Israel Medical Association Journal

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: Chlamydia pneumoniae has previously been associated with higher prevalence of valvular and cardiac calcifications.

Objectives: To investigate a possible association of seropositivity for C. pneumoniae and the presence of cardiac calcifications (mitral annular or aortic root calcification, and aortic valve sclerosis).

Methods: We retrospectively analyzed serological data (immunoglobulin G TWAR antibodies) from the AZACS trial (Azithromycin in Acute Coronary Syndromes), and correlated the serological findings according to titer levels with the presence of cardiac calcifications as detected by transthoracic echocardiography.

Results: In 271 patients, age 69 ± 13 years, who underwent both serological and echocardiographic evaluation, we found no significant association between the "calcification sum score" (on a scale of 0–3) in seropositive compared to seronegative patients (1.56 ± 1.15 vs.1.35 ± 1.15, respectively, P = 0.26). The median "calcification sum score" was 1 (interquartile range 0–3) for the seronegative group, and 2 (interquartile range 0–3) for the seropositive group (P = 0.2757). In addition, we did not find a significant correlation of any of the individual sites of cardiac calcification and Chlamydia pneumoniae seropositivity.

Conclusion: Our findings suggest that past C. pneumoniae infection may not be associated with the pathogenesis of valvular and cardiac calcifications.
 

Background: The evaluation of influenza vaccine activity and potency are based on the immune response to hemagglutinin, and protection is indicated when a ≥ 1:40 titer of hemagglutination inhibition serum antibody is present. Neuraminidase, the second surface glycoprotein, may also have a role in protection, but little information on the immunologic response to this component is available.

Objectives: To determine whether any response to neuraminidase is evoked by intranasal immunization with a novel, whole, inactivated anti-influenza vaccine.

Methods: This study was part of a more comprehensive study of mucosal and serum immune response to this vaccine. Fifty-four young adults were immunized intranasally, 9 intramuscularly and 18 received a placebo. Twenty-three elderly people were immunized intramuscularly, and 21 elderly and 17 children were immunized intranasally. Serum and nasal antibodies to antigens N1 and N2 were determined by the lectin neuraminidase test.

Results: Serum response following intranasal vaccination was lower than after intramuscular vaccination, and ranged from 21.4 to 35.3% and 33.3 to 64.7% following intranasal vaccination and 52.2 to 77.8% and 47.8 to 88.9% after intramuscular vaccination, to N1 and N2 respectively. Nasal antibody response was low and was found only after intranasal vaccination, and response to N2 was better than to the N1 antigen.

Conclusions: It may be beneficial if future vaccines would include competent hemagglutinin and neuraminidase, which would afford a higher level of protection.
 

Background: Seroepidemeliogic surveys have provided valuable information on the prevalence and incidence of herpes simplex virus-2 infection in general and in selected populations.

Objective: To review the reliability of traditional diagnostic approaches in herpes simplex virus-2 infection.

Methods: In this cross-sectional study, 472 patients attending a clinic for sexually transmitted disease in 1998-1999 were evaluated for HSV-2 infection through collection of epidemiologic and clinical data.

HSV-2 infection was confirmed by the presence of specific Viral glycoprotein, gG-2, antibody in sera.

Results: The seroprevalence of HSV-2 among clinic attendees was 9.33%. Of these attendees only 22% presented with or reported a history of typical vesicular lesions in the genital area. Infection rate was  higher in patients with multiple sex partners (20.8% vs. 8.7%, P< ( 0.0023 in individuals aged 30 or older (12.6 vs. 6.4%, P = 0.03) and  in the Israeli Jewish population as compared to the Israeli Arab population (11.1% vs. 2.4%, P ~ 0.01). Females with multiple sex partners exhibited higher rates of infection than did their male counterparts (50 vs. 16.1%, P < 0.0275(.

Conclusion: The findings support the need for HSV-2 serologi  testing in patients presenting to STD clinics even when typical genital  lesions are not evident but where risk factors for HSV-2 infection are  identified.
 

Background: DHEAS, the most abundant steroid secreted by the adrenal cortex, is suggested to have an important role in the development of immune reaction by activating T cell function and increasing antibody response, and has been tried as a vaccine adjuvant in elderly people.

Objectives: We examined the correlation between endogenous DHEAS and antibody response in the neonatal period by comparing the serum DHEAS levels with the amount of antibody response against hepatitis B vaccination in neonates.

Methods: Vaccine was administered to 12 healthy infants within 24 hours of birth (day 0), and blood specimens were obtained on days 0 and 30 for determination of anti-hepatitis B surface antibody concentration and DHEAS levels.

Results: DHEAS levels varied widely (range 0.38-3.70 μg/ml, mean±SD 2.14±0.98). While we could identify two groups of patients - those with high DHEAS levels (2.90±0.56) and those with lower levels (1.30±0.56) - there was no correlation between DHEAS levels and the antibody response to hepatitis B vaccine (γ=-0.05).

Conclusions: In neonates, antibody response to hepatitis B vaccine does not correlate with DHEAS serum levels. These results do not support the usage of DHEAS as a vaccine adjuvant in neonates.

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DHEAS= dehydepiandrosterone sulphate

Background: Anti-endomysial antibodies are sensitive and specific markers for celiac disease. This antibody has recently been identified as an antibody to tissue transglutaminase, an enzyme that cross-links and stabilizes extracellular matrix proteins.

Objectives: To evaluate the clinical usefulness of an enzyme-linked immunoassay for anti-transglutaminase antibodies, and to compare the results with those of AEA, the current gold standard serological test for celiac disease.

Methods: Serum samples were collected from 33 patients with biopsy-proven celiac disease and AEA tests were performed. Control samples for anti-transglutaminase were obtained from 155 patients. An ELISA test for immunoglobulin A anti-transglutaminase utilizing guinea pig liver transglutaminase was developed and performed on all sera.  Cutoff values for the test were performed using logistic regression and receiver operating curves analysis.

Results: An optical density cutoff value of 0.34 was established for the assay. The mean value was 0.18±0.19 optical density for controls, and 1.65±1.14 for patients with celiac disease (P<0.001). Sensitivity and specificity of the assay were both 90%, while AEA had a sensitivity and specificity of 100% and 94%, respectively.

Conclusions: A tissue transglutaminase-based ELISA test is both sensitive and specific for  detection of celiac disease.

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AEA = anti-endomysial antibody