The prevalence of antibodies to histones induced by procainamide in old people, in cancer patients, and in rheumatoid-like disease

Anti-histones antibodies in systemic lupus erythematosus: prevalence and frequency in neuropsychiatric lupus

To investigate the specificity, sensitivity, and concomitant presence of antibodies against histones (H), histone H1 (H1), and histone H3 (H3) in patients with systemic lupus erythematosus (SLE) and analyze their association with SLE. Serum IgG anti-histones antibodies were detected by enzyme-linked immunosorbent assay in 144 SLE patients consisting of 24 neuropsychiatric lupus (NPSLE), 65 lupus nephritis (LN), and 55 SLE, 100 other rheumatic diseases patients, as well as 40 healthy controls. Clinical and biological parameters of the patients were also evaluated. Anti-H, anti-H1, and anti-H3 antibodies yielded a sensitivity of approximately 33% and a specificity of more than 93% for SLE, which was comparable to that found for anti-double-stranded DNA (anti-dsDNa) antibodies. More significantly, anti-histone antibody is found in approximately 50% of patients with NPSLE compared with LN. Moreover, the titers of anti-histones antibodies of NPSLE patients were significantly higher than that of patients with SLE and LN. The sequential analysis revealed a close correlation of anti-H and anti-H1 antibodies with SLE disease activity. There was an approximate 30% positive rate of anti-histones antibodies in 144 SLE patients lacking anti-nucleosome, anti-mDNA, anti-Sm, and anti-dsDNA antibodies. Antibodies to histones H1 and H3 are markers with high specificity of 93.6-96.4% for SLE. The anti-histone antibody markers are prevalent in approximately 50% of NPSLE. Furthermore, there was a strong correlation with SLE disease activity index and levels of antibodies to histones and H1.

Diversity of antinuclear antibody responses in hepatocellular carcinoma

BACKGROUND/AIMS

The development of antinuclear antibodies (ANA) in malignancies has been described but its mechanism is still not understood. The aim of this study was to examine ANA specificities in hepatocellular carcinoma to further understand autoimmunity in cancer.

METHODS

Two hundred and four hepatocellular carcinoma patients were compared with 68 chronic hepatitis C, with 126 chronic hepatitis B and with 30 alcoholic liver cirrhosis patients, as well as with 87 healthy donors. Indirect immunofluorescence, immunoblotting, and immunoprecipitation were used to study ANA reactivities.

RESULTS

Hepatocellular carcinoma had a significantly higher frequency of ANA using HEp-2 cells as substrate (31%) than chronic hepatitis C (10%), chronic hepatitis B (9.5%), alcoholic liver cirrhosis (10%) or healthy donors (4.5%). A great diversity of ANA specificities was found in hepatocellular carcinoma. Three hepatoma sera had antibodies that co-localized with non-snRNP splicing factor SC35, suggesting that the antigenic targets might be involved in mRNA splicing. We identified antibodies to two known nuclear autoantigens: fibrillarin and p330d/CENP-F. These autoantigens are involved in the 5' processing of precursor ribosomal RNA transcripts and in mitotic functions, respectively.

CONCLUSIONS

Diversity was found in the autoantibody specificity, in contrast to the specific subsets of autoantibodies seen in several systemic rheumatic autoimmune diseases. Our data suggest that immune response in hepatocellular carcinoma targets important proteins involved in cellular biosynthetic or proliferative functions.

IgA antihistone antibodies in isoniazid-treated tuberculosis patients

A retrospective study of tuberculosis patients treated with isoniazid was undertaken in order to establish the prevalence and specificity of antibodies against histones, chromatin and denatured DNA. Each patient had an average of 2.7 +/- 0.4 antibody activities out of the 8 tested antigens using ELISA. These reactivities tended to be higher for non-native forms of the antigens such as denatured histones and DNA with essentially no reactivity to the (H2A-H2B)-DNA subunit of chromatin. Greater than half of the patients were isotype restricted to only IgA or IgM antihistone antibodies, and IgA antihistone antibodies were the most common and reactive. Thirty-five percent of the patients had elevated levels of one or more immunoglobulin classes, and the IgA level was strongly correlated with IgA antihistone activity. These results suggest that isoniazid treatment results in modest increases in antihistone antibodies of the specificities and class typical of drug-induced autoimmunity in the absence of lupus-like disease. The IgA antihistone predominance suggests that serum antoantibodies may be the consequence of stimulation by isoniazid of lymphocytes in the gut-associated Peyer's patches or intestinal lymphoid follicles.

