Israel Medical Association Journal

Background: Methotrexate is the most frequently administered first-line treatment for rheumatoid arthritis (RA). The disease-modifying effects of methotrexate are mainly associated with enhanced release of free adenosine. The downstream anti-inflammatory effects of adenosine are mediated via its binding to adenosine receptor 2A (ADORA2A) and 3 (ADORA3). Many clinically important single nucleotide polymorphisms (SNPs) were reported in ADORA2A and ADORA3 genes.

Objectives: To investigate whether tagging ADORA2A and ADORA3 polymorphisms influences methotrexate treatment in RA.

Methods: In total, 212 RA patients treated with methotrexate were genotyped for tagging ADORA2A (rs2298383, rs8141793, rs2236624, rs5751876, rs35320474, and rs17004921) and ADORA3 SNPs (rs2298191, rs1544223, rs78594984, rs35511654, rs2229155, rs3393, and rs3394).

Results: RA patients who carried ADORA3 rs35511654 G allele showed a tendency toward better response to methotrexate treatment (P = 0.054). Carriers of ADORA2A polymorphic allele rs2298383 (P = 0.011), rs2236624 (P = 0.027), rs5751876 (P = 0.018), and rs35320474 (P = 0.026) were less likely to experience methotrexate induced adverse events. All associations remained significant after adjustment for clinical factors. The effects of these polymorphisms were also significant in haplotype analyses.

Conclusions: Polymorphisms in the ADORA2A gene may influence methotrexate treatment response and may be considered as a potential biomarker for methotrexate treatment in rheumatoid arthritis.

Background: Diffuse large B-cell lymphoma (DLBCL) accounts for 30% of all non-Hodgkin lymphomas (NHL) and 80% of agressive lymphomas. Besides the traditional International Prognostic Index (IPI), some other factors may also influence the prognosis of DLBCL patients.

Objectives: To study how the genetic polymorphisms in the metabolic pathway influence the event-free and overall survivals and therapeutic responses in DLBCL.

Methods: The study was comprised of 51 patients (32 men, 19 women). The average age was 53.1 years. DLBCL was diagnosed between 2011 and 2016 and the average follow-up time was 3.78 years. These patients received 1–8 cycles (an average of 6.2 cycles) of rituximab, cyclophosphamide, doxorubicin, vincristin, prednisolon (R-CHOP) immunochemotherapy. Real-time polymerase chain reaction was used to determine the genetic polymorphisms of CYP2E1, GSTP1, NAT1, and NAT2 genes.

Results: Our results showed that the polymorphisms of CYP2E1, GSTP1, and NAT1 genes did not influence the prognosis of DLBCL patients significantly. In terms of the NAT2 gene, GG homozygous patients showed slightly better therapeutic response and survival results compared to those bearing an A allele; however, the differences were not statistically significant.

Conclusions: Our results could not confirm that genetic polymorphism in metabolic pathways has any predictive role in DLBCL. 

 

Vitamin D deficiency is becoming an increasing problem worldwide. It should not be underestimated, not only due to the well-known consequences vitamin D deficiency has on bone health, but primarily because recent studies have shown how the biologically active form of vitamin D – 1,25(OH)2D – is involved in many biological processes, including immune system modulation. Moreover, the presence of a vitamin D receptor was discovered in almost all immune cells and some of its polymorphisms were found to be associated with increased incidence of autoimmune diseases. This finding led to a proposed link between vitamin D deficiency and autoimmune diseases. Patients affected by various autoimmune diseases showed low levels of vitamin D. However, it is not always clear whether vitamin D deficiency is the cause or rather a consequence of the disease. Limitations of the studies, such as the small number of patients, heterogeneity of selected groups, environmental conditions, methods used to measure vitamin D serum concentration and other confounding factors do not lead to unequivocal results to demonstrate a direct link between low vitamin D levels and autoimmune disease. Therefore, randomized trials are needed to clarify conflicting results.

There is growing interest in the contribution of vitamin D deficiency to autoimmunity. Several studies have shown an association between low levels of vitamin D and autoimmune disorders, including multiple sclerosis, rheumatoid arthritis, type 1 diabetes, autoimmune thyroid diseases, celiac disease, and systemic lupus erythematosus (SLE). Vitamin D receptor ligands can mediate immunosuppressive effects. It has been suggested that low levels of this hormone contribute to the immune activation in lupus and other autoimmune diseases. This review updates and summarizes the literature on the association between vitamin D and SLE, and discusses the various correlations between vitamin D and SLE activity, clinical expressions, serology, and gene polymorphisms of vitamin D receptors.

