Drug-induced anti-histone autoantibodies display two patterns of reactivity with substructures of chromatin.

Increasing evidence suggests that autoantibodies in the rheumatic diseases are a consequence of immune selection by self-material, but the nature of the in vivo immunogen is unknown. Insight into this problem may be obtained by measuring autoantibody binding to various forms of a target antigen. Antihistone antibodies arising as a side effect of therapy with various drugs offer an opportunity to explore this premise because many forms of histone have been characterized and adapted to ELISA formats. Two patterns of antibody reactivity were observed. All 21 patients with symptomatic procainamide-induced lupus and 7 of 12 patients with quinidine-induced lupus had IgG antibodies reacting predominantly with the (H2A-H2B)-DNA complex and with chromatin. In contrast, antibodies in 19 of 24 patients taking procainamide without accompanying lupus-like symptoms did not show any pattern. The second pattern was observed in 18/19 chlorpromazine-treated patients and 14/17 patients with hydralazine-induced lupus in which IgM antibodies displayed more reactivity with DNA-free histones than with the corresponding histone-DNA complexes and almost no binding to H1-stripped chromatin. Absorption studies were entirely consistent with these results. Thus, the two patterns of reactivity with nucleosomal components reflect the molecular substructure of chromatin, suggesting that two processes underlie antihistone antibody induction by drugs. In one, IgG autoantibodies appear to be elicited by chromatin, whereas in the other, autoimmune tolerance to native chromatin appears largely intact, and IgM antibodies may be driven by DNA-free histone.

Autoantibodies associated with lupus induced by diverse drugs target a similar epitope in the (H2A-H2B)-DNA complex.

IgG reactivity with the (H2A-H2B)-DNA complex, a subunit of the nucleosome, has been detected in many patients with lupus induced by procainamide and quinidine, but the similarity among the epitopes targeted by these antibodies in this heterogeneous patient group as well as the prevalence of this specificity in lupus induced by other drugs is unknown. Studies with histone-DNA complexes formed by sequential addition on a solid phase demonstrated that complexes containing single histones had negligible antigenicity, indicating that DNA stabilizes a protein epitope in the H2A-H2B dimer or that the complete epitope is generated by a surface feature involving H2A-H2B and DNA. F(ab')2 isolated from a patient with procainamide-induced lupus blocked greater than 90% of the anti-[(H2A-H2B)-DNA] reactivity in six of six sera from patients with lupus induced by procainamide, four of four quinidine-induced patients and in sera from patients with lupus induced by acebutolol, penicillamine, and isoniazid, but not methyldopa or auto-antibodies to the component macromolecules. Fab fragments purified from the IgG of two quinidine-induced lupus patients and patients with isoniazid- and procainamide-induced lupus retained 39% +/- 8% of their original IgG reactivity compared to 34 +/- 28% of the original anti-tetanus toxoid activity of Fab fragments in two of the same sera and two normal sera. These results indicate that anti-[(H2A-H2B)-DNA] does not require divalent antigen-antibody complexes for stability, and that the complete epitope is created by the monomeric, trimolecular histone-DNA complex. We conclude that despite their pharmacologic and chemical heterogeneity, many lupus-inducing drugs elicit near identical autoantibodies.

Mechanisms of drug-induced lupus. II. T cells overexpressing lymphocyte function-associated antigen 1 become autoreactive and cause a lupuslike disease in syngeneic mice.

