Diagnosis of Anti-Nuclear Antibody Using Calf Thymus Coated Glass in Patient with Lupusf Thymus Coated Glass in Patient with Lupus

Indirect immunofluorescence test is a most common test for the detection of Systemic Lupus Erythematosis (SLE), however, it is very expensive and is not easily available for all field laboratories. We aimed to evaluate the diagnostic performance of five micrometer thick sections prepared from bovine thymus for the detection of SLE patients.
Totally 48 serum samples (25 negative and 23 positive) were drained from SLE suspected patients. Bovine thymus was purchased from the slaughterhouses. Five micrometer thick sections prepared from bovine thymus. Also rat liver was prepared through the laboratory animal dissection, and assayed in parallel with HEp-2 tests. Two fold serial dilutions (1:40 to 1:640) were prepared for each serum sample using phosphate buffer solution and assayed for ANA. Immunostained cells were observed using a blue filter equiped fluorescent microscope with 200x magnification and any bright green fluorescence accumulation in the cell nucleus was considered as positive for the presence of ANA.
Our findings showed sections prepared from thymus cells can be used for the detection of ANA in patient samples and the calculated sensitivity, specificity and accuracy of the test were 82.6%, 100% and 91.7%, respectively. Positive predictive value and negative predictive value of the test were 100% and 86.2%, respectively.
We concluded that thymic cells can be easily prepared and used for detection of ANA in SLE patients. However, minor improvements in section preparation and assay conditions as well as determination of a new cut off point is necessary to gain 100% efficiency of the assay.