How should we investigate CUO (C-Reactive Protein elevation of Unknown Origin)? A case-based discussion of infective endocarditis in an octogenarian

Management of fever in prolonged profound neutropenia remains challenging with many possible infectious and non-infectious causes. We investigated whether procalcitonin (PCT) is superior to C-reactive protein (CRP) in discriminating between different etiologies of fever in this setting. CRP and PCT were tested daily during 93 neutropenic episodes in 66 patients. During this study period 121 febrile episodes occurred and were classified into four categories based on clinical and microbiological findings: microbiologically documented infection (MDI); clinically documented infection (CDI); proven or probable invasive fungal disease (IFD); fever of unknown origin (FUO). Values of PCT and CRP at fever onset as well as 2 days later were considered for analysis of their performance in distinguishing etiologies of fever. At fever onset no significant difference in PCT values was observed between different etiologies of fever, whereas median CRP values were significantly higher in case of IFD (median 98.8 mg/L vs 28.8 mg/L, p=0.027). Both PCT and CRP reached their peak at a median of 2 days after fever onset. Median PCT values on day 2 showed no significant difference between etiologies of fever. Median CRP values on day 2 were significantly higher in IFD (median 172 mg/L versus 78.4 mg/L, p=0.002). In MDI median CRP values rose > 100 mg/L, whereas they did not in CDI or FUO. PCT has no added value over CRP for clinical management of fever in prolonged profound neutropenia. When performing reassessment 2 days after fever onset, CRP has better discriminatory power between etiologies of fever.

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18F-FDG-PET/CT in unexplained elevated inflammatory markers

Nuklearmedizin ◽

10.3413/nukmed-0798-16-02 ◽

2016 ◽

Vol 55 (06) ◽

pp. 242-249 ◽

Cited By ~ 1

Author(s):

Isabell Braune ◽

Birgit Meller ◽

Carsten Sahlmann ◽

Carsten Ritter ◽

Johannes Meller ◽

...

Keyword(s):

Fdg Pet ◽

Unknown Origin ◽

Final Diagnosis ◽

C Reactive Protein ◽

Protein Levels ◽

Reactive Protein ◽

Pet Ct ◽

Significant Difference ◽

18F Fdg ◽

Fdg Pet Ct

SummaryThe diagnostic strategy in patients with fever or inflammation of unknown origin remains a major clinical challenge. The aim of this study was to evaluate the role of 18F-FDG-PET/CT in patients with unexplained elevated C-reactive protein with or without fever. Contribution of 18F-FDG-PET/CT to the final diagnosis was evaluated. In addition we determined whether a differentiation between patients with or without fever is clinically reasonable. Patients, methods: We retrospectively analysed 72 consecutive patients with unexplained elevated C-reactive protein levels (above 8mg/l) that underwent 18F-FDG-PET/ CT in our facility between 10/2009 and 11/2012. 18F-FDG-PET/CT was considered a so-called diagnostic scan when results decisively led to a final diagnosis and adequate therapy with a response of symptoms was initiated due to the PET/CT result. Results: In 60/72 patients (83%) a final diagnosis was established. Diagnoses included infections (58%), non-infectious inflammatory diseases (29%) and malignancies (8%). 18F-FDG-PET/CT was true positive in 47 cases (65%) and the diagnostic scan in 29 patients (40%). Sensitivity of 18F-FDG-PET/CT was 81% and specificity was 86%. Diagnostics, final diagnoses, 18F-FDG-PET/CT results, SUVmax, C-reactive protein levels and the diagnostic scan did not differ significantly between patients with fever and patients without fever. Conclusion: 18F-FDG-PET/CT is a useful method in the diagnostic workup of patients with inflammation of unknown origin. In our series there was no significant difference between patients with or without fever. Regarding 18F-FDG-PET/CT-imaging inflammation of unknown origin and unexplained fever can be joined to one entity.

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