Monday, November 9, 2009

What do those lab tests mean?

The CD57 test (only from Labcorp) measures a subset of NKT cells. These are Natural Killer T Cells. These T cells are actors in the innate immune response. In other words, these cells automatically attack what our immune system sees as foreign invaders. Our immune systems are naturally smart (anthropomorphically). They have pattern recognition cells which can determine tissues/cells that belong in our bodies from things (like bacteria) that do not belong in our bodies. The second part of the immune system, the acquired immune system relates to a complex set of reactions by which the immune system learns to make specific antibodies to attack the foreign invader. In some situations only the innate immune system is in play. Primarily this occurs when the "invaders" are intracellular. The acquired responses just don't work here. In the case of Lyme disease it is the intracellula- L-forms which are attacked by the NKT cells. When the CD57 count is low it would appear these cells are busy combating the L-forms of Lyme. Unfortunately, the innate immune system is never 100% effective in eliminating the bacteria. This is one of the mechanisms by which Lyme is able to persist in the face of antibiotics and immune responses.

C3a and C4a (Labcorp) are products of the complement system, cleaved from C3 and C4. These proteins are mobilized by the immune system as part of its acquired and to a lesser extent innate immune responses. These proteins can attach to unwanted bacteria and target them for destruction. These tests are sensitive indicators of a busy immune system attacking unwanted proteins or germs. These markers can provide a general sense of immune activation in the face of infection or inflammation.

C3d (Quest only) is a test for circulating immune complexes (CIC). These antibody/antigen complexes are not supposed to be present in our blood. The presence of these CICs indicates infection or inflammation and can be used as another indicator of disease activity.

C-reactive protein (CRP) is a naturally occurring protein found in blood circulation. It is one of two proteins which activate the complement system associated with immune activation. This is another marker which can help assess disease activity. This marker is elevated in many diseases and is not specific for Lyme disease. When used here, the clincially useful cut-off points may be much lower than the "normal" reported by the lab.

There are many other labs/markers of infection/inflammation. But here a few that seem to confuse many patients (and doctors).

9 comments:

bobcat said...

Ever test C1Q Immune Complexes? I think it might be LabCorp that does it.

I think the C stands for complement. My understanding is that an immune complex is an antigen and its antibody joined together. Obviously you know that, but just clarifying what test I'm speaking of for you.

bobcat said...

ps-- the whole thinking behind checking for the immune complexes, is that the antibodies for a disease may not be floating around, if they are all bound to antigens.

This is all simply how it was explained to me.

Cyclone said...

My LLMD uses the CD57 from Quest. Why do you state LabCorp?

Erik said...

@Cyclone
The last I heard Labcorp owned the patent on the CD57 test. Two options with your blood being drawn by quest:
1. They send some off the blood off to Labcorp for them to test
2. They have licensed the test and can run it themselves.

Im both options it is cheaper to get the test done at Labcorp. Labcorp has been the benchmark for this test since they own this test so it may be better to get the test from them.

PTmom said...

FYI......my LLMD doctor said that the CD57 can be artificially lowered by Strep. That was true in my case. Mine dropped almost in half after being treated for Strep with 12 bicillin shots

PTmom said...

OOPS! I meant that Strep can artificially RAISE CD57. Brain fog moment....

Lori said...

I was tested by quest with a cd57 panel- the numbers seem low to me...any info on what is low with quest? would mycoplasma pnemoniae lower the number.

idemeter said...

hi-
regarding C4A lab, mine is 12,400.

What else besides lyme can cause this to go up?

I want to make sure that this is not MS (only have UBO's), LUPUS(tested negative-ANA), HIV/AIDS (not tested, but not concerned for that one)?

Then there is C3A, what role does it play when combined with C4A results, in pointing toward one disease versus another disease? Do combinations of different results with both these complements together point to different cause of inflammation?

My ESR, CRP, C3, have been extremely normal on several testings. No inflamation. So why is C4A so high. I will Be testing C3A soon, how do these differ from the regular C3/C4 labs?

I have neurological/neuromuscular symptoms,muscle weakness,swallowing/tongue problems.I have a Positive serum PCR either plasmid or genomic(don't recall). CD57 is 42 (low).

Any knowledge would be appreciated,
thank you,
Ann

Jennifer said...

Ann, did you figure out what was going on? Have you checked for mold exposure? I think C4A is high for Mold and CD57 can be low as well with that.