Protein antigens of the RNA-protein complexes detected by anti-SM and anti-RNP antibodies found in serum of patients with systemic lupus erythematosus and related disorders.

Evidence has been obtained previously indicating that the antigens reacting with the anti-Sm and anti-RNP sera are present as a large complex, and similar protein bands are obtained with both types of sera. Inthe present study, it proved possible to break up this complex using SDS treatment before immunoprecipitation. After such treatment, different protein bands were immunoprecipitated by the two antisera; Sm determinants resided, at least partially, in a 19-kd protein. Sequential immunoprecipitation with and without prior SDS treatment provided further evidence for these specificities and suggested that two classes of particles exist in different tissues, one containing proteins immunoreactive with the Sn and RNP antisera and the other containing proteins immunoreactive only with the Sm antisera. The latter particle contained all the bands seen with the first type except for the absence of the 19-kd band. Nitrocellulose blot analyses confirmed the assignment of the 25- and 16-kd polypeptides to Sm antigenic determinants; analyses for RNP proved les informative by this technique. Some differences in the banding patterns were obtained using cells from different species: the 25-kd Sm band was usually double in human cells and single in rat and rabbit tissue. Methods of extraction also caused some differences which was especially true for the rabbit thymus extract widely used for Sm and RNP studies. Additional immunoreactive bands at 68 and 70 kd also were detected when the Sm and RNP antisera were used in nitrocellulose blot analyses. Furthermore, evidence was obtained for a number of other antibodies in lupus sera which have not as yet been detected by serological methods.

Role of antigen selectivity in autoimmune responses to the Ku (p70/p80) antigen.

Levels of anti-Ku (p70/p80) antibodies were measured longitudinally in sera from four individuals with systemic lupus erythematosus or related disorders. Antibodies to the native Ku antigen (p70/p80 complex) varied over a range of up to 577-fold. Large fluctuations were also observed in the levels of autoantibodies to several distinct epitopes of the Ku (p70/p80) antigen. Levels of these individual autoantibody populations generally paralleled one another, suggesting that they are coordinately regulated. A similar pattern of anti-DNA antibody fluctuation was seen in some sera. To examine the possibility that these autoantibodies were generated by polyclonal B cell activation, the levels of anti-Ku (p70/p80) and anti-DNA antibodies were compared to the levels of antibodies to Escherichia coli proteins, tetanus toxoid, and bovine insulin, transferrin, cytochrome c, serum albumin, and thyroglobulin. In sera from the same individual, anti-Ku (p70/p80) antibodies were sometimes produced in the complete absence of polyclonal activation, and at other times were accompanied by increased polyclonal activation. Anti-DNA antibody levels more closely paralleled the level of polyclonal activation than did the anti-Ku (p70/p80) levels. These studies suggest that anti-Ku (p70/p80) antibodies are generated by an antigen-selective mechanism, but that polyclonal activation frequently, although not invariably, accompanies autoantibody production. This observation is consistent with the possibility that polyclonal activation might be secondary to autoantibody production.

Autoimmune sera reactive with Sm antigen contain high levels of RNP-like antibodies.

Ribonucleoprotein particles containing Sm antigen were separated from particles containing both Sm and RNP antigens by ion-exchange chromatography to study the recognition of these antigens by autoimmune sera. By using the separated antigens, anti-Sm and/or anti-RNP antibodies were detected in approximately 60% of sera from systemic lupus erythematosus patients by both enzyme-linked immunosorbent assay and immunoprecipitation of radiolabeled antigens followed by analysis on sodium dodecyl sulfate-polyacrylamide gels. These antibodies were detected in 30% of the same sera using the standard passive hemagglutination technique. Competition experiments demonstrated that all of the sera tested that contained anti-Sm antibodies also had anti-RNP-like reactivity. This latter reactivity usually represented 80% or more of the total Sm and RNP binding activity in lupus sera. The binding to RNP-like determinants by several of the sera was uniquely resistant to treatment of the antigen with snake venom exonuclease. These studies indicate that humoral immunity against Sm and RNP antigens in systemic lupus erythematosus is directed primarily against a single type of ribonucleoprotein particle in which the two antigens are physically associated. The specific binding to a single type of ribonucleoprotein particle suggests that this particle may be especially immunogenic and that it might play an important role in induction of the humoral immune response to Sm and RNP.

