Israel Medical Association Journal

Medical screening is not a tangible existent tool in autoimmune disorders as it is in other illnesses. Numerous attempts are made to identify individuals destined to develop an autoimmune disease, including analysis of the genetic background, which along with the immunological profile, may assist in identifying those individuals. If these efforts turn out to be successful they may lead to the possibility of proactive measures that might prevent the emergence of such disorders. This review will summarize the attempts made to pursue autoantibodies specific for the central nervous system as potential predictors of autoimmune neurological disorders.

Idiotypic analyses of anti-DNA autoantibodies were widely reported a decade ago. More than 100 studies were conducted on one of the main analyzed idiotypes, the 16/6 Id of the anti-ssDNA monoclonal antibody. In this review we summarize current knowledge on the characteristics of the 16/6 Id[1], its link to infection and its target epitopes on other molecules known so far. This includes the modulation of T and B cell responses and gene expression by the 16/6 mAb[2] in vitro and in vivo. We focus on the ability and mechanisms by which this idiotype induces experimental lupus in naïve mice, manifested by autoantibody spread, kidney and brain involvement, and leukopenia associated with enhanced sedimentation rate. We also discuss various therapeutic modalities to treat 16/6 induced lupus in mice.

Background: Infectious agents are important in the pathogenesis of autoimmune disease since they are a major part of the environmental trigger of autoimmunity. A negative relationship between latitude and infectious disease species richness has been suggested.

Objectives: To examine whether their prevalence differs in two latitudinally different populations.

Methods: The prevalence of infections with Toxoplasma gondii, rubella virus, cytomegalovirus, Epstein-Barr virus and Treponema pallidum was compared between subjects from Italy and Colombia.

Results: We found high titers of antibodies against four of five microorganisms tested, Toxoplasma gondii (50.8%), rubella virus (German measles) (75%), cytomegalovirus (86.3%), Epstein-Barr virus (83.3%) and Treponema pallidum (6.3%) in completely healthy individuals from a tropical country (Colombia) and a European country (Italy). Differences between two groups of volunteers were noted regarding two infectious agents. The prevalence of immunoglobulin G anti-rubella antibodies was significantly higher among Italian subjects (85% vs. 67.9%, P = 0.002), whereas antibodies against CMV[1] were less prevalent among Italian as compared to Colombian subjects (77% vs. 92.9%, P < 0.001).

Conclusions: These differences might also result in a different tendency towards development of autoimmune diseases associated with these infectious agents in different populations.

Background: Serology of amebiasis is affected by low sensitivity and specificity.

Objectives: To evaluate the advantage of the indirect hemagglutination assay and enzyme-linked immunosorbent assay in the diagnosis of amebiasis, using Entamoeba histolytica soluble antigen (macerated amebic antigens) prepared from four different virulent isolates, continuously cultivated in the presence of the original enteric bacteria.

Methods: Using IHA[1] and ELISA[2] with MAA[3] antigen we examined 147 sera samples from patients with gastrointestinal symptoms, and 11 sera from amebiasis cases (confirmed by microscopy and copro-antigen ELISA ).

Results: Of 104 of the 147 (70.7%) symptomatic cases that were amebiasis positive by IHA, 81 (55.1%) were positive by MAA-ELISA. In addition, of 11 amebiasis cases confirmed by microscopy and copro-antigen ELISA , 7 (64%) were amebiasis positive by both tests. Four species of bacteria were isolated from the ameba cultures: Escherichia coli, Morganella morganii, Proteus mirabilis, and Streptococcus lactis. Elimination of the bacteria from the cultures by an antibiotics cocktail containing gentamicin, imipenem, piperacillin-tazobactam and vancomycin was the preferred method. Absorption of patients' sera to bacterial antigen prior to serological analysis had only a marginal effect.

Conclusions: These results indicate a correlation of 61% between the ELISA developed in this study and the IHA tests in the diagnosis of amebiasis.

Background: Type 2 diabetes, an extreme state of glucose intolerance, has been found to be associated with cancer mortality; less is known about impaired glucose tolerance and cancer incidence.

Objectives: To examine the association between fasting and post-load plasma glucose and insulin, and the 20 year incidence of cancer.

Methods: We followed a sample of the Jewish Israeli population (n=2780), free of cancer at baseline,

from 1977-1980 to 1999 for cancer incidence and mortality. Baseline fasting and 1 and 2 hour post-load plasma glucose levels were recorded, as was insulin in 1797 of them.

Results: During 20 years, 329 individuals (11.8%) developed cancer. Cancer incidence for all sites differed between men and women (13.0% and 10.7%, P = 0.03), and among different glucose tolerance status groups (P = 0.01). Cancer incidence hazard ratio, by glucose status adjusted for gender, age, ethnicity, smoking and body mass index, was 1.24 (95%CI 0.96–1.62, P = 0.10) for impaired fasting glucose or impaired glucose tolerance, and 1.32 (95%CI 0.96–1.81, P = 0.09) for type 2 diabetes mellitus, compared to those who were normoglycemic at baseline. Fasting insulin and cancer incidence were not associated.

Conclusions: An increased long-term cancer risk for individuals with impaired fasting glucose or glucose tolerance, or diabetes, is suggested. Even this modest association could have substantial public health consequences.