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.

Chronic fatigue syndrome is a heterogeneous disorder with unknown pathogenesis and etiology, characterized by disabling fatigue, difficulty in concentration and memory, and concomitant skeletal and muscular pain. Several mechanisms have been suggested to play a role in CFS[1], such as excessive oxidative stress following exertion, immune imbalance characterized by decreased natural killer cell and macrophage activity, immunoglobulin G subclass deficiencies (IgG-1[2], IgG-3) and decreased serum concentrations of complement component. Autoantibodies were also suggested as a possible factor in the pathogenesis of CFS. Recent studies indicate that anti-serotonin, anti-microtubule-associated protein 2 and anti-muscarinic cholinergic receptor 1 may play a role in the pathogenesis of CFS. It has been demonstrated that impairment in vasoactive neuropeptide metabolism may explain the CFS symptoms

Background: Surgical repair of tetralogy of Fallot may leave the patient with pulmonary regurgitation causing eventual right ventricle dilatation and dysfunction. Predicting clinical deterioration may help to determine the best timing for intervention.

Objectives: To assess whether the clinical and humoral status of patients in the second decade after repair of ToF[1] is worse than that of patients in the first decade after repair.

Methods: Twenty-one patients with repaired ToF underwent clinical assessment, electrocardiogram, echocardiogram and measurement of plasma B-type natriuretic peptide and N-terminal pro-BNP[2] as well as the 6 minute walk distance test. Patients were divided into two groups: group A – less than 10 years after repair (n=10, age < 12 years old), and group B – more than 10 years after repair (n=11, age > 12 years old). The age at repair was similar in both groups.

Results: In all but one patient the distance in the 6 min walk test was less than the minimum for age. RV[3] end-diastolic volume and the 6 min walk test correlated with age. NT-proBNP[4] levels were significantly higher in the ToF group compared to 26 healthy controls (P < 0.0001) and were inversely correlated with RV ejection fraction. Comparison of the two groups showed no difference in RV end-diastolic volume indexed for body surface area, pulmonary regurgitation severity, right or left ventricular myocardial performance index, RV ejection fraction, QRS duration, or 6 min walk indexed to minimum for age.

Conclusions: In this group of patients with similar age at operation and pulmonary regurgitation severity, most clinical, echocardiographic and humoral parameters were not worse in the second decade after repair of ToF. These data suggest that very early pulmonary valve replacement may not be of benefit.

Background: The measurement of maternal serum human chorionic gonadotropin as a predictor of fetuses with Down syndrome has been in use since 1987.

Objectives: To determine the correlation between extremely high levels of hCG[1] at mid-gestation and maternal and fetal complications.

Methods: The study group consisted of 75 pregnant women with isolated high levels of hCG (> 4 MOM) at mid-gestation, and the control group comprised 75 randomly selected women with normal hCG levels (as well as normal alpha-fetoprotein and unconjugated estriol levels). The data collected included demographic details, fetal anomalies, chromosomal aberrations, pregnancy complications, and results of neonatal tests.

Results: There was a significant increase in the frequency of fetal anomalies (detected by ultrasound), low birth weight and neonatal complications in the study group. We also found an increased rate of fetal/neonatal loss proportional to the increasing levels of hCG (up to 30% in levels exceeding 7 MOM).

Conclusion: Our study demonstrated an increased frequency of obstetric complications that was closely associated with raised hCG levels. The study also raises questions about the accuracy of the Down syndrome probability equation in the presence of extremely high levels of hCG where data on the frequency of Down syndrome is severely limited.