Israel Medical Association Journal

Background: Autoimmune hepatitis (AIH) may be associated with other autoimmune diseases. Autoantibodies are common in AIH suggesting their potential role in the pathogenesis of the disease. Among these autoantibodies, thyroid autoantibodies have been reported in patients with chronic hepatitis, with greater prevalence in patients with chronic hepatitis C infection.

Objectives: To assess the prevalence of thyroid dysfunction among patients with AIH.

Methods: In this case-control, retrospective study, we examined patients diagnosed with AIH according to both the original and revised international AIH group scoring systems. Patients with other hepatic pathologies were excluded AIH was evaluated as an independent risk factor for thyroid disease by a logistic regression model. Univariate and multivariate regression analyses were conducted using hypothyroidism and hyperthyroidism as the dependent variables.

Results: Our cohort comprised 163 patients diagnosed with AIH and 1104 healthy age- and gender-matched controls. Hypothyroidism was more prevalent among those with AIH compared to controls (17.7% vs. 5%, respectively, 95% confidence interval [95%CI] 1.68–2.48, P <  0.001). Hyperthyroidism was more prevalent in AIH patients compared to controls (odds ratio 3.2% and 1.2%, respectively, 95%CI 1.68–2.47, P <  0.001). Using a multivariate logistic analysis, we found an independent association between AIH and hypothyroidism but not with hyperthyroidism.

Conclusions: Thyroid dysfunction is more prevalent in patients with AIH. Whether thyroid dysfunction is the cause or a risk factor for AIH, or vice versa, is still unclear. Screening for thyroid dysfunction is warranted after AIH is diagnosed.

Background: Vitamin D insufficiency is associated with autoimmune and chronic inflammatory diseases such as tuberculosis and sarcoidosis. 

Objectives: To evaluate the vitamin D-dependent mechanisms of immunity and autoimmunity in different forms of pulmonary tuberculosis and sarcoidosis.

Methods: We measured the serum levels of 25(OH)D and 1,25(OH)2D, individual autoimmune profiles, plasma concentrations of cathelicidin, several hormones, and production of nine cytokines in patients with short- and long-duration tuberculosis and sarcoidosis.

Results: The level of 25(OH)D was significantly decreased in all patients. Concentration of 1,25(OH)2D was elevated only in sarcoidosis, prolactin content was augmented only in tuberculosis. We saw no expected increase of cathelicidin levels in tuberculosis and sarcoidosis. The individual mean immune reactivity levels of autoantibodies to 24 antigens were significantly lower in tuberculosis and sarcoidosis patients compared to healthy controls. Pronounced deviations from individual mean immune reactivity levels were found for several autoantigens in all patients. The induced production of interferon gamma-γ, interleukin (IL) 2, 17, and 8 by peripheral blood mononuclear cells was significantly increased in patients of both tuberculosis groups, but spontaneous production of tumor necrosis factor-α, IL-2, and IL-6 was lower in the tuberculosis patients than in healthy controls. We registered marked differences in the groups of tuberculosis patients. 

Conclusions: We demonstrated the role of vitamin D deficiency in poor cathelicidin response in  tuberculosis and sarcoidosis. Both diseases are accompanied by significant changes in the autoimmune profile, probably related to the status of vitamin D and cytokine regulation. 

 

Systemic sclerosis (SSc) is characterized by extensive collagen deposition, microvasculopathy and autoantibodies. All three features can be promoted by activation of T cells and B cells. T cells are of Th2 type producing profibrotic cytokines IL-4 and IL-13 and inducing dendritic cell maturation that promotes Th2 response. B cells are overactivated and promote fibrosis by autoantibodies that activate fibroblasts or inhibit the degradation of extracellular matrix. They also promote fibrosis by cell-cell contact with fibroblasts or dendritic cells. B cells, through autoantibodies, may promote vasoconstriction and obliterative vasculopathy. They may also sustain activation of T cells by functioning as antigen-presenting cells. An immunoregulatory subset of B cells, namely IL-10-producing Bregs, is decreased in SSc. Finally, B cells have a critical role in animal models of SSc. All this evidence suggests an important role for B cells in the pathogenesis of SSc and makes B cells a potential target for therapeutic intervention in this disease. 

 

Autoimmune diseases constitute a diverse group of disorders characterized by cellular and humoral responses against self. The humoral autoimmune responses are directed against various cellular and extracellular components. These responses are highly specific for each autoimmune disease and result in the production of autoantibodies that characterize certain disease entities, representing a valuable tool for the diagnosis of autoimmune diseases. Furthermore, certain autoantibodies are helpful in the prognosis of disease development, progression and severity, as well as in the classification of patients with distinct disease subtypes. Today, the value of autoantibodies in the follow-up of patients is limited, but preliminary data suggest that they may be useful in predicting response to treatment. 

Antiphospholipid syndrome (APS) is an autoimmune systemic disease characterized by vascular thrombosis (arterial or venous) and/or pregnancy complications associated with the occurrence of autoantibodies, specifically lupus anticoagulant, anticardiolipin antibodies, and/or anti-β2 glycoprotein-I antibodies confirmed at least twice over a 12 week period according to the 2006 Sydney criteria. Antiphospholipid antibodies are encountered  in the general population with a reported prevalence of 1% to 5%  However, APS is far more infrequent with a prevalence of 40–50/100,000 persons and an incidence of about 5 new patients/100,000 persons. APS can be diagnosed in patients with no apparent clinical or laboratory pathology (primary APS) or it may be related to numerous other conditions, autoimmune diseases (usually systemic lupus erythematosus), malignancies, infections and drugs (secondary APS). Women are at risk for APS since the disease is encountered in both the primary and the secondary state in females more often than in men. In addition, women in their reproductive years can develop APS (either classical or obstetric), and special attention is warranted in pregnant women with a diagnosis of APS. The benefits of hormonal therapy in the form of contraception or hormone replacement treatment should be carefully weighed against the increased risk for vascular complications in women with APS.