Ena $$$

Antibodies against nuclear and cytoplasmic components soluble at physiological salt concentrations:

• Sm antibodies
• SS-A(Ro antibody)
• SS-B(La antibody)
• U1-RNp antibody
• Scl-70 antibody
• CENP-B (centromere protein B)
• Mi-1 antibody,
• Mi-2 antibody
• Jo-1 antibody
• PM-1 antibody
• Histones (histone proteins and histone complexes)
• PM-Scl (polymyositis scleroderma antigen)
• pCNA (Proliferating cell nuclear antigen - cyclin)
• Fibrillarin (protein of the U3-RNP)

• U1-RNP antibodies are characteristic for mixed connective tissue disease (mixed collagenosis or Sharp syndrome).
• Centromere antibodies are typical for the limited form of systemic scleroderma (formerly known as CREST syndrome ).
• In the diffuse form of systemic scleroderma, antibodies against antitopoisomerase 1 (SCL-70) are often found.
• Sm-antibodies are diagnostic guidelines for systemic lupus erythematosus.
• Ro-(SSA)-antibodies as well as La-(SSB)-antibodies are indicative of Sjögren's syndrome and subacute cutaneous lupus erythematosus.

The term ENA is historically explained by the extraction of nuclear, nucleolar or subcellular antigens from the nucleus or cytoplasm, respectively. Today, many "extractable antigens" are molecularly defined.

The naming has not been uniform so far. They were named either after the first letters of the patients in whom the respective antibody was first detected (e.g. Sm after Smith, Ro after Robert), after the biochemical structure of the antigen (RNP=ribonucleoprotein) or after the clinical picture in which this AK was first detected (SCL-70 = scleroderma).