Normal CRP with elevated ESR seen in
a) RA
b) SLE
c) Scleroderma
d) Polymyalgia rheumatica
Correct Answer - B
Ans. is ‘b’ i.e., SLE
Both ESR and CRP are markers of inflammation
Erythrocyte sedimentation rate or ESR is used to separate
inflammation from non-inflammation.
Another sign of inflammation is the rise in blood level of number of
proteins called as acute phase proteins.
One of the proteins is C-reactive protein (CRP).
Like ESR and other acute phase proteins, CRP also goes up in
inflammation.
In systemic lupus however the level does not rise unless there is
infection associated.
The normal response to active inflammatory disease is an increase
in plasma CRP concentration. o For reasons that remain unclear tht
response is either significantly lower in magnitude or entirely absent
in a few inflammatory conditions.
This has proven diagnostically useful because there are very few
inflammatory conditions in which ESR is significantly raised
(reflecting an inflammatory process) but plasma CRP is only slightly
raised or even normal.
One ofthese conditions is systemic lupus erythematosus (SLE or
lupus), a relatively common chronic autoimmune disease that
predominantly affects women of child-bearing age
When this inflammation occurs in the lupus patient it is accompanied
as expected by a marked increase in ESR. However in contrst to
most other inflammatory condition, the plasma CRP remains
resolutely normal. The combination of raised ESR and normal CRP
is a useful diagnostic feature of SLE.
Other disorders where CRP is not increased
Osteoarthritis, leukemia, anemia
Polycythemia, viral infection
Ulcerative colitis, pregnancy, estrogen.