Primary antiphospholipid syndrome emerging following thymectomy for myasthenia gravis: additional evidence for the kaleidoscope of autoimmunity

Surgical treatment is effective in treating thymoma accompanied with non-myasthenia gravis autoimmune diseases: a single-center clinical experience

BACKGROUND AND AIMS

Although thymoma is inextricably linked to autoimmune disease, its best treatment method remains unclear. In this study, we sought to evaluate therapeutic effect of surgical resection of thymoma on non-myasthenia gravis autoimmune diseases.

MATERIALS AND METHODS

This was a retrospective study covering 32 patients with thymoma accompanied with non-myasthenia gravis autoimmune disease. The relationships between surgical treatment, thymoma pathological type, and prognosis of autoimmune diseases were analyzed from postoperative follow-up data.

RESULTS

In total, 32 patients in this study underwent surgical treatment. The mean age of the patients was 51.7 years. By the last follow-up, 2 patients had died, while the other 30 patients showed no sign of tumor recurrence and metastasis. According to the postoperative follow-up data, 22 patients (68.75%) showed improvement or even complete recovery of autoimmune disease symptoms, 9 patients (28.13%) showed no significant change, and only 1 patient's (3.12%) postoperative symptom was aggravated. Female patients and patients aged 50 and older were more likely to combine with non-organ-specific autoimmune diseases (p = 0.036, p = 0.017).

CONCLUSIONS

In conclusion, this study presents that surgical treatment achieves a satisfactory prognosis for thymoma combined with non-myasthenia gravis autoimmune disease.

Risk of incident autoimmune diseases in patients with thymectomy

OBJECTIVES

The data concerning the association between Tx and ADs remain unclear and are scarce. This study was undertaken to investigate whether people with Tx are more likely to develop ADs, compared to those without Tx.

METHODS

Individuals who received Tx between 2002 and 2015 were identified and matched on age and sex with individuals without Tx. We performed multivariate and stratified analysis using the Kaplan-Meier method and Cox proportional hazards models in order to estimate the association between Tx and the risk of developing ADs.

RESULTS

A total of 2550 thymectomized (Txd) patients and 24,664.941 non-Txd comparison subjects were selected from NHIRD. Tx-MG (myasthenia gravis) as compared with general population (nonTx-nonMG), adjusted hazard ratio (aHR) were higher for incident Addison disease (aHR = 10.40, 95% CI 1.01-107), autoimmune hemolytic anemia (aHR = 21.54, 95% CI 2.06-14.8), Hashmoto thyroiditis (aHR = 5.52, 95% CI 1.34-34.7), ankylosing spondylitis (aHR = 2.73, 95% CI 1.09-6.84), rheumatoid arthritis (aHR = 5.25, 95% CI 1.79-15.47), primary Sjogren syndrome (pSS) (aHR = 3.77, 95% CI 1.30-11.0), and systemic lupus erythemtoasus (aHR = 10.40). Tx-nonMG as compared with general population, aHR were higher for incident autoimmune hemolytic anemia (aHR = 25.50), Hashmoto thyroiditis (aHR = 6.75) and systemic lupus erythematosus (SLE) (aHR = 13.38). NonTx-MG as compared with general population, aHR were higher for incident Hashmoto thyroiditis (aHR = 6.57), pSS (aHR = 4.50), SLE (aHR = 17.29), and systemic vasculitis (aHR = 25.86).

INTERPRETATION

In conclusion, based on a retrospective cohort study throughout Taiwan, patients with Tx have a higher risk of new onset ADs than patients without Tx.

Ischaemic stroke in a patient with myasthaenic crisis and antiphospholipid antibody syndrome

While autoimmune diseases have been frequently found to coexist in the same patients, the co-occurrence of myasthaeniagravis and antiphospholipid antibody syndrome (APAS) has only been reported in eight cases. We present a case of a 46-year-old Filipina who developed ischaemic stroke while admitted at the neurocritical unit for myasthaenic crisis. She was successfully thrombolysed with intravenous recombinant tissue plasminogen activator (rTPA), given a regimen of intravenous Ig and a dose of cyclophosphamide prior to discharge. Extensive workup revealed APAS to be the aetiology of her stroke. Twenty-one months into her follow-up, she is doing well with a modified Rankin Score of 0. Our case suggests that rTPA followed by immunomodulators may be given safely in myasthaenic crisis patients who develop ischaemic stroke. We emphasise the importance of doing a comprehensive neurological evaluation in agitated patients in the critical care unit.

