Аутоиммунная панель 18 антигенов

The PROTIA ANA Profile 18 (ANA-specific antibodies, ENA panel) assesses serum for a broad set of antinuclear IgG autoantibodies to support evaluation of suspected systemic autoimmune connective tissue diseases. It is commonly applied after a positive antinuclear antibody (ANA) screen to define antibody specificity and to aid the differential diagnosis of conditions such as systemic lupus erythematosus, Sjögren syndrome, systemic sclerosis, idiopathic inflammatory myopathies with overlap features, mixed connective tissue disease, and primary biliary cirrhosis. This panel may also be used alongside clinical assessment and routine laboratory data to track the course of known systemic connective tissue disorders. Results are not diagnostic in isolation and require integration with the patient’s presentation.

Antinuclear antibodies to extractable nuclear antigens are autoantibodies directed against soluble nuclear and ribonucleoprotein components. They are typically absent in healthy individuals but arise when immune tolerance is lost in systemic autoimmune diseases. After an initial positive ANA screen, immunoblotting provides antibody specificity and helps discriminate among connective tissue diseases by detecting multiple targets in parallel, which may occur alone or in combination. Some specificities co-occur because they recognize components of the same macromolecular complexes, such as SS-A with SS-B or RNP with Sm. Within this profile, anti-Sm antibodies (to U1-, U2-, and U4-ribonucleoproteins) are highly specific for systemic lupus erythematosus (SLE) and constitute a classification criterion, although titers do not reflect SLE activity. Anti-RNP targets U1-RNP and is typical of mixed connective tissue disease (Sharp syndrome), with less frequent detection in SLE and other rheumatic disorders. Anticentromere (CENP-B) antibodies appear in systemic sclerosis, SLE, and rheumatoid arthritis; in systemic sclerosis, they are associated with a more favorable course and a lower likelihood of internal organ involvement. SS-A (Ro) antibodies, directed against RNA-associated proteins, are most often found in Sjögren syndrome and SLE and in SLE correlate with photosensitivity, Sjögren features, and increased rheumatoid factor production; maternal SS-A positivity is linked to neonatal lupus risk. SS-B (La) antibodies occur in Sjögren syndrome and in late-onset SLE and are associated with a lower frequency of nephritis. Scl-70 (topoisomerase I) antibodies are highly specific for systemic sclerosis, more common in the diffuse form, and confer a poor prognosis for pulmonary fibrosis. Anti-PM/Scl marks a subset with scleroderma–polymyositis overlap. Anti-Jo-1 (histidyl–tRNA synthetase) is characteristic of antisynthetase syndromes, frequently accompanied by interstitial lung disease and Raynaud phenomenon, and it may have prognostic value for disease progression. Antihistone antibodies represent a subtype of ANA often seen early in SLE, while antinucleosome antibodies are sensitive for SLE, occur essentially only in SLE, and are often associated with lupus nephritis. Anti-dsDNA is a hallmark ANA specificity for SLE, and rising levels are part of SLE classification criteria. Anti-PCNA is another highly specific marker for SLE. Antibodies to ribosomal phosphoprotein P0 reflect immune responses to ribosomal P proteins, integral to protein synthesis. Results from the PROTIA ANA Profile 18 must be interpreted in the context of the clinical picture and other laboratory findings. Detection of disease-specific antibodies does not, by itself, establish a diagnosis, and a negative profile does not exclude a systemic autoimmune connective tissue disorder.