A second C-reactive protein (CRP) test to detect inflammatory burst in patients with acute bacterial infections presenting with a first relatively low CRP

Abstract

A first C-reactive protein (CRP) test, as often performed by clinicians during the presentation of patients with an acute bacterial infection, might be misleading. The aim of our study was to explore the dynamic between a second CRP test taken within 12 hours from admission CRP test in a cohort of patients diagnosed with acute bacterial infection in comparison to CRP in a control group of apparently healthy individuals. This was a historical cohort study comprised of all patients admitted to the Sourasky Tel-Aviv Medical Center, Israel, between July 2007 and March 2016. The study cohort included adult patients who were diagnosed as having an infection, assumed to be of bacterial etiology (cellulitis and erysipelas, pneumonia, cholecystitis, pyelonephritis, or septicemia), who had a CRP test during the first 6 hours of hospital admission (baseline CRP), and a successive CRP test up to 12 hours from the first one (recurrent CRP). The control group was of healthy subjects who attended our medical center for a routine annual check-up. The study included 950 patients. Baseline CRP ranged from 0.04 to 454 mg/L. The median CRP velocity was 0.53 mg/L/h. Patients were grouped by baseline CRP into 4 groups (CRP < 10, 10–74.9, 75–199.9, ≥200). There was an increase in median CRP velocity between the first (0.48 mg/L/h) and the second (0.93 mg/L/h) groups, which then was decreased in the next 2 groups (0.46 and −2.58 mg/L/h, respectively). In 45 of 103 (44%) patients of the group of baseline CRP concentration less than 10 mg/dL with bacterial diagnosis, there was a complete overlap with CRP values of apparently healthy individuals during their routine annual checkup. A first single low CRP result cannot exclude the presence of a significant bacterial infection. Patients with acute bacterial infection might present with a relatively low CRP value that at times correspond to normal limit CRP concentrations. A second test, obtained within 12 hours of admission, might serve as an important tool to identify patient with an evolving inflammatory burst commonly seen during acute bacterial infection.

Gain-of-Function Mutations R249C and S250C in Complement C2 Protein Increase C3 Deposition in the Presence of C-Reactive Protein

“…Importantly, a certain threshold of CRP must be reached to significantly elevate deposition of C3, as evidenced by ELISA assays (Figures 2A, B) and the fact that we could not see this effect on glomerular endothelial cells when patient serum containing 22.6 mg/ml was used. However, the CRP concentration of 150 mg/ml used in the immunofluorescence imaging and flow cytometry experiments is not unusual and can be achieved in case of infections but also non-infectious inflammatory lesions, as reported in (24)(25)(26)(27). Another lesson from our experiments is that the GoF phenotype of both C2 variants can be observed when CRP but not human immunoglobulins are coated on ELISA plates (Figure 2).…”

Role of C-Reactive Protein in Diabetic Inflammation

“…The level of CRP is usually low in healthy individuals but can elevate 100- to 200-fold or higher in acute systemic inflammation [ 12 ] and is chronically elevated in patients with T2DM. In individuals with T2DM, CRP levels range between 4.49 and 16.48 mg/L [ 13 , 14 ] and among individuals with acute systemic inflammatory response syndromes from 31.08 [ 15 ] to 226.1 mg/L [ 16 ].…”

Sepsis Related Mortality Associated with an Inflammatory Burst in Patients Admitting to the Department of Internal Medicine with Apparently Normal C-Reactive Protein Concentration

“…We have recently shown that patients who are admitted with very low CRP concentrations do not necessarily present a benign course of their disease [ 3 ]. In addition, we could show that a follow-up CRP test could add significant prognostic information to the medical team [ 4 , 5 , 6 , 7 , 8 ]. In fact, a second CRP test could single out those individuals who are at an increased risk of death during hospitalization [ 9 ].…”