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Abstract: FR-PO1083

A Clone-Directed Treatment Approach for the Monoclonal Gammopathies of Renal Significance

Session Information

Category: Glomerular Diseases

  • 1203 Glomerular Diseases: Clinical, Outcomes, and Trials

Authors

  • Dinh, Alex, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Cohen, Jordana B., University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Palmer, Matthew, University of Pennsylvania, Philadelphia, Pennsylvania, United States
  • Garfall, Alfred, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Dember, Laura M., University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Vogl, Dan T., University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Weiss, Brendan M., University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
  • Hogan, Jonathan J., University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, United States
Background

Monoclonal gammopathy of renal significance (MGRS) is a non-malignant hematologic condition causing paraprotein-mediated kidney disease. We recently published our experience using a clone-directed approach to patients with PGNMID. Here, we present our experience using the same approach to 22 patients with non-PGNMID paraprotein-mediated nephropathies.

Methods

We retrospectively reviewed 22 patients with MGRS to describe their renal and hematologic presentations and outcomes. For patients with initial proteinuria <0.5 g, complete renal response (CR) was defined as proteinuria <0.01 g (24h urine) or g/g (Uprot/Cr ratio) and partial renal response (PR) as proteinuria reduction by 50%. For patients starting with nephrotic range proteinuria, CR and PR were defined as proteinuria <0.5 g and <3.5 g, respectively. For patients with initial proteinuria between 0.5 and 3.5 g, CR and PR were defined as proteinuria <0.49 g and 50% reduction of proteinuria, respectively. Renal response required stable/improved eGFR. Hematologic studies and responses are presented descriptively.

Results

Histologic diagnoses included LCDD (n= 9), immunotactoid glomerulopathy (n= 3), paraprotein-associated C3 GN (n= 2), monoclonal membranous nephropathy (n= 3), and 1 case each of monoclonal fibrillary GN, heavy chain deposition disease, light and heavy chain deposition disease, type 1 cryoglobulinemic GN, and light chain proximal tubulopathy. Median eGFR (interquartile range) was 30 mL/min (18 to 48 mL/min). Median baseline proteinuria (IQR) was 2.11 g (1.1 to 3.9 g). 4 patients presented on RRT. An underlying clone was detected in 18 patients (82%), of whom 13 had plasma cell clones and 5 had B cell clones. 17 (77%) patients had detectable paraprotein on serum or urine immunofixation. 4 patients were not treated due to stable renal disease. Of 18 patients who underwent treatment, 3 achieved renal CR and 6 achieved renal PR (50% overall response rate). No patient on HD came off RRT, and 1 patient progressed to ESRD during follow-up. Of patients who received clone-directed therapy and were not on RRT at diagnosis, the overall renal response rate was 64%. 71% of patients had an improvement in paraprotein levels.

Conclusion

Clone-directed therapy led to a high overall response rate in patients with MGRS.