Anti-Rib-P

The test is designated to determine the quantity of IgG antibodies to ribosomal P-proteins in human serum. Common epitope of three phosphoproteins P0, P1 and P2 of the 60s subunit of the ribosomal complex is recognized. Similar to anti-nuclear antibodies (ANA), the anti-cytoplasmic antibodies act in the rheumatic diseases. Antiribosomal antibodies (ARA) are best distinguished of them. Autoantibodies to ribosomal P-proteins are highly specific markers for the diagnosis of systemic lupus erythematosus, as they are rarely found in other autoimmune diseases. ARA is found in only 10% of randomly selected SLE population, but it is found in up to 40% of active SLE population. It is recommended to test for anti-Rib-P in cases of suspected SLE, when Sm antigen and double-stranded DNA antibodies are absent. It is also recommended to test for suspected lupus-induced psychosis.