Assessment of antinuclear antibodies (ANA): National recommendations on behalf of the Croatian society of medical biochemistry and laboratory medicine

National laboratory recommendations (27 items) for ANA testing adapted from EASI international recommendations. Covers IIF HEp-2 as reference method, titer cutoffs, ICAP reporting, reflex algorithms, and explicit advice that serial ANA titer monitoring is not indicated for disease activity. Candidate notes: ANA-screen assay should be used for diagnostic purposes only and not for follow-up of disease activity or therapy response. IIF on HEp-2 (or HEp-2000) is the reference/gold-standard first-line ANA screen. Weak ANA may be found in ~30% of healthy subjects at 1:40 and ~5% at 1:160. International recommendations cited recommend screening cutoff around 1:160 for adults; titration of positives at least to clinically significant titer ~1:640. Specific antibody testing generally after positive IIF (often titer >=1:160), guided by pattern; exceptions for clinical suspicion of Jo-1, SS-A, ribosomal P despite negative IIF. Variation in ANA titer over time has no established clinical significance and should not guide therapy adjustment. Anti-dsDNA dynamics can correlate with SLE activity and flares; repeat anti-dsDNA is clinically justified, unlike routine serial ANA/ENA. Limits noted in the record: National (Croatia) recommendations; some cutoff choices and algorithms vary by local care setting. A positive ANA is not a diagnosis. Claims in this record are not verified.

A positive ANA is not a diagnosis. Claims in this record are not verified.

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