Current theories propose that systemic lupus erythematosus develops when genetically predisposed individuals are exposed to certain environmental agents, although how these agents trigger lupus is uncertain. Some of these agents, such as procainamide, hydralazine, and UV-light inhibit T cell DNA methylation, increase lymphocyte function-associated antigen 1 (LFA-1) (CD11a/CD18) expression, and induce autoreactivity in vitro, and adoptive transfer of T cells that are made autoreactive by this mechanism causes a lupuslike disease. The mechanism by which these cells cause autoimmunity is unknown. In this report, we present evidence that LFA-1 overexpression is sufficient to induce autoimmunity. LFA-1 overexpression was induced on cloned murine Th2 cells by transfection, resulting in autoreactivity. Adoptive transfer of the transfected, autoreactive cells into syngeneic recipients caused a lupuslike disease with anti-DNA antibodies, an immune complex glomerulonephritis and pulmonary alveolitis, similar to that caused by cells treated with procainamide. These results indicate that agents or events which modify T cell DNA methylation may induce autoimmunity by causing T cell LFA-1 overexpression. Since T cells from patients with active lupus have hypomethylated DNA and overexpressed LFA-1, this mechanism could be important in the development of human autoimmunity.

Drug-induced lupus associated with synthetic conjugated estrogens.

OBJECTIVE: To report a case of drug-induced lupus (DIL) in a patient taking Cenestin, a combination product of synthetic conjugated estrogens. CASE SUMMARY: A 54-year-old white female presented with a 4 month history of bilateral arm pain that developed and progressively worsened after initiating Cenestin 0.625 mg daily. The patient's symptoms, findings on physical examination (eg, degenerative changes of the acromioclavicular joint), and laboratory test results (eg, antinuclear antibody titer 1-640 [normal <1-40]) were suggestive of DIL. Her symptoms rapidly resolved with discontinuation of Cenestin and promptly resumed with reinitiation of the drug. Laboratory test values also improved significantly with discontinuation of Cenestin. Based on these findings and the Naranjo probability scale score, this reaction was probably associated with Cenestin. DISCUSSION: DIL differs from systemic lupus erythematosus in that it is caused by prolonged exposure at adequate doses to a drug rather than being an autoimmune reaction. The most commonly reported and studied medications are hydralazine, quinidine, and procainamide. Other medications have been associated with DIL; however, data are limited in these reports, especially with estrogen. There have been no previous reports in the literature of synthetic estrogen products associated with DIL. CONCLUSIONS: A diagnosis of DIL can be very challenging to make, especially since there are no clear criteria on which to base it. While estrogen has rarely been reported to be associated with DIL, it may be considered as a possible cause.

Minocycline-induced lupus in adolescents: clinical implications for physical therapists.

STUDY DESIGN: Resident's case problem. BACKGROUND: In the United States, minocycline is a frequently prescribed medication for the treatment of moderate to severe acne, a common condition in adolescents. The use of minocycline has been associated with severe adverse effects that frequently comprise a musculoskeletal component, including drug-induced lupus. Physical therapists have the responsibility to identify drug reactions that mimic musculoskeletal symptoms. The patient described herein was a 15-year-old adolescent boy who had taken minocycline for 14 days. He was initially treated by his primary physician on the 15th day of minocycline therapy for symptoms of fever, joint swelling, and a rash. The patient presented to a physical therapist on the 22nd day with complaints of severe myalgia, arthralgia, and severely limited mobility secondary to pain. The patient was referred to a pediatric rheumatologist because of the systemic nature and severity of the symptoms. DIAGNOSIS: The patient was subsequently diagnosed as having drug-induced lupus by a pediatric rheumatologist. The patient's myalgia and arthralgia subsided within 6 weeks, but his strength, coordination, and endurance did not reach their prior levels for 3 to 4 months. DISCUSSION: Physical therapists who include a comprehensive pharmacovigilance component in their patient examination may recognize musculoskeletal symptoms that arise from a nonmusculoskeletal origin. Minocycline is commonly prescribed in the United States as an antibiotic and for treatment of acne and rheumatoid arthritis. Therefore, physical therapists should screen for minocycline use when an adolescent patient or a patient with rheumatoid arthritis presents with diffuse musculoskeletal symptoms. An automated medication monitoring system would provide physical therapists with a means of accessing current information on medication use.

Induction of lupus-related specific autoantibodies by non-specific inflammation caused by an intraperitoneal injection of n-hexadecane in BALB/c mice.

