Hypothesis: the aging paradox and autoimmune disease

Autoimmune Hepatitis in the Elderly: Diagnosis and Pharmacologic Management

Autoimmune hepatitis (AIH) may present as acute or chronic hepatitis in the elderly. Advanced hepatic fibrosis and cirrhosis are common on first presentation in this population. In this review, we discuss the presentation, approach to diagnosis and management of AIH in the elderly. As polypharmacy is common in the elderly, careful medication use history is essential for detecting drug-induced AIH-like hepatitis. Steroid-sparing or minimizing therapeutic regimens are preferred to treat AIH in the elderly. For the purpose of induction, budesonide or lower dose prednisone in combination with azathioprine (AZA) regimens are preferred over high-dose prednisone monotherapy due to the higher risk of side effects of the later in the elderly. The goal of maintenance therapy should be to achieve full biochemical and histologic remission. Bone density monitoring and interventions to prevent steroid-related bone disease should be implemented throughout the course of the disease. Liver transplantation should be considered in the elderly patient with liver failure or early hepatocellular carcinoma if there are no significant comorbidities or compromise in functional status.

Review article: permanent drug withdrawal is desirable and achievable for autoimmune hepatitis

BACKGROUND

Autoimmune hepatitis can be rendered treatment-free, but the difficulty, frequency and risks associated with the pursuit of this outcome are unclear.

AIM

To describe the frequency that autoimmune hepatitis can be rendered treatment-free, identify the features that characterise these patients, examine the pathogenic pathways that may sustain or terminate the disease and indicate management protocols that can obtain this result.

METHODS

Studies cited in Pub Med from 1972-2014 for autoimmune hepatitis, treatment, relapse, remission and outcome were selected.

RESULTS

The frequency of a treatment-free state varies from 19% to 40% in patients observed for ≥3 years after drug withdrawal. Complete laboratory resolution and reversion to normal liver tissue prior to drug withdrawal favours this response. The development of cirrhosis during therapy may increase treatment-dependence. Persistent liver damage and the generation of neo-antigens during the apoptosis of hepatocytes may perpetuate the disease. Genetic and age-related effects on the vigour of the immune response may also contribute. Reversion to normal liver tissue is achieved in only 22% of patients during conventional corticosteroid therapy, and the emerging pharmacological and biological interventions may improve this frequency. A management strategy designed to achieve a treatment-free state accommodates all candidates for this outcome, and it can be modified to a long-term maintenance strategy as warranted by the clinical response.

CONCLUSIONS

Permanent drug withdrawal is a treatment outcome that is desirable and achievable in patients with autoimmune hepatitis. Normalisation of liver tests and liver tissue during treatment enhances this occurrence.

Autoimmune hepatitis

Autoimmune hepatitis (AIH) was the first chronic liver disease in which remission was achieved by immunosuppression. Prognosis is poor when left untreated. Since the original description in 1950 by Waldenström, the initially reported treatment option has remained until today and is the core of the basic therapeutic strategy of inducing remission with steroids and azathioprine. Immunosuppression as a treatment concept spans different situations including the induction and maintenance of remission, treatment of nonresponders, avoidance of side effects, perioperative treatment of liver transplantation candidates and the issue of withdrawal. Alternative immunosuppressive drugs such as transplantation immunosuppressants have been administered and reported in small series. In an attempt to optimize side effect management, a recent large multicenter prospective treatment trial suggests that budesonide may offer an alternative for noncirrhotic AIH patients with lower steroid side effects. With an early diagnosis and effective therapy, only 4% of transplant candidates are transplanted for AIH. After liver transplantation there is a considerable risk for graft loss because of recurrent AIH, and lifelong vigilance and therapeutic attention is important.

Acute and acute severe (fulminant) autoimmune hepatitis

Autoimmune hepatitis frequently has an abrupt onset of symptoms, and it can present with acute liver failure. The abrupt presentation can indicate spontaneous exacerbation of a pre-existent chronic disease, newly created disease, a superimposed infectious or toxic injury, or new disease after viral infection, drug therapy, or liver transplantation. Deficiencies in the classical phenotype may include a low serum immunoglobulin G level and low or absent titers of the conventional autoantibodies. The original revised diagnostic scoring system of the International Autoimmune Hepatitis Group can guide the diagnostic evaluation, but low scores do not preclude the diagnosis. Liver tissue examination is valuable to exclude viral-related or drug-induced liver injury and support the diagnosis by demonstrating centrilobular necrosis (usually with interface hepatitis), lymphoplasmacytic infiltration, hepatocyte rosettes, and fibrosis. Conventional therapy with prednisone and azathioprine induces clinical and laboratory improvement in 68-75 % of patients with acute presentations, and high dose prednisone or prednisolone (preferred drug) is effective in 20-100 % of patients with acute severe (fulminant) presentations. Failure to improve or worsening of any clinical or laboratory feature within 2 weeks of treatment or worsening of a mathematical model of end-stage liver disease within 7 days justifies liver transplantation in acute liver failure. Liver transplantation for acute severe (fulminant) autoimmune hepatitis is as successful as liver transplantation for autoimmune hepatitis with a chronic presentation and other types of acute liver failure (patient survival >1 year, 80-94 %). Liver transplantation should not be delayed or superseded by protracted corticosteroid therapy or the empiric institution of nonstandard medications.

