The ANA IFA method is perceived to have major advantages by offering both semi-quantitation and “pattern”. In the hands of the skilled observer, pattern indicates the specific autoimmune antigen and thus the probable associated disease. At the common screening dilution of 1:40, laboratories routinely experience between 70 – 85% negative results. Another group of specimens are positive at the screening dilution but titer no higher, raising issues of interpretation of weak positive results. Some laboratories have sought to reduce this problem by screening at a higher dilution. Positive results at this higher dilution can be judged as significant.
    With the increased recognition that possible underlying autoimmune phenomenon may be associated with a variety of diseases, the percentage of screen-negative specimens is likely to increase, perhaps substantially. Simultaneously, the same skill and equipment resources needed to perform ANA screening by IFA, are also engaged in performing numerous non-autoimmune IFA assays such as infectious disease serology.
     This situation is an ideal setting for automation. Replacement of manual, subjective initial screening with an automated ELISA based assay that can identify all specimens requiring IFA titer and pattern analysis, provides an opportunity to manage laboratory workflow more effectively and focus resources to gain maximum benefit.