Increasing titers and changing specificities of antinuclear antibodies in patients with chronic liver disease who develop hepatocellular carcinoma

BACKGROUND

Patients with liver cirrhosis and chronic hepatitis are at high risk for development of hepatocellular carcinoma (HCC). In HCC and other malignant neoplasms, antinuclear antibodies (ANA) have been detected, but the clinical and biologic significance of these autoantibodies has not been established. This study documents changing ANA manifested as seroconversion from a negative to positive ANA status, increasing titers, and changing antibody specificities in patients in whom chronic liver disease has progressed to HCC.

METHODS

Sera were collected from patients with chronic liver diseases and HCC in Japan. Indirect immunofluorescence was used to detect ANA, and Western blotting, two-dimensional immunoblotting, and enzyme-linked immunosorbent assay were used to characterize nuclear antigen-antibody systems.

RESULTS

ANA were detected in 57 of 183 (31%) patients with HCC, a statistically higher frequency than in patients with the most common antecedent clinical conditions, liver cirrhosis (9 of 64 patients [14%]; P < 0.05) or chronic hepatitis (16 of 123 patients [13%]; P < 0.001). One patient with autoimmune hepatitis observed for 9 years had a decrease in ANA titer after therapy with corticosteroid and azathioprine and had a rebound increase in ANA titer associated with development of HCC. Immunologic assays demonstrated dramatic decreases in levels of autoantibodies to histones during therapy and the appearance of new autoantibodies coincident with HCC. Changes in ANA associated with the appearance of auto-antibodies of new specificities were documented in four other patients with chronic liver disease in whom HCC developed.

CONCLUSIONS

Changes in ANA, especially alterations in autoantibody specificities, are seen infrequently in systemic autoimmune diseases. It is possible that in HCC such changes in ANA might reflect autoimmune responses to intranuclear antigens that are perturbed in cellular transformation.

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.

Autoantibodies in the sera of patients with lymphoma

Sera of 84 patients with Hodgkin's disease (HD) and 55 patients with non-Hodgkin's lymphoma (NHL) were examined for the presence of autoantibodies to ssDNA, dsDNA, Poly (I), Poly (G), cardiolipin, histones, RNP. Sm, Ro (SS/A), La (SS/B) and the common anti-DNA idiotype (16/6) using an enzyme-linked immunosorbent assay (ELISA). Anti-ssDNA antibodies were detected in the sera of 20 patients with lymphoma (23.8%), more among those with NHL than HD (16 vs. 4 patients p < 0.01). Anti-RNP and anti-Sm antibodies were found in 16 (21.7%) and 14 lymphoma patients (20%) respectively, significantly more than in the controls (p < 0.05) in both antibodies). These findings remained valid following subgrouping of the patients into those with HD and NHL. With all the other autoantibodies examined no significant difference could be observed in the incidence between lymphoma patients and controls. These results differ from our previous survey carried out on sera of patients with solid tumors in whom no increased frequency of any of the autoantibodies could be determined. In view of the evidence suggesting an increased risk of lymphoma in a number of autoimmune diseases our results extend this relationship to an increased incidence of autoantibodies among patients with lymphoma.

Serodiagnosis of cancers by ELISA of anti-histone H2B antibody

An enzyme-linked immunosorbent assay method for serodiagnosis of cancers was developed by employing histone H2B. This method measures anti-histone H2B antibody levels in sera and includes a device for coating the plastic immunoplate with a mixture of histone H2B and diluted fetal calf serum. The coating of immunoplates with this mixture decreased apparent sensitivity of the assay compared with that in the absence of fetal calf serum, but effective reduction of nonspecific background enabled a specific assay of anti-histone H2B antibody with excellent reproducibility. By this method cancer patients were discriminated from normal healthy subjects at detection rates of 37% for lung cancer, 33% for liver cancer, 50% for pancreatic cancer, 42% for colon cancer, and 78% for cervical cancer. However, stomach and esophagus cancers showed detection rates of less than 17%, which are comparable to the values for benign diseases. It is likely that this assay method detects squamous cell carcinomas at relatively high rates.