Advances in the current treatment of autoimmune hepatitis

Current treatment strategies for autoimmune hepatitis are complicated by frequent relapse after drug withdrawal, medication intolerance, and refractory disease. The objective of this review is to describe advances that have improved treatment outcomes by defining the optimum objectives of initial therapy, managing relapse more effectively, identifying problematic patients early, and incorporating the new pharmacological interventions that have emerged as frontline and salvage therapies. Initial corticosteroid treatment should be continued until serum aminotransferase, γ-globulin, and immunoglobulin G levels are normal, and maintenance of this improvement for 3-8 months before liver tissue assessment. Improvement to normal liver tissue is the ideal histological result that justifies drug withdrawal, but it is achievable in only 22 % of patients. Minimum portal hepatitis, inactive cirrhosis, or minimally active cirrhosis is the most common treatment end point. Relapse after drug withdrawal warrants institution of a long-term maintenance regimen, preferably with azathioprine. Mathematical models can identify problematic adult patients early, as also can clinical phenotype (age ≤ 30 years and HLA DRB1 03), rapidity of treatment response (≤ 24 months), presence of antibodies to soluble liver antigen, and non-white ethnicity. The calcineurin inhibitors (cyclosporine and tacrolimus) can be effective in steroid-refractory disease; mycophenolate mofetil can be corticosteroid-sparing and effective for azathioprine intolerance; budesonide combined with azathioprine can be effective for treatment-naïve, non-cirrhotic patients. Standard treatment regimens for autoimmune hepatitis can be upgraded without adjustments that require major new expertise.

Therapy of autoimmune hepatitis

Autoimmune hepatitis was the first chronic liver disease with a favourable response to drug therapy and a dismal prognosis when left untreated. Since its original description in 1950 and first treatment studies the basic therapeutic strategy of inducing remission with steroids and azathioprine has not been modified in principle. A timely diagnosis before cirrhosis develops, the avoidance of immunosuppressant side effect, non-responders to standard induction therapy, and adherence to therapy are the greatest challenges. Alternative immunosuppressive drugs have been tested in small series and include transplant immunosuppressants. A recent large multicenter prospective treatment trial suggests that budesonide may offer an alternative in non-cirrhotic AIH patients capable of minimizing unwanted steroid effects. The ultimate treatment approach upon drug treatment failure is liver transplantation. Only four percent of transplant candidates are transplanted for AIH but the risk for graft loss because of recurrence has to be considered and recurrent AIH treated after transplantation.

Genetic factors affecting the occurrence, clinical phenotype, and outcome of autoimmune hepatitis

Autoimmune hepatitis is a polygenic disorder of unknown cause in which the genetic risk factors that affect occurrence, clinical phenotype, severity, and outcome still are being clarified. The susceptibility alleles in white North American and northern European patients reside on the DRB1 gene, and they are DRB1*0301 and DRB1*0401. These alleles encode a 6 amino acid sequence at positions 67-72 in the DRbeta polypeptide chain of the class II molecules of the major histocompatibility complex. This sequence is associated with susceptibility, and lysine at position DRbeta71 is the key determinant. Molecular mimicry between foreign and self-antigens may explain the loss of self-tolerance and the occurrence of concurrent immune diseases in anatomically distant organs. Disease severity is associated with the number of alleles encoding lysine at DRbeta71 (gene dose) and the number of polymorphisms, including those of the tumor necrosis factor-alpha gene, cytotoxic T lymphocyte antigen-4 gene, and tumor necrosis factor-receptor superfamily gene, that can modify the immune response. Individuals in different geographic regions may have different susceptibility alleles that reflect indigenous triggering antigens, and these may provide clues to the etiologic agent. Knowledge of the genetic predispositions for autoimmune hepatitis may elucidate pathogenic mechanisms, identify etiologic agents, characterize susceptible populations, foresee outcomes, and target new therapies. These lessons may be applicable to autoimmune disease in general.

