Kidney Transplantation and Clinical Outcomes in Patients With Multiple Myeloma: Evidence From the United States Nationwide Inpatient Sample.

Purpose: Patients with multiple myeloma (MM) are prone to developing persistent renal insufficiency. Novel therapeutic medications have improved long-term survival, making kidney transplantation (KT) a viable treatment option for MM survivors with end-stage renal disease. This study aimed to investigate the clinical outcomes in patients with MM who have received KT.

Methods: Data from hospitalized patients ≥ 40 years of age with MM in the Nationwide Inpatient Sample 2016-2018 of the United States were queried. Patients were classified as having or not having undergone KT, as well as the stage of chronic kidney disease (CKD) for those who had not received KT. Propensity-score matching (PSM) was applied to balance the characteristics between the groups. Binary logistic regression was utilized to determine the associations between study variables and inhospital mortality, unfavorable discharges, prolonged length of stay (LOS), and major complications.

Results: In total, 50,654 hospitalized patients with MM were identified, of whom 165 (0.3%) had received KT and 50,489 had not (5,905 at stage 5 CKD [CKD5D], 11,559 at stage 1-4 CKD [CKD1-4D], and 33,025 who were CKD-free). After PSM, between-group demographic and hospital-related characteristics were balanced. Binary regression analysis revealed that, compared to patients who were CKD-free, patients at CKD5D were significantly more likely to experience a prolonged LOS (odds ratio [OR], 1.31; 95% confidence interval [CI], 1.01-1.70) after adjusting for relevant confounders. Furthermore, compared to CKD-free patients, those who underwent KT were significantly more likely to have sepsis (OR, 1.48; 95% CI, 1.02-2.14). However, KT showed no association with the other adverse inpatient outcomes.

Conclusion: Although KT is not common in MM patients, those who had undergone KT had comparable hospital outcomes to CKD-free patients. These data will help clinicians deliver better consultations to MM patients attempting to receive KT.