Monoclonal Gammopathies in Kidney Transplant Recipients: A Retrospective Analysis of Incidence, Clinical Characteristics, and Outcomes.

Objectives: Monoclonal gammopathies represent a spectrum of clinical and biological abnormalities characterized by monoclonal immunoglobulin production from plasma cell clones. In kidney transplant recipients, monoclonal gammopathies and their identification constitute a complex and multifactorial phenomenon involving immunological alterations and underlying pathologies such as multiple myeloma or lymphoproliferative diseases.

Materials and methods: We retrospectively studied patients who underwent kidney transplant at the Nephrology Department of Sahloul University Hospital from November 1, 2007, to December 31, 2024, and who had detection of monoclonal gammopathies during follow -up.

Results: Among 332 kidney transplant recipients, 10 (3.0 % ) developed monoclonal gammopathies. Mean age was 42.4 years (range, 27 -58 years ), with male predominance (70 % ). Hypertension was the most frequent comorbidity (50 % ). Only 1 patient had preexisting monoclonal gammopathies before transplant. Chronic interstitial nephropathy was the most common initial nephropathy (62.5 % ). Mean time to diagnosis of monoclonal gammopathies posttransplant was 58.9 months. Serum protein electrophoresis revealed monoclonal peaks in the gamma -globulin region (70 % ), beta -1 globulin (20 % ), and beta -2 globulin (10 % ). Immunofixation showed immunoglobulin G lambda (40 % ), immunoglobulin G kappa, immunoglobulin A lambda and kappa, and isolated light chains. Proteinuria was present in 60 % and anemia in 70 % of cases. Evolution included return to hemodialysis in 3 patients, infectious complications in 4 patients, and 1 death.

Conclusions: The effect of monoclonal gammopathies on kidney transplant recipients remains an evolving research domain where diagnostic and therapeutic advances play a key role in improving management of these vulnerable patients.