Why CRP and ESR
►increase in concentration relatively high
compared to basal concentration
►relatively short lag time from the moment of
►Discovered in 1930
►Till 1970 only qualitative estmation after
that now its quantitative estimation.
►Synthesized in the liver by hepatocytes
►Cytokines IL-6 induces the synthesis of crp.
►The clearance rate of CRP is constant.
►therefore the level of CRP in the blood is
regulated solely by synthesis.
►The plasma levels of CRP 1 mg/L with
normal being <10 mg/L.
►levels begin increasing 4-6 hr after initial
►Doubles every 8-9 hr exponentially.
►Returns to normal with restoration of
tissue structure and function.
►It’s a measure of the vertical column in
the westergen tube.
►Response of acute phase reactants
increase fibrinogen in the plasma which
increase positively charged RBC’S
►Increased rouleaux formation thereby
► shape of red blood cells,
► plasma composition
► fluid status
► Age temperature
► CRP is independent of the physical properties.
Clinical Significance of CRP and
►Predicting post-op infection before the
development of clinical symptoms.
►Common clinical symptoms are masked by
the effects of the procedure itself.
►Pain, fever, tachycardia and elevated WBC
can be due to surgery or infection.
Larsson et al
►Studied the the natural CRP course for
►Once the natural CRP response after
uncomplicated surgery is known, then
deviation from normal should raise clinical
suspicion that a complication may be
► 193 pts 4 types of surgeries were done.
► THR, TKR, Revision Hip, discectomy
► CRP levels were measured days 0, 5, 10, 14, 21,
► All four procedures had a peak CRP response 2
to 3 days after surgery
► biphasic rapid decline.
► Day 3-5 1st decline
► Day 14-21 2nd decline
► ESR was high to 42 days, in rev hip upto 1 year.
►The conclusion from the study is that a
normalized CRP response that follows a
typical biphasic response seems to
indicate an uneventful recovery.
►Any deviation from the normal response
curve indicates an chance of post op
Mustard et al.
► Study size-108
► Measured the levels of CRP pre and post op.
► Positive CRP response
- level on day 3 or 4 > 80% of day 2
- after day 4, inc on two consecutive days
► Subjects who had postive crp response had later
developed post op infection.
Waleczek et al
►Study group 107.
►Compared esr, crp, wbc, body temp, clinical
►7 out of 107 had abnormal crp patterns and
all of them developed wound infections
Meyer et al
► 400 patients underwent discectomy out of which
15 had post op infection and all 15 had crp level
on day 5 was more than day 1.
►The sensitivity of CRP was thus determined
to be 100%, specificity 95.8%
► CRP is better than ESR in diagnosis and
monitoring treatment of infection in post op pts.
► Single CRP reading holds very limited value.
► Trend must be observed for its usefulness.
► CRP rises early and before the onset of clinical
symptoms, and declines with the resolution of
► It is a biologic warning sign that should raise an
index of suspicion for infection if a rising trend.