Antibodies against the soluble nuclear antigen, also called ENA (for extractable nuclear antigen) antibody or antiextraits thymus cells (anti-ECT) recognize soluble compounds of the nucleus. Only a small number of them are sought routinely.
Balance sheet of connective.
Venous blood clotted.
These antibodies are not present in normal subjects.
The anti-Sm antibodies (discovered for the first time in a patient named Smith) is very specific for systemic lupus erythematosus (SLE), but it is observed in 30% of cases.
When it exists, it ensures the diagnosis.
The anti-RNP antibody directed against ribonucleoprotein (RNP) nuclear, is suggestive of a MCTD (or MCTD) when present at high titer.
It is also observed in 30 to 40% of lupus and 10 to 20% of Sjogren’s syndrome.
Anti-SSA (or anti-Ro) antibody and anti-SSB (or anti-La):
The anti-SSA antibody (anti-Ro) and / or anti-SSB antibodies (or anti-La) are specific for Sjögren’s syndrome where they are found in about 90% of cases by ELISA.
The anti-SSA is also present in SLE (30% of cases).
Antihistones antibodies can detect lupus induced by drugs (isoniazid, hydralazine, hydantoins, procainamide, etc.):
• a high titer of histone antibodies, contrasting with low titer or no anti-dsDNA antibodies, lupus drug recalls;
• conversely, the absence of antibody antihistones exclude the diagnosis of drug-induced lupus.
Some antinuclear antibodies:
Lupus anti dsDNA
Lupus drug antihistones so isolated
Anti-SSA (anti-Ro) Sjögren’s syndrome
Anti-SSB (anti-La) Sjögren’s syndrome