Tests for Autoimmune Diseases

Quest Diagnostics clinical FAQ (FAQS.177 v4) on autoimmune testing covering IFA vs multiplex ANA approaches, pattern significance, reflex antibody cascades, screening titer change to 1:80 in 2026, and prevalence of specific autoantibodies. Candidate notes: ANA IFA on HEp-2 is a traditional first-line SARD screen; combining IFA with antigen-specific screening can improve sensitivity and specificity versus either alone. Negative ANA IFA usually predicts negative specific ANA antibodies, with exceptions such as Jo-1 in some myositis and SSA in some SLE/Sjogren cases. Positive ANA IFA reflexes to titer and pattern; titers <1:80 may associate with preclinical disease or lack of disease, while titers >1:80 are described as consistent with autoimmune disease (still requiring clinical context). Quest reports nuclear, cytoplasmic, and mitotic patterns per ICAP when observed, each with corresponding titer. In 2026 Quest moved ANA screening dilution from 1:40 to 1:80 to increase specificity; healthy-population positivity ~20% at 1:40 vs ~10% at 1:80 (per cited studies). Multiplex screens limited to ~11 autoantibodies are less sensitive than IFA, which can detect ~150 autoantibodies. Limits noted in the record: Laboratory FAQ reflecting Quest methods and panels; Document FAQS.177 Version 4 effective 06/08/2026. 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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