A single intraperitoneal (i.p.) injection of pristane, incomplete Freund's adjuvant (IFA), or the adjuvant oil squalene, but not high molecular weight medicinal mineral oils, induces lupus-related autoantibodies to nRNP/Sm and -Su in non-autoimmune strains of mice. This ability appears to be associated with the low molecular weight and adjuvanticity of hydrocarbon. n-Hexadecane (C(16)H(34)), which is present in petroleum, has adjuvant activity and induces arthritis in rodents like other lupus-inducing oils. In addition to dietary exposure to n-hexadecane in mineral oils, exposure also occurs via inhalation of oil mist, jet fuel, or diesel exhaust or by absorption through the skin. Since n-hexadecane is a low molecular weight adjuvant hydrocarbon oil similar to other lupus-inducing hydrocarbons, the present study examined whether it can also induce lupus-related autoantibodies in mice. Female BALB/cJ mice received a single i.p. injection of 0.5 ml of n-hexadecane, pristane, or saline (control). Pathology and serology (immunoglobulin levels, autoantibodies by immunofluorescence, immunoprecipitation, and ELISA) were examined 3 months later. Unexpectedly, all n-hexadecane-treated mice, but none in the other groups, developed inflammatory ascites within 2.5 months. n-Hexadecane induced hypergammaglobulinemia (IgG1, IgG2a), antinuclear (titer>1:160, 67%) and -cytoplasmic antibodies (58%) and autoantibodies to nRNP/Sm (25%), Su (33%), ssDNA (83%), and chromatin (100%). Therefore, non-specific inflammation caused by n-hexadecane resulted in the production of a limited set of specific autoantibodies. These previously unrecognized immunological effects of n-hexadecane may have implications in monitoring human exposure to hydrocarbons and in the pathogenesis of autoimmune diseases.

Acceleration of autoimmunity by organochlorine pesticides in (NZB x NZW)F1 mice.

Systemic lupus erythematosus (SLE) is an autoimmune disorder that affects women more frequently than men. In the (NZB times NZW)F1 mouse, a murine SLE model, the presence or absence of estrogen markedly influences the rate of progression of disease. Three organochlorine pesticides with estrogenic effects were administered chronically to ovariectomized female (NZB times NZW)F1 mice, and we measured the time to development of renal disease, the principal clinical manifestation of lupus in this model. Treatment with chlordecone, methoxychlor, or o,p -dichlorodiphenyltrichloroethane (o,p -DDT) significantly decreased the time to onset of renal impairment, as did treatment with 17ss-estradiol used as a positive control. In an expanded study of chlordecone, we found a dose-related early appearance of elevated anti-double-strand DNA autoantibody titers that corresponded with subsequent development of glomerulonephritis. Immunohistofluorescence confirmed early deposition of immune complexes in kidneys of mice treated with chlordecone. These observations are consistent with an effect of these organochlorine pesticides to accelerate the natural course of SLE in the (NZB times NZW)F1 mouse. Although we originally hypothesized that the effect on progression of autoimmunity was due to estrogenic properties of the pesticides, autoimmune effects and estrogenicity, assessed through measurement of uterine hypertrophy, were not well correlated. This may indicate that uterine hypertrophy is a poor indicator of comparative estrogenic effects of organochlorine pesticides on the immune system, or that the pesticides are influencing autoimmunity through a mode of action unrelated to their estrogenicity.

A nondeletional mechanism for central T-cell tolerance.

