An ANA test on HEp-2 cells shows nucleolar staining in interphase cells. What is the most likely cause of this staining pattern?

An ANA test on HEp-2 cells shows nucleolar staining in interphase cells. What is the most likely cause of this staining pattern?

• A. Antifibrillarin antibody
• B. Antiribosomal p antibody
• C. A serum with nucleolar and homogeneous patterns
• D. Technical artifact

Answer: (A)

Nucleolar staining patterns observed in an ANA (antinuclear antibody) test performed on HEp-2 cells can be indicative of specific types of autoimmune profiles. When the staining appears predominantly nucleolar, it typically suggests the presence of antibodies directed against nucleolar components within the cell. The presence of antifibrillarin antibodies is particularly characteristic of certain autoimmune conditions, such as systemic sclerosis (scleroderma). These antibodies target fibrillarin, a protein found within the nucleolus, which explains the distinct nucleolar staining pattern observed in interphase cells. This association is well-documented in the clinical setting and helps in the diagnosis and characterization of autoimmune diseases. While antiribosomal P antibodies can also lead to specific staining patterns, they are more commonly associated with a diffuse staining in some other contexts, rather than a singular nucleolar pattern. Serum with mixed nucleolar and homogeneous patterns typically does not specifically denote a single antibody presence and can indicate a more varied autoimmune response. Lastly, a technical artifact would not result in a consistent and repeatable staining pattern observed across similar tests, which lending to the validity of the antifibrillarin antibody as the most likely cause of distinct nucleolar staining observed in this scenario. Thus, antifibrillarin antibody

Nucleolar staining patterns observed in an ANA (antinuclear antibody) test performed on HEp-2 cells can be indicative of specific types of autoimmune profiles. When the staining appears predominantly nucleolar, it typically suggests the presence of antibodies directed against nucleolar components within the cell.

The presence of antifibrillarin antibodies is particularly characteristic of certain autoimmune conditions, such as systemic sclerosis (scleroderma). These antibodies target fibrillarin, a protein found within the nucleolus, which explains the distinct nucleolar staining pattern observed in interphase cells. This association is well-documented in the clinical setting and helps in the diagnosis and characterization of autoimmune diseases.

While antiribosomal P antibodies can also lead to specific staining patterns, they are more commonly associated with a diffuse staining in some other contexts, rather than a singular nucleolar pattern. Serum with mixed nucleolar and homogeneous patterns typically does not specifically denote a single antibody presence and can indicate a more varied autoimmune response. Lastly, a technical artifact would not result in a consistent and repeatable staining pattern observed across similar tests, which lending to the validity of the antifibrillarin antibody as the most likely cause of distinct nucleolar staining observed in this scenario.

Thus, antifibrillarin antibody