Israel Medical Association Journal

Background: Dialysate purity contributes to the inflammatory response that afflicts hemodialysis patients.

Objectives: To compare the clinical and laboratory effects of using ultrapure water produced by a water treatment system including two reverse osmosis (RO) units in series, with a system that also includes an ultrapure filter (UPF).

Methods: We performed a retrospective study in 193 hemodialysis patients during two periods: period A (no UPF, 6 months) and period B (same patients, with addition of UPF, 18 months), and a historical cohort of patients treated in the same dialysis unit 2 years earlier, which served as a control group.

Results: Mean C-reactive protein, serum albumin and systolic blood pressure worsened in period B compared to period A and in the controls.

Conclusions: A double RO system to produce ultrapure water is not inferior to the