Relationship between antinuclear antibody and microalbuminuria in the general population: the Takahata study

BACKGROUND

Microalbuminuria, a marker of vascular damage, is associated with increased risk of progressive renal deterioration, cardiovascular disease and mortality. However, the relationship between antinuclear antibody (ANA) and microalbuminuria in the general population is unknown. Thus, we conducted a cross-sectional study to examine the relationship between ANA and microalbuminuria.

METHODS

The subjects of this community-based study were individuals over 40 years old in Takahata, Japan. The urine albumin-creatinine ratio (UACR) was calculated from a single-spot urine specimen collected in the morning. ANA was examined by enzyme immunoassay (EIA).

RESULTS

Among the 2,875 subjects (mean age 63 years; men 1,276; women 1,599), positive ANA (ANA index >or=20.0) was detected in 16.9% of the total population (men 12.9%, women 20.3%) and the prevalence of positive ANA increased with age. The prevalence of microalbuminuria (UACR 30-300 mg/g), but not macroalbuminuria (UACR > 300 mg/g), was significantly higher in the positive ANA group than the negative ANA group (24.1% vs. 16.0%, respectively, P < 0.001). Along with the increase of the ANA index, the prevalence of microalbuminuria and UACR levels were increased. Multivariate logistic regression analyses showed that ANA was significantly associated with microalbuminuria (odds ratio [OR] 1.63 and 95% confidence interval [95%CI] 1.27-2.10). These associations were significant in women, but not men, when examined separately.

CONCLUSIONS

These results indicate that the presence of ANA is associated with microalbuminuria in the general population, especially women.

Distinctive clinical phenotype and treatment outcome of type 1 autoimmune hepatitis in the elderly

Autoimmune hepatitis is classically a disease of young women. Our aims were to determine its occurrence, clinical phenotype, and outcome in elderly patients and contrast findings to young adults. Two-hundred-and-five white North American adults with definite type 1 autoimmune hepatitis were grouped according to age at presentation and the groups compared. Forty-seven patients (23%) were aged > or = 60 years (median age, 68 years), and 31 patients (15%) were aged < or = 30 years (median age, 25 years). The patients > or = 60 years had a higher frequency of cirrhosis at presentation than the patients < or = 30 years (33% versus 10%, P = .03). They also had thyroid or rheumatic diseases more commonly (42% vs. 13%, P = .006). HLA DR3 occurred more frequently in the patients < or = 30 years than in those > or = 60 years (58% vs. 23%, P = .004), and HLA DR4 occurred more often in the patients > or = 60 years (47% vs. 13%, P = .003). Patients aged > or = 60 years failed corticosteroid treatment less commonly than those aged < or = 30 years (5% vs. 24%, P = .03). Autoimmune hepatitis occurred in patients aged 18-30 years (15%), 31-39 years (15%), 40-49 years (21%), 50-59 years (25%), and > or = 60 years (23%). Differences in age distribution, HLA frequencies, and treatment outcome occurred after age > or = 40 years. In conclusion, elderly patients have a greater frequency of cirrhosis at presentation and HLA DR4 than patients < or = 30 years, and they have a lower occurrence of treatment failure. Transitions in clinical and genetic phenotypes occur after age > or = 40 years. Genetic susceptibilities may favor etiologic factors that are age-related.

High prevalence of autoantibodies among Danish centenarians

The aim of this study was to investigate the prevalence of organ and nonorgan specific autoantibodies in relation to disability and comorbidity in an unselected population of centenarians. A population-based survey of all persons living in Denmark who celebrated their 100th birthday during the period 1 April 1995 to 31 May 1996, a total of 276 persons, was undertaken. Participants underwent an interview, a physical examination and blood sampling. Organ specific autoantibodies (Tg-ab, TPO-ab, PCA-ab) and nonorgan specific autoantibodies (ANA, IgM RF, IgA RF, MPO-ab, c-ANCA, p-ANCA, oxLDL-ab, IgM ACA, IgG ACA, PR3-ANCA, histone-ab, SSA-ab, SSB-ab, Mit-ab) were measured, and comorbidity and disability (Katz Index of ADL) were registered. In all, 207 (75.0%) of 276 eligible subjects participated, and 148 agreed to blood tests. A large majority (79.3%) had at least one autoantibody detected. Organ specific autoantibodies were present in 32.1% of the centenarians. The high level of autoantibodies did not reflect an equally high level of overt autoimmune disease. While nonorgan specific autoantibodies were equally represented in less-disabled/disabled subjects as well as in subjects with low/high comorbidity, significantly fewer subjects with organ specific autoantibodies were found among less-disabled subjects or subjects with low comorbidity. Autoantibodies (both nonorgan and organ specific) are common in an unselected population of centenarians of today, but do not reflect an equally high level of overt autoimmune disease. Non-organ specific autoantibodies are evenly distributed irrespective of the level of disability or comorbidity, suggesting underlying, undiagnosed pathological processes which may be part of the processes involved in frailty.

