Table 3. Current practice in assessment of ANA testing.
|
Laboratories performing ANA testing (N = 17) |
N (proportion) |
|---|---|
| Method | |
| IIF on Hep-2 cells | 7 (0.41) |
| FEIA | 6 (0.35) |
| ELISA | 3 (0.18) |
| Line - blot | 1 (0.06) |
| Assessment of ANA by IIF on Hep-2 cells (N = 7) |
N (proportion) |
| 1. Fluorescence patterns on Hep-2 cells recognized and reported: | |
| Homogenous | 7 (1.0) |
| Speckled | 7 (1.0) |
| Centromere | 7 (1.0) |
| Nucleolar | 7 (1.0) |
| Nuclear envelope | 5 (0.71) |
| Mitotic apparatus | 4 (0.57) |
| Fluorescence of cytoplasm | 6 (0.86) |
| Nuclear dots | 4 (0.57) |
| PCNA– like pattern | 3 (0.43) |
| 2. Initial sample dilution: | |
| 1 / 100 | 6 (0.86) |
| 1 / 80 | 1 (0.14) |
| 3. Titration: | |
| Yes | 6 (0.86) |
| No | 1 (0.14) |
| 4. Titration up to: | |
| dilution with the last detectable fluorescence | 2 (0.29) |
| 1 / 320 | 2 (0.29) |
| 1 / 10,000 | 1 (0.14) |
| 1 / 40,960 | 1 (0.14) |
| we do not determine the titer | 1 (0.14) |
| 5. Reporting of different patterns of fluorescence in the same sample: | |
| Different fluorescence patterns but with only one titre | 4 (0.57) |
| Different fluorescence patterns with corresponding titres | 2 (0.29) |
| Different fluorescence patterns without titre | 1 (0.14) |
| 6. Inclusion of interpretative comment on report: | |
| Yes, in the case of fluorescence pattern indicating the presence of unusual antibodies (Golgi, lysosomes, peroxisomes, etc) | 3 (0.43)* |
| Yes, in the case of cytoplasmic fluorescence patterns indicating the presence of SMA or AMA. | 4 (0.57)* |
| No interpretative comment on report | 1 (0.14) |
| 7. Examination of IIF slides: | |
| Exclusively by one examiner | 1 (0.14) |
| By two examiners with report issued in agreement | 3 (0.43) |
| By one examiner in consultation with another if necessary | 3 (0.43) |
| 8. Examination of IIF slides is done by: | |
| Specialist in medical biochemistry and laboratory medicine | 4 (0.57) |
| Master of medical biochemistry and laboratory medicine | 2 (0.29) |
| Master of molecular biology | 1 (0.14) |
| Assesment of ANA by methods other than IIF (N = 10) | N (proportion) |
| 1. Specification of included antigens on laboratory report | |
| Yes | 5 (0.5) |
| No | 5 (0.5) |
| Reflex testing for antibody specificities in ANA-screen positive samples (irrespective of method) (N = 14) ** | N (proportion) |
| No | 6 (0.43) |
| Yes, depending on the ANA titre | 4 (0.29) |
| Yes, depending on the fluorescence pattern | 2 (0.14) |
| If requested, irrespectively of ANA-screen test result | 2 (0.14) |
| *One laboratory applies both offered options.**Answers obtained for 14 out of 17 laboratories that perform ANA testing. ANA = antinuclear antibodies. IIF = Indirect immunofluorescence. Hep-2 cells = Human epithelial type 2 cells. FEIA = Fluorescence enzyme immunoassay. ELISA = Enzyme-linked immunosorbent assay. PCNA = Pleomorphic cell nuclear antigen. SMA = Smooth muscle antibodies. AMA = antimitochondrial antibodies. | |