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Management of Systemic Lupus Erythematosus

           The  2019  European  Alliance  of  Associations  for  Rheumatology/
           American College of Rheumatology (EULAR/ACR) classification criteria
           for SLE include a positive ANA ≥1:80 by HEp-2 IIF at least once, as an
           obligatory entry criterion. 23

           •   Anti-double stranded deoxyribonucleic acid antibodies
           Anti-dsDNA  antibodies  react  against  antigenic  determining  factors
           present  in  the  deoxyribonucleic  acid  (DNA).  It  is  highly  specific  for
           the  diagnosis  of  SLE  with  ≥90%  specificity. 23;  24,  level  III   Anti-dsDNA
           antibodies are identified in 60 - 80% of SLE patients and only <2.5% in
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           healthy controls.
           •   Extractable nuclear antigen autoantibodies
           Autoantibodies  to  ENA  are  important  diagnostic  markers  for  several
           systemic autoimmune diseases including SLE. Among ENA antibodies
           for  SLE  are  anti-Smith  (anti-Sm),  anti-Sjögren’s-syndrome-related
           antigen A (anti-SSA), anti-Sjögren’s-syndrome-related antigen B (anti-
           SSB) and antibodies to ribonucleoprotein (anti-RNP).

           Anti-Sm antibodies are highly specific and predictive but less sensitive
           compared with ANA in the diagnosis of SLE. They are never found in
           healthy individuals and rarely identified in patients with other rheumatic
           disease. 21; 23
           Anti-SSA  and  anti-SSB  are  also  known  as  anti-Ro  and  anti-La
           autoantibodies  respectively.  Both  have  the  highest  prevalence
           in  Sjögren’s  syndrome  where  the  presence  of  anti-Ro  antibodies
           constitutes  a  classification  criterion.  The  prevalence  of  anti-Ro  and
           anti-La antibodies in SLE patients is around 25 - 30% and 10 - 15%
           respectively. 25, level III

           Anti-RNP  are  antibodies  against  small  ribonucleic  acid  (RNA)
           component  of nuclear  riboproteins  and  have  structural similarities
           with  anti-Sm  antibodies.  They  are  present  in  25  -  40%  of  SLE
           patients. 25, level III

           Anti-SSA/SSB  and  anti-RNP  antibodies  are  less-specific  markers
           of  SLE as they are found in other autoimmune rheumatic disorders as
           well  as  SLE. 21;  23   However,  these  antibodies  were  associated  with
           pulmonary arterial hypertension in a case-control study on patients with
           SLE: 26, level II-2
               anti-RNP (OR=12.399, 95% CI 3.581 to 42.934)
               anti-SSA (OR=4.836, 95% CI 1.675 to 13.598)
           •   Antiphospholipid antibodies
           aPL are autoantibodies directed against phospholipid-binding proteins.
           The common clinical assays for aPL include lupus anticoagulant (LA)

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