Systemic lupus erythematosus-myasthenia gravis overlap syndrome: Presentation and treatment depend on prior thymectomy

In this study, we investigated four patients who met the diagnostic criteria for overlapping systemic lupus erythematosus (SLE) and myasthenia gravis (MG) but responded differently to treatment. All patients were acetylcholine receptor (AChR) and antinuclear antibody positive at the time of SLE diagnosis. Two patients presented with SLE who have been effectively treated with cholinesterase inhibitors for MG. These patients developed SLE with photosensitivity, rash, and arthritis post thymectomy, which had been performed 29 years and 40 years earlier, respectively. Two other patients were found to have AChR antibodies and MG in the context on new-onset SLE. These subjects were responsive to hydroxychloroquine and immunosuppression but failed cholinesterase inhibitors. The evolution of these cases is relevant for the role of thymus in lupus pathogenesis during aging and for treatment selection in SLE-MG overlap patients.

Autoantibody induction and adipokine levels in patients with psoriasis treated with infliximab

This study was aimed to analyse the prevalence of antinuclear antibodies in patients with psoriasis after treatment with infliximab and correlates the development of antibodies with both response to treatment and adipokines levels. Serum levels of ANA, anti-dsDNA, anti-histone, anti-nucleosome and anti-ENA antibodies at baseline after 2 and 12 months of treatment with infliximab were measured in 27 patients with psoriasis, as well as in 27 matched controls. Serum C-reactive protein (CRP), chemerin, visfatin and resistin were also assessed. The prevalence of ANA increased from 22 to 37% and 63% (p < 0.01) during treatment with infliximab, with a gradual progressive increase both in ANA titre and in percentage of ANA pattern. The prevalence of other antibodies also increased from 7 to 30% and 48% (p < 0.01) for anti-ds-DNA and from 7 to 26% and 37% for anti-nucleosome antibodies (p < 0.05), whereas the prevalence of anti-histone and anti-ENA antibodies was unchanged throughout the study period. Basal chemerin, resistin and CRP levels were higher in patients than in controls, and their levels progressively normalized during treatment (p < 0.01). Conversely, visfatin levels gradually increased (p < 0.01). ANA+ patients tended to show a faster decrease in PASI score, CRP and chemerin levels after 2 months, but the PASI score did not differ between ANA+ and ANA- patients at 12 months. A higher increase of visfatin was also found in ANA+ patients at 2 and 12 months. The antinuclear antibody response induced by infliximab was restricted to ANA, anti-dsDNA and anti-nucleosome antibodies. Patients who developed ANA positivity showed a faster clinical, inflammatory and immunological response to infliximab therapy.

The mosaic of environment involvement in autoimmunity: the abrogation of viral latency by stress, a non-infectious environmental agent, is an intrinsic prerequisite prelude before viruses can rank as infectious environmental agents that trigger autoimmune diseases

An autoimmune disease (AD), organ-specific or systemic, results from an aberrant response in which the protective immune system normally schooled to recognize and destroy invading infectious agents (viruses, etc.) instead fails to distinguish self-antigens and proceeds to attack and destroy the host's organs. There can be familial aggregation in which a single AD may occur in members of a family, or a single family may be afflicted with multiple ADs. Finally, sometimes multiple ADs co-occur in a single individual: the kaleidoscope of autoimmunity. Autoimmunity is a multifactorial process in which genetic, hormonal, immunological and environmental factors act in concert to materialize the mosaic of autoimmunity phenomenon. A genetically primed individual may yet not develop an AD: the contribution by an environmental factor (non-infectious or infectious) is essential for completion of the act. Of the non-infectious factors, stress plays a determinative step in autoimmunity in that it abrogates viral latency and thereby ordains the viruses to qualify as infectious environmental factors that trigger ADs. This is note-worthy as viruses rank first as the most important environmental triggers of ADs. Furthermore, all these viruses experience going through latency. Hence the hypothesis: "The abrogation of viral latency by stress, a non-infectious environmental agent, is an intrinsic prerequisite prelude before viruses can rank as infectious environmental agents that trigger autoimmune diseases". There is collaboration here between non-infectious- and infectious-agent to achieve the cause of autoimmunity. We say viral latency and stress have a covenant: continued perpetration of autoimmunity is dependent on the intervention by stress to reactivate latent infections.