Autoantibodies in neoplasia. An unresolved enigma

One hundred sixty-four sera samples of patients with malignant diseases were analyzed for the presence of autoantibodies to ssDNA, dsDNA, poly(I), Poly(G), cardiolipin, histones, RNP, Sm, Ro(SSA), and La (SSB). No distinction could be made between these patients and a comparative group composed of age-adjusted healthy subjects when measuring antibody levels to these autoantigens by the ELISA technique. This finding remained valid after further subgrouping of the patients according to age, sex, and histologic origin of the tumor. The authors conclude that in contrast to the known clinical coexistence of neoplasia in autoimmune states, there is no increased incidence of antinuclear autoantibodies in malignant conditions.

Age-dependent LH and FSH effect on the proliferation of women's peripheral blood lymphocytes in vitro

Pituitary gonadotropic hormones (LH and FSH) were found to induce an age-dependent proliferation of women's peripheral blood lymphocytes (PBL). Results showed that PBL of elderly women gave a higher gonadotropic response than those of younger donors and that the number of responders to the mitogenic stimulus of the hormones was always more important in older than in younger women. A negative correlation between the mitogenic effect of FSH (10(-9) g/ml) and the level of plasma concentration of some steroid hormones (17-beta-estradiol or both 17-beta-estradiol and progesterone) was observed in younger donors. It was also found that physiological concentrations of LH and FSH can either increase or decrease the Concanavalin A (Con A)-induced proliferation in vitro of PBL taken from both young or postmenopausal women. In certain elderly women (4/9) a synergistic effect of Con A and LH, giving rise to high levels of thymidine incorporation similar to those achieved by Con A-stimulated PBL of young women, was observed. The possible physiological significance of these results is discussed.

In vitro anti-histone antibody production by peripheral blood cells from patients with systemic lupus erythematosus

Anti-histone antibodies (AHA) have been demonstrated frequently in the sera of patients with systemic lupus erythematosus (SLE). In the present studies, we found that peripheral blood mononuclear leukocytes (PBL) from a large subset of SLE patients spontaneously produce elevated levels of AHA in culture. In contrast, detectable production by normal mononuclear cells was extremely rare. Spontaneous production by patients' PBL correlated with both disease activity and elevated serum AHA levels, and thus appeared to reflect in vivo production. Interestingly, spontaneous AHA production was independent of polyclonal B-cell activation as measured by total Ig synthesis in culture. Production also appeared to be T-cell-independent in that cultures depleted of T cells produced AHA levels similar to those of cultures with unseparated PBL. Although PBL from normal individuals rarely produce AHA spontaneously, the presence of histone-specific B cells in normal peripheral blood could be detected after pokeweed mitogen stimulation. The present studies provide a basis for a further understanding of the mechanisms responsible for autoantibody production in SLE.

Autoantibodies against the H1(0) subtype of histone H1

The specificity of antinuclear autoantibodies in a patient with a sensory neuropathy associated with cancer has been analyzed. The autoantibodies recognize the histone H1(0) as shown by its dissociation from DNA, perchloric solubility, electrophoretic mobility in SDS or urea/acid polyacrylamide gels, and by the capacity of purified H1(0) to block the reactivity of these autoantibodies. Almost no reactivity was observed with other subtypes of H1. To our knowledge, this is the first autoantibody described with such specific reactivity for the H1(0) subtype.

Detection of antibodies to total histones and their subfractions in systemic lupus erythematosus patients and their asymptomatic relatives

Sera drawn from 75 patients with systemic lupus erythematosus, 141 healthy relatives (from the families of 51 patients), and 115 healthy control subjects were examined, by enzyme-linked immunosorbent assay, for IgG and IgM antibodies to total histones and their subfractions. Compared with the controls, statistically significant numbers of patients and their relatives had antihistone antibodies of both isotypes. Among the relatives, the sera from females, notably sisters of the patients, contained the highest levels of anti-total histone antibody. Anti-H2A/H2B and H3 antibodies were most prevalent among the lupus patients, but many of the relatives had IgM anti-H4 antibodies. These findings indicate that antihistone antibodies can serve as a genetic marker in patients with systemic lupus erythematosus.

