Ankylosing Spondylitis has vague clinical manifestations and is often misdiagnosed or diagnosed late!
|Flow Cytometry – Indentifies HLA – B27 alleles based on cell morphology||PCR – identifies the Gene encoding the HLA – B27 allele|
|It provides False – Positive results.|
1) It cannot distinguish between HLA – B27 subtypes. Hence, gives a positive result even for HLA – B27:06 and HLA – B27:09 which are not associated with Ankylosing Spondylitis
|Provides True-negative results & True positive results.|
1) Can distinguish between HLA – B27 subtypes
2) Provides Negative results of HLA – B27:06 and HLA – B27:09 which are not associated with Ankylosing Spondylitis
|Provides intermediate / borderline results in 2 – 3% cases||Intermediate / Borderline samples can be classified as positive or negative|