Immune function in systemic lupus erythematosus. Impairment of in vitro T-cell proliferation and in vivo antibody response to exogenous antigen.

Peripheral blood mononuclear cells from 46 systemic lupus erythematosus (SLE) patients showed reduced ability to proliferate in vitro in response to the soluble antigen, tetanus toxoid, as compared with 96 normal controls. Special studies of 27 untreated SLE patients also revealed significantly decreased blastogenic responses to tetanus toxoid. In both the total and untreated SLE populations, decreased mean tetanus antibody titers also were found as compared with the control population. However, the reduction in antibody titer and blastogenic response was not strictly parallel. A limited immunization program was initiated in low-responding volunteers from the SLE and normal populations. Three out of four SLE patients did not develop a significant blastogenic response despite increases in anti-tetanus titers after immunization, whereas all normals showed significant increases in both blastogenic and antibody responses. The accumulated evidence indicated that the unresponsiveness was the result of a defect in T-cell function. Monocyte reactivity was demonstrated to be normal, and no evidence was found for the presence of suppressor cells, inhibition by immune complexes, or increased prostaglandins to explain the defect.

Increased levels of 16 alpha-hydroxyestrone-modified proteins in pregnancy and in systemic lupus erythematosus.

The ketolic estrogen 16 alpha-hydroxyestrone (16 alpha OHE) reacts with lysine residues, forming stable covalent adducts with proteins. To determine the extent of protein modification by 16 alpha OHE in vivo, we measured the level of 16 alpha OHE-lysine present within proteins of varying half-lives obtained from normal subjects, patients with systemic lupus erythematosus (SLE), and pregnant women. The latter groups have higher than normal levels of plasma 16 alpha OHE. The proteins analyzed were membrane proteins of the red cell and the lymphocyte and basement membrane proteins of the glomerulus. We report that elevated levels of plasma 16 alpha OHE led to increased formation of 16 alpha OHE-protein adducts and that the level of these adducts increases with the half-life of the protein. In the case of erythrocyte membrane proteins, pregnant women and women with SLE had significantly higher mean levels of 16 alpha OHE-lysine than normal women (normal, 5.2 pmol 16 alpha OHE-lysine/mmol leucine; SLE, 15.7; pregnant, 24.9). A similar elevation in the modification of lymphocyte proteins in women was found (normal, 15.6; SLE, 40.5). Since the degree of protein modification also was dependent on the ambient level of free 16 alpha OHE, these measurements provide a useful indicator of the long term 16 alpha OHE status of an individual. The modification of proteins by 16 alpha OHE may be a link in the relationship between female hormones, pregnancy, and systemic lupus erythematosus.

Increased 16 alpha-hydroxylation of estradiol in systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is one of many chronic diseases with a predilection for the human female. The reasons for the high female to male (9:1) incidence remain unknown. The total extent of hydroxylation estradiol at either C-16 to more estrogenic metabolites or at C-2 to the catechol estrogens was determined by a radiometric method in the human. Comparing 23 SLE patients to 44 normal controls, an increase in the extent of hydroxylation toward the 16 alpha-metabolites was found in SLE (SLE 15.2 +/- 4.3%, range 8.8-30%; normal 9.1 +/- 2.3%, range 5.3-14.4%; P less than 0.001). Increased 16 alpha-hydroxylation was found in both males (SLE 13.2 +/- 3.0%, normal 8.3 +/- 2.1%) and females (SLE 15.7 +/- 5%, normal 9.9 +/- 2.2%) with disease when compared to normal subjects. In addition, studies of several other chronic diseases by the same method did not indicate a similar alteration in 16 hydroxylation. No change in hydroxylation at C-2 was found in male patients, but a decrease was found in female patients. These data suggest that increased hydroxylation of estradiol at C-16 occurs in SLE. The 16 alpha-metabolites have been shown to be potent estrogens, and these data might give some insight into the pathogenesis of the disease.

