Does leukemia increase procalcitonin levels?

Procalcitonin Elevation in Leukemia

Yes, leukemia can increase procalcitonin levels, particularly in patients with acute myeloid leukemia, even in the absence of bacterial infection. 1, 2

Relationship Between Leukemia and Procalcitonin

• Patients with hematological disorders, especially acute leukemia, demonstrate higher baseline procalcitonin (PCT) concentrations compared to those with solid tumors (mean value 0.09 vs. 0.05 μg/L; p < 0.0015) 3
• In acute myeloid leukemia (AML) patients, PCT levels can be elevated even without bacterial infection, making interpretation more challenging 2
• Hospitalized leukemia patients typically have higher PCT values than outpatients (0.10 vs. 0.05 μg/L; p < 0.0013), reflecting the severity of their condition 3

Clinical Significance in Leukemia Patients

• Despite elevated baseline levels, PCT still shows value in detecting bacterial infections in leukemia patients, with significantly higher levels in infected versus uninfected patients (p < 0.001) 4
• Bacteremia specifically increases PCT levels above 0.5 ng/mL in AML patients undergoing chemotherapy 5
• PCT demonstrates high accuracy in discriminating bacteremic infection in leukemia patients (area under ROC curve: 0.883) 4
• PCT is particularly useful for identifying Gram-negative bacteremia in leukemia patients (area under ROC curve: 0.779) 4

Interpretation Challenges

• Normal reference ranges for PCT must be adjusted when evaluating leukemia patients due to their higher baseline levels 3
• In febrile neutropenic leukemia patients, a PCT cutoff of 1.27 ng/mL on day one of fever showed high clinical sensitivity for detecting bacterial infection 1
• PCT levels correlate with infection severity in leukemia patients along a continuum: 0.5-2.0 ng/mL for systemic inflammatory response syndrome, 2-10 ng/mL for severe sepsis, and >10 ng/mL for septic shock 6
• Serial PCT measurements are more valuable than single readings in neutropenic leukemia patients 5, 1

Clinical Applications

• PCT levels can predict bacteremia at day 15 of chemotherapy in AML patients, potentially guiding decisions to alter antibiotic regimens 5
• PCT shows superior accuracy compared to C-reactive protein (CRP) in determining infection in acute leukemia patients with febrile neutropenia (AUC of 0.931 vs. lower values for CRP) 1
• PCT concentrations correlate with the severity of bacterial sepsis in leukemia patients 1
• Persistently elevated PCT levels despite appropriate therapy may indicate treatment failure in leukemia patients with infection 6

Pitfalls and Limitations

• PCT is not a useful predictive marker of infection in oncohematologic neutropenic patients before infection occurs 3
• Non-infectious causes can elevate PCT in leukemia patients, including reactions to drugs or blood products and tumor-associated events 5
• PCT has a half-life of 22-35 hours, which must be considered when interpreting serial measurements in leukemia patients 6
• PCT levels are influenced by renal function and different techniques of renal replacement therapy, which may be relevant in leukemia patients with organ dysfunction 6

In conclusion, while leukemia (particularly acute myeloid leukemia) can increase baseline procalcitonin levels, PCT remains a valuable biomarker for detecting bacterial infections in these patients when appropriate cutoff values are used and serial measurements are performed.