case illustrates the importance of early Infectious Disease consultation to meet the challenges exhibited by febrile transplant patients. Infectious Diseases physicians are trained to consider, diagnose, and treat tick‐borne infections, contributing to improved clinical outcome. [ABSTRACT FROM AUTHOR]