Microsomal hydroxylation as measured by pentobarbital elimination in patients with idiopathic systemic lupus erythematosus.

A mechanism postulated for drug- or chemical-induced systemic lupus erythematosus (SLE) is that the chemical is covalently bound to nuclear macromolecules increasing the immunogenicity of the macromolecule. This may require metabolic activation by oxidation. There are many similarities between drug-induced and idiopathic SLE. Twelve patients with idiopathic SLE and 12 normal subjects were given 100 mg pentobarbital orally to evaluate their microsomal hydroxylating activity. Plasma pentobarbital concentration was measured by gas-liquid chromatography. Mean plasma pentobarbital half-life was 24 +/- 10 (mean +/- SD) hr in the SLE patients, which is only slightly shorter than the 26 +/- 12 hr in the control subjects. The mean apparent volume of distribution in the patients was 1.28 +/- 0.30 l/kg, which is slightly above the 1.00 +/- 0.37 l/kg in the normal subject (P less than 0.05). Mean metabolic clearance rate in the SLE patients was 0.045 +/- 0.022 l/hr/kg, which is more than the 0.028 +/- 0.008 l/hr/kg in the normal control subjects (P less than 0.02). Since the metabolic clearance rate of a drug is the proper value for evaluating metabolism rate, we conclude that patients with SLE hve an increased elimination rate for drugs or other foreign compounds that are biotransformed by microsomal oxidation and may more rapidly bioactivate chemicals to reactive compounds.

Campylobacteriosis in man: pathogenic mechanisms and review of 91 bloodstream infections.

Five patients with Campylobacter fetus(previously called "Vibrio fetus") bacteremia are presented with enteric symptoms in four patients, a self-limited course in three, and with possible nosocomial infection in one patient who had disseminated malignancy. The clinical syndromes of 91 bacteremic patients with campylobacteriosis and C. fetus taxonomy and pathogenicity are reviewed. Studies of potential pathogenic mechanisms in enteric infections failed to reveal the production of either heat-stable or heat-labile, cholera-like enterotoxin, cytotoxicity or invasiveness. In comparison with different species of vibrio infections, C. fetus appears to produce disease by a different mechanism, one which involves a bloodstream infection, perhaps following penetration through the intestinal mucosa as has been demonstrated experimentally with salmonellae and yersinia. Such a pattern is consistent with the clinical pattern of C. fetus infections and the experimental studies reported herein.

Enhancement of protein S anticoagulant function by beta2-glycoprotein I, a major target antigen of antiphospholipid antibodies: beta2-glycoprotein I interferes with binding of protein S to its plasma inhibitor, C4b-binding protein.

Thrombosis in the antiphospholipid syndrome has been associated with acquired deficiency of the anticoagulant protein S. We sought evidence that beta2-glycoprotein I, a major target antigen for antiphospholipid antibodies, is involved in regulation of protein S activity. Incubation of purified protein S or plasma with beta2-glycoprotein I reversed functional modulation of protein S by its plasma inhibitor, the C4b-binding protein. In a plasma-free ELISA, beta2-glycoprotein I prevented the binding of protein S and C4b-binding protein when preincubated with immobilized protein S but not when similarly preincubated with C4b-binding protein. beta2-glycoprotein I in fluid phase interfered with precipitation of protein S by sepharose-bound C4b-binding protein. Effects of beta2-glycoprotein I on protein S function were inhibited by one of four monoclonal anti-beta2-glycoprotein 1 antibodies. These data suggest that beta2-glycoprotein I helps maintain adequate plasma levels of circulating free, active protein S. Antiphospholipid (anti-beta2-glycoprotein I) antibodies might cause sporadic thrombosis, at least in part, by impairing this novel regulatory mechanism.

