Speckled pattern refers to the presence of uniform or variable-sized speckles. This is one of the most commonly observed patterns of fluorescence and therefore the least specific. It reflects the presence of antibodies to non-DNA nuclear constituents such as Sm antigen, ribonucleoprotein, and SS-A and SS-B reactive antigens. Nucleolar pattern refers to the presence of a few discrete spots of fluorescence within the nucleus and represents antibodies to RNA. This pattern is repoed most often in patients with systemic sclerosis. Rim or peripheral staining patterns are most often indicative of antibodies to double-stranded DNA and sometimes to nuclear envelope proteins Centromeric pattern Patients with systemic sclerosis often contain antibodies specific for centromeres, which give rise to this pattern.