Monoclonal B lymphocytosis in a kidney transplant recipient

Monoclonal B lymphocytosis (MBL) is a lymphoproliferative condition characterised by expansion of a B-cell clone in peripheral blood, with an often indolent clinical course. The presence of a B clonal population alone is several hundred times more common in the general population than chronic lymphocytic leukaemia and other non-Hodgkin's lymphoma subtypes, it usually does not represent a malignant condition and it requires follow-up only, without specific treatment. There are few studies describing MBL in solid organ transplant recipients, thus, the concern is raised when enrolling MBL affected subjects in waiting lists. We report the experience of a patient affected by MBL who underwent kidney transplantation, with particular attention to preoperative screening and immunosuppressants impact on post-transplant lymphoproliferative disease risk, to aid clinicians in the evaluation process of transplant candidates affected by similar conditions. 2021 BMJ Publishing Group Limited. Published by BMJ.