Systemic lupus erythematosus: learning disability in the male offspring of female patients and relationship to laterality.

Systemic lupus erythematosus (SLE) is a multisystemic disease that predominates in women during the childbearing years. One system frequently affected is the central nervous system. Seizures and psychoses are criteria useful in the diagnosis of SLE. The effects of this disease on disorders of learning and handedness in both patients and first degree relatives are the subject of the present report. Dyslexia and other disorders of learning were present in 45% (24/55) of male offspring of female SLE patients. Ten percent of male siblings of female SLE patients were learning-impaired. Dyslexia and other disorders of learning are also common in women with SLE (dyslexia 12.5%) and men with SLE where the proband is one of two or more cases of SLE in the same family (dyslexia 27.6%). Tests for handedness in the lupus population indicated that there were slightly more patients (mostly women) (p = 0.08) who were lefthanded by the Oldfield laterality test compared to normal volunteers. Handedness did not correlate with the degree of dyslexia in either the patients or their first degree relatives.

Sex hormones and systemic lupus erythematosus.

Lupus is one disease in which sex hormones and gender are quite important. Studies of autoimmune diseases like lupus have made the hormone connection more important and increased our overall understanding of the sexual dimorphism of the immune system. It is clear that some fundamental biologic mechanism is at work here and that only knowledge of the molecular mechanisms behind the action of the hormones can help us to understand the gender preference in this illness. Hormones may be potent regulators of cytokine levels and, consequently, disease activity.

Brain protein kinase in synaptic vesicles is inhibited by a factor in sera from systemic lupus erythematosus patients with central nervous system manifestations.

Sera from systemic lupus erythematosus patients with clinical central nervous system manifestations had a high mean percent of brain synaptic vesicle protein kinase inhibition (62 +/- 9.3, P less than 0.001). This conclusion was derived from screening sera of a total of 287 patients with heterogeneous diseases and from 12 healthy controls. Low levels of synaptic vesicle protein kinase inhibition also were detected in the sera of patients with certain autoimmune, inflammatory, neurological and/or psychiatric symptoms. Because 87.5% of the patients whose sera showed strong synaptic vesicle protein kinase inhibition (over 50%) had neuropsychiatric manifestations, we postulate this relationship may be due to the presence of an inhibitor factor, of which the etiology and molecular characteristics were investigated.

Lupus psychosis: differentiation from the steroid-induced state.

Steroid induced psychosis in SLE is rare but clinically important, and often difficult to distinguish from lupus cerebritis. We report a patient with SLE who became depressed following an increase in her steroid dosage. Based on her clinical presentation and high levels of antibodies to P ribosomal proteins (both in CSF and serum) a diagnosis of lupus cerebritis was made. Steroid dosage, time intervals, and the duration of mental changes may help in differentiating steroid psychosis from lupus cerebritis. No single laboratory test sufficient to establish a definitive diagnosis of lupus cerebritis is available at the present time. However, elevated levels of antibodies to P ribosomal proteins may assist in confirming the diagnosis of this condition.

The effects of anabolic steroids and strength training on the human immune response.

