Francesca MORGANS-SLADER, Ola SULIMAN, Henry H.L. WU, Rajkumar CHINNADURAI
Turkish Journal of Nephrology - 2026;35(1):82-83
There is limited discussion detailing the disease course, outcomes, and effectiveness of current management strategies for kidney transplant recipients with human metapneumovirus (HMPV). Given the number of HMPV cases continuing to rise worldwide, having an awareness of how HMPV impacts immunosuppressed patients such as kidney transplant recipients is of rising clinical importance. Tailored guidance is indicated to optimize outcomes for kidney transplant recipients with HMPV infection. We performed a scoping search evaluating peer-reviewed publications reporting on HMPV infection in kidney transplant recipients. Literature search was performed for original full-text publications between January 2005 and January 2025. Inclusion criteria are publications examining the prevalence, incidence, or impact of HMPV infection in kidney transplant recipients, and publications reporting on clinical outcomes such as graft failure, mortality, or adverse events in kidney transplant recipients with HMPV infection. Publications that were not published in English and/or not focused on kidney transplant recipient(s) and/or not reporting on HMPV infection were excluded. Databases used in the search process include PubMed, EMBASE, Cochrane Library, Web of Science and MEDLINE. Combination keywords used in the search process included: "HMPV" AND "Kidney transplant"; "HMPV" AND "Renal Transplant"; "Human metapneumovirus" AND "Renal transplant"; "Human metapneumovirus" AND "kidney transplant"; "HMPV" AND "Kidney transplant" AND "Immunosuppression"; "Human metapneumovirus" AND "Kidney Transplant" AND "Immunosuppression"; "HMPV" AND "Renal transplant" AND "Immunosuppression" and "Human metapneumovirus" AND "Renal Transplant" AND "Immunosuppression". There were 7 original full-text publications (3 case reports and 4 observational studies) published in English between October 2005 and September 2024 that described clinical presentations, management, and clinical outcomes of HMPV infection in kidney transplant recipients. There are vast variations in the severity and disease course of kidney transplant recipients presenting with HMPV. The case presented by Noel et al, for instance, reported a self-limiting disease course, while the retrospective observational study published by Koo et al noted 6 of 59 (10.1%) solid organ transplant recipients (there were 37 kidney transplant recipients among these 59 patients) requiring intensive care unit (ICU) support following acute HMPV infection. Mean length of hospital stay in the 6 ICU patients was 62 +/- 72 days. The potential severe implications of acute HMPV infection in transplant recipients are reflected in the adverse outcomes reported in these 6 patients admitted to ICU. In all 6 patients, there was extensive bilateral involvement of pneumonia that affected all 6 lung lobes. Three of the 6 patients developed persistent fibrotic post-inflammatory sequelae in the involved area on follow-up computed tomography images. One patient died in ICU as a result of severe HMPV pneumonia. A potential reason explaining these variations could be the dosage of post-transplant steroid therapy received. Samannodi et al reported that being on a dose of >10 mg prednisolone per day was a risk factor for developing respiratory viral illness in solid organ transplant recipients. Mixed findings relating to graft dysfunction, varying between acute graft rejection and no adverse effects on graft function, have been observed. It would be important to meticulously monitor graft status during acute HMPV infection, nevertheless, to identify events of acute rejection so timely intervention could be commenced if indicated. Otherwise, a documented long-term adverse effect of HMPV infection among kidney transplant recipients are alveolar fibrotic changes. A standardized strategy for the management of HMPV in kidney transplant recipients is not presently available. Numerous patients were prescribed ribavirin, an antiviral medication that acts by causing mutations in the genomes of RNA viruses, with mixed results. Data surrounding the efficacy of ribavirin as a treatment for HMPV are inconclusive, and high-quality research supporting ribavirin as an effective treatment for respiratory viral illnesses is lacking. Randomized-controlled trials have been considered in the past but were abandoned due to low numbers of study participant recruitment. The use of intravenous immunoglobulin in this setting was considered, but convincing evidence supporting its efficacy remains unestablished. The approach toward immunosuppression adjustment in kidney transplant recipients following diagnosis of HMPV infection is personalized on a case-by-case basis, dependent on the patient's initial clinical presentation and projected clinical trajectory. In summary, it should now be recognized that HMPV can possess significant risks for the kidney transplant population. There remains insufficient high-quality evidence to support a convincing management approach in this scenario, and more research, in particular randomized controlled trials, is needed to establish standardized treatment protocols. Ongoing efforts to develop subunit and live-attenuated vaccines for HMPV, which demonstrated promise in animal models, may provide a future preventive strategy for the kidney transplant population.
