TY - JOUR
T1 - How should a District General Hospital immunology service screen for antinuclear antibodies?
T2 - An "in the field" audit
AU - Hira-Kazal, Ravina
AU - Shea-Simonds, Philip
AU - Peacock, Janet L
AU - Maher, John
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Antinuclear antibody (ANA) testing assists in the diagnosis of several immune-mediated disorders. The gold standard method for detection of these antibodies is by indirect immunofluorescence testing on HEp-2 cells. However, many laboratories test for these antibodies using solid phase assays such as ELISA, which allows for higher throughput testing at reduced cost. In this study, we have audited the performance of a previously established ELISA assay to screen for ANA, making comparison with the gold standard HEp-2 immunofluorescence test. A prospective and unselected sample of 89 consecutive ANA test requests by consultant rheumatologists were evaluated in parallel over a period of 10 months using both tests. ELISA and HEp-2 screening assays yielded 40 (45%) and 72 (81%) positive test results respectively, demonstrating lack of concordance between test methods. Using standard and clinical samples, it was demonstrated that the ELISA method did not detect several ANA with nucleolar, homogeneous and speckled immunofluorescence pattern. None of these ELISA(NEG) HEp-2(POS) ANA were reactive with a panel of 6 extractable nuclear antigens or with double stranded DNA. Nonetheless, thirteen of these samples (15%) originated from patients with recognised ANA-associated disease (n=7) or Raynaud's phenomenon (n=6). We conclude that ELISA screening may fail to detect clinically relevant ANA that lack defined specificity for antigen.
AB - Antinuclear antibody (ANA) testing assists in the diagnosis of several immune-mediated disorders. The gold standard method for detection of these antibodies is by indirect immunofluorescence testing on HEp-2 cells. However, many laboratories test for these antibodies using solid phase assays such as ELISA, which allows for higher throughput testing at reduced cost. In this study, we have audited the performance of a previously established ELISA assay to screen for ANA, making comparison with the gold standard HEp-2 immunofluorescence test. A prospective and unselected sample of 89 consecutive ANA test requests by consultant rheumatologists were evaluated in parallel over a period of 10 months using both tests. ELISA and HEp-2 screening assays yielded 40 (45%) and 72 (81%) positive test results respectively, demonstrating lack of concordance between test methods. Using standard and clinical samples, it was demonstrated that the ELISA method did not detect several ANA with nucleolar, homogeneous and speckled immunofluorescence pattern. None of these ELISA(NEG) HEp-2(POS) ANA were reactive with a panel of 6 extractable nuclear antigens or with double stranded DNA. Nonetheless, thirteen of these samples (15%) originated from patients with recognised ANA-associated disease (n=7) or Raynaud's phenomenon (n=6). We conclude that ELISA screening may fail to detect clinically relevant ANA that lack defined specificity for antigen.
U2 - 10.1111/cei.12556
DO - 10.1111/cei.12556
M3 - Article
C2 - 25412573
SN - 1365-2249
VL - 180
SP - 52
EP - 57
JO - Clinical and Experimental Immunology
JF - Clinical and Experimental Immunology
IS - 1
ER -