From the Guidelines
Yes, bone marrow inflammation can affect cystatin C levels, a marker of impaired renal function.
Key Points
- Cystatin C is considered an inflammatory marker or acute phase reactant, which can be elevated in conditions such as bone marrow inflammation 1.
- The measurement properties of serum cystatin C are similar to or better than those of serum creatinine, but its performance as a GFR surrogate can be affected by non-GFR determinants, including inflammation 1.
- Combining filtration markers (creatinine and cystatin C) is more accurate and would support better clinical decisions than either marker alone, but cystatin C levels can be influenced by factors such as inflammation, liver dysfunction, and malignancy 1.
- In patients with recognized altered creatinine or cystatin C production, such as those with inflammation, malignancy, or liver dysfunction, measured GFR (mGFR) should be considered instead of estimated GFR (eGFR) based on creatinine and cystatin C 1.
From the Research
Relationship Between Bone Marrow Inflammation and Cystatin C Levels
- Cystatin C is a marker of renal function that appears to be associated with inflammation 2, 3, 4.
- Studies have shown that cystatin C levels are positively correlated with inflammatory markers such as C-reactive protein and fibrinogen 3, 4.
- Monocytes, which play an important role in chronic inflammation and atherosclerosis, have been found to be independently related to cystatin C concentrations 2.
- Cystatin C has been shown to be a marker of inflammation as well as renal function, and its levels are correlated with proinflammatory cytokines such as tumor necrosis factor-alpha and interleukin-6 4.
Mechanism of Cystatin C and Inflammation
- Cystatin C has been found to play a modulatory function in the regulation of natural immunity, protecting the body against viruses, bacteria, and parasites 5.
- Cystatin C can influence non-specific immune response through the inhibition of superoxide anion generation, phagocytosis, chemotaxis, and apoptosis of neutrophils 5.
- Cystatin C can also modulate specific immune response through the inhibition of cathepsin S, binding membrane receptors for TGF-beta, or increasing MHC class II expression on dendritic cells 5.
Clinical Implications
- The relationship between cystatin C and inflammation suggests that even small reductions in renal function may be associated with adverse pathophysiologic consequences 3.
- Cystatin C may be a useful marker for predicting increased cardiovascular risk, as it is associated with inflammation and renal dysfunction 2, 3, 4.
- Further studies are needed to fully understand the relationship between cystatin C, inflammation, and renal function, and to explore the potential clinical implications of this relationship 6.