Double seronegative myasthenia gravis with antiphospholipid syndrome: a case report

Introduction

Myasthenia gravis is an autoimmune disease characterized by fluctuating muscle weakness. It is often associated with other autoimmune disorders, such as thyroid disease, rheumatoid arthritis, systemic lupus erythematosus, and antiphospholipid syndrome. Many aspects of autoimmune diseases are not completely understood, particularly when they occur in association, which suggests a common pathogenetic mechanism.

Case presentation

We report a case of a 42-year-old Caucasian woman with antiphospholipid syndrome, in whom myasthenia gravis developed years later. She tested negative for both antibodies against the acetylcholine receptor and against muscle-specific receptor tyrosine-kinase, but had typical decremental responses at the repetitive nerve stimulation testing, so that a generalized myasthenia gravis was diagnosed. Her thromboplastin time and activated partial thromboplastin time were high, anticardiolipin and anti-β2 glycoprotein-I antibodies were slightly elevated, as a manifestation of the antiphospholipid syndrome. She had a good clinical response when treated with a combination of pyridostigmine, prednisone and azathioprine.

Conclusions

Many patients with myasthenia gravis test positive for a large variety of auto-antibodies, testifying of an immune dysregulation, and some display mild T-cell lymphopenia associated with hypergammaglobulinemia and B-cell hyper-reactivity. Both of these mechanisms could explain the occurrence of another autoimmune condition, such as antiphospholipid syndrome, but further studies are necessary to shed light on this matter.

Clinicians should be aware that patients with an autoimmune diagnosis such as antiphospholipid syndrome who develop signs and neurological symptoms suggestive of myasthenia gravis are at risk and should prompt an emergent evaluation by a specialist.

Hepatoportal sclerosis (obliterative portal venopathy) and nodular regenerative hyperplasia in a patient with myasthenia gravis: A case report and review of the published work

Nodular regenerative hyperplasia (NRH) and hepatoportal sclerosis, also known as obliterative portal venopathy (OPV), are two causes of non-cirrhotic portal hypertension (NCPH). NCPH is an increasingly recognized entity that can be seen in association with collagen vascular diseases and with the use of medications such as azathioprine and didanosine, but oftentimes the etiology remains unidentified. We herein report a case of NCPH occurring due to OPV and NRH in a 64-year-old woman with myasthenia gravis (MG), status post-thymectomy. Portal hypertension was diagnosed incidentally on computed tomography in the absence of predisposing factors. Extensive work-up to determine the etiology of any underlying liver disease was unrevealing. NRH and OPV were identified on liver biopsy. Subsequently, the patient had variceal bleeding that necessitated transjugular intrahepatic portosystemic shunt placement. A few similar cases of NCPH occurring in the setting of MG have been previously reported, suggesting that the immunological mechanisms involved in the pathogenesis of myasthenia may also have contributed to the development of NCPH.

Rheumatoid arthritis and primary biliary cirrhosis: cause, consequence, or coincidence?

Primary biliary cirrhosis (PBC) is a progressive cholestatic liver disease characterized serologically by cholestasis and the presence of high-titre antimitochondrial antibodies and histologically by chronic nonsuppurative cholangitis and granulomata. PBC patients often have concomitant autoimmune diseases, including arthropathies. This raises the question as to whether there are shared features in the pathogenesis of those diseases with the pathogenesis of PBC. Epidemiological and large case studies have indicated that although the incidence of rheumatoid arthritis (RA) is not significantly raised in PBC patients, there appears to be a higher rate of RA in PBC patients and their relatives. Genetic studies have demonstrated that several genes implicated in PBC have also been implicated in RA. Epigenetic studies provided a wealth of data regarding RA, but the findings on epigenetic changes in PBC are very limited. As well, certain infectious agents identified in the pathogenesis of PBC may also play a role in the pathogenesis of RA. These data suggest that although RA is not significantly present in PBC, some individuals with certain genetic traits and environmental exposures may develop both conditions. This concept may also apply to other concomitant diseases found in PBC patients.

