The frequency of sicca syndrome in an elderly female population.

In a population of 103 elderly Caucasian women, 39% had sicca symptoms and 24% had abnormal Schirmer's tear tests. Two (2%) satisfied criteria for Sjögren's syndrome and 12 (12%) were felt to have possible Sjögren's syndrome. Fifty percent of those with sicca were taking medications that might induce mucosal dryness. Fibrosis was noted on all 23 labial minor salivary gland biopsy specimens obtained. Mucosal drying medications and senile salivary gland atrophy seemed to contribute to the high frequency of sicca in this population with a lesser proportion of the subjects demonstrating previously undiagnosed Sjögren's and possible Sjögren's syndrome.

Values of the U.S. National Reference Serum for human antibodies to native DNA obtained with commercial immunoassays for anti-DNA in systemic lupus erythematosus.

The Arthritis Foundation and the Centers for Disease Control have recently prepared a "U.S. National Reference Serum" for human antibodies to native DNA. We tested this serum with 13 commercial assays for antibodies to native DNA, to permit comparisons of the values obtained in each test. Titers ranged from 10 to 2560 in Crithidia luciliae immunofluorescence assays. The serum produced 794 int. units/mL in the Cordis ELISA assay, 136 Amersham units/mL in a radioimmunoassay, and 88 FIAX units in a fluorometric immunoassay. These results can be used for interlaboratory comparisons of differing methodologies for measuring anti-DNA.

Reproducibility studies for anti-DNA antibody detection in systemic lupus erythematosus and related diseases. FIAX fluorometric immunoassay and Farr radioimmunoassay.

We compared the FIAX fluorometric immunoassay for antiDNA antibodies with a Farr radio-immunoassay. Neither was precise; coefficients of variation usually exceeded 10%. The 2 assays correlated well (r = 0.87). Both were almost completely specific for numbers of sera with elevated antiDNA preferable to the Farr assay and probably to all other antiDNA assays currently used in clinical situations, although its reproducibility needs improvement.

Plasma concentrations of four pregnancy proteins in complications of pregnancy.

Toxemia of pregnancy was associated with an elevation of the pregnancy-associated plasma protein (PAPP)-A concentration, as compared to the level in normal pregnancy in the last month of gestation. The other pregnancy proteins measured were not altered in toxemia. In twin pregnancies, the PAPP-A, PAPP-C, and human placental lactogen levels were all increased, particularly PAPP-A. On the other hand, pregnancy zone protein was not affected by twinning. Pregnancy with diabetes showed normal levels of these proteins.