Differentiating between bacterial and viral infections by estimated CRP velocity.

PURPOSE: Differentiating between acute viral and bacterial infection is challenging due to the similarity in symptom presentation. Blood tests can assist in the diagnosis, but they reflect the immediate status and fail to consider the dynamics of an inflammatory response with time since symptom onset. We applied estimated C-reactive protein (CRP) velocity (eCRPv), as derived from the admission CRP level divided by time from symptom onset, in order to better distinguish between viral and bacterial infections. METHODS: This cross-sectional study included patients admitted to the emergency department with a confirmed viral (n = 83) or bacterial (n = 181) infection. eCRPv was defined as the ratio between the absolute CRP level upon admission to time from symptom onset (in hours). Absolute CRP and eCRPv values were compared between the 3 groups. RESULTS: Bacterial patients presented with higher CRP levels (133 mg/L) upon admission compared to viral patients (23.31 mg/L) (P < 0.001). Their median value of eCRPv velocity was 4 times higher compared to the viral patients (1.1 mg/L/h compared 0.25 mg/L/h, P < 0.001). Moreover, in intermediate values of CRP (100-150 mg/L) upon admission, in which the differential diagnosis is controversial, high eCRPv is indicative of bacterial infection, eCRPv >4 mg/L/h represents only bacterial patients. CONCLUSIONS: During an acute febrile illness, the eCRPv value can be used for rapid differentiation between bacterial and viral infection, especially in patients with high CRP values. This capability can potentially expedite the provision of appropriate therapeutic management. Further research and validation may open new applications of the kinetics of inflammation for rapid diagnosis of an infectious vs. a viral source of fever.

C-reactive protein velocity discriminates between acute viral and bacterial infections in patients who present with relatively low CRP concentrations.

BACKGROUND: To assess the utility of C-reactive protein (CRP) velocity to discriminate between patients with acute viral and bacterial infections who presented with relatively low CRP concentrations and were suspected of having a bacterial infection. METHODS: We analyzed a retrospective cohort of patients with acute infections who presented to the emergency department (ED) with a relatively low first CRP measurement (CRP1) ≤ 31.9 mg/L and received antibiotics shortly after. We then calculated C-reactive protein velocity (CRPv), milligram per liter per hour, for each patient based on CRP1 and the second CRP value (CRP2) measured within the first 24 h since admission. Finally, we compared CRPv between patients with bacterial and viral infections. RESULTS: We have presently analyzed 74 patients with acute bacterial infections and 62 patients with acute viral infections at the mean age of 80 and 66 years respectively, 68 male and 68 female. CRP1 did not differ between both groups of patients (16.2 ± 8.6 and 14.8 ± 8.5 for patients with viral and bacterial infections respectively, p value = 0.336). However, the CRP2 was significantly different between the groups (30.2 ± 21.9 and 75.6 ± 51.3 for patients with viral and bacterial infections respectively, p-value < 0.001) and especially the CRPv was much higher in patients with acute bacterial infections compared to patients with acute viral infections (0.9 ± 1.2 and 4.4 ± 2.7 respectively, p-value < 0.001). CONCLUSION: CRPv and CRP2 are useful biomarkers that can discriminate significantly between patients who present with acute bacterial and viral infections, and relatively low CRP concentration upon admission who were suspected of having a bacterial infection.

The superiority of 72 h leukocyte descent over CRP for mortality prediction in patients with sepsis.

BACKGROUND: Detection of an eventful course in the early days of sepsis treatment is clinically relevant. The white blood cell count (WBCC) and C-reactive protein (CRP) are used in daily practice to monitor the intensity of the inflammatory response associated with sepsis. It is not entirely clear which of the two might better discriminate the outcomes of patients with sepsis. METHODS: 30-day mortality was assessed in a cohort of patients who were hospitalized with sepsis in the departments of Internal Medicine in a tertiary medical center. Admission and 72-hour time points were analyzed to discriminate between patients with increased versus decreased 30 days mortality risk. RESULTS: The study included 195 patients. Higher 72 h CRP, WBCC, neutrophil counts and neutrophils to lymphocyte ratio were associated with increased mortality (p < 0.02). Baseline WBCC and CRP failed to discriminate between patients who died and those who survived (AUC = 0.551, 0.479). In multivariate analysis of the 72 h tests, higher WBCC count (OR = 1.12, 95%CI 1.05-1.20, p = 0.001), was associated with increased mortality whereas CRP was not (OR = 1.004, 95%CI 0.998-1.01, p = 0.146). CONCLUSION: Patients who presented a 72-hour leukocyte descent had a better outcome and in this regard, WBCC was superior to 72-hour CRP in predicting 30 days mortality.