The Diagnostic and Differential Value of the Serum Albumin-to-Globulin Ratio in Multiple Myeloma

Background: This study aimed to investigate the clinical value of the serum albumin-to-globulin ratio (AGR) in diagnosing multiple myeloma (MM) and its differential diagnosis from other conditions such as liver and kidney diseases to provide scientific evidence for clinical decision-making. Methods: A total of 52 newly-diagnosed MM patients from Tongxiang First People's Hospital between January 2020 and June 2024 were selected as the study group. Additionally, 56 patients newly diagnosed with liver disease and 58 patients newly diagnosed with kidney disease during the same period were used as disease control groups, along with 54 healthy individuals serving as the normal control group. Serum total protein (TP), albumin (ALB), globulin (GLB), and AGR levels were measured and compared across groups. Receiver operating characteristic (ROC) curves were used to assess the diagnostic and differential diagnostic efficacy of these biomarkers for MM. Results: Significant differences were observed in TP, ALB, GLB, and AGR levels across the four groups (p < 0.05). The MM, liver disease, and kidney disease groups had significantly higher TP and GLB levels and lower ALB and AGR levels compared to the healthy controls (p < 0.05). The MM group had significantly higher TP and GLB levels and lower ALB and AGR levels than the other three groups (p < 0.05). ROC curve analysis revealed that the areas under the curve (AUC) for TP, ALB, GLB, and AGR in diagnosing MM were 0.821, 0.865, 0.909, and 0.910, respectively, with GLB and AGR showing high diagnostic value (AUC > 0.9) and AGR demonstrating the highest sensitivity. In differentiating MM from liver disease, the AUCs for TP, ALB, GLB, and AGR were 0.849, 0.670, 0.881, and 0.884, respectively, with GLB and AGR showing high diagnostic value. In distinguishing MM from kidney disease, the AUCs for TP, ALB, GLB, and AGR were 0.897, 0.618, 0.901, and 0.905, respectively, with both GLB and AGR having high differential diagnostic value (AUC > 0.9) and AGR demonstrating the highest sensitivity (88.6%). Conclusions: AGR, a simple, cost-effective, and routinely available biochemical marker, demonstrates significant value in the diagnosis and differential diagnosis of MM. Its clinical use should be emphasized and promoted.