The immune response was assessed in 13 competitive bodybuilders self-administering anabolic-androgenic steroids and ten competitive bodybuilders not administering these drugs. Laboratory assessment included the number and relative distribution of T-cells, T-helper/inducer cells, T-cytotoxic/suppressor cells, activated T-cells, lymphocyte transformation to the mitogens, pokeweed mitogen (PWM), phytohemagglutinin (PHA), Concanavalin-A (CON-A), Staphylococcus aureus Cowan strain I (SAC), serum immunoglobulins, and natural killer (NK) activity. There were no significant differences in T-cell subsets among steroid users and non-users, but lymphocyte transformation studies revealed that the anabolic-androgenic steroid-using group had enhanced proliferative ability to the B-cell mitogen, SAC, in comparison to non-bodybuilding controls. NK activity was significantly (P less than 0.05) augmented in the anabolic-androgenic steroid users but not in the non-using bodybuilders. Serum immunoglobulin levels, in particular IgA, were significantly (P less than 0.017) lower in the steroid-using group. Four of 13 steroid users and three of eight non-steroid-using bodybuilders had detectable antinuclear antibodies. These studies indicate that 1) anabolic-androgenic steroid use as practiced by contemporary athletes is a potent modulator of immune responsiveness and 2) autoantibodies are prevalent in strength-trained men even in the absence of anabolic steroid use.

Rheumatoid arthritis. New disease-modifying and anti-inflammatory drugs.

Treatment options for rheumatoid arthritis (RA) are expanding as research has provided a more complete understanding of the pathophysiology of the disease. Three disease-modifying agents approved in the last 18 months for early intervention in RA are etanercept, leflunomide, and infliximab. For the relief of the signs and symptoms of RA, the new selective cyclooxygenase-2 (COX-2) inhibitors are joining the available nonsteroidal anti-inflammatory drugs. One COX-2 inhibitor is approved for use in RA, and another is under investigation for that indication. As a class, the COX-2 inhibitors offer efficacy similar to traditional NSAIDs but with less GI and platelet toxicity.

Collagen disease: the enemy within.

Surprisingly, the autoimmune diseases predominate in women of childbearing years. Recent evidence suggests that these diseases are the result of some interaction of the hypothalamic-gonadal axis with the immune system. The median age for rheumatoid arthritis is 45 years, the median age for lupus erythematosus is 25. Other illnesses, which are autoimmune in character, such as Sjögren syndrome, scleroderma and the vasculitides, are also more commonly found in women. There is no link that ties these illnesses together, except for gender and various disparate immune manifestations such as autoantibodies. The etiopathogenesis of these diseases is reviewed. These diseases are notoriously difficult to diagnose; they mimic other illnesses in their early presentations. Accompanying illnesses such as migraine headaches, Hashimoto's thyroiditis, and fibromyalgia are discussed as related entities. Immunosuppression of diseases like rheumatoid arthritis and lupus erythematosus, is discussed. Various methods of management are considered, such as the use of steroids, cytotoxic agents, and new experimental agents, such as DHEA and IVIG.

Predisposing factors to autoimmune disease.

There are many factors that predispose women to autoimmune disease. The protective effect of testosterone during development prevents most males from getting autoimmune disease, although in some instances this protective effect can be bypassed by either genetic anomalies or endocrinopathies. Autoimmunity is defined as the development of symptoms and antibodies referable to one or another autoimmune disease. Some of the factors that predispose young women to autoimmunity also directly involve the endocrine system and indirectly, disorders of gonadal development. Altered sex steroid metabolism is one endogenous factor that predisposes a young woman to autoimmunity. The metabolism of estrone which can be directed to either the 16-or the 2-metabolites by diet, thyroid function, or certain drugs has a major influence on immune function and possibly gonadal pathology. Attempts to shift the metabolism of estrone to the 2-compounds with a variety of agents actually decreases the predisposition to autoimmunity. Other pre-disposing factors are all related to hormone metabolism and include hyperprolactinemia, the use of exogenous estrogenic agents, or compounds that change basic steroid metabolism. Most of these conditions are reversible.

Klinefelter's syndrome: hormone metabolism in hypogonadal males with systemic lupus erythematosus.

Estrone hydroxylation, testosterone oxidation and the products of such hormone metabolism were studied in hypogonadal males. The sex steroid metabolism of patients with Klinefelter's syndrome with systemic lupus erythematosus (SLE) is similar to that of women with SLE.