Autoimmunity and geriatrics: clinical significance of autoimmune manifestations in the elderly

The immune system undergoes continuous morphologic and functional changes throughout the years, and it is now believed that the immune response has its peak function in puberty and gradually decreases with age (immunosenescence). Recent studies in healthy octogenarian patients suggest that the immune system, instead of suffering a generalized deterioration, undergoes a remodelling/readjustment of its major functions. Increase in two contrasting phenomena coexist in immunosenescence: on the one hand, a decrease in the capacity of the immune response and, on the other hand autoantibody production. The possible consequences of this progressive 'ageing' of the immune system are the increase in autoimmune phenomena, incidence of neoplasia and predisposition to infections. The study of autoimmune manifestations in elderly populations should be considered a priority for future medical research because of increasing life expectancy, especially in developed countries. This review analyses the main immune disorders associated with immunosenescence, the prevalence and clinical significance of autoantibodies in the elderly and the clinical expression of the main autoimmune diseases in older patients.

[Systemic lupus erythematosus with disease onset after age 65]

OBJECTIVES

Systemic lupus erythematosus with disease-onset in the elderly has rarely been studied (only one report about 21 patients with disease onset at 65 and older). Is the management of this pathology modified in this population?

METHODS

Seventeen hospitalised cases of lupus patients with disease onset at 65 or older are retrospectively reported between 1988 and 2000. The results are compared with those of younger subjects.

RESULTS

The female to male ratio is 1.83. Mean age at disease onset is 71.9 +/- 3.5 years. Mean duration of follow-up is 3.5 +/- 2.4 years. Main initial symptoms are: deterioration of general status (41%), arthritis (35%), cutaneous manifestations (35%), thrombo-embolism (24%) and pleuritis (18%). Malar rash is uncommon (12%). Nephropathy is never a revealing symptom and is rarely serious during the disease's evolution. Like in neurologic manifestations, the etiology has to be discussed in relation to associated co-morbidities. Concerning haematologic features, lymphopenia is found in 82% of the cases with a questionable specificity. Antinuclear antibodies are constant, anti-dsDNA antibodies are found in 82% of the cases, antibodies to extractable nuclear antigens in 50%, and anticoagulant circulating activity in 59%. Prognosis is difficult to assess in such a limited series but 5-years survival probability is 83%. Glucocorticoid lead to 50% of major complications.

CONCLUSIONS

This study focuses on the particular initial manifestations of systemic lupus erythematosus in the elderly (deterioration of general status, thrombosis, unusual cutaneous symptoms), and on the specificity of differential diagnosis and treatment.

Sustained remission after corticosteroid therapy for type 1 autoimmune hepatitis: a retrospective analysis

Autoimmune hepatitis commonly relapses after corticosteroid therapy, and long-term management strategies have been proposed based on the premise that repeated relapses after drug withdrawal are inevitable. Our goal was to determine the frequency that remission can be sustained after its induction and termination of therapy. A total of 107 patients who had entered remission on conventional regimens were assessed for sustained remission after initial treatment and after relapse and re-treatment. Re-treatment strategies included conventional regimens and long-term maintenance schedules. Twenty-two patients (21%) achieved a sustained remission after initial treatment, and 24 of 85 patients who relapsed and were re-treated (28%) had a similar outcome. The probability of a sustained remission was 47% after 10 years of follow-up. Patients who sustained remission after initial therapy were distinguished only by a lower serum gamma-globulin level at entry. Conventional re-treatment schedules after relapse were able to induce a sustained remission more commonly then long-term maintenance schedules (59% vs. 12%, P =.00002). In conclusion, patients who respond to initial corticosteroid therapy can achieve a sustained remission after treatment withdrawal or after relapse and re-treatment. All patients are candidates for this outcome, and withdrawal of medication, even during maintenance schedules, is necessary to assess its likelihood.

