Table 3 Studies of biomarkers in the diagnosis of bacterial meningitis (BM) and its distinction from viral meningitis (VM)
Marker | Study 1st author, [ref] | Study design | Number of patients, n | Level of evidence | End-point | Main result |
|---|---|---|---|---|---|---|
| Â | Â | Â | Â | Â | Â | Absolute risk reduction (RR) |
PCT | Gendrel D, [42] | Single-centre observational study | 59 children (18 BM, 41 VM) | Very low | Comparison of PCT and CRP level in patients with bacterial or viral meningitis | A serum PCT level >0.5 μg/L is associated with bacterial meningitis (Se = 94%; Sp = 100%). |
| Â | Â | Â | Â | Â | Â | Large overlap for CRP values |
PCT/CRP/INF-Ï’ | Marc E, [43] | Single-centre observational study | 58 viral | Very low | Antibiotic initiation and hospital days, based on a serum PCT < 0.5 to not initiate or stop antibiotics. If PCT >0.5, antibiotics stopped if negative cultures and/or INF or PCR (+) in CSF | 41 patients did not receive antibiotics; antibiotics stopped in 15/17 pts treated by day 1 or 2, because of a PCT < 0.5. |
| Â | Â | Â | (enterovirus outbreak) | Â | Â | Â |
|  |  |  | Children (2 mo – 14 yr) |  |  |  |
| Â | Â | Â | Â | Â | Â | Hospital days reduced to 2 days. |
PCT/CRP/sCD 163 | Knudsen T, [58] | Single-centre observational study (ID department) | 55 adult patients suspected of BM | Very low | Comparison of PCT, CRP and sCD163 levels in patients with bacterial or viral meningitis, or other infection | Diagnostic value of CRP (AUC = 0.91) and PCT (AUC = 0.87) superior (p < 0.02 and p < 0.06) to sCD163 (AUC = 0.72); |
| Â | Â | Â | Â | Â | Â | sCD163 most specific for systemic bacterial infection (Sp = 0.91). |
PCT/CRP | Viallon A [61] | Single-centre observational study | 254 adults (183 VM, 97 BM) | Low | Predictive value of serum PCT and CRP for the diagnosis of BM | AUROC PCT = 0.86; threshold 0.28 μg/mL (Se = 0.97; Sp = 1, VPP = 0.97, VPN = 1) |
| Â | Â | Â | Â | Â | Â | AUROC CRP = 0.92; threshold 37 mg/L (Se = 0.86, Sp = 0.84, VPP = 0.46, VPN = 0.97) |
CRP | Gerdes L, [62] | Meta analysis of 10 studies | Children and adults | low | Predictive value of serum CRP for bacterial meningitis | Threshold value for CRP varies across studies from 19 to 100 mg/l. |
| Â | Â | Â | Â | Â | Â | Se varies from 92% to 94% and NPV is >97%. |
Summary table | ||||||
| Â | Total number of patients | Highest level of evidence | Directness* | Consistency of results** | Overall strength of evidence | Number of studies |
| Â | 371 | Low | Yes | Yes | Low | 3 (PCT) |