Faculty Bibliography

The identification of etiological factors in the induction of autoimmunity has remained elusive despite an enormous effort at dissection of the molecular structure of the target antigens and effector mechanisms. One characteristic feature of autoantigens is their repetitive structure as well as their conservation and evolution. Toxoplasma (T.) gondii is a primitive protozoan. We hypothesized that patients with autoimmune disease would have broad reactions against Toxoplasma antigens based on autoantigen conservation. To address this issue, we assessed serologic evidence of reactivity to Toxoplasma gondii along with a large profile of autoantibodies in patients with various autoimmune diseases (AID). We included sera of 1514 patients with 11 different AID collected from referral centers in Europe and Latin America as well as from 437 geographically matched controls, for the prevalence of anti Toxoplasma antibodies (ATxA) IgG and IgM and serum autoantibodies utilizing the BioPlex 2200 system (Bio- Rad Laboratories, USA). Serum ATxA IgG were positive in 42% of patients with AID versus 29% of controls (p < 0.0001). Among Europeans, ATxA IgG were associated with anti-phospholipid syndrome (APS; p < 0.0001), cryoglobulinemia (p < 0.0001), ANCA-associated vasculitides (p < 0.01), autoimmune thyroid diseases (p < 0.0001), systemic sclerosis (SSc; p < 0.0001) and rheumatoid arthritis (RA; p < 0.0001). Of note, Latin American RA sera exhibited similar frequency of ATxA IgG as controls. ATxA IgM were more prevalent in European patients with APS (p < 0.01), SSc (p < 0.05) and inflammatory bowel disease (IBD, p < 0.05) than in controls. Further, in AID patients the presence of ATxA correlated with autoantibodies characteristic of APS (anti- cardiolipin, B2GPI, complex of cardiolipin- B2GPI, prothrombin, phosphatydilethanolamine), and of SSc (anti-centromere, Scl-70). Our findings suggest that T. gondii may contribute to the pathogenesis of AID. This interaction may depend on or explain observed geoepidemiological variance in AID.

INTRODUCTION/BACKGROUND:The association between infections and autoimmune diseases (AID) has been well described in the medical literature. Several infectious agents have been implicated as inducers of autoimmune responses, such as Parvovirus B19, Epstein-Barr virus, cytomegalovirus, and hepatitis viruses. PATIENTS AND METHODS/METHODS:We examined 1,173 sera from patients with 14 different AID and 238 sera from geographically matched healthy controls, for evidence of prior infection with rubella. All samples were tested for the presence of serum antibodies against rubella using the Bio-Rad BioPlex 2200 system. RESULTS:As a group, patients with AID had a higher prevalence of IgM anti-rubella antibodies as compared to healthy controls (11.7% versus 5.4%; P = 0.001). The prevalence of IgM anti-rubella antibodies was significantly higher in 5/14 AID, namely in patients with giant cell arteritis (33.3%), primary biliary cirrhosis (24%), antiphospholipid syndrome (20.6%), polymyositis (16%), and inflammatory bowel disease (16%). A similar prevalence of IgM anti-rubella antibodies was detected among controls from different countries. A high prevalence of IgG anti-rubella antibodies was detected among patients with AID (89.9%) and controls. CONCLUSION/CONCLUSIONS:The increased prevalence of IgM anti-rubella antibodies in AID suggests a possible role for rubella in the etiopathogenesis of several AID.

BACKGROUND:Currently not much is known regarding the environmental factors involved in primary biliary cirrhosis (PBC). It is even more unclear which factors may determine the subgroup (i.e., AMA status) of patients with PBC. We thus tested AMA+and AMA- PBC patients' sera for antibodies (Abs) against multiple infectious agents. METHODS:Sera from 69 patients with PBC (49 AMA+and 20 AMA-) and 100 matched controls were screened for IgG-Abs against Toxoplasma gondii, Helicobacter pylori, Epstein-Barr virus (EBV), cytomegalovirus (CMV), hepatitis B, and hepatitis C utilizing the BioPlex 2200 and ELISA kits (Bio-Rad Laboratories, USA). RESULTS:The prevalence of four anti-infectious agents Abs was significantly elevated among PBC patients when compared with controls, namely anti-T. gondii (ATxA; 71% vs. 40%, p<0.0001), EBV early antigen (EA; 44% vs. 12%, p<0.0001), H. pylori (54% vs. 31%, p<0.01), and CMV (90% vs. 75%, p<0.05) Abs, respectively. The co-occurrence of these four anti-infectious agents Abs was highly common in PBC, whereas this infection burden was rare in healthy subjects (20% vs. 3% respectively, p<0.0001). Furthermore, specific infections interactions possibly increasing PBC risk were noted as well. Seropositivity of ATxA was inversely associated with cirrhosis among PBC patients (p<0.05). Finally, no differences were observed between AMA- sera and their AMA+counterparts with regard to seroprevalence of any of the investigated infectious agents. CONCLUSIONS:We note the association of ATxA and PBC, with the possibility of a milder disease manifestation. We also suggest that multiple exposures to infectious agents may contribute to PBC risk.

