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