Treatment of Newly Diagnosed Myeloma (excluding t-cell redirection therapy)

Category: Treatment of Newly Diagnosed Myeloma (excluding t-cell redirection therapy)

Renal histopathologic spectrum and factors associated with reversibility of renal injury in newly diagnosed patients of multiple myeloma

(PA-434) Renal Histopathologic Spectrum and Factors Associated with Reversibility of Renal Injury in Newly Diagnosed Patients of Multiple Myeloma

Wednesday, September 17, 2025

Sanjeev Sanjeev, MD

Additional professor
SGPGI

Introduction: Myriad of etiologic factors underlie renal impairment in patients of multiple myeloma(MM). Renal involvement portends a poor prognosis in MM and renal injury is reversible only in 30%-50% of cases. We studied the renal histopathologic spectrum, renal recovery and survival of patients of newly diagnosed MM with renal impairment.

Methods: This was a prospective, single-centre study, conducted at a tertiary care centre in North India. All patients with newly diagnosed MM with renal impairment (defined as serum creatinine >2 mg/dl or an eGFR < 60 ml/min/1.73m²) were included. Renal biopsy was performed in all patients after obtaining a written informed consent. Patients received Bortezomib-based triplet or quadruplet (with Daratumumab) induction. Renal and hematologic responses were assessed as per IMWG 2016 criteria.

Results: A total of 52 patients of MM with renal impairment underwent renal biopsy and were included in this study. Median age of the cohort was 54 years (IQR 49-64). Thirty-seven(71%) were male. Median creatinine and eGFR was 3.8 mg/dl and 17 ml/min/1.73m², respectively. Nineteen(36.5%) required dialysis at presentation. Cast nephropathy(n=22, 42.3%) followed by MIDD(n=8, 15.4%) were the most common finding on renal biopsy. Five(10%) patients had diabetic nephropathy on renal histology. Majority(n=43, 83%) received bortezomib/cyclophosphamide/dexamethasone (VCD) induction. Best hematologic response (>VGPR) occurred in 70.5%. Thirty-one(59.6%) achieved a renal response. Median time to best renal response was 16 weeks. Out of 19, 10(53%) became dialysis independent at a median of 3 weeks. Hypercalcemia at presentation was associated with improved renal recovery(p=0.01). Lambda light-chain isotype had higher renal recovery compared to kappa isotype (OR=3.46, 95% CI1.05-11.32, p=0.04). Out of 5 patients with diabetic-nephropathy, none achieved renal response(p=0.008). Presence of severe interstitial-fibrosis and tubular-atrophy(IFTA)(n=5) was associated with lack of renal-response(p=0.016). Median overall survival was not reached in patients with renal response (72% at 22 months), compared to 8 months in non-renal responders (95% CI 0-28, p=0.006). At a median follow-up of 16 months, out of 52 patients, 8(15.3%) died, while 11(21%) were lost to follow up.

Conclusions: Our study underscores the value of renal biopsy in MM and also identifies important clinical, hematologic and histopathologic factors associated with renal response and survival. Our study underscores the value of renal biopsy in MM and also identifies important clinical, hematologic and histopathologic factors associated with renal response and survival.