Results are reported as 'Negative' or 'Positive' with the antibody titre on HEp2 cells reported as:

1:80 (low level) to >1:640 (strongly positive)

A large number of staining patterns have been described but only the following most common patterns are reported here.

Homogeneous* Indicates presence of antibodies to dsDNA, ssDNA or histones. Suggestive of SLE but also found in other CTDs, drug-induced lupus and autoimmune liver disease.

Speckled ** Caused mainly by antibodies to Sm, RNP, Ro and La. Pattern found in SLE, mixed connective tissue disease (MCTD) and SS but also other CTDs.

Nucleolar** Caused by many autoantibodies including PM-Scl, Th/To, RNA Polymerase III, RNA and RNA Helicase. High titre associated with scleroderma, low titre found in other CTDs.

Centromere*** Most frequently found in CREST (Clacinosis, raynaud's phenomenon, Oesophageal dysmotility, Sclerodactyly and Telangectasia) variant of Progressive Systemic Sclerosis but also in Sjogren's disease and Raynaud's (where it is likely to indicate future CREST). Its presence in Primary Biliary Cirrhosis is indicative of a more severe disease progression.

Nuclear Membrane *** Found rarely in a variety of connective tissue diseases.

* A positive homogeneous pattern of 1:80 or greater (in any combination) will trigger a dsDNA ELISA.

** A positive speckled and/or nucleolar pattern of 1:160 or greater (in any combination) will trigger an ENA screen ELISA.

*** A positive centromere, nuclear dots or nuclear membrane staining pattern will trigger an Anti-Mitochondrial antibody +/- Mitochondrial M2 ELISA test.