The influence of kidney function parameters in different phases of multiple myeloma

Background: Patients with multiple myeloma are characterized by increased production of light chains of immunoglobulins and thus increase in the concentration of proximal nephron tubule lumen that leads to renal injury. Methods: This cross-sectional study involved 62 patients with MM. They were characterized in three different stage groups of the disease using Salmon-Durie classification and by International Staging System (ISS). Blood samples were drawn to measure concentration of Cystatin C, Immunoglobulins, Free light chains (FLC), C-reactive protein (CRP), polyclonal chains, while urine is collected to measure creatinine level. ELISA and nephelometry were employed to determine those concentrations. Statistical analyzes were performed by SPSS 16. System. Results: In patients without renal injury and with renal injury differ among the phases. Significant difference was observed between the mean values ​​of CRP, creatinine, serum kappa chains and the ratio of serum kappa and λ chains (p <0.05) while in the „steady” phase, difference was observed between the mean values ​​of Cystatin C levels and creatinine. In ISS stage 1, the mean serum Cystatin C level in patients without renal injury and with renal impairment statistically differ as well as serum creatinine, CRP and serum κ chains levels in ISS stage 2. In ISS stage 3, no statistically significant difference was observed between the mean values ​​of the examined parameters and renal injury. Conclusion: This confirms that beside serum Cystatin C, serum creatinine level, serum CRP level and serum κ chains' level were early signs of kidney impairment as well.