BACKGROUND:Gastrointestinal (GI)-related autoantibodies (Abs) are rarely evaluated in autoimmune diseases (AID) other than inflammatory bowel disease, autoimmune hepatitis and celiac disease. Our aim was to determine the prevalence of these antibodies in a wide spectrum of AID. METHODS:We examined 923 serum samples representing 18 AID and compared them with 338 samples from healthy subjects. We used the BioPlex 2200-immunoassay (Bio-Rad, USA) to test samples for the presence of IgA and IgG directed at gliadin (AGA), tissue-transglutaminase (tTG), and Saccharomyces cerevisiae (ASCA). RESULTS:Prevalence of IgA AGA was significantly higher in antiphospholipid syndrome (APS) (7.1 %, P=0.012) and in pemphigus vulgaris (25%, P =0.008) patients, as compared with healthy controls. Presence of IgG-AGA was more common among Crohn's disease (20.5%, P = 0.023) and rheumatoid arthritis (6.5%, P=0.027) patients. IgG anti tTG were frequently observed in APS (6.1%, P=0.012), in giant cell arteritis (11.5%, P=0.013) and in ulcerative colitis (11.1%, P=0.018) patients, and as expected, higher prevalence of ASCA (IgA 19.3% and IgG 27.7%) was found in Crohn's disease. IgG ASCA were also found in systemic lupus erythematosus (SLE) (4.5%, P=0.01), in Graves' disease (5.7%, P=0.018), in cryoglobulinemia (7.1%, P=0.006), and in patients with vasculitides (6.5%, P=0.002). In contrast, lower prevalence of IgG type AGA was found in SLE (P=0.034), cryoglobulinemia (P=0.019) and vasculitides (P=0.013) patients. CONCLUSIONS:Our findings suggest an association between GI-related- Abs and a wide spectrum of AID. The clinical implication of these findings is yet to be determined.

Pemphigus and bullous pemphigoid are two autoimmune diseases that have a similar pathogenesis. Both have a genetic predisposition which promotes the production of auto-antibodies targeted against different components of the epidermal desmosome and hemidesmosome. Environmental factors play an important role in the pathogenesis of this autoimmune disease. Among these, the role of infectious agents was debated as a causative factor. We sought to determine a possible connection between various infectious agents and autoimmune bullous disease (ABD). A cohort of 148 serum samples of patients with pemphigus, bullous pemphigoid and controls was screened for evidence of a prior infection with HBV, HCV, EBV, CMV, Helicobacter pylori, Toxoplasma gondii and Treponema pallidum, utilizing the Bio-Rad BioPlex 2200 system as well as ELISA assays to complete the panel. HBV, HCV, H. pylori, T. gondii and CMV were demonstrated to have significantly higher prevalence of antibodies in patients with pemphigus and bullous pemphigoid in comparison to controls. Among them, we found a novel association between H. pylori and ABD. Our study suggests a contributing role for HBV, HCV, H. pylori, T. gondii and CMV in inducing ABD in the genetically susceptible host.

Infections are believed to contribute to the maturation of the immune system from the innate to the adaptive phases and therefore may take part in the induction of autoimmune conditions. In the current study, we present an extensive analysis conducted on sera samples of patients with rheumatoid arthritis in order to seek evidence of previous or coexisting infectious processes using the Bio-Rad BioPlex immunoassay analyzer. We detected higher rates of serological evidence of infections with Epstein-Barr virus and cytomegalovirus viruses. Our findings may indicate a role of these viruses in the pathogenesis of RA.

