C-Reactive Protein-to-Albumin Ratio and Its Association with Inflammatory and Renal Parameters in Multiple Myeloma

Background: Multiple myeloma (MM) is a hematological malignancy characterized by systemic inflammation and frequent renal involvement. The C-reactive protein-to-albumin ratio (CAR) has emerged as a potential inflammation-based biomarker; however, its clinical significance in MM remains incompletely understood. Methods: This retrospective single-center study included 62 patients with MM. Clinical and laboratory data at diagnosis were collected, and CAR was calculated as the ratio of CRP to serum albumin. Patients were stratified into low and high CAR groups based on the median value (0.13). Survival outcomes were assessed using the Kaplan–Meier method. Results: The mean age was 65.9 ± 9.9 years, and 54.8% of patients were male. Higher CAR levels were associated with shorter overall survival (123 vs. 89 months, p = 0.32) and progression-free survival (60 vs. 36 months, p = 0.16), although these differences did not reach statistical significance. An unexpected finding was that the requirement for dialysis was higher in the low-CAR group (21.2% vs. 3.4%, p = 0.04). Other clinical and laboratory parameters were comparable between groups. Conclusions: CAR may reflect systemic inflammatory status in patients with MM; however, its prognostic value for survival remains uncertain in this cohort. The observed findings, particularly regarding renal outcomes, should be interpreted with caution. Larger prospective studies are needed to clarify the clinical utility of CAR in MM.