Ehrlichiosis and Anaplasmosis Infections in Solid Organ Transplant Recipients: A Single-Center Series

Authors:
Benjamin Fisher, Pravin Meshram, Michael Megaly, Rubeena Naaz, Anmol Nigam, Anna Sachdeva, Jo-Anne Young, Michael Park, Raja Kandaswamy, James Harmon

Body of Abstract:
Introduction

Ehrlichiosis and anaplasmosis are emerging tick-borne rickettsial infections in the bacterial family of Anaplasmataceae. This series describes three cases of ehrlichiosis and four cases of anaplasmosis after organ transplantation at a single center. We report the time between transplant and infection diagnosis, laboratory values, and comorbidities.

Methods

We conducted a 13-year (2011-2024) retrospective cohort study using data from our institutional database. Demographic characteristics, transplant history, comorbidities, medications, and laboratory data were analyzed using R. Relevant laboratory measures and antibiotic usage were identified using pattern-based searches chronologically to characterize trends for each recipient.

Results

We identified a total of 727 patients who were diagnosed with ehrlichiosis or anaplasmosis at our center. The median age was 66 years and 65% of these patients were male. Seven infections occurred in solid organ transplant (SOT) recipients. The median age of the 7 recipients was 65 years, and all were white. Six of 7 were male, and outdoor hobbies and occupations will be assessed with a later chart review. The dates of organ transplantation ranged from 1982 to 2022. Ehrlichiosis was diagnosed in 3 patients following kidney transplantation. Anaplasmosis was diagnosed in 4 recipients, 3 of whom were heart transplant recipients, and 1 of whom was a liver transplant recipient. One patient was diagnosed using cell-free DNA testing. Three of 7 were diagnosed during a hospital stay. Infections were diagnosed between June and November, consistent with the typical exposure season. The median time between transplant and diagnosis of ehrlichiosis was 4 years (range, 2-5), and anaplasmosis was 8 years (range, 2-31). The liver transplant recipient died 5 months after anaplasmosis infection. All recipients were chronically immunosuppressed with agents including tacrolimus, mycophenolate mofetil, everolimus, cyclosporine, and/or azathioprine. Recipient comorbidities included systemic hypertension in 7, chronic kidney disease in 6, coronary artery disease in 5, heart failure in 2, and diabetes in 1. CRP was elevated in all recipients in whom it was measured (4 out of 7, ehrlichiosis 3, anaplasmosis 1). Leukopenia, anemia, thrombocytopenia (5 out of 7, all less than 100,000), hyponatremia, and elevated creatinine were noted in 5 out of 7 transplant recipients. Aspartate aminotransferase was elevated in 5 of 7 recipients (range, 46-920; upper limit normal 33 U/L), and total bilirubin was elevated in 1 recipient. All recipients were treated with 100mg Doxycycline BID for 9-15 days.

Conclusion

We report 7 transplant recipients who were diagnosed with ehrlichiosis or anaplasmosis at a single center. Immune-suppressed transplant recipients are typically at increased risk of poor outcomes following infection. Our report highlights the features of ehrlichiosis and anaplasmosis infection in SOT recipients.