T lymphocytes of rheumatoid arthritis patients show augmented reactivity to a fraction of mycobacteria cross-reactive with cartilage

An acetone-precipitable fraction of Mycobacterium tuberculosis cross-reacts with human cartilage. Immune responses to this antigen were assessed in 34 patients with rheumatoid arthritis, 16 patients with degenerative joint disease, and 15 healthy controls. The RA patients differed from the other two groups in having more pronounced T lymphocyte responses to the antigen; their serum antibody levels were not higher. The responses of RA patients varied with duration of disease. In the first year (7 patients) T lymphocyte reactivity was increased in the synovial exudates of affected joints but not in peripheral blood, whereas the 19 with disease of 1-10 years' duration showed high reactivity in peripheral blood; in the 8 with disease for more than 10 years, lymphocyte reactivity did not differ from that in the patients with degenerative joint disease or the healthy controls. The observation that the three groups did not differ in their responses to streptococci and a T-cell mitogen indicates that reactivity of the RA patients to the mycobacterial fraction was specific. These results raise the possibility that bacterial antigens cross-reactive with cartilage proteoglycans may be relevant to the pathogenesis of RA.

Serologic changes during induction of lupus-like disease by procainamide

Procainamide-induced lupus is a well-recognized syndrome, but the events leading up to clinical symptoms are obscure. In the present study, serologic changes in a 69-year-old man were monitored during his treatment with procainamide and after discontinuation of procainamide because of symptoms of drug-induced lupus. Antihistone antibodies of unique specificity and in vivo complement activation were detected after one year of procainamide therapy during a period prior to development of significant clinical symptoms. Antihistone antibodies and complement activation substantially increased during a full-blown episode of lupus-like symptoms. Progressive return to normal laboratory findings occurred after procainamide was discontinued. The antihistone/complement profile may be useful in the diagnosis of drug-induced lupus and warn of impending clinical deterioration in patients with minimal symptoms.

IgG antibodies to the histone complex H2A-H2B characterize procainamide-induced lupus

Patients treated with procainamide and other drugs commonly develop antinuclear antibodies and occasionally symptoms of lupus erythematosus. However, the pathological events which lead to clinical symptoms in some patients but only abnormal serology in others have not been established. The present study examines the incidence, amount, immunoglobulin class, and antigen-binding specificity of anti-histone and anti-denatured DNA (anti-dDNA) antibodies in three groups of patients. These comprised a prospective study of patients treated with procainamide, patients with clinical drug-induced lupus symptoms, and a group undergoing therapy for many years without any symptoms. Procainamide elicited IgG and IgM anti-dDNA antibodies concordantly. Anti-histone IgM antibodies also appeared de novo during this period but IgG anti-histone antibodies were detected less frequently. Asymptomatic patients tended to have an antibody profile consisting of highly elevated anti-dDNA, IgM antibodies reactive with all histones and IgG antibodies specific for only one or two histone classes. In contrast symptomatic patients usually had little anti-dDNA or antibodies to individual histones but had pronounced IgG antibodies to the histone complex H2A-H2B. This unique antibody was characteristics of procainamide-induced lupus and was not detected in patients whose disease was induced by hydralazine. Anti-(H2A-H2B) decreased after procainamide was discontinued, concomitant with subsidence of symptoms. The finding that autoantibodies elicited by procainamide in patients with lupus symptoms have a characteristic immunoglobulin class and specificity may be of pathogenic significance and suggests that patients susceptible to procainamide-induced lupus have a unique immune response. In addition, this information could be of diagnostic value in predicting which procainamide-treated patients will develop overt symptoms of lupus.

Antinuclear antibody determination: the present state of diagnostic and clinical relevance

Determination of antinuclear antibodies (ANA) will gain in diagnostic significance if a specific type of ANA can be related to a defined clinical disorder. The past decade has brought us quite a lot of papers dedicated to this subject. Yet, with exception of the DNA/anti-DNA system, observed correlations have remained scarce or contradictory. Also, still little is known about the pathogenic role of ANA. Perhaps more recent approaches using biochemical technologies will provide us with highly purified nuclear antigens necessary to study possible correlations at a more sophisticated level.