Predictors of Kidney and Patient Survival in Monoclonal Gammopathy-Associated Kidney Disease: A Single-Center Cohort from Colombia.

INTRODUCTION: Monoclonal gammopathies can induce various kidney disorders through the deposition of monoclonal immunoglobulin. Precise recognition and classification are essential for predicting outcomes and customizing treatment. However, data on prognostic factors in Hispanic and Latin American populations remain scarce. This study aimed to determine the predictors of kidney and patient survival in adults with biopsy-proven monoclonal gammopathy-associated kidney disease. METHODS: We conducted a retrospective cohort involving 98 individuals with biopsy-confirmed disease evaluated between 2011 and 2022. Kidney and patient survival were estimated using Kaplan-Meier analysis, and differences across histopathologic subtypes were assessed with the log-rank test. Predictors of end-stage kidney disease (ESKD) and mortality were identified using univariate and multivariable Cox regression after verification of the proportional hazards' assumption. RESULTS: Approximately one third of patients required kidney replacement therapy (KRT) at presentation. The need for KRT (hazard ratio [HR] 4.86, 95% confidence interval [CI] 2.01-11.79) and an estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m² (HR 4.02, 95% CI 1.38-11.71) independently predicted progression to ESKD. Amyloidosis (HR 2.38, 95% CI 1.22-4.86) and age > 60 years (HR 1.96, 95% CI 1.06-3.61) were associated with higher mortality. The median follow-up was 41 months (interquartile range 24-68); 31% progressed to ESKD and 46% died. CONCLUSIONS: Severe kidney dysfunction and the need for replacement therapy at diagnosis are strong predictors of poor renal outcomes. Amyloidosis and older age significantly affect overall survival. Early recognition of high-risk patients and access to effective, clone-directed therapy are essential to improve prognosis in resource-limited settings.