In primary biliary cirrhosis (PBC) serum markers other than anti-mitochondrial antibodies (AMA) are promising in terms of disease severity and comorbidities, as well represented by anti-nuclear antibodies (ANA). The aim of the present study was thus to evaluate the prevalence and clinical significance of a large profile of serum autoantibodies in PBC sera. We utilized 69 sera from European patients with PBC (including 20 AMA-negative) and 297 sera from geographically and sex-matched healthy controls. All sera were tested for the presence of ANA and autoantibodies associated with thrombophilia, vasculitis, and gastrointestinal disease. Autoantibodies other than AMA were detected in 53/69 (76%) PBC sera vs. 105/297 (35%) among controls. The prevalence of ANA (targeting dsDNA, Sm, chromatin, ribosomal-P, RNP, SmRNP, SSA, SSB, and centromere) and thrombophilia-associated autoantibodies (i.e. anti-beta2GPI, phosphatydilserine, prothrombin) was common among patients with PBC. When clinical features were compared, the presence of anti-prothrombin IgM was associated with a worse prognosis as represented by a higher Mayo score. We demonstrate an increased prevalence of ANA and thrombophilia-associated autoantibodies in PBC sera and an association between the latter autoantibodies and PBC stage. The role of thrombophilia-associated antibodies will warrant further studies, based in particular on the incidence of portal hypertension at early stages of PBC.

OBJECTIVE:To evaluate the prevalence of serum antibodies against hepatitis C virus and other infectious agents in a large cohort of well-characterized patients with autoimmune diseases (AID). METHODS:We utilized 1322 sera from patients with 18 different AID and 236 sera from healthy controls from the same countries and with similar age and sex distribution. All sera were tested for the presence of serum anti-hepatitis C virus (HCV) antibodies as well as antibodies directed at other infectious agents and autoantibodies. RESULTS:Anti-HCV antibody was detected in 115/1322 (8.7%) of patients with AID and 0.4% of matched healthy controls (P < 0.0001). The prevalence of anti-HCV antibody was significantly higher in 7/18 different AID (i.e. cryoglobulinemia, mixed cryoglobulinemia pemphigus vulgaris, vasculitis, secondary anti-phospholipid syndrome, Hashimoto's thyroiditis, and inflammatory bowel disease) compared to controls. Patients with AID and serum anti-HCV positivity had an increased prevalence of antibodies against hepatitis B virus, Toxoplasma gondii and Cytomegalovirus as opposed to a lower frequency of serum autoantibodies. CONCLUSIONS:The enhanced prevalence of anti-HCV serum antibodies in AID may suggest a role for HCV in tolerance to breakdown, similarly to its established role in mixed cryoglobulinemia. This immune mediated effect does not rule out the role of other infectious agents.

BACKGROUND:Inflammatory myopathies (IM) are associated with autoimmune diseases. AIM/OBJECTIVE:To evaluate the titers of auto-antibodies specific to various autoimmune diseases in patients with IM compared with controls. METHODS:Sera from 99 IM patients and 100 healthy controls were tested for autoantibodies for vasculitis (myeloperoxidase, PR3, and glomerular basement membrane) and autoimmune gastrointestinal diseases (IgA and IgG antigliadin, antitissue transglutaminase, and Saccharomyces cerevisiae) utilizing the BioPlex 2200 Multiplexed Immunoassay method (Biorad). RESULTS:Antigliadin IgA levels were significantly elevated in IM patients compared with controls (0.37 units +/- 0.44 vs. 0.24 units +/- 0.15, P = 0.017). Antitissue transglutaminase IgA was marginally increased in IM patients versus controls (0.36 units +/- 1.12 vs. 0.2 units +/- 0.0, P = 0.08). CONCLUSIONS:Antibodies to gliadin and tissue transglutaminase characteristic for celiac disease were elevated in patients with IM compared with controls. This may indicate a higher prevalence of gluten sensitivity or celiac disease in IM.

Patients with neurological disease of unknown etiology sometimes present with antigliadin and antitissue transglutaminase antibodies. The association between these antibodies and multiple sclerosis has been previously suggested. The purpose of this study was to determine the prevalence of these antibodies in multiple sclerosis patients. We determined the level of serum immunoglobulin A and immunoglobulin G antigliadin and antitissue transglutaminase antibodies in 98 patients with multiple sclerosis. We found a highly significant increase in titers of immunoglobulin G antibodies against gliadin and tissue transglutaminase in the multiple sclerosis patients. Seven patients had a positive IgG AGA, whereas only 2 controls presented positive titers (P = 0.03). Four patients had positive IgG anti-tTG while all the controls tested negative (P = 0.02). However, immunoglobulin A antibodies against gliadin and tissue transglutaminase were not statistically higher in the multiple sclerosis group in comparison to the control group. Our findings support the associations between antibodies against gliadin and tissue transglutaminase to multiple sclerosis. The specific role of these antibodies in the pathogenesis of multiple sclerosis remains uncertain and requires additional research. A gluten free diet should be considered in specific cases of patients who present with gluten antibodies.