Association of Thymectomy With Infection Following Congenital Heart Surgery

Background: Congenital absence of the thymus can lead to profound immunodeficiency, suggesting that thymic function during fetal development is essential to normal lymphocyte development. How vital the thymus after birth is to human immune competence and regulation is not known. Routine thymectomy, especially at an early age, may influence immunity, and therefore the risk of infection, autoimmunity, or malignancy. Methods: A retrospective review of cardiac surgery patients followed at Seattle Children’s Hospital was performed. The primary outcome was rate of serious infections requiring hospitalization. Secondary analyses included age, type of infection, cardiac diagnosis, surgical procedure, and comorbidities. Results: Patients fell into 2 groups: 60 with complete thymectomy and 35 with partial or no thymectomy. There was no statistical difference between groups in the overall prevalence of serious infections (16.7% vs 17.2%, P = 1.0). There was a nonsignificant trend toward reduced time between surgery and onset of first infection in patients in the total thymectomy group versus those without thymectomy (1.7 years vs 4.6 years, P = .07). Total thymectomy before 6 months of age also tended to increase infection rate, but the effect was not significant (0.09/year vs 0.02, P = .14). Gastroesophageal reflux in patients with total thymectomy increased the risk of infection ( P = .013), suggesting a cumulative effect. Conclusions: Though infections occurred frequently in the childhood cardiac surgery population, total thymectomy was not associated with increased risk of serious infection. Comorbid conditions may be more important contributing factors increasing the risk of infection in this complex and vulnerable population.

Thymoma and autoimmunity

The thymus is a central lymphatic organ that is responsible for many immunological functions, including the production of mature, functional T cells and the induction of self-tolerance. Benign or malignant tumors may originate from the thymus gland, with thymoma being the most common and accounting for 50% of anterior mediastinal tumors. Malignancies linked to thymoma include the loss of self-tolerance and the presence of autoimmunity. In this review, we compiled the current scientific evidence detailing the various interactions between thymoma and autoimmune diseases, including myasthenia gravis, systemic lupus erythematosus, inappropriate antidiuretic hormone secretion, pure red cell aplasia, pernicious anemia, pemphigus and autoimmune thyroid diseases. In recent years, several mechanisms have been proposed to explain these interactions. Most are based on the assumption that the 'sick' thymus, like the 'normal' thymus, can generate mature T cells; however, the T cells generated by the sick thymus are impaired and thus may exert cellular autoreactivity. Here, we present several theories that may shed light on the loss of self-tolerance associated with this epithelial tumor of the thymus.

Evolving connective tissue disease influenced by splenectomy: beneath the sword of Dameshek

In years past, there was concern that splenectomy could lead to dissemination of occult systemic lupus erythematosus. Clinical studies subsequently effectively refuted that concept. However, there remains uncertainty regarding the role of the spleen in autoimmune diseases and the effect of splenectomy on their course. We present a case of a 56-year-old woman with autoimmune hepatitis and rheumatoid arthritis, without clinical or serologic features of lupus, who developed glomerulonephritis and antiphospholipid syndrome subsequent to an elective splenectomy. Literature review was performed to identify examples of the effect of splenectomy on other autoimmune diseases. Splenectomy has been linked with the development of new autoimmune phenomenon, alterations in the clinical course of patients with prior autoimmune disease, such as in our patient, and in a progressive redistribution of memory B cells that may influence autoimmune disease activity and may have been involved in the alteration in our patient's clinical course.

