[Dense cytoplasmic fluorescence on Hep-2 cells: do not overlook anti-PL]

Area of Science:

• Immunology
• Autoimmunity
• Cellular fluorescence assays

Context:

• Dense cytoplasmic fluorescence on Hep-2000 cells can indicate various autoimmune conditions.
• Distinguishing between different autoantibodies is crucial for accurate diagnosis and patient management.

Purpose:

• To investigate dense cytoplasmic fluorescence on Hep-2000 cells for the presence of anti-PL antibodies.
• To differentiate anti-PL antibodies from other autoantibodies like anti-ribosomes, anti-JO1, and anti-SSA.

Summary:

• A study of twelve patients with dense cytoplasmic fluorescence on Hep-2000 cells was conducted.
• Testing excluded anti-ribosome and anti-JO1 antibodies, with sera sent for confirmation and anti-PL antibody detection.
• Results showed anti-PL7 (4 patients), anti-PL12 (3 patients), and anti-SSA antibodies (4 patients); one patient had no antibody detected.

Impact:

• Systematic exploration of dense cytoplasmic fluorescence efficiently diagnosed five new cases of antisynthetase syndrome, including three not clinically suspected.
• Improved recognition of anti-PL antibodies, preventing confusion with anti-SSA antibodies.
• Enhanced diagnostic capabilities for autoimmune myopathies.