To be positively selected, immature thymocytes must receive signaling through their T-cell receptor (TCR), and engagement of relatively low-affinity self-peptides permits further T-cell maturation. However, mature T cells no longer overtly respond to such low-affinity antigens, indicating that T cells acquire a higher threshold for activation during thymopoiesis. We wondered whether partial interference in positive selection could produce T cells that respond to the selecting self-peptide. This possibility was tested by injecting procainamide-hydroxylamine (PAHA), a lupus-inducing drug, into the thymus of adult normal mice. Three weeks after the second injection, IgG antichromatin antibodies appeared in the circulation and remained for several months. The murine antichromatin antibodies reacted with the (H2A-H2B)-DNA subnucleosome complex, the predominant specificity in patients with procainamide-induced lupus. In thymus organ and reaggregate cultures, PAHA had no effect on negative selection of T cells with high affinity for a co-present antigen, but acted on CD4+ CD8+ immature T cells as they underwent positive selection. TCR transgenic T cells specific to cytochrome c peptide 88-104 acquired the capacity to respond to the low-affinity analogue at position 99 (lys-->ala) if PAHA was present during their development. PAHA also blocked the capacity of a T-cell line to become anergic after anti-CD3 treatment, suggesting that PAHA prevents the production of negative regulators that accumulate in response to partial signaling through the TCR. These results are consistent with the view that T cells acquire self-tolerance during positive selection, and disruption of this process can result in autoreactive T cells and systemic autoimmunity.

Drug-induced lupus.

Autoantibodies and, less commonly, systemic rheumatic symptoms are associated with treatment with numerous medications and other types of ingested compounds. Distinct syndromes can be distinguished, based on clinical and laboratory features, as well as exposure history. Drug-induced lupus has been reported as a side-effect of long-term therapy with over 40 medications. Its clinical and laboratory features are similar to systemic lupus erythematosus, except that patients fully recover after the offending medication is discontinued. This syndrome differs from typical drug hypersensitivity reactions in that drug-specific T-cells or antibodies are not involved in induction of autoimmunity, it usually requires many months to years of drug exposure, is drug dose-dependent and generally does not result in immune sensitization to the drug. Circumstantial evidence strongly suggests that oxidative metabolites of the parent compound trigger autoimmunity. Several mechanisms for induction of autoimmunity will be discussed, including bystander activation of autoreactive lymphocytes due to drug-specific immunity or to non-specific activation of lymphocytes, direct cytotoxicity with release of autoantigens and disruption of central T-cell tolerance. The latter hypothesis will be supported by a mouse model in which a reactive metabolite of procainamide introduced into the thymus results in lupus-like autoantibody induction. These findings, as well as evidence for thymic function in drug-induced lupus patients, support the concept that abnormalities during T-cell selection in the thymus initiate autoimmunity.

Minocycline and lupuslike syndrome in acne patients.

BACKGROUND: Recently several case reports described the association between minocycline and lupuslike syndrome. Minocycline, one of the tetracyclines, is widely used to treat acne. We aimed to examine the association of exposure to minocycline and other tetracyclines with the development of lupuslike syndrome. METHODS: We conducted a nested case-control study in a cohort of 27 688 acne patients aged 15 to 29 years, using data automatically recorded on general practitioners' office computers in the United Kingdom. Controls were matched to cases on age, sex, and practice. The main outcome was lupuslike syndrome defined as the occurrence of polyarthritis or polyarthralgia of unknown origin, with negative rheumatoid factor or latex agglutination test, positive or unmeasured antinuclear factor, elevated or unmeasured erythrocyte sedimentation rate, and absence of or unmeasured antinative DNA antibody levels. RESULTS: We identified 29 cases and selected 152 controls. Current single use of minocycline was associated with an 8.5-fold (95% confidence interval [CI], 2.1-35) increased risk of developing lupuslike syndrome compared with non-users and past users of tetracyclines combined. The risk of past exposure to any of the tetracyclines was closely similar to nonuse (relative risk, 1.3; 95% CI, 0.5-3.3). Current use of doxycycline, oxytetracycline, or tetracycline combined was associated with a 1.7-fold (95% CI, 0.4-8.1) increase of risk. The risk increased with longer use. CONCLUSION: Current use of minocycline increased the risk of developing lupuslike syndrome 8.5-fold in the cohort of young acne patients. The effect was stronger in longer-term users. However, the absolute risk of developing lupuslike syndrome seems to be relatively low.

