Objective:

To investigate the utility of hsCRP as a blood biomarker for the diagnosis and prognosis of acute mTBI, and explore its trends compared to symptom severity and recovery. 

Background:

Inflammatory biomarkers have been associated with poorer longitudinal outcomes following mTBI. Previous studies have established relationships between CRP levels and TBI, but the utility of hsCRP in assessing mTBI requires further exploration. 

Design/Methods:

Retrospective review of 590 acute mTBI patients (mean age 24.4±14.6; 56% female) seen within 21 days of injury. Patients with any comorbid diagnosis known to cause elevation of inflammatory proteins were excluded. Serum hsCRP levels were collected routinely. Concussion symptoms were assessed using the Post-Concussion Symptom Scale. Stepwise logistic regression models were used to examine associations between symptom severity and hsCRP. Adjusted odds ratios (aOR) with 95% confidence intervals were calculated, adjusting for potential confounders including age, BMI, and sex. 

Results:

Mean baseline hsCRP was 1.1±2.4 in 474 patients. In the univariate analysis between patients with elevated hsCRP (≥1mg/L), age (28.4y vs. 21.7y) and BMI (23.4 vs. 20.9) were significantly higher in the elevated group (p<0.001 for both). Symptoms of neck pain, feeling slowed down, feeling in a fog, and difficulty remembering were significantly higher in patients with elevated hsCRP, who also had a higher percentage of depression history. Higher BMI and irritability were significantly associated with increased odds of elevated hsCRP (aOR=1.22;1.25). Neck pain demonstrated a positive association with high hsCRP (aOR=1.17;p=0.083). Conversely, difficulty concentrating was inversely associated with elevated hsCRP (aOR=0.81;p=0.037).  

Conclusions:

These findings demonstrate a complex interplay between somatic and cognitive symptoms in relation to inflammation in mTBI patients. Our data suggests that hsCRP may be a viable addition to acute biomarker panels for mTBI, but further exploration is needed to reveal longitudinal trends in relation to symptom resolution across recovery.