From the Guidelines
Chronic kidney disease (CKD) can indeed elevate procalcitonin levels, even in the absence of bacterial infection, due to reduced kidney function and chronic inflammation associated with CKD. This is a crucial consideration when interpreting procalcitonin levels in CKD patients, as failure to account for this baseline elevation could lead to overdiagnosis of bacterial infections 1. The degree of elevation typically correlates with the severity of kidney dysfunction, with hemodialysis patients showing the highest baseline levels.
Key Points to Consider
- Procalcitonin is partially cleared by the kidneys, and reduced kidney function leads to its accumulation in the bloodstream.
- Chronic inflammation associated with CKD contributes to increased procalcitonin production.
- When interpreting procalcitonin levels in CKD patients, clinicians should use higher threshold values (often 1.5-2 ng/mL rather than the standard 0.5 ng/mL) to diagnose bacterial infections.
- The relationship between CKD and procalcitonin levels is important to understand when using procalcitonin as a biomarker for infection in CKD patients.
Clinical Implications
- CKD patients, especially those with advanced disease (stages 4-5) or those on dialysis, often have baseline procalcitonin levels that are higher than the normal range of <0.5 ng/mL.
- Clinicians should be aware of the potential for elevated procalcitonin levels in CKD patients and adjust their diagnostic thresholds accordingly.
- Further research is needed to investigate the role of nonkidney biomarkers, such as procalcitonin, to identify patient populations at risk for AKI 1.
Management and Treatment
- An integrated approach to patient care with a multidisciplinary focus can help achieve the necessary shift in clinical care of patients with CKD.
- The use of newer classes of glucose-lowering agents, such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide 1 receptor agonists, has changed the therapeutic landscape for patients with CKD, offering unprecedented opportunities to reduce the risk for progression of kidney disease and the risk of death 1.
From the Research
CKD and Procalcitonin Levels
- Chronic kidney disease (CKD) has been associated with elevated procalcitonin (PCT) levels in several studies 2, 3, 4, 5, 6.
- A study published in 2014 found that PCT levels were higher in patients with confirmed infections than in those without, and that a cutoff value of 0.5 ng/mL offered good sensitivity and specificity for the early diagnosis of systemic bacterial infection in patients with CKD 2.
- Another study from 2005 found that PCT levels increased in parallel to the deterioration of CKD, and that oliguria, advanced CKD, peritoneal dialysis, hemodialysis, cardiovascular disease, and elevated C-reactive protein were independently associated with PCT elevation 3.
- A 2002 study found that PCT levels were not significantly affected by loss of renal function, immunosuppressive agents, or autoimmune disorders, and that significantly elevated PCT concentrations offered good sensitivity and specificity for the early diagnosis of systemic bacterial infection in patients with CKD or end-stage renal disease 4.
- A 2017 study found that the baseline PCT level in CKD patients increased as renal function decreased, and that PCT had a significant advantage in predicting sepsis compared to traditional inflammatory markers such as C-reactive protein, white blood cell count, and neutrophil percentage 5.
- A 2020 case-control study found that the PCT level was significantly higher in CKD patients than in healthy controls, and that the PCT level was increased with advanced clinical stage 6.
Factors Associated with Elevated PCT Levels in CKD
- Advanced CKD stage 3, 5, 6
- Oliguria 3
- Peritoneal dialysis 3
- Hemodialysis 3
- Cardiovascular disease 3
- Elevated C-reactive protein 3
- Reduced renal elimination and increased synthesis by peripheral blood mononuclear cells 3