Drug-induced antinuclear antibodies and lupus syndromes.

Drugs capable of triggering the onset of systemic lupus erythematosus may be divided into those that do so by pharmacological properties of their own and those that do so by eliciting allergic reactions which bring about lupus. Drugs in the first group vary in their potency to activate lupus. They all elicit antinuclear antibodies in the majority of patients who receive them but they only cause lupus in a small percentage of patients. This dichotomy suggests that a predisposition is required for the development of lupus upon intake of these drugs. The mechanism whereby these drugs elicit antinuclear antibodies seems to relate to coupling to and/or modification of, nuclear antigens. The patterns of antinuclear antibodies elicited by these drugs in individuals who receive them correlate well with their known reactivity with various nuclear antigens.

A lupus-like syndrome associated with infliximab therapy.

Infliximab, a chimeric monoclonal antibody targeting tumor necrosis factor alpha (TNF-alpha), is efficacious in the treatment of rheumatoid arthritis and Crohn's disease. We report in detail an unusual adverse reaction to infliximab therapy, a drug-induced lupus-like clinical syndrome. A 45-year-old woman with steroid-dependent Crohn's colitis, successfully managed with maintenance infliximab infusions and methotrexate, developed a lupus-like syndrome eight months after her initial infusion. This was characterized by inflammatory arthritis and an urticarial and papulosquamous rash and was accompanied by high titers of antinuclear, double-stranded DNA, glomerular-binding, and histone antibodies and by reduced levels of the C4 component of complement. After discontinuance of infliximab infusions and treatment of symptoms with intermittent courses of prednisone, the patient's arthritis progressively improved, with accompanying decrements in autoantibody titers. One year later, she has minimal joint discomfort and no rash or gastrointestinal symptoms despite also discontinuing prednisone and methotrexate. Infliximab therapy may cause a lupus-like syndrome that is reversible upon discontinuing this agent. These findings support recent evidence identifying TNF-alpha as an inhibitor of autoantibody formation.

Low-dose exposure to inorganic mercury accelerates disease and mortality in acquired murine lupus.

Inorganic mercury (iHg) is known to induce autoimmune disease in susceptible rodent strains. Additionally, in inbred strains of mice prone to autoimmune disease, iHg can accelerate and exacerbate disease manifestations. Despite these well-known links between iHg and autoimmunity in animal models, no association between iHg alone and autoimmune disease in humans has been documented. However, it is possible that low-level iHg exposure can interact with disease triggers to enhance disease expression or susceptibility. To address whether exposure to iHg can alter the course of subsequent acquired autoimmune disease, we used a murine model of acquired autoimmunity, lupus-like chronic graft-versus-host disease (GVHD), in which autoimmunity is induced using normal, nonautoimmune prone donor and F1 recipient mice resistant to Hg-induced autoimmunity. Our results indicate that a 2-week exposure to low-dose iHg (20 or 200 micro g/kg every other day) to donor and host mice ending 1 week before GVHD induction can significantly worsen parameters of disease severity, resulting in premature mortality. iHg pretreatment clearly worsened chronic lupus-like disease, rather than GVHD worsening iHg immunotoxicity. These results are consistent with the hypothesis that low-level, nontoxic iHg preexposure may interact with other risk factors, genetic or acquired, to promote subsequent autoimmune disease development.

Lupus and pulmonary nodules consistent with bronchiolitis obliterans organizing pneumonia induced by carbamazepine.

Carbamazepine-induced lupus is uncommon; its frequency is less than 0.001% of the cases of lupus treated. Herein we describe a 52-year-old woman who had development of facial erythema, arthralgia, dyspnea, and multiple pulmonary rounded masses and nodules while she was taking carbamazepine for epilepsy. Pulmonary histologic examination showed bronchiolitis obliterans organizing pneumonia. Antinuclear antibodies and antihistone antibodies were present without antibodies to double-stranded DNA. Thirteen months after carbamazepine had been withdrawn, all symptoms had disappeared without the use of anti-inflammatory drugs. Even though pulmonary involvement is possible during carbamazepine treatment, to our knowledge, bronchiolitis obliterans organizing pneumonia on its own or associated with carbamazepine-induced lupus has not been previously described.

