Monoclonal gammopathy of renal significance (MGRS): Real‐world data on outcomes and prognostic factors

Abstract

Monoclonal gammopathy of renal significance (MGRS) is a recognized clinical entity. Literature regarding treatment and its outcomes in MGRS is sparse due to the rarity and misdiagnosis of MGRS. We retrospectively analyzed 280 adults with an MGRS diagnosis from 2003 to 2020 across 19 clinical centers from 12 countries. All cases required renal biopsy for the pathological diagnosis of MGRS. Amyloidosis‐related to MGRS (MGRS‐A) was present in 180 patients; nonamyloidosis MGRS (MGRS‐NA), including a broad spectrum of renal pathologies, was diagnosed in 100 patients. The median overall survival in the studied cohort was 121.0 months (95% CI: 105.0–121.0). Patients with MGRS‐A had a shorter overall survival than patients with MGRS‐NA (HR = 0.41, 95%CI: 0.25–0.69; p = 0.0007). Both hematologic and renal responses were associated with longer survival. Achievement of ≥VGPR was generally predictive of a renal response (OR = 8.03 95%CI: 4.04–115.96; p < 0.0001), one‐fourth of patients with ≥VGPR were renal nonresponders. In MGRS‐A, factors associated with poor prognosis included elevated levels of creatinine, beta‐2‐microglobulin, and hemodialysis at diagnosis. In MGRS‐NA, only age >65 years was associated with increased risk of death. Treatments provided similar hematologic response rates in both types of MGRS. Autologous stem cell transplantation led to better response than other treatments. This multicenter and international effort is currently the largest report on MGRS.

Liquid biopsy and blood-based minimal residual disease evaluation in multiple myeloma

“…MM can be preceded by precursor stages of monoclonal gammopathy of undetermined significance (MGUS) or smouldering MM that are asymptomatic. However, novel conditions of monoclonal gammopathies of clinical significance (MGCS) have been reported in which organ damage can be present, even with a small clone in the marrow [3][4][5][6]. Novel drugs, such as proteasome inhibitors and immunomodulatory and monoclonal antibodies, have elicited complete responses in MM patients [7].…”

Treatment of Light Chain Deposition Disease: A Systematic Review

“…Overall, non-amyloidosis-associated MGRS was found to have an overall response rate (ORR) of 72% compared to 56% in amyloidosis-associated disease. VGPR or better hematologic response was associated with a better probability of renal response in the non-amyloidosis MGRS group (renal response of 77% vs. 47% with ≥ VGPR vs. PR/stable disease hematologic response, respectively) [ 24 ]. Both these studies were not included in our quantitative analysis as individual data and outcomes for study participants or subgroups were not reported separately.…”

Monoclonal Gammopathies of Clinical Significance: A Critical Appraisal

“…AL amyloidosis plays a central role in patients with MGCS, particularly MGRS [ 57 , 58 , 68 ]. The epidemiology of AL has just been reviewed [ 111 ].…”

“…However, one out of four patients in this study had no hematologic and/or renal evaluation of response. Therefore, there is room for improvement in the management of MGRS patients [ 68 ].…”