Introduction: Patients with multiple myeloma (MM) and end stage kidney disease (ESKD) experienced unfavourable outcomes with kidney replacement therapy. Kidney transplantation (KT) is rarely performed for patients with MM and ESKD due to concerns for poor kidney outcomes, disease recurrence and heightened infection risk.
Method: Comprehensive search on electronic databases (MEDLINE, PubMed and EMBASE) from inception to March 19, 2024 were carried out using appropriate keywords and Medical Subject Headings (MeSH) terms. We included case reports and case series of individuals fulfilling diagnosis of MM and received treatment with or without autologous stem cell transplant (ASCT) before KT. We excluded case series on individuals with monoclonal gammopathy of renal significance, individuals with a diagnosis of MM after KT, case reports/ case series of allogenic stem cell transplant and conference abstracts without full text. Two reviewers performed full-text screening independently, and a third reviewer arbitrated disagreements between the two reviewers. Systematic review is registered with PROSPERO [CRD42024513832]. We also included 8 patients of our own experience into data analysis.
Results: A total of 15 articles and 63 KTs were included in the analysis. Median age was 53 years old; 49 patients (77.8%) had an autologous stem cell transplant (ASCT) prior to KT, while 2 (3.2%) had ASCT within 6 months after KT. Prior to KT, MM remission status of complete remission (CR), very good partial remission (VGPR), and partial remission (PR) were achieved in 37 (58.7%), 14 (22.2%) and 4 (6.3%) patients respectively. Median wait time to KT after MM treatment was 36 months (range 5-166 months) and 17 (27.0%) patients had a wait time for KT of 24 months or shorter. One (1.6%) patient had primary non function (PNF). Overall survival at 1, 3 and 5 years were 96.7%, 71.0%, and 62.3% respectively. The main causes of death were MM progression (8 patients, 12.7%), infection (8 patients, 12.7%) and solid organ cancers (3 patients, 4.8%). Solid organ cancers developed in 4 (6.3%) patients with mortality of 75%. MM relapse-free survival at 1, 3, and 5 years were 75.9%, 54.1%, and 48.8% respectively. Death-censored graft survival at 1, 3 and 5 years were 93.5%, 87.8%, and 78.8% respectively. Causes of graft loss were MM relapse in 5 patients (7.9%), rejection in 4 patients (6.3%), chronic allograft nephropathy in 1 patient (1.6%) and PNF in 1 patient (1.6%). Rejection was reported in 16 patients (25.3%). Wait time to KT after MM treatment shorter than 24 months, use of a proteasome inhibitor and MM remission status prior to KT did not affect patient survival, graft survival, nor MM-relapse rate.
Conclusion: Outcome of MM patients receiving KT are acceptable but significant morbidity remains. Shorter wait time to KT after MM treatment is not associated with poorer outcome and may be considered.