Clinical utility of screening for antinuclear antibodies by enzyme immunoassay--a preliminary study.
Article
in English
| IMSEAR
| ID: sea-93146
ABSTRACT
AIMS OF THE STUDY To evaluate the advantages and reliability of screening for antinuclear antibodies (ANA) by enzyme immunoassay (ELISA). METHODOLOGY:
Sera from 96 patients comprising 51 with systemic lupus erythematosus (SLE), 11 with other systemic rheumatological diseases (SRD) and 34 with various other diseases (non-SRD) were tested using a commercial ELISA kit (ANA-Ease, Genesis Biotechnology, U.K.). These sera consisted of 53 immunofluorescence assay (IF) ANA-positive and 43 IF ANA-negative samplesRESULTS:
We observed that when compared to the IF for ANA the sensitivity, specificity, predictive values for positives (PPV) and negatives (NPV) of ELISA were 90.7%, 85.7%, 89.1% and 87.8% respectively. Exclusion of borderline ELISA positive by slightly raising the cut-off optical density (OD) increased the specificity and PPV to 93.1%, and 94.1% respectively. Importantly, none of the non-SRD sera were positive when this higher cut-off was used. ELISA was noted to be strongly positive in three IF ANA-negative SLE patients. However there was no correlation between the ELISA ANA semi-quantitative index and the IF ANA titers.CONCLUSIONS:
ELISA appears to be suitable as a preliminary screening test for ANA. An appropriate cut-off should be identified to segregate low positive samples that could be false-positives. Nevertheless, IF will need to be performed to estimate the titers, identify patterns of ANA positive samples and confirm results of low positive "gray-zone" samples and ELISA negative sera from patients with a high index of clinical suspicion of SLE.
Full text:
Available
Index:
IMSEAR (South-East Asia)
Main subject:
Humans
/
Enzyme-Linked Immunosorbent Assay
/
Biomarkers
/
Mass Screening
/
Antibodies, Antinuclear
/
Predictive Value of Tests
/
Sensitivity and Specificity
/
False Negative Reactions
/
False Positive Reactions
/
Lupus Erythematosus, Systemic
Type of study:
Diagnostic study
/
Evaluation studies
/
Prognostic study
/
Screening study
Language:
English
Year:
2004
Type:
Article
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