Israel Medical Association Journal

Background: Several murine models are susceptible to atherosclerosis, such as low density-lipoprotein receptor-deficient (LDLR^-/-) and apolipoprotein E-deficient (apoE^-/-) mice, and are used for studying pathophysiological mechanisms. Atherosclerotic lesions in the aortic valve and thoracic/abdominal aorta are commonly associated with hyperlipidemia. We recently demonstrated the development of large atherosclerotic plaques in Helicobacter pylori-infected heterozygous LDLR^+/- apoE^+/- mice.

Objectives: To measure novel biomarkers related to atherosclerosis, blood coagulation, and oxidative stress in order to investigate their possible pathogenic roles in atherosclerosis-prone mice.

Methods: Mice were fed with a normal chow diet or high-fat diet and sacrificed at different age intervals to measure aortic plaque size. Plasma cholesterol was enzymatically measured. Enzyme-linked immunosorbent assay was used to measure oxidized LDL (oxLDL)/beta-2-glycoprotein I (β2GPI) complexes, immunoglobulin M (IgM) antibodies against native LDL, oxLDL, or oxLDL/β2GPI, and urine 11-dehydro-thromboxane B₂ (11-dhTxB₂) or 8-hydroxy-deoxyguanosine.

Results: There was a parallel increase in plaque size, plasma cholesterol, and urinary 11-dhTxB₂ in atherosclerosis-prone mice. In contrast to atherosclerosis-prone strains, an elevation of urinary 11-dhTxB₂ with no significant plaque generation was observed in LDLR^+/- apoE^+/- mice. The atherogenic autoantigen oxLDL/β2GPI complex was detected only in LDLR^-/- mice. These levels seem to depend on plaque size. IgM antibodies against oxLDL in apoE^-/- mice were found, accompanied by atherosclerotic progression.

Conclusions: Progression of atherosclerotic lesions was associated not only with cholesterolemia but also with platelet activation and natural autoimmune-mediated regulatory mechanism(s) in murine models.
 

Background: Multiple sclerosis (MS) is a common demyelinating disorder of the central nervous system (CNS) and although it is a well-established autoimmune disease its ethiopathogenesis has yet to be fully elucidated. The disease may present in several clinical forms that are closely associated with disease morbidity. In recent years various environmental and hormonal factors have been implicated in the pathogenesis of autoimmunity.

Objectives: To evaluate ferritin and prolactin levels in MS patients and their correlation with clinical manifestations of the disease.

Methods: Serum samples from 150 multiple sclerosis patients were evaluated for demographic characteristics, clinical parameters as well as prolactin and ferritin levels utilizing the Liaison chemiluminescent immunoassays (DiaSorin, Italy). Sera from 100 matched healthy donors were used as controls.

Results: Hyperprolactinemia was documented in 10 of 150 MS patients (6.7%) and hyperferritinemia in 12 (8%), both of which were significantly more common in this group compared with healthy controls (P ≤ 0.01 and P = 0.02 respectively). Among female MS patients, elevated prolactin levels were related to the secondary progressive type of disease (P = 0.05), whereas hyperferritinemia was associated with male gender (P = 0.03) and with the relapsing progressive type of the disease (P = 0.02). An inverse association was found between hyperferritinemia and the relapsing-remitting type of MS in male patients (P = 0.05)

Conclusions: Our results suggest a plausible association between these biomarkers and certain clinical types and gender among MS patients. Further studies combining clinical data, CNS imaging and these markers are warranted.
 

Background: Hypovitaminosis D has been shown to be extremely common in various regions around the world, mostly at high latitudes. Israel is characterized by certain features – cultural (e.g., ethnic isolates) and geographic (e.g., sunny climate) – that have been identified for their possible association with vitamin D status.

Objectives: To conduct an ecological study on a representative sample of the population of Israel, testing vitamin D status across age groups, genders, ethnic groups, and seasons.

Methods: We obtained serum samples from 195 healthy Israeli volunteers representing a broad demographic spectrum. Serum concentrations of 25(OH)D were measured with the commercial kit Liaison 25(OH)D Assay (DiaSorin, Italy).

Results: The mean vitamin D level for the entire cohort was surprisingly low (22.9 ± 10.1 ng/ml), with 149 subjects (78%) suffering from vitamin D insufficiency (< 30 ng/ml). Vitamin D status was better in infants than in older age groups. Differences by gender were significant only in the infant age group (i.e., vitamin D status was worse among females) and were not prominent across older ages. Israelis of Ashkenazi origin had higher vitamin D mean levels than those of Sephardic origin, who, in turn, had higher vitamin D levels than Arab subjects (31.4 ± 12, 24.1 ± 10, and 17.6 ± 9 ng/ml respectively). With regard to season, there were no differences between the samples collected in winter and the samples collected in summer.

Conclusions: The results suggest that hypovitaminosis D is common across all ages, genders and seasons in Israel, a country characterized by a sunny Mediterranean climate. Specific ethnic groups may be at especially high risk.

Background: Epidemiological data show significant associations of vitamin D deficiency and autoimmune diseases. Vitamin D may prevent autoimmunity by stimulating naturally occurring regulatory T cells.

Objectives: To elucidate whether vitamin D supplementation increases Tregs[1] frequency (%Tregs) of circulating CD4+ T cells.

Methods: We performed an uncontrolled vitamin D supplementation trial among 50 apparently healthy subjects including supplementation of 140,000 IU at baseline and after 4 weeks (visit 1). The final follow-up visit was performed 8 weeks after the baseline examination (visit 2). Blood was drawn at each study visit to determine 25-hydroxyvitamin D levels and %Tregs. Tregs were characterized as CD4+CD25++ T cells with expression of the transcription factor forkhead box P3 and low or absent expression of CD127.

Results: Forty-six study participants (65% females, mean age ± SD 31 ± 8 years) completed the trial. 25(OH)D[2] levels increased from 23.9 ± 12.9 ng/ml at baseline to 45.9 ± 14.0 ng/ml at visit 1 and 58.0 ± 15.1 ng/ml at visit 2. %Tregs at baseline were 4.8 ± 1.4. Compared to baseline levels we noticed a significant increase of %Tregs at study visit 1 (5.9 ± 1.7, P < 0.001) and 2 (5.6 ± 1.6, P < 0.001).

Conclusions: Vitamin D supplementation was associated with significantly increased %Tregs in apparently healthy individuals. This immunomodulatory effect of vitamin D might underlie the associations of vitamin D deficiency and autoimmune diseases. Hence, our finding provides a rationale for further studies to investigate vitamin D effects on autoimmunological processes.