Refresher Course: Lupus and ANA Titers

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The ANA (anti-nuclear antibodies) blood test is one of the ruling

factors in diagnosing Lupus, but it is not the only test that is

considered when diagnosing Lupus. A person can have a positive ANA and

NOT have Lupus. A person can have a negative ANA and still have all the

other clinical symptoms of Lupus. (Confused yet?)

ANA stands for Antinuclear Antibody. This literally means 'substance

against the cell nucleus'. The nucleus is the 'headquarters' of the

living cell, therefore the ANA can damage or destroy cells and tissues.

If the ANA destroys the nucleus of the cell, the cell dies. Enough cells

die and organ tissue dies.

To diagnose lupus, the physician has to look very carefully at the titer

(number) and pattern of the ANA test. The pattern of the cell is the

determining factor in whether the diagnosis will be Lupus, arthritis,

polymyositis, scleroderma, or another connective tissue disease.

The titer shows how many times the technician had to mix fluid from the

patient's blood to get a sample free of ANAs. Thus a titer of 1:640

shows a greater concentration of ANA than 1:320 or 1:160, since it took

640 dilutions of the plasma before ANA was no longer detected.

A negative ANA is any number LESS than 1:80 (this is " pronounced " one to

80 parts). (Plasma was diluted 1 part plasma with 8 parts diluting

solution.)

Since each dilution involves doubling the amount of test fluid, it is

not surprising that titers increase rapidly. In fact, the difference

between titers of 1:160 and 1:320 is only a single dilution. And it

doesn't necessarily represent a major difference in disease activity.

Lower than 1:20 is considered a negative result.

1:80 is considered a " low positive " and more tests should be ordered.

95% of people with 1:80 ANA do not have Lupus.

1:16 is considered positive and if SED rates and Complement tests are

positive, Lupus is considered.

1:32 is a definite positive and mean the disease is active.

1:64 is considered very high and tissue damage is imminent if no

treatment is started.

For more information on ANA:

http://www.itzarion.com/lupusana.html