Can a markedly elevated high-sensitivity C-reactive protein (hs-CRP) be associated with acute myeloid leukemia (AML) in a 54-year-old woman?

Elevated hs-CRP Can Be Associated with AML, But It Reflects Infection and Inflammation Rather Than the Leukemia Itself

Yes, markedly elevated hs-CRP can be associated with AML in a 54-year-old woman, but this elevation typically indicates infectious complications or systemic inflammation rather than being a direct marker of the malignancy itself.

Understanding the Relationship

hs-CRP as an Infection Marker in AML

The primary association between elevated hs-CRP and AML relates to infectious complications, which are extremely common in these patients:

• CRP levels correlate with infection severity in neutropenic AML patients 1. In AML patients with chemotherapy-induced neutropenia:

  • CRP <32 mg/L suggests no infection
  • CRP 32-105 mg/L indicates localized infection or fever of unknown origin
  • CRP >105 mg/L signals systemic infection (SIRS/sepsis)

• Automated CRP peak detection can identify bloodstream infections, capturing 71-76% of documented bloodstream infection episodes in AML patients 2

hs-CRP and Disease Status

Recent evidence shows CRP elevation may reflect disease burden and patient condition:

• The C-reactive protein/platelet ratio (CPR) associates with myeloblast burden in bone marrow at diagnosis and throughout treatment 3

• High CPR before hematopoietic stem cell transplantation predicts worse outcomes, with 2-year overall survival of 49.7% (high CPR) vs 73.1% (low CPR), and increased non-relapse mortality (27.6% vs 13.0%) 3

Important Caveats

CRP is NOT a prognostic marker for AML itself. A 2025 study found that CRP, albumin, and CRP-to-albumin ratio did not predict complete remission rates, recurrence, overall survival, or event-free survival in newly diagnosed AML patients 4. The only significant prognostic factor identified was allogeneic stem cell transplantation.

Clinical Interpretation Algorithm

When encountering elevated hs-CRP in a 54-year-old woman with suspected or confirmed AML:

1. First, rule out infection (the most common cause):

   • Obtain blood cultures, chest imaging, urinalysis
   • Check procalcitonin (PCT ≥0.255 ng/mL increases infection risk) 5
   • Assess neutrophil count (<0.475×10⁹/L increases infection risk) 5

2. Assess disease burden markers:

   • Bone marrow blast percentage
   • Platelet count (<84×10⁹/L associated with infections) 5
   • Hemoglobin (<110.5 g/L associated with infections) 5

3. Consider systemic inflammation severity:

   • CRP >105 mg/L suggests systemic infection requiring aggressive management 1
   • High CPR (>0.05) may indicate higher disease burden and poorer performance status 3

Key Clinical Pitfalls

• Do not use hs-CRP as a diagnostic marker for AML - it lacks specificity and sensitivity for the malignancy itself
• Do not rely on hs-CRP for AML prognosis - cytogenetics, molecular markers (FLT3, NPM1), and risk stratification per ELN guidelines 6, 7 remain the gold standard
• Do not dismiss elevated hs-CRP - it warrants thorough infection workup, as pulmonary infections occur in 42% of elderly AML patients and significantly worsen prognosis 5