The prevalence of autoantibodies in an elderly sub-Saharan African population

In the present prospective, census-based study we have investigated the prevalence of organ-specific and non-organ-specific autoantibodies (AAb) in 152 unselected Cameroonians aged 60 years and older living in the community. AAb were detected in 49% of the participants. Non-organ-specific AAb (47%) predominated over organ-specific AAb (7%). Anti-TPO, anti-Tm, anti-Tg and anti-PC AAb were completely absent. RF was the most frequent AAb, being found in 57 (38%) cases. The prevalences of anti-SMA and RF were significantly higher in women than in men (respectively, P=0.023 and P=0.016). Higher serum concentrations of gammaglobulins were accompanied by a higher prevalence of RF (P < 0.0001) and a lower prevalence of ANA (P=0.036). The overall prevalence of AAb was higher in the filaria-infected (60%) compared to the non-infected (42%) participants (P=0.046). There was no significant influence of the vitamin D status, number of pregnancies, physical activity or medication use on the prevalence of AAb. In this study a heterogeneous pattern for the presence of the various AAb was found. Some AAb, which are commonly encountered in other studies on elderly subjects, were completely absent in this population. This diversified pattern of AAb prevalence therefore argues in favour of exogenous influences in the occurrence of AAb in elderly populations.

The aging paradox: free radical theory of aging

There are more than 300 theories to explain the aging phenomenon. Many of them originate from the study of changes that accumulate with time. Among all the theories, the free radical theory of aging, postulated first by Harman, is the most popular and widely tested, and is based on the chemical nature and ubiquitous presence of free radicals. This review aims to recapitulate various studies on the role of free radicals in DNA damage-both nuclear as well as mitochondrial-the oxidative stress they impose on cells, the role of antioxidants, the presence of autoantibodies, and their overall impact on the aging process.

Drug therapy in the management of type 1 autoimmune hepatitis

Prednisone alone or in combination with azathioprine is the treatment of choice for severe type 1 autoimmune hepatitis. The combination regimen is preferred, especially in the elderly, because of a lower incidence of corticosteroid-related complications. Only patients with sustained severe laboratory abnormalities, bridging necrosis or multilobular necrosis on histological assessment, and/or incapacitating symptoms, have absolute indications for treatment based on controlled clinical trials. The institution of therapy must be individualised in other patients, based mainly on symptoms and disease behaviour. Serum aspartate aminotransferase and gamma-globulin levels are the most useful indices to monitor during therapy. Liver tissue examination is the best method of evaluating completeness of response. Most patients enter remission, but relapse occurs in 50 to 86% after drug withdrawal. Maintenance therapy with low dosages of prednisone or azathioprine can be used long term in patients who have relapsed repeatedly. Inability to achieve remission after 3 years (incomplete response), deterioration during therapy (treatment failure) and drug toxicity are unsatisfactory responses that warrant alternative strategies. Liver transplantation is effective in managing decompensated disease, but recurrence of autoimmune hepatitis after transplantation is possible. Tacrolimus and budesonide are promising new drugs.

Self-reactive antibodies (natural autoantibodies) in healthy individuals

Antibodies that are present in the serum of healthy individuals in the absence of deliberate immunization with any antigen, are refered to as natural antibodies. A vast majority of natural antibodies react with one or more self antigens and are termed as natural autoantibodies. The importance of natural autoantibodies in immune regulation has long been neglected, since tolerance to self was thought to be primarily dependent on the deletion of autoreactive clones, rather than on peripheral suppressive mechanisms. Clonal deletion and energy cannot account, however, for the prevalence of natural autoreactivity among healthy individuals. It is now well established that autoreactive antibodies and B cells, and autoreactive T cells, are present in healthy individuals, and in virtually all vertebrate species. Autoreactive repertoires are predominantly selected early in ontogeny. Questions pertaining to the role of natural antibodies in the regulation of the immune response and maintenance of immune homeostasis and to the distinction between natural autoreactivity and pathological autoimmunity have not been adequately addressed. Here, we focus on the current knowledge on the physicochemical and functional properties of NAA in man, and the use of NAA for therapeutic intervention. reserved.

Binding of circulating antibodies to reactive oxygen species modified-DNA and detecting DNA damage by a monoclonal antibody probe

Circulating antibodies in the sera of normal, healthy humans of different age groups to native DNA (nDNA) and reactive oxygen species modified DNA (ROS-DNA) was studied by competition ELISA. Sera from the young population (< 50 years of age) showed negligible levels of anti-DNA antibodies. In contrast, anti-DNA antibodies were found in three sera from the moderately aged group (50-59 years) with a high binding to ROS-DNA (43-47%). In the aged group (> 60 years), four sera showed higher recognition of ROS-DNA (> 60% inhibition) over nDNA (55-60%). Oxidative lesions in human genomic DNA were immunochemically detected using the monoclonal anti-ROS-DNA antibody as a probe. The antibody has a high specificity for ROS-DNA and preferentially recognizes ROS-modified epitopes on nucleic acids. The study indicates low recognition of DNA isolated from the younger population, while in the age group 50-59 years, one DNA isolate showed a high inhibition (57%) in monoclonal antibody binding. Four DNA isolates from the aged group showed substantial inhibition in antibody activity to the extent of 49, 53, 64 and 69%. The results demonstrate an age-related increase in the levels of anti-DNA antibodies, with a higher recognition and binding to ROS-DNA. A high reactivity of DNA isolated from aged individuals by the monoclonal antibody indicates increased oxidative stress leading to DNA damage. It is suggested that free radical damage to DNA in vivo, particularly in the aged, alters its antigenicity and stimulates an immune response against modified DNA. These antibodies are cross-reactive to nDNA.

