The risk of cancer was ascertained in 136 women with sicca syndrome followed at the National Institutes of Health (NIH). Seven patients developed non-Hodgkin's lymphoma from 6 months to 13 years after their first admission to NIH. This was 43.8 times (P less than 0.01) the incidence expected from the rates of cancer prevailing among women of the same age range in the general population during this time. In addition, three cases of Waldenstrom's macroglobulinemia occurred in this study group. Eight patients developed cancers other than lymphoma, similar to the number expected based on the rates prevailing in the general population. Patients with a history of parotid enlargement, splenomegaly, and lymphadenopahy had an increased risk of lymphoma. These clinical conditions did not appear to be early manifestations of undiagnosed lymphoma but rather seemed to identify a subgroup of patients with sicca syndrome with marked lymphoid reactivity, who had a particularly high risk of subsequently developing lymphoma.

Increased Risk of Lymphoma in Sicca Syndrome

Publisher Summary Autoantibodies to nuclear antigens (ANAs) have assumed an important place in the diagnostic armamentarium of the clinician because of distinct profiles of ANAs in different diseases. Profiles of ANAs have, therefore, been extremely useful in differential diagnosis, where the disease does not have classical or full-blown manifestations.. Immune complexes formed in the circulation or in situ mediate tissue injury by the activation of complement and other inflammatory mediators. Not only do these antibodies precipitate their respective antigens but also other proteins or nuclear RNAs that might be associated with them in special ways. The reasons for these special associations of protein antigens with specific sets of nuclear RNAs is unknown, but the possibility that there might be functional relationships in these complexed particles is not unreasonable. The key question that pervades the minds of many investigators in this field is the reason for the appearance of ANAs in certain individuals. It is highly improbable that the phenomenon is a random immune response to nuclear breakdown products, because the types of ANAs in different diseases are strikingly different. Some known environmental agents are drugs, such as hydralazine and procainamide, that together with lower levels of hepatic acetyltransferase enzyme predispose the host to the development of ANAs. Another agent may be the Epstein–Barr virus that is a ubiquitous environmental agent.

Autoantibodies to nuclear antigens (ANA): their immunobiology and medicine.

Autoantibody Explosion in Systemic Lupus Erythematosus: More Than 100 Different Antibodies Found in SLE Patients

Antinuclear antibodies wer demonstrated in the sera of 43 of 45 (96%) patients with progressive systemic sclerosis (22 of 24 with diffuse scleroderma and 21 of 21 with the CREST syndrome variant). This high percentage of positive reactions resulted from the use of a tissue culture substrate (Hep-2) to detect antinuclear antibodies by the indirect immunofluorescent method. Patterns of nuclear staining included diffuse fine speckles, large coarse speckles, nucleolar and centromere staining. When organ sections such as mouse kidney were used as substrate for the detection of antinuclear antibodies, nucleolar staining and centromere staining were the two patterns most frequently overlooked. Three types of antibodies appeared to be highly specific for scleroderma: antibody to Sc1-70 antigen, antibody to centromere, and antinucleolar antibody. The anti-centromere antibody appeared to be highly selective for the CREST variant of progressive systemic sclerosis.

Diversity of antinuclear antibodies in progressive systemic sclerosis

The RNP and Sm antigens recognized by lupus erythematosus antibodies are located on discrete particles containing single small nuclear RNA's complexed with proteins. The antigens Ro and La are also on ribonucleoproteins. The small RNA's in ribonucleoproteins with Ro are discrete, like those associated with RNP and Sm; in contrast, ribonucleoproteins with La contain a striking highly banded spectrum of small RNA's from uninfected cells as well as virus-associated RNA from adenovirus-infected cells.

https://science.sciencemag.org/content/sci/211/4480/400.full.pdf

Two novel classes of small ribonucleoproteins detected by antibodies associated with lupus erythematosus.

Autoantibodies in Sjogren's syndrome (SS) were identified by their precipitin reactions with tissue antigens in immunodiffusion. The source of antigens was a sonicated extract of human lymphoid cells (WiI2) grown in tissue culture. Three distinct precipitin systems were identified and referred to as precipitins SS-A and SS-B, and rheumatoid arthritis precipitin. These studies show that precipitins SS-A and SS-B are present in high frequency in sera of patients with SS without associated rheuamtoid arthritis (RA) and are absent or present in low frequency in many other connective tissue diseases. On the other hand patients with SS who also had clinical features compatible with RA (SS-RA) did not have precipitins SS-A and SS-B but had rheumatoid arthritis precipitin (RAP). The latter precipitin was also present in RA patients in a similar order of frequency as in SS-RA. All three precipitin systems were shown to be reactions betweeen immunoglobulins and cellular antigens. The origin of SS-A and SS-B antigens was demonstrated by immunofluorescence to be primarily from the nucleus but the origin of RAP in the cell has not been established.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780190214

Differentiation and characterization of autoantibodies and their antigens in Sjögren's syndrome.

Randomly selected sera from 88 patients with systemic lupus erythematosus (SLE) were studied for the frequency of antibodies to SS-A, SS-B, RANA, RNP, Sm, Sc-1, and dsDNA. Results were in agreement with previous reports except for an increased incidence of anti-SS-A antibody (33%). Nine of 14 patients with anti-SS-A antibody on whom serial studies were performed had fluctuating titers. Titer changes often correlated with disease activity and dsDNA antibody levels.

Anti-SS-A antibody and other antinuclear antibodies in systemic lupus erythematosus.

Sera from 48 patients with Sjogren's syndrome were examined for immune complexes by the Raji cell assay. There was no correlation between levels of immune complexes and the degree of lymphocytic infiltration of the labial salivary glands. Serum complement levels were normal. Five patients were serially followed during the development of pseudolymphoma or malignant lymphoma. Immune complex levels in 4 of the 5 patients were generally unchanged throughout the illness and did not parallel disease activity, rheumatoid factor, or SS-A and SS-B concentrations. Possible roles for immune complexes in Sjogren's syndrome are discussed.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/art.1780230703

Margaret A. Alspaugh

Papers

Differentiation and characterization of autoantibodies and their antigens in Sjögren's syndrome.

Anti-SS-A antibody and other antinuclear antibodies in systemic lupus erythematosus.

Immune complexes in Sjögren's syndrome.