Advices for Life


November 28, 2016 00:11

Antibodies to extractable nuclear antigens in blood

Normally antibodies to the extracted concentration nuclear antigens RNP / Sm, Sm, SS-A (Ro), SS-B (La) - less than 20 IU / ml 20-25 IU / ml - boundary values;antigen Scl-70 antibodies normally absent.

This study is the quantitative determination of IgG-antibodies against extractable nuclear antigens - RNP / Sm, Sm, SS-A (Ro) and SS-B (La) in the blood serum.Antibodies to the extracted nuclear antigens (ENA), the complexes are soluble ribonucleoproteins.Antibodies against various nuclear antigens - an important diagnostic feature for the monitoring and diagnosis of different rheumatic diseases.

  • antibodies to antigens RNP / Sm (antibodies to the protein components of the U1 - small nuclear ribonucleoprotein - U1RNK) show with mixed connective tissue disease, rarely systemic lupus erythematosus and other rheumatic diseases.Antibody concentrations did not correlate with the development and exacerbation of activity.Patients with systemic lupus erythematosus, in which blood serum contains antibodies to Sm
    -Ar, ribonucleoprotein antibodies do not detect.In order to exclude false-positive results using immunoblotingovy analysis.
  • Sm-Ar consists of five small nuclear RNA (U1, U2, U4, U5, U6), associated with the 11 or more of the polypeptides (A ', B' / B ', C, D, E, F, G).Antibodies to Sm antigen specific for systemic lupus erythematosus and are present in 30-40% of patients with the disease.These antibodies very rarely appear in other diseases of connective tissue (in the latter case the detection point to their combination of diseases).The concentration of antibodies to Sm antigen activity does not correlate with clinical subtypes and systemic lupus erythematosus.Antibodies to antigen Sm - one of the criteria for the diagnosis of systemic lupus erythematosus.

frequency of detection of antibodies to various extractable nuclear antigens

Type AT




Systemic lupus erythematosus



Systemic lupus erythematosus


Mixed connective tissue disease


SS-A (Ro)

Systemic lupus erythematosus


Systemic scleroderma


Neonatal lupus


Sjogren's syndrome


SS-B (La)

Systemic lupus erythematosus


Systemic scleroderma


Sjogren's syndrome



Systemic scleroderma


  • SS-a (Ro) - polypeptides form complexes with RNA Ro (hY1, hY3 and hY5).AT to Ar SS-A (Ro) most often found in the syndrome / disease Sjogren and systemic lupus erythematosus.In systemic lupus erythematosus production of these antibodies is associated with a certain set of clinical and laboratory manifestations of disorders: photosensitivity, Sjogren's syndrome, rheumatoid factor overproduction.The presence of these antibodies in the blood of pregnant women increases the risk of neonatal volchanochnopodobnogo syndrome in newborns.Ar AT to SS-A (Ro) can be elevated in 10% of patients with rheumatoid arthritis.
  • SS-B (La) Ar - nukleotsitoplazmatichesky fosfoproteinovy ​​complexed with small nuclear RNA Ro (Ro hY1-hY5), transkriptor RNA polymerase III.Antibodies to SS-Ar in (La) exhibit at the disease and Sjogren's syndrome (in 40-94%).In systemic lupus erythematosus, antibodies to SS-B (La) often detected early in the disease, which develops in old age (at 9-35%), and is associated with lower incidence of nephritis.
  • Scl-70-Ag - topoisomerase I - a protein with a molecular weight of 100 000 or a fragment thereof having a molecular weight of 67 to 000. AT increasingly Scl-70 was detected by the diffuse (40%), less often with limited (20%) form the systemscleroderma.They are highly specific for the disease (sensitivity 20-55% depending on the analytical method), and are a poor prognostic sign.The presence of Scl-70 antibodies in systemic sclerosis in conjunction with the carriage of the genes HLA-DR3 / DRw52 17-fold increased risk of developing pulmonary fibrosis.Detection of blood Scl-70 antibodies in patients with isolated Raynaud's phenomenon indicating a high probability of systemic scleroderma.