Age-related changes in the tiger salamander retina

Tiger salamanders have been used in visual science because of the large size of their cells and the ease of preparation and maintenance of in vitro retinal preparations. We have found that salamanders over 27 cm in length show a variety of visual abnormalities. Compared to smaller animals (15-23 cm), large animals exhibited a decrease in visual responses determined by tests of the optomotor reflex. Small animals responded correctly an average of 84.5% of the time in visual testing at three light levels compared to an average of 68.4% for the large animals with the poorest visual performance at the lowest level of illumination. In addition, large animals contained (i) histological degeneration of the outer retina, in particular, loss and disruption of outer segments and abnormalities of the retinal pigmented epithelium, (ii) loss of cells, including photoreceptors, by apoptosis as evaluated with the TUNEL technique, and (iii) an increase in the number of macrophages and lymphocytes within the retina as determined by morphological examination. These histological changes were present in all large animals and all quadrants of their retinas. In contrast, small animals showed virtually no retinal degeneration, no TUNEL-positive cells, and few immune-like cells in the retina. Since large animals are also older animals. the visual changes are age-related. Loss of visual function and histological degeneration in the outer retina also typify aged human eyes. Thus, we propose that large salamanders serve as an animal model for age-related retinal degeneration. In addition to providing a source of aging retina that is readily accessible to experimental manipulation, the salamander provides a pigmented retina with a mixed (2:1, rod:cone) population of photoreceptors, similar to the degeneration-prone parafoveal region of the human eye.

Prevalence of organ-specific and non organ-specific autoantibodies in healthy centenarians

In the present study we have investigated the prevalence of organ-specific and non organ-specific autoantibodies in 26 healthy centenarians (6 men, 20 women; age range 101-106 years), using as controls 54 healthy old (33 men and 21 women, age range 71-93) and 56 young subjects (29 men and 27 women, age range 26-60). We assayed sera of each group for the following organ-specific autoantibodies, anti-gastric mucosa (anti-PCA), anti-thyroglobulin (anti-Tg) and non organ-specific autoantibodies, anti-cardiolipin (anti-APA IgG and IgM), anti-nuclear antigens (anti-ANA), anti-double strand DNA (anti-ds-DNA), anti-extractable nuclear antigens (anti-ENA). Finally, natural anti-alpha-galactosyl (anti-alpha-GAL) antibodies were also analyzed. As expected, in the old subjects there was a significant increase of prevalence of anti-Tg and anti-PCA autoantibodies. By contrast, in centenarians the prevalence of organ specific anti-Tg and anti-PCA antibodies was not significantly different from that observed in controls aged less than 60 years. The prevalence of non organ-specific autoantibodies anti-APA (IgG), anti-APA (IgM), anti-ANA, was significantly increased both in the elderly and centenarians when compared with the prevalence observed in sera from the young. Anti-ENA and anti-dsDNA antibodies were not detected in all groups studied. Finally, the prevalence of natural anti-alpha-GAL antibodies significantly increases with age, including centenarians. In conclusion, we confirm and extend the results previously obtained by other authors. In fact, as already described, the prevalence of organ-specific autoantibodies in the elderly is not seen after the tenth decade of life. Interestingly, the prevalence of non organ-specific autoantibodies is instead increased in these subjects, suggesting that different mechanisms are involved in the pathogenesis of these autoantibodies. Particularly, these autoantibodies could be the expression of a damaged tissue process rather than of an autoimmune one, as suggested by data concerning natural antibodies.

