Parvovirus B19 in living-donor kidney transplantation: incidence, clinical impact, and diagnostic algorithm

Parvovirus B19 (B19V) infection in immunocompromised patients can cause prolonged infection and significant clinical manifestations, mainly due to its tropism for erythroid progenitor cells in the bone marrow and its impact on hemopoiesis. However, B19V is often overlooked as a cause of severe post-transplant anemia, particularly early after transplantation when intensified immunosuppression increases susceptibility. Delayed diagnosis may lead to ineffective management. Data on the epidemiology and clinical impact of B19V in living-donor kidney transplantation (LDKT) remain limited. A single-center prospective observational study of 37 LDKT recipients and 37 corresponding living donors. Combined serological (anti-B19V IgG and IgM) and molecular (B19V DNA PCR) screening was performed pre- and post-transplantation, with clinical and hematological follow-up at 1, 3, 6, and 12 months. Anemia was defined as hemoglobin < 10 g/dL after exclusion of common reversible causes. Six out of 37 recipients (16.2%) showed laboratory signs of active B19V infection. A first subgroup included three patients with medium/high-level viremia (> 10 3 copies/mL) and one patient with persistent low-level (< 10 3 copies/mL) viremia. Two further patients showed only an episodic low-level viremia. Hypoproliferative anemia affected 83.3% of infected patients, while non-anemic cases occurred only in those receiving erythropoiesis-stimulating agents. Other findings included leukopenia (33.3%), renal impairment (33.3%), and fatigue (100%); rash, arthralgia, and increased infection susceptibility were rare. Combined pre and post-transplant, donor-recipient screening enabled discrimination between primary infection, possible reactivation, or graft-mediated transmission. Our findings provide novel epidemiological data in the LDKT population and support implementation of integrated serological and molecular screening in recipients and donors within kidney transplant screening protocols. A structured interpretative algorithm may enable timely diagnosis, clarify infection dynamics, and reduce misdiagnosis and inappropriate treatment.