Guide interpretation to ANA profiles

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Rheumatology

Diagnostics Laboratory:

ANA Profiles in

ANA Positive Rheumatic Disease

Guide to Interpretation

Antibody Specificity

Active SLE

MCTD

PSS

CREST

1° Sjogren's

RA

Drug Induced SLE

ANA

> 95%

> 95%

70-90%

60-90%

> 70%

40-50%

100%

Anti-ds DNA

60%

neg

neg

neg

neg

rare

neg

Anti-Sm

30%

neg

neg

neg

neg

neg

neg

Anti-RNP

30%

> 95%

(high titer)

common

(low titer)

neg

rare

(low

titer)

rare

10-20%

(low

titer)

Anti-Centromere

rare

rare

10-15%

60-90%

neg

neg

neg

Anti-Ro

(SS-A)

30%

rare

rare

neg

70%

rare

neg

Anti-La

(SS-

15%

rare

rare

neg

60%

rare

neg

Anti-Nucleolar

occas.

neg

common

neg

occas.

rare

neg

Anti-Scl-70

neg

neg

10-20%

neg

neg

neg

neg

Anti-Histone

60%

neg

occas.

occas.

neg

20%

95%

GUIDE TO INTERPRETATION

1. A negative ANA

excludes active SLE in > 95% of cases.

2. False-positive ANAs occur in <5% of healthy adults - usually with low

titer and homogeneous pattern. The number of false positives increases with

age.

3. Positive ANAs lack specificity, and can be seen in many autoimmune

rheumatic diseases, chronic inflammatory and infectious diseases, and can be

induced by certain drugs.

4. Anti-Centromere Ab strongly suggest

CREST Syndrome and is occasionally seen in PSS and Raynaud's.

5. Anti-ds DNA Abs are essentially restricted to SLE, and rarely

severe RA. Increases in anti-ds DNA Ab titers predict flares

in SLE.

6. Anti-Sm is highly specific for SLE.

7. High titered Anti-RNP (>1:10,000) is characteristic of MCTD,

particularly if unaccompanied by other ANAs.

8. Anti-RNP is

commonly seen in SLE, but titers are usually modest.

9. Anti-RNP can also

be seen in PSS, myositis and rarely in other

ANA-positive rheumatic diseases, again in low to modest titers.

10. Anti-Ro and

Anti-La are seen in 1° Sjogren's Syndrome

>SLE> 2° Sjogren's.

11. Anti-Ro is

strongly linked with neonatal lupus, subacute cutaneous LE, as well as homozygous C2 deficiency

accompanied by an SLE-like illness.

12. Anti-Scl-70 (anti-topoisomerase 1) is seen exclusively in Progressive

Systemic Sclerosis.

13. Anti-Cardiolipin Abs are the hallmark of antiphospolipid

syndromes and identify patients at risk for arterial and venous thromboembolic episodes, recurrent fetal loss and

thrombocytopenia.

14. Anti-PCNA Abs are highly specific for SLE.

15. Anti-Ribosomal P

Protein Abs are associated with SLE psychosis.

16. Anti-mitochondrial Abs are associated with primary biliary

einbosis, scleroderma and

CREST syndrome.

Hugs,

Deanna