Cytokine production pathway in the elderly

It is well known that aging is associated with various alterations in lymphoid cell functions, particularly with a progressive decline in immune responsiveness to exogenous antigens and increasing incidence of autoimmune phenomena. Many studies have been focused on the mechanisms of the immunologic features of aging. this review describes our results of studies performed to determine the influence of age on the capacity to produce interleukin-2 (IL-2), interferon-gamma (IFN-gamma), interleukin-4 (IL-4), interleukin-t (IL-5), interleukin-6 (IL-6) and tumor necrosis factor (TNF). Mitogen-stimulated cultures of mononuclear cells (MNC) from human beings were assessed for cytokine-producing capacity. A significant decrease in IFN-gamma and IL-2 production by MNC cultures from elderly individuals was observed. No significant difference was instead observed between cultures from elderly individuals and those from young ones as regards TNF-alpha, IL-4 and IL-6 production. Mitogen or antigen-stimulated cultures of MNC from aged mice also displayed a significant decrease in IFN-gamma and IL-2 production as well as TNF-beta. Instead IL-4 and IL-5 production significantly increased in these cultures. We suggest that this imbalanced cytokine production may well account for the pattern of immune response which may be observed in the elderly, i.e. a normal or increased humoral response (including autoimmune responses) in face of a low T cell immune responsiveness.

Antinuclear antibodies in healthy aging people: a prospective study

In order to evaluate the expression of antinuclear antibodies (ANA) in normal elderly individuals over time and clinical significance, a cross-sectional ANA testing in healthy Japanese was performed, followed by annual evaluations of ANA positive aged (> or = 65 years) and a control group. ANA was more prevalent in the aged (11.4% vs. 3.8%) and most were persistent after 4 years. Anti-ssDNA and anti-histone antibodies were increased in aged ANA positive as compared to ANA negative controls. Except for a history of spontaneous abortion, there was no differences in clinical findings. HLA DRB1*0901 and the DQB1*0602 + 0302 + 0303 set of alleles were increased in ANA positive. Therefore, ANA in the aged were persistent, apparently directed toward chromatin elements, and shared MHC associations with autoimmune diseases. Longer follow-up may be necessary to improve the evaluation of clinical significance of ANA in the aged.

Thymus function, ageing and autoimmunity

We suggest that the thymus is the critical time-keeper in the ageing process with respect to immune responses. Because the thymus involutes asymmetrically, a clonal imbalance occurs with ageing since the proportion of autoantigen-specific helper/inducer T cells increases relative to the number of autoantigen-specific regulatory T cells. As a result, circulating autoantibody levels rise with age. On the other hand, nonspecific immunoregulatory mechanisms increase with age. As the thymic cortex atrophies, the response to foreign antigens declines, whereas the response to self-antigen rises, generating the ageing paradox.

In vitro cytokine production by HLA-B8,DR3 positive subjects

It is well known that healthy subjects carrying the HLA-B8,DR3 haplotype may show an impairment of immune system, the T cells being the most affected. To gain insight into the mechanism(s) of the impairment displayed by these subjects, efforts have been centered on the study of in vitro cytokine production because of the pivotal role played by these mediators in the activation and control of several immune functions. The available results indicate that the ability to several immune functions. The available results indicate that the ability to produce interleukin-1 (IL-1), IL-2 and the soluble form of its receptor (sIL-2R) is impaired in HLA-B8,DR3 positive healthy subjects. To better characterize the cytokine production capacity of HLA-B8,DR3 positive subjects, we have investigated the pattern of in vitro production of IL-2, sIL-2R, IL-4. IL-6 and gamma-interferon (gamma-IFN) by mononuclear cells from HLA-B8, DR3 positive subjects after phytohaemoagglutinin stimulation. A significant decrease of IL-2, sIL-2R and gamma-IFN production by HLA-B8,DR3 positive subjects was observed. No significant difference was instead found between the HLA-B8,DR3 positive subjects and the negative ones as regards IL-4 and IL-6 production. We suggest that this imbalanced cytokine production may well account for the pattern of immune response that may observed in HLA-B8,DR3 positive subjects, i.e. a normal or increased humoral response in face of a low T cell immune responsiveness.

Astrocytic hypertrophy: an important pathological feature of chronic experimental autoimmune encephalitis in aged rats

