This trial is active, not recruiting.

Condition bacterial infections
Treatment neutrophil to lymphocyte ratio
Sponsor Centre Hospitalier Universitaire, Amiens
Start date February 2016
End date February 2017
Trial size 342 participants
Trial identifier NCT02848534, RNI2015-40 Schmidt-2


The "gold standard" for diagnosing a bacterial infection is isolation of the pathogenic germ, which is not easy in routine clinical practice.

Conventional markers do not have sufficient diagnostic value for making a rapid diagnosis on admission. A 2004 literature calculated the diagnostic values of C-reactive protein (CRP) and procalcitonin (PCT) levels for the diagnosis of bacterial infections, relative to other causes of inflammation. For CRP, the sensitivity was 75% (95% CI: 62%-84%) and the specificity was 67% (95% CI: 56%-77%). For PCT, the sensitivity was 88% (95% CI: 62%-84%) and the specificity was 81% (95% CI: 67%-90%).

The first cellular immune response to infection consists of the mobilization of polynuclear neutrophils from the bone marrow to the infection site under the effect of pre-inflammatory cytokines, as well as the apoptosis of lymphocytes and their sequestration at the infection site. This results in lymphopenia and the elevated polynuclear neutrophil count (PNN) observed in bacterial infections.

Hence, it is legitimate to hypothesize that the neutrophil to lymphocyte ratio (NLR) can be used in the diagnosis of bacterial infection. This ratio's value in the diagnosis of sepsis in the emergency department was studied and the researchers found higher diagnostic values than for CRP and PCT.

The NLR's potential value in the diagnosis of a bacterial infection in a context of fever or hyperthermia (regardless of the presence or absence of bacteraemia) has not been studied before. This ratio could also be compared with standard biomarkers (CRP and PCT levels, the white blood cell count and the PNN). It will be assessed in patients over the age of 75, since immunosenescence can change this ratio.

United States No locations recruiting
Other Countries No locations recruiting

Study Design

Observational model cohort
Time perspective retrospective

Primary Outcomes

time frame: 1 day
time frame: 1 day
NLR / white blood cell count
time frame: 1 day
time frame: 1 day

Eligibility Criteria

Male or female participants at least 18 years old.

Inclusion Criteria: - All consecutive patients admitted for fever/inflammatory syndrome to the internal medicine department at Amiens University Hospital between January 1 st 2011 and December 31 st 2014 (hyperthermia > 38°5 and/or inflammatory syndrome, defined as an increase in CRP >10 mg/L). Exclusion Criteria: - Known conditions or treatments that may influence the blood count (haematological and neoplastic diseases, seropositivity for HIV, chemotherapy, and corticotherapy). - Pregnancy. - A course of antibiotics administered in the 48 hours before the - blood count (risk of sample negativity).

Additional Information

Official title The Value of the Neutrophil to Lymphocyte Ratio in the Diagnosis of Bacterial Infections
Principal investigator Jean Schmidt, MD
Trial information was received from ClinicalTrials.gov and was last updated in July 2016.
Information provided to ClinicalTrials.gov by Centre Hospitalier Universitaire, Amiens.