Indicate whether the following laboratory assays are highly specific or nonspecific for RA:
1)Cyclic citrullinated peptide (CCP)antibodies
2)Antibodies to anti-perinuclear factor (APF)
3)Antibodies to keratin (AKA)
4)Antinuclear antibodies (ANAs)

Question

Quizplus · Accepted Answer

A,A,B
CCP antibodies are a highly specific indicator for RA.Antibodies to CCPs (anti-CCP1)were first described in 1998,following the introduction of commercial ELISA products using the so-called second-generation peptides.Antibodies to APF and AKA are highly specific for RA.Antibodies to APF are reported to be present in the sera of 49% to 91% of patients with RA,with specificity greater than 70%.ANAs have been found in 14% to 28% of patients with RA,who usually have advanced disease.However,disease manifestation is the same in ANA-positive and ANA-negative patients.

Indicate Whether the Following Laboratory Assays Are Highly Specific or Nonspecific