Experimental autoimmune encephalomyelitis (EAE) was induced in young (2-3 month old), middle-aged (12-13 month old) and geriatric (24-26 month old) Lewis (JC) rats by active immunisation with myelin basic protein (MBP) in complete Freund's adjuvant (CFA). It was found that aged Lewis (JC) rats developed a more chronic form of EAE than younger rats of the same strain, a phenomenon observed in both male and female rats despite males developing more severe disease than females at all ages. Middle-aged recipients also developed more severe disease than young recipients when EAE was induced by the adoptive transfer of lymphocytes from actively immunised young donors, suggesting that disease chronicity in middle-aged animals is a property of the central nervous system (CNS) milieu. Histological studies demonstrated that disease chronicity did not correlate with the number of inflammatory lesions in the CNS, young animals containing substantial numbers of CNS lesions following recovery and lesions being largely absent from middle-aged animals which still exhibited signs of disease. No significant differences were found in the degree of fibrin deposition or demyelination between young and middle-aged or symptomatic and asymptomatic animals. However, astrocytic hypertrophy was found to correlate with manifestation of disease in both young and middle-aged animals and in particular with disease chronicity in middle-aged animals. In parallel studies, no significant differences were found in the levels of the inflammatory mediators tumor necrosis factor (TNF)-alpha, prostaglandin E (PGE)2, reactive nitrogen intermediates (RNI) and corticosterone in young and middle-aged animals. However, markedly elevated corticosterone levels were found in both young and middle-aged animals with the development of clinical signs which returned to baseline levels with the resolution of clinical signs. Elevated levels of RNI were evident in animals immediately prior to and during the early stages of symptomatic EAE. Although these results suggest that nitric oxide may play a role in the pathogenesis of disease, whereas corticosterone may play a role in the immunoregulation of the disease, these factors cannot explain differences in disease chronicity evident in middle-aged animals.(ABSTRACT TRUNCATED AT 400 WORDS)

Expression and control of the natural autoreactive IgG repertoire in normal human serum

We have investigated the autoreactive repertoire expressed by serum IgG of healthy individuals of various age groups using a large panel of self antigens. Natural IgG autoantibodies against all self antigens of the panel were found in the purified IgG fraction of the serum of all donors that were tested. The mean binding activity to self antigens of IgG of pregnant women was higher than that of IgG purified from the serum of infants, young adults and aged individuals. No increase in IgG autoreactivity was observed with aging neither in the purified IgG fraction of serum nor in whole serum. Whereas autoantibody activity was easily detectable in purified IgG, it was low in serum. No difference was observed, however, between the binding activity of purified IgG and of IgG in serum in the case of foreign antigens nor in the case of anti-thyroglobulin autoantibodies of patients with hashimoto's thyroiditis. Purified IgM from normal serum bound to F(ab')2 fragments of autologous IgG in a dose-dependent fashion and inhibited the binding of autologous IgG to self antigens. Our results thus indicate that autologous IgM contributes to regulate expression of the natural IgG autoreactive repertoire through V region-dependent interactions, resulting in low levels of IgG autoreactivity in serum under physiological conditions.

Autoimmunity in depression: increased antiphospholipid autoantibodies

Some groups have recently reported higher titers of autoantibodies in depressed subjects than in normal controls. The present study investigates whether depressed patients exhibit increased antiphospholipid antibody titers compared with normal controls. The authors measured the binding index (BI) of antiphosphatidylserine (APSA), antipartial thromboplastin (APTA) and anticardiolipin (ACA) in 22 minor, 23 simple major and 20 melancholic depressives, 10 healthy controls and 104 normal controls with negative autoantibody sera. Depressed subjects exhibited significantly higher APSA and APTA antibody titers compared with normal controls. A large number of depressed subjects (+/- 54%) showed APTA and APSA positivity, defined as BI > or = 2 standard deviations above the mean BI of normal controls. There was a significant discrimination (> or = 2.8 standard deviations) between melancholic subjects and healthy controls with respect to BI of ACA, APSA and APTA. However, by using a more conservative value for phospholipid positivity (i.e., BI > or = 5 standard deviations above the mean BI of a reference sample of normal sera), the subject's autoantibody titers were, on the whole, within the normal range. Our results point towards a higher expression of antiphospholipid antibodies during depression but a much lower incidence of positive patients than in classical autoimmune disorders, such as systemic lupus erythematosus.

gamma-Interferon, interleukin-4 and interleukin-6 in vitro production in old subjects

It is well known that ageing is associated with various alterations of the lymphoid cell functions. Although both B and T cell are affected, the last appear to be more sensitive to ageing process. During the past years, to gain insight into thé mechanism(s) of this impairment, effort has been centered on the helper T cells specifically engaged in the production of interleukin-2 (IL-2) because of the pivotal role played by this cytokine in the activation of several immune functions. The results have demonstrated that the ability to produce IL-2 declines with age. In this paper we report the results of a study performed to determine the influence of age on the capacity to produce gamma-interferon (gamma-IFN), interleukin-4 (IL-4) and interleukin-6 (IL-6). Mononuclear cells from young and old subjects were assessed for cytokine producing capacity in response to phytohaemagglutinin stimulation. A significant decrease of gamma-IFN production by old subjects has been observed. No significant difference was instead observed between the old subjects and the young ones as regards IL-4 and IL-6 production. We suggest that this imbalanced cytokine production may well account for the pattern of immune response which may be observed in elderly, i.e. a normal or increased humoral response in face of a low T cell immune responsiveness.