Circulating antibodies to certain nuclear antigens are of diagnostic use and contribute to our ability to determine prognosis in terms of predicting particular organ system involvement in the rheumatic diseases. Examples include antibodies to DNA and to the Sm antigen associated with systemic lupus erythematosus (SLE) (l), antibodies to nuclear ribonucleoprotein n-RNP associated with mixed connective tissue disease (2), and antibodies to another nucleic acidic protein antigen, PM-1, which have a high specificity for polymyositis (3). A recent report of 16 patients who had circulating Sm antibodies suggested that this serologic pattern might be indicative of a more benign form of SLE with nonprogressive nephritis (4). The purpose of the present study was to compare the disease patterns in patients with circulating Sm and DNA antibodies and to determine the relative importance of the presence of Sm antibody or the absence of DNA antibody in the disease which occurred. MATERIALS AND METHODSCalf thymus nuclear extract, extractable nuclear antigen (ENA), and DNA were prepared by previously published techniques (5). The Sm antigen was prepared from the washed DNA-histone fraction of the nuclear extract. The resulting pellet was treated with DNase (Worthington Biochemical Corporation) for one hour at 37OC in the presence of 5 M/ml of MgCI,. The resulting supernatant, which had Sm antigen activity but no RNP activity, was further concentrated by 30% saturated ammonium sulfate, lyophilized, and stored at -10°C. This partially purified Sm antigen was then used in hemagglutination to determine the Sm antibody titer.All sera were analyzed for the presence of Sm and n-RNP by passive hemagglutination (2), immunodiffusion (6), and counterimmunoelectrophoresis (7) according to pre-

Hyperprolactinemia has been reported in some patients with active systemic lupus erythematosus (SLE). To determine if there was an association between selected autoantibodies and hyperprolactinemia, we assayed prolactin concentrations in sera from women submitted to a reference antinuclear antibody laboratory. Autoantibody-positive samples were separated into groups that contained antibodies to double-stranded DNA (anti-DNA), antibodies to SSA/Ro (anti-SSA/Ro), or antibodies to both SSA/Ro and SSB/La (anti-SSA/Ro-SSB/La). Results were compared with autoantibody-negative sera from age-matched women, submitted to the same laboratory. We also compared the study groups with a separate cohort of 84 healthy women who were not referred for autoantibody testing. Elevated prolactin levels were clustered in 20% of sera from anti-DNA-positive women < or = 50 years of age. Twenty-one percent of anti-SSA/Ro-SSB/La-positive women < 50 years of age were hyperprolactinemic. Four of the 15 hyperprolactinemic women identified in this survey had no known cause of elevated prolactin. In the other 11 individuals secondary causes such as hypothyroidism, pregnancy, chronic renal failure, and medications may have accounted for high serum prolactin values. We also examined sera by Western blot, to determine if immunoblot patterns were associated with elevated serum prolactin concentrations. The hyperprolactinemic sera yielded novel bands migrating at 70 kd, 32 kd, and 16.5 kd. This study confirmed the reported associations of hyperprolactinemia with SLE and Sjögren's syndrome. Multiple factors appeared to contribute to elevated serum prolactin levels in women with connective tissue diseases, and the presence of hyperprolactinemia was related to unique findings on immunoblot analysis.

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