A nuclear antigen associated with cell proliferation (proliferating cell nuclear antigen-PCNA) and blast transformation is recognized by autoantibodies in the sera of some patients with systemic lupus erythematosus. This autoantibody is a precipitating antibody and also reacts in immunofluorescence, staining the nucleoplasm of proliferating and blast-transformed cells. The autoantibody was used as a reagent to determine the distribution of PCNA in a synchronized continuous B lymphoid cell line (WiL-2) and in mitogen-induced blast-transformed lymphocytes. In WiL-2 cells, PCNA was detected as speckled nucleoplasmic staining in G1, S, and G2 phases of the cell cycle. In addition, during late G1 and early S phases, PCNA was also detected in the nucleolus. During mitogen-induced blast transformation of lymphocytes, PCNA was noticed in the nucleolus before the initiation of DNA synthesis and later became nucleoplasmic with disappearance of nucleolar staining. These studies demonstrate that the relationship of PCNA to proliferation and blast transformation may be associated with events related to DNA synthesis in these cells.
Using highly monospecific anti‐SS‐A containing sera and specific antibody to SS‐A antigen dissociated from immune precipitates, tissue sections and cell culture lines were evaluated by the indirect immunofluorescence technique to determine the intracellular location, tissue distribution, and species specificity of the SS‐A/Ro antigen. The SS‐A/Ro antigen is predominantly a nuclear antigen giving an immunofluorescence staining pattern of discrete nuclear speckles. The SS‐A/Ro antigen is present in a wide variety of human tissue, including kidney and liver parenchymal cells, lymphocytes, fibroblasts, and epithelioid cells. However, the SS‐A/Ro antigen does appear to have a variable species distribution, with significant quantities of the antigen detected by immunofluorescence in cells of human, monkey, dog, and guinea pig, but absent to low amounts detected in cells of mouse, rat, rabbit, hamster, and chicken.
In 155 women with systemic lupus erythematosus, there were no significant differences in the rates of fertility or adverse fetal outcome between the 47 (30%) with serum anti-SS-A antibody and the 108 without anti-SS-A, except in the frequency of congenital heart block. This complication occurred in 6 of 96 pregnancies in women with anti-SS-A and was associated with high-titer maternal antibody. The overall risk of a woman with lupus having an infant with congenital heart block was estimated to be 1:60, but the risk was considerably higher (1:20) if anti-SS-A antibody was present.Systemic lupus erythematosus (SLE) is a connective tissue disorder that occurs primarily in women during the childbearing years. It is characterized by
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