Abstract: SA-PO0198
"Mind the Gap": Could a Low Anion Gap Predict Risk of Monoclonal Gammopathy?
Session Information
- Onconephrology: MGRS, HSCT, Electrolytes, RCC, and More
November 08, 2025 | Location: Exhibit Hall, Convention Center
Abstract Time: 10:00 AM - 12:00 PM
Category: Onconephrology
- 1700 Onconephrology
Authors
- Nemalidinne, Krishna Vani, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
- Vanteru, Abinay Siva kumar Reddy, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
- Nemalidinne, Kiran Reddy, Rutgers The State University of New Jersey, New Brunswick, New Jersey, United States
- Chevireddy, Akshara, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
- Karakala, Nithin, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
- Arthur, John M., University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
Background
Monoclonal gammopathies (MG), including multiple myeloma (MM), frequently manifest with renal and metabolic abnormalities. Early identification of biochemical changes may offer valuable insight into disease onset. Although a low anion gap (AG) is often observed in patients with MG, it has not been established if low anion gap precedes the diagnosis of MG.
Methods
We performed a retrospective analysis of patients diagnosed with MG at our institution from 2014 to 2024. A total of 7044 patients were identified through EMR data, the inclusion criteria included biopsy-proven MG or MM. Patients with ESRD were excluded. Laboratory values were grouped into three intervals: 0–6 months, 6–12 months, and 12–18 months, preceding the confirmatory diagnosis of MG. Median AG values were taken to minimize outlier effects, and Delta-Delta Gap (D/D) values were calculated.
Results
Across all the 3 time intervals, median AG values were consistently lower in the group that developed MG, clustering at median 8 (IQR: 6-9) for 0-6 month, and 7 (IQR: 6-9) for 6-12 months, and 8 (IQR 6-10) in the 12-18 month interval, compared to control (10, IQR: 8-12). The D/D gap values were similarly lower in the MG group with the median at -0.8 (IQR: -2 to 0) in 0-6 months, -1.0 (IQR: -2 to -0.37) in 6-12 month and -0.75 (IQR: -1.5 to 0) in 12-18 months before diagnosis.
Conclusion
A persistently low anion gap and a negative D/D gap may precede the clinical diagnosis of MGs. These findings suggest the potential role of low AG as an early, and non-invasive biochemical marker of disease development.