Abstract

Background: Hyperhomocysteinemia is associated with increased cardiovascular risk, but treatment with folic acid has no effect on outcome in unselected patient populations.

Objectives: To confirm previous observations on the association of homozygosity for the TT MTHFR genotype with B12 deficiency and endothelial dysfunction, and to investigate whether patients with B12 deficiency should be tested for 677MTHFR genotype.

Methods: We enrolled 100 individuals with B12 deficiency, tested them for the MTHFR C677T polymorphism and measured their homocysteine levels. Forearm endothelial function was checked in 23 B12-deficient individuals (13 with TT MTHFR genotype and 10 with CT or CC genotypes). Flow-mediated dilatation (FMD) was tested after short-term treatment with B12 and folic acid in 12 TT MTHFR homozygotes.

Results: Frequency of the TT MTHFR genotype was 28/100 (28%), compared with 47/313 (15%) in a previously published cohort of individuals with normal B12 levels (P = 0.005). Mean homocysteine level was 21.2 ± 16 mM among TT homozygotes as compared to 12.3 ± 5.6 mM in individuals with the CC or CT genotype (P = 0.008). FMD was abnormal (£ 6%) in 9/13 TT individuals with B12 deficiency (69%), and was still abnormal in 7/12 of those tested 6 weeks after B12 and folic treatment (58%).

Conclusions: Among individuals with B12 deficiency, the frequency of the TT MTHFR genotype was particularly high. The TT polymorphism was associated with endothelial dysfunction even after 6 weeks of treatment with B12 and folic acid. Based on our findings we suggest that B12 deficiency should be tested for MTHFR polymorphism to identify potential vascular abnormalities and increased cardiovascular risk. 

Background: Type 1 diabetes in humans is an autoimmune disease in which T cells target pancreatic islets of Langerhans, leading to the progressive destruction of the insulin-producing beta cells. Both genetic and environmental factors contribute to the development of autoimmune diabetes. The non-obese diabetic (NOD) mouse model of human type 1 diabetes demonstrates two missense mutations in the transient receptor potential vanilloid receptor-1 (TRPV1) gene.

Objectives: To investigate whether polymorphism in the TRPV1 gene may play a role in the predisposition to human type 1 diabetes.

Methods: We genotyped 146 Ashkenazi Jewish type 1 diabetic patients and 205 Ashkenazi Jewish healthy controls for the rs222747 (M315I), rs224534 (T469I) and rs8065080 (I585V) variants of the TRPV1 gene.

Results: There was a significant increase in the rs222747 (M315I) variant of the TRPV1 gene in the type 1 diabetes cohort compared to the control: rs222747 (M315I) homozygous: (61% vs. 48.3%, P = 0.02). Logistic regression analysis revealed that type1 diabetes was significantly associated with rs222747 (M315I), such that having diabetes increased the odds of rs222747 homozygosity (M315I) by 67.2%, odds ratio 1.6, 95% confidence interval 1.08–2.57, P < 0.02. No difference was found in the rs224534 (T469I) and rs8065080 (I585V) allelic variants. There was no difference in any of the TRPV1 variants by gender, age when type1 diabetes was diagnosed, body mass index, glycemic control, blood pressure, positive autoantibodies (ICA, GAD, IAA), and other autoimmune diseases.

Conclusions: Our study demonstrates that TRPV1 may be a susceptible gene for type 1 diabetes in an Ashkenazi Jewish population. These results should be replicated in the same ethnic group and in other ethnic groups.

In Israel, Yemenite Jews and other populations including Ethiopian Jews and Bedouins have a low neutrophil count. This phenomenon has been called “benign neutropenia” since it has not been associated with any increased risk of infection and has also been described in other populations around the world including Africans, African Americans and Afro-Carribeans. Here we describe the recent success in mapping the gene that underlies benign neutropenia in African American populations. We discuss the known function of the gene and consider potential mechanisms for the effect on neutropenia. We also consider the possibility that this gene underlies the same effect observed in Yemenite Jews, Ethiopian Jews and Bedouins in Israel.
 