Antibodies to histones in systemic lupus erythematosus and drug-induced lupus syndromes.

Antihistone antibodies are some of the most frequent autoantibodies in rheumatic diseases and can represent useful diagnostic markers in some autoimmune syndromes. Histone epitopes are often located in accessible regions of chromatin or are conformational determinants resulting from the association of several components. These observations and studies with murine models of lupus strongly support the view that histones play a direct stimulatory role in triggering autoantibody production.

Drug-related lupus. Incidence, mechanisms and clinical implications.

Adverse side effects to drugs and chemicals in which immune mechanisms may be responsible have been described in drug-related lupus (DRL). The spectrum of drugs that may elicit DRL includes such classes as the hydrazines, arylamines, and chemicals that can be metabolised to amines. The 2 major pathways of metabolism--acetylation and N-hydroxylation--are described in detail. The events leading to autoantibody production are not well understood; however, specific consideration of the genetic makeup of patients who are candidates for treatment with these drugs may help identify those at risk of developing DRL.

Case report: distinctive immune abnormalities in a patient with procainamide-induced lupus and serositis.

To gain insight into the immunopathogenesis of drug-induced autoimmune disorders, lymphocyte and immunoglobulin distributions and cytokine levels were monitored in the peripheral blood and pleural fluid of a patient with procainamide-induced lupus and pleural effusion. Approximately 80% of the B cells in both compartments were CD5+ compared to 10% to 25% in normal adults. CD4/CD8 ratio and percentage CD4 were normal in peripheral blood. Serum levels of IgG (particularly IgG2), IL-6, and soluble IL-2R were slightly elevated, and those of IgA were significantly elevated compared to normal controls. Analysis of the pleural effusion revealed an increased CD4/CD8 ratio because of an increased percentage of CD4+CD29+ helper memory T cells, lack of expression of the resting B-cell marker CD21, immune complex deposition and complement consumption, increased relative levels of ANA, abnormally high levels of IL-6 and soluble IL-2R, and detectable levels of IL-1b, IFN-g and TNF-a. These observations provide evidence for the involvement of CD5+ B cells and differential helper T-cell activity in procainamide-induced lupus and for an association between local lymphocyte activation and organ pathology.

A comprehensive review and evaluation of the side effects of the tumor necrosis factor alpha blockers etanercept, infliximab and adalimumab.

For more than 5 years, infliximab and etanercept have been utilized to treat rheumatoid arthritis and Crohn's disease. There is therefore much post-approval data on their side effects. A variety of Medline searches were done at the beginning of June 2004 using the terms 'etanercept', 'infliximab' and 'adalimumab' and the words 'lymphoma', 'infection', 'congestive heart failure', 'demyelinating disease', 'lupus', 'antibodies', 'injection site reaction', 'systemic', 'side effects' and 'skin'. Approximately 150 articles were so identified. In addition, FDA and manufacturers' data obtained by internet searches using Google were reviewed. The important side effects that have been most extensively related to TNFalpha blockers include: lymphoma, infections, congestive heart failure, demyelinating disease, a lupus-like syndrome, induction of auto-antibodies, injection site reactions, and systemic side effects. The risk of these side effects is very low. Nevertheless, it is important for clinicians to be aware of these side effects when prescribing therapy.

Lupus-like syndrome in a mother and newborn following administration of hydralazine; a case report.

A very-low-birth-weight infant died from pericardial effusion and cardiac tamponade confirmed by the post-mortem findings. The mother suffered from lupus-like syndrome consequent to hydralazine treatment for pregnancy-induced hypertension. The possible relationship between mother-infant pathology and hydralazine administration is discussed.