Coexistence of four autoimmune diseases in one patient: the kaleidoscope of autoimmunity

Genetic, immune, hormonal, and environmental factors are associated with the multifactorial origin of autoimmunity. When one or more of these factors are altered, a "switch" from one autoimmune condition to another can occur, developing the so called "kaleidoscope phenomenon" of autoimmunity. We present the case of a 30-year-old woman with myasthenia gravis and hypothyroidism probably resulting from autoimmune thyroiditis. A thymectomy was performed, and 1 year later, rheumatoid arthritis was diagnosed based on clinical, radiological, and serological features. Nine years after thymectomy, systemic lupus erythematosus was diagnosed based on skin, renal, hematologic, and immunologic manifestations. We suggest that the immune system function was modified when thymectomy was performed, playing an important role in the development of the new autoimmune conditions. Thymectomy increases the risk of developing a new autoimmune disease because it modifies, by mechanisms not well defined, the equilibrium and normal function of the immune system. This patient presents the infrequent association of four autoimmune conditions. When a patient has one autoimmune disease, she is at risk for another.

Acquired generalised neuromyotonia, cutaneous lupus erythematosus and alopecia areata in a patient with myasthenia gravis

We describe a patient with the diagnoses of acquired neuromyotonia, cutaneous lupus erythematosus and alopecia areata, occurring many years after a thymectomy for myasthenia gravis associated with a thymoma. We review the current literature on autoimmune conditions associated with myasthenia gravis and thymectomy. To our knowledge, this combination of multiple autoimmune conditions has not been reported previously.

Coexistence of thyroid autoimmunity with other autoimmune diseases: friend or foe? Additional aspects on the mosaic of autoimmunity

Autoimmunity encompasses a wide spectrum of diseases from organ-specific diseases like Hashimoto thyroiditis, to systemic diseases such as systemic lupus erythematosus. These diseases are characterized by inflammation and the production of a wide range of autoantibodies directed against multiple autoantigens. Although their etiology is still poorly understood, genetic, immunological, hormonal, and environmental factors are major predisposing and triggering factors. These multiple factors, like pieces in a mosaic, may interplay in different forms, leading to the expression of various autoimmune manifestations and diseases. This phenomenon, which has been referred by us as the "mosaic of autoimmunity", illuminates the diversity of autoimmune manifestations among susceptible individuals. From this theoretical framework we conducted a wide search of the literature, on the prevalence of thyroid autoimmunity, the commonest of the autoimmune conditions, among other autoimmune diseases, and discuss the possible clinical significance of this association.

Infection, vaccines and other environmental triggers of autoimmunity

The etiology of autoimmune diseases is still not clear but genetic, immunological, hormonal and environmental factors are considered to be important triggers. Most often autoimmunity is not followed by clinical symptoms unless an additional event such as an environmental factor favors an overt expression. Many environmental factors are known to affect the immune system and may play a role as triggers of the autoimmune mosaic.Infections: bacterial, viral and parasitic infections are known to induce and exacerbate autoimmune diseases, mainly by the mechanism of molecular mimicry. This was studied for some syndromes as for the association between SLE and EBV infection, pediatric autoimmune neuropsychiatric disorders associated with streptococcal infection and more. Vaccines, in several reports were found to be temporally followed by a new onset of autoimmune diseases. The same mechanisms that act in infectious invasion of the host, apply equally to the host response to vaccination. It has been accepted for diphtheria and tetanus toxoid, polio and measles vaccines and GBS. Also this theory has been accepted for MMR vaccination and development of autoimmune thrombocytopenia, MS has been associated with HBV vaccination. Occupational and other chemical exposures are considered as triggers for autoimmunity. A debate still exists about the role of silicone implants in induction of scleroderma like disease.Not only foreign chemicals and agents have been associated with induction of autoimmunity, but also an intrinsic hormonal exposure, such as estrogens. This might explain the sexual dimorphism in autoimmunity.Better understanding of these environmental risk factors will likely lead to explanation of the mechanisms of onset and progression of autoimmune diseases and may lead to effective preventive involvement in specific high-risk groups. So by diagnosing a new patient with autoimmune disease a wide anamnesis work should be done.

Thymus alterations and systemic sclerosis

OBJECTIVES

The pathogenesis of systemic sclerosis (SSc) includes complex alterations to the immune system, possibly responsible for diffuse microvasculature and fibroblast dysfunction. Previous anecdotal observations suggest a possible role for thymus alterations in some autoimmune rheumatic diseases, including SSc. This study aimed to investigate the prevalence of radiological thymus alterations in SSc patients.