Background: Ulcerative colitis (UC) is a common and difficult-to-treat disease. In non-smokers the relative risk of developing UC[1] is 2.9 compared with smokers, who tend to have a later onset and a milder disease. Nicotine is the component of cigarette smoke responsible for the favorable effects in UC. Nicotine is metabolized by the enzyme CYP2A6. Subjects who are homozygotes for CYP2A6*4 gene polymorphism are poor nicotine metabolizers, while homozygotes for CYP2A6*1A polymorphism are extensive metabolizers.

Objectives: To compare the frequency of CYP2A6 and CHRNA3 polymorphisms among smokers and non-smokers with UC, and their effect on disease severity.

Methods: Data on the age at onset of disease, disease activity, and treatment were obtained from questionnaires completed by the 69 subjects in our study group. CYP2A6

*1A,*4A and CHRNA3 polymorphisms were determined by polymerase chain reaction and restriction enzyme analysis.

Results: Nine percent of the patients were current smokers, 30% were former smokers and 61% non-smokers. Among smokers and former smokers 63% were homozygotes for CYP2A6*1A and 4% were homozygotes for CYP2A6*4A, whereas among non-smokers 66% were homozygotes for CYP2A6*4A (P < 0.0001). There was no significant effect of CYP2A6 or CHRNA3 genotype on UC activity.

Conclusions: We found a very high proportion of poor nicotine metabolizers among non-smoking patients with UC and a very low proportion among current and former smokers, making it difficult to determine the effect of poor metabolizer genotype on disease activity in smokers with UC. However, it may be possible to identify UC patients who are poor metabolizers of nicotine and who may benefit from nicotine or nicotine-like pharmacological treatment.

Background: Cancer is a leading cause of mortality worldwide. The most effective way to combat cancer is by prevention and early detection.

Objectives: To evaluate the outcome of screening an asymptomatic population for the presence of benign and neoplastic lesions.

Methods: Routine screening tests for prevention and/or early detection of 11 common cancers were conducted in 300 consecutive asymptomatic, apparently healthy adults, aged 25–77 years. Other tests were performed as indicated.

Results: Malignant and benign lesions were found in 3.3% and 5% of the screenees, respectively, compared to 1.7% in the general population. The most common lesions were in the gastrointestinal tract followed by skin, urogenital tract and breast. Advanced age and a family history of a malignancy were associated with increased risk for cancer with an odds ratio of 9 and 3.5, respectively (95% confidence interval 1.1–71 and 0.9–13, respectively). Moreover, high serum C-reactive protein levels and polymorphisms in the APC and CD24 genes indicated high cancer risk. When two of the polymorphisms existed in an individual, the risk for a malignant lesion was extremely high (23.1%; OR[1] 14, 95% CI[2] 2.5–78).

Conclusions: Screening asymptomatic subjects identifies a significant number of neoplastic lesions at an early stage. Incorporating data on genetic polymorphisms in the APC and CD24 genes can further identify individuals who are at increased risk for cancer. Cancer can be prevented and/or diagnosed at an early stage using the screening facilities of a multidisciplinary outpatient clinic.

Background: Cardiovascular disease is now well established as a multifactorial disease. In a given individual, the level of cardiovascular risk is due to the interaction between genetic and environmental components. The BIP cohort comprised 3000 patients with cardiovascular disease who were tested for the benefits of bezafibrate treatment. This cohort has the data for the lipid profile of each individual, fibrinogen, Insulin, as well as clinical, demographic and lifestyle parameters

Objectives: To genotype up to 64 variable sites in 36 genes in the BIP cohort. The genes tested in this assay are involved in pathways implicated in the development and progression of atherosclerotic plaques, lipid and homocystein metabolism, blood pressure regulation, thrombosis, rennin-angiotensin system, platelet aggregation, and leukocyte adhesion.

Methods:  DNA was extracted from 1000 Israeli patients from the BIP cohort. A multilocus assay, developed by the Roche Molecular System, was used for genotyping. Allele frequencies for some of the markers were compared to the published frequencies in a healthy population (the French Stanislas cohort, n=1480).

