Anti-pseudo-PCNA type 1 (anti-SG2NA) pattern: Track down Cancer, not SLE

Abstract Objective Describe the clinical significance of anti-SG2NA antibodies also called anti-pseudo-PCNA type 1 (proliferating cell nuclear antigen auto-antibodies) which are rare antinuclear antibodies (ANAs) staining distinctly S/G2 proliferative HEp-2 cells by indirect immunofluorescence. By analogy with anti-PCNA antibodies, they have been suspected to be associated with systemic lupus erythematosus (SLE), cancers or viral diseases. Methods From May 2006 to February 2013, 16,827 patients were tested positive for ANAs in the Laboratory of Immunology, Strasbourg, France. We retrospectively analyzed clinical and biological data from 126 patients with anti-pseudo-PCNA type 1 antibodies. Results There was a 0.75% prevalence of anti-pseudo-PCNA type 1 Abs among ANAs + patients. Median age was 56.9 years (standard deviation [SD] 13.4 years) with a sex ratio female/male of 1.9. Compared to ANAs + patients, many more patients have been hospitalized in the Oncology and Hematology Department (23% vs. 6.3%, P + Abs group ( P −6 ) were. Finally, the presence of anti-pseudo-PCNA type 1 Abs was associated in 30 cases with other auto-Abs reflecting a more general breakdown of B cell tolerance against other self-antigens. Conclusion Considering our results, explorations for tumors should be at least recommended for patients with anti-pseudo-PCNA type 1 Abs. Lupus disease is not associated with these autoAbs.