High C-reactive protein in Crohn's disease patients predicts nonresponse to infliximab treatment.
BACKGROUND
Infliximab (IFX) is effective in treating Crohn's disease (CD) and C-reactive protein (CRP) is a useful biomarker in assessing inflammatory activity.


OBJECTIVE
Correlate CRP levels before beginning of IFX, at week 14 and CRP delta within the first year of IFX treatment.


METHODS
Retrospective study of CD patients undergoing treatment with IFX. Primary nonresponse (PNR) was defined as no symptomatic improvement and CRP persistently elevated; sustained response (SR) as symptomatic improvement for at least 1 year without therapeutic adjustment; response after therapeutic adjustment (RTA) as analytic and clinical response but requiring IFX dose/frequency adjustment or association with another drug.


RESULTS
Baseline CRP levels were higher in PNR compared with SR (26.2mg/L vs 9.6 mg/L, p=0.015) and RTA (26.2mg/L vs 7.6 mg/L, p=0.007). CRP levels greater than 15 mg/L at baseline predict PNR with 67% sensitivity and 65% specificity. Lower CRP levels at week 14 were more likely to predict SR relative to RTA (3.1mg/L vs 7.6 mg/L p=0.019) and PNR (3.1mg/L vs 9.1mg/L; p=0.013). CRP levels greater than 4.6 mg/L at week 14 predict PNR with 67% sensitivity and 62% specificity. A higher CRP delta between beginning of treatment and week 14 is more likely to predict SR relative to RTA (5.2mg/L vs 0.6 mg/L p=0.027).


CONCLUSIONS
CRP levels at week 14 were associated with SR in patients treated with IFX, independently of baseline CRP serum levels. High inflammatory burden at beginning of IFX treatment was correlated with a worse response.
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal; Institute of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, Portugal; IBMC - Institute for Molecular and Cell Biology, University of Porto, Porto, Portugal. Electronic address: fm@med.up.pt.
Fernando
F
Magro
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal.
Eduardo
E
Rodrigues-Pinto
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal; Department of Biochemistry, Faculty of Medicine, University of Porto, Portugal.
João
J
Santos-Antunes
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal.
Filipe
F
Vilas-Boas
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal.
Susana
S
Lopes
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal.
Amadeu
A
Nunes
CIDES - Department of Health Information and Decision Sciences, Faculty of Medicine, University of Porto, Portugal.
Claudia
C
Camila-Dias
Gastroenterology Department, Centro Hospitalar São João, Porto, Portugal.
Guilherme
G
Macedo
D000293:Adolescent; D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use*; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism*; D003424:Crohn Disease / Q000097:blood* / Q000188:drug therapy*; D005260:Female; D006801:Humans; D000069285:Infliximab; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D017211:Treatment Failure; D055815:Young Adult
D000894:Anti-Inflammatory Agents, Non-Steroidal; D000911:Antibodies, Monoclonal; D015415:Biomarkers; D002097:C-Reactive Protein; D000069285:Infliximab
C-reactive protein; Crohn disease; Infliximab; Prognosis; Treatment outcome