Results: Among the 26 comparable alleles checked in the two cohorts, 16 allele frequencies were significantly different from the healthy French population: ApoE (E3, E2, E4), ApoB (71ile), ApoC (3482T, 455C, 1100T, 3175G, 3206G), CETP (405val), ACE (Del), AGT (235thr), ELAM (128arg); p<0001 and LPL (93G, 291Ser, 447ter); p < 005.

Conclusions: Although a comparable healthy Israeli population study is needed for more precise interpretation of these results, frequency differences in these polymorphic alleles, associated with lipid metabolism, renin-angiotensin system and leukocyte adhesion mechanism, between CVD patients and healthy individuals nevertheless implicate these candidate genes as predisposing for CVD.lic safety.
 

Background: It has been argued that arginine replacement in locus16 (Arg16) of ß₂ adrenergic receptor with glycin (Gly16) increases asthma severity, while glutamin replacement in locus 27 (Gln27) with glutamic acid (Glu27) decreases it. In addition, ethnic dependency of these polymorphisms has been described, but few studies investigated its relation to asthma severity in a non-anglosaxic population.

Objectives: To investigate non-anglosaxic ethnic influences on ß₂AR[1] polymorphisms and its correlations to asthma severity.

Methods: Sixty-six Israeli Jewish and Arab asthmatics who had near-fatal asthma and/or severe nocturnal asthma and/or steroid-dependency were investigated for genetic polymorphisms of ß₂AR and compared to matched controls. The Jewish patients included both Ashkenazi (of East European origin) and non-Ashkenazi (originating from the Middle East or North Africa). The results were compared with those of ethnically matched 113 non-asthmatic Israelis, and of non-asthmatic Anglo-Saxons described in the literature.

Results: We found no significant genetic differences between the asthmatics and their controls or between the various ethnic groups of our population. However, the prevalence of Glu27 was significantly lower in non-asthmatic Israelis compared to non-asthmatic Anglo-Saxons.

Conclusions: The genetic distribution of ß₂AR polymorphisms in severe Israeli asthmatics is not different from that of non-asthmatic Israelis and therefore its clinical impact on asthma is probably minimal.

Background: The precise genes involved in conferring prostate cancer risk in sporadic and familial cases are not fully known.

Objectives: To evlauate the genetic profile within several candidate genes of unselected prostate cancer cases and to correlate this profile with disease parameters.

Methods: Jewish Israeli prostate cancer patients (n=224) were genotyped for polymorphisms within candidate genes: p53, ER, VDR, GSTT1, CYP1A1, GSTP1, GSTM1, EPHX and HPC2/ELAC2, followed by analysis of the genotype with relevant clinical and pathologic parameters.

Results: The EPHX gene His113 allele was detected in 21.4% (33/154) of patients in whom disease was diagnosed above 61 years, compared with 5.7% (4/70) in earlier onset disease (P < 0.001). Within the group of late-onset disease, the same allele was noted in 5.5% (2/36) with grade I tumors compared with 18% (34/188) with grade II and up (P = 0.004). All other tested polymorphisms were not associated with a distinct clinical or pathologic feature in a statistically significant manner.

Conclusions: In Israeli prostate cancer patients, the EPHX His113 allele is seemingly associated with a more advanced, late-onset disease. These preliminary data need to be confirmed by a larger and more ethnically diverse study.

Background: Gaucher disease results from the accumulation of glucosylceramide (glucocerebroside) in tissues of affected persons. Patients sharing the same genotype present with widely varying degrees of lipid storage and of clinical manifestations.

Objectives: To determine whether variation in the glucosylceramide synthase (UDPGlucose ceramide glucosyltransferase) gene, which encodes the enzyme that regulates the synthesis of glucocerebroside, could account for the variability and clinical manifestations.

Methods: Patients homozygous for the 1226G (N370S) mutation, the most common in the Ashkenazi Jewish population, were investigated. The exons and flanking sequences of the gene were sequenced using DNA derived from five very mild Gaucher disease patients and four patients with relatively severe Gaucher disease. Results: One polymorphism was found in the coding region, but this did not change any amino acids. Seven other polymorphisms were found in introns and in the 5' untranslated region. Some of these were single nucleotide polymorphisms; others were insertions. The mutations appear to be in linkage equilibrium and none were found with a significantly higher frequency in either severe or mildly affected individuals.

Conclusions: Mutations in the glucosylceramide synthase gene do not appear to count for the variability in expression of the common Jewish Gaucher disease mutation.