e****0
发帖数: 678 | 1 为什么要强调 low complement especially low C4 in cryoglobulinemia | u*****o
发帖数: 125 | 2 鉴别，有的是C3,C4都降低，比如post-streptococcal glomerulonephritis | Q****g
发帖数: 190 | 3 in the MTB2,it said cryoglobulinemia associated with chronic hepatitis C and
HepC has decreased C4.But didn't find the mechanism | e****0
发帖数: 678 | 4 我又查了一下啊。
classical complement pathway activates C4 as well as C3. This can lead to
low C3 and
C4 levels which lead to decreased CH 50. This would typically be seen with
complement
activation driven by immune complexes (lupus, hepatitis C, cryoglobulinemia)
alternative complement pathway activation is typically driven by bacterial
or microbial
antigens: C3 is directly activity producing low C3 and decreased CH 50 C4 is
normal.
C3 may also be directly activated by C3 nephritic factor which is an
antibody which
activates C3 convertase directly (associated with membranoproliferative
marrow
nephritis, type II- also described as dense deposit disease.
diseases which do not have bacterial/microbial antigens or circulating
immune complex
will typically have normal levels of serum complement and normal CH 50.
IgA nephritis does not cause low serum complements as IgA is a poor
complement
activator.
ANCA diseases do not produce circulating immune complexes, for us,
complement levels are normal.
For unclear reasons, anti-GBM disease typically presents
with normal complement levels |
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