METHODS

Thirthy-four unselected patients [28 female and 6 male, mean age (+/- S.D.) 49.7 +/- 9.5 yr, range 33-67 yr] and 34 age- and sex-matched controls were included in the study. The presence of major radiological thymus alterations, i.e. an abnormally enlarged or nodular thymus, were blindly investigated by means of unenhanced multidetector computed tomography.

RESULTS

Abnormally enlarged or nodular thymuses were detected in a statistically significant percentage of SSc patients compared with controls (21 vs 0%, P = 0.011). More interestingly, radiological thymus alterations were invariably observed in patients with shorter disease duration (< or =5 yr, 41% vs >5 yr, 0%; P = 0.007), frequently associated with serum anti-Scl70 antibodies (P = 0.017). Among patients with thymus alterations one developed myasthenia gravis while two others showed thymus hyperplasia at histopathological evaluation after thymectomy.

CONCLUSIONS

The present study suggests a possible role of thymic disorders, mainly thymus hyperplasia, in a significant number of SSc patients. Due to the limitations of radiological evaluation, the actual relevance of such an association might be underestimated. The relationship of thymus alterations with shorter disease duration, as well as with serum anti-Scl70, suggests that thymic dysfunction could play a pathogenetic role mostly in the early phases of the disease, and possibly in specific SSc patient subsets.

The antiphospholipid syndrome

The antiphospholipid (aPL) antibody syndrome is an autoimmune condition in which vascular thrombosis and/or recurrent pregnancy losses occur in patients with laboratory evidence for antibodies that bind to phospholipids. There have been significant advances in the recognition of the role of phospholipid-binding cofactors, primarily beta2GPI, as the true immunologic targets of the antibodies. Recent evidence suggests that the antibodies disrupt phospholipid-dependent anticoagulant mechanisms and/or that aPL antibodies induce the expression of procoagulant and proadhesive molecules on endothelial cells. Current diagnosis is based on clinical findings and empirically derived tests, such as assays for antibodies that bind to phospholipids or putative cofactors and coagulation assays that detect inhibition of phospholipid-dependent coagulation reactions. Current treatment relies primarily on anticoagulant therapy. Research advances are expected to bring mechanistically based diagnostic tests and improved therapy that target the roots of the disease process.

Bcg and autoimmunity: another two-edged sword

BCG immunotherapy for bladder carcinoma has been a long-standing treatment modality that has proved itself efficient and safe. Most of the side-effects of this treatment are minor and of short duration. There have been, nevertheless, several reports regarding more severe and long-term complications of BCG therapy-namely inflammatory arthritis, and occasionally systemic autoimmune manifestations. Here, we present four cases of patients who received intravesical instillation with BCG for bladder carcinoma and developed long-standing inflammatory arthritis. One of these patients developed Reiter's syndrome. We also refer to the possible immune mechanisms by which BCG can trigger arthritis, as well as to the link between mycobacterial infection, BCG immunotherapy and autoimmunity.

Autoantibodies against malondialdehyde-modified lipoprotein(a) in antiphospholipid syndrome

OBJECTIVE

To demonstrate the existence of antibodies that react against malondialdehyde (MDA)-modified lipoprotein(a) (MDA-Lp[a]), a molecule that exhibits behavioral similarities to MDA-modified low-density lipoprotein (MDA-LDL), and to assess the possible relationship of these antibodies (anti-MDA-Lp[a]) to anti-MDA-LDL antibodies (anti-MDA-LDL) in the antiphospholipid syndrome (APS).

METHODS

We studied 104 patients with APS (61 with primary APS and 43 with APS secondary to systemic lupus erythematosus) and 106 healthy controls. Anti-MDA-Lp(a) were measured by enzyme-linked immunosorbent assay (ELISA) using MDA-Lp(a) as antigen. Plasma levels of Lp(a) were determined. Anti-MDA-LDL, anticardiolipin antibodies (aCL), and anti-beta2-glycoprotein I antibodies (anti-beta2GPI) were also measured by ELISA. Inhibition assays were performed to determine the presence of cross-reactivity between anti-MDA-Lp(a) and anti-MDA-LDL.

RESULTS

Anti-MDA-Lp(a) were detected in 38 of 104 patients (37%) but in only 6 of 106 controls (6%) (chi2 = 28, P<0.0001). Levels of anti-MDA-Lp(a) were also higher in patients than in controls (P<0.0001). Titers of these antibodies did not correlate with plasma levels of Lp(a). The presence of anti-MDA-Lp(a) was significantly associated with that of anti-MDA-LDL (chi2 = 22.09, P<0.0001). There was a strong correlation between the titers of anti-MDA-Lp(a) and anti-MDA-LDL (r = 0.59, P<0.0001), and inhibition assays showed significant cross-reactivity between the 2 populations of antibodies. Anticardiolipin antibodies and anti-beta2GPI were present in sera from 67 patients (64%) and 48 patients (46%), respectively. No correlation was found between the titer of anti-MDA-Lp(a) and titers of either aCL or anti-beta2GPI.

CONCLUSION

We report for the first time the existence of autoantibodies against MDA-Lp(a). The presence of antibodies reacting not only against MDA-LDL but also against MDA-Lp(a) supports the hypothesis of a role for oxidative phenomena in the pathogenesis of APS and atherosclerosis.

Inhibition of diabetes in NOD mice by idiotypic induction of SLE

The present study was undertaken to investigate whether active induction of systemic lupus erythematosus (SLE) in non-obese diabetic (NOD) mice could affect their development of insulin-dependent diabetes mellitus (IDDM). NOD mice were immunized with a human IgM mAb carrying the 16/6 idiotype (MIV-7) or with control human IgM. The mice were bled monthly and tested for SLE-associated autoantibodies in the serum and for the presence of leukopenia, thrombocytopenia, proteinuria and immunoglobulin deposits in the kidneys. The development of diabetes was determined by a blood glucose level exceeding 15 mM on two consecutive weekly determinations and by the presence of insulitis in the pancreas. The NOD mice immunized with MIV-7 developed high and persistent levels of autoantibodies, including anti-DNA, anti-histones and anti-cardiolipin, untreated mice and those immunized with normal human IgM did not produce these autoantibodies. The MIV-7-immunized mice also manifested an elevated erythrocyte sedimentation rate, leukopenia, thrombocytopenia and significant proteinuria, as well as deposits of Ig in their kidney glomeruli. Thus, NOD mice immunized with MIV-7 developed both autoantibodies and clinical features of SLE. The MIV-7-treated mice, however, showed a significantly lower incidence of IDDM (25%vs. 90%, P<0.003), accompanied by amelioration of the insulitis. The present study indicates that the induction of SLE by idiotypic immunization can protect NOD mice from developing IDDM, pointing to the importance of immune dysregulation in shift from one autoimmune disease to another.

Long-term immunologic effects of thymectomy in patients with myasthenia gravis

BACKGROUND

Thymectomy (Tx) is a common therapeutic option to treat myasthenia gravis (MG), but its effects on the immune system are still obscure in humans.

OBJECTIVE

We sought to evaluate long-term immunologic effects of therapeutic Tx in patients with MG.

METHODS

T- and B-cell subsets and T-cell repertoire were analyzed in 35 patients with MG, 16 with previous Tx (at least 8 years before), 6 with recent (<1 year) Tx, and 13 without Tx, as well as in 32 healthy subjects used as normal control subjects. Serum immunoglobulins and a variety of autoantibodies were also measured. A subsequent 3-year clinical follow-up was performed to verify the possible appearance of systemic autoimmune diseases.

RESULTS

The long-term thymectomized (Txd) patients had mild T-cell lymphopenia and an expansion of some Vbeta families among circulating CD4+ and CD8+ T cells. They displayed a normal number of total B and CD5+ B-circulating lymphocytes, but they also displayed a polyclonal increase in serum IgM and IgG associated with the presence of high levels of a variety of organ- and nonorgan-specific autoantibodies, including anti-dsDNA and anticardiolipin, without clinical evidence of autoimmune disease. These serologic abnormalities were not detectable in both non-Txd and recently Txd patients. After 3 years, 2 long-term Txd patients had systemic lupus erythematosus and an undifferentiated connective tissue disease.

CONCLUSIONS

The association between MG and laboratory findings of systemic autoimmune disease may be in part related to Tx rather than to MG. Tx may represent a risk for the development of systemic autoimmune disorders over years in patients with MG.