Anti-DNA antibodies include anti-double-stranded DNA antibodies, anti-single-stranded DNA antibodies, and anti-zDNA antibodies. The test generally refers to an anti-double-stranded DNA antibody that reacts with both double-stranded DNA and single-stranded DNA. Anti-double-stranded DNA antibody positive is a marker of systemic lupus erythematosus, with a positive rate of more than 90% and high specificity. Therefore, anti-double-stranded DNA antibodies are extremely important for the diagnosis and treatment monitoring of systemic lupus erythematosus. Anti-double-stranded DNA antibodies have a low positive rate in other autoimmune diseases.

Basic Information

Specialist classification: inspection classification: immune examination

Applicable gender: whether men and women apply fasting: fasting

Analysis results:

Below normal:

Normal value:
no

Above normal:

negative:
normal.

Positive:
Anti-double-stranded DNA antibody positive is a marker of systemic lupus erythematosus, with a positive rate of more than 90% and high specificity. Therefore, anti-double-stranded DNA antibodies are extremely important for the diagnosis and treatment monitoring of systemic lupus erythematosus. Anti-double-stranded DNA antibodies have a low positive rate in other autoimmune diseases.

Tips: In view of the different sources of DNA antigens in the detection reagents, the base composition and sequence may be different, and the epitopes bound by the antibodies may change. Normal value

The Farr method binding activity is less than or equal to 20%.

Indirect immunofluorescence was negative.

The spot immunobinding assay was less than 1:40 (negative).

(Note the specific reference value depends on each laboratory.)

Clinical significance

Positive or increased:

May be systemic lupus erythematosus, can also be seen in other connective tissue diseases, chronic active hepatitis and so on.

Positive results may be diseases: systemic lupus erythematosus, systemic lupus erythematosus, systemic lupus erythematosus caused by spinal cord disease

Requirements for examination: It is generally believed that the titer of anti-double-stranded DNA is parallel to the condition, that is, when the disease is active, the anti-DNA antibody titer is increased, and when the condition is relieved, the titer is lowered. Since the methods of measurement vary from place to place, the normal values ​​are also different. Generally speaking, the combination rate is more than 20% to have clinical significance.

The specificity of the detection technique is not 100%. For example, although the Physcoma sinensis does not contain ssDNA, it may contain a small amount of histones. The dsDNA used as an antigen, such as radioimmunoassay, ELISA, and drip diafiltration, often contains ssDNA, even if contaminated ssDNA. Less than 1%, the false positives can be as high as 6%. Therefore, the detection results against dsDNA should be combined with clinical analysis and should be observed dynamically if necessary. In addition, in view of the different sources of DNA antigens in the detection reagents, the base composition and sequence may be different, and the epitopes to which the antibodies bind may be changed.

Inspection process

Inspection methods: There are various methods for determining anti-double-stranded dSDNA, such as immunodiffusion, convective immunoelectrophoresis, agglutination test, body-binding assay, indirect immunofluorescence, radioimmunoassay, enzyme-linked immunosorbent assay, and the like. Currently the most commonly used are radioimmunoassay, indirect immunofluorescence and enzyme-linked immunosorbent assay.

Not suitable for the crowd

Those who do not have an indication for examination are prohibited from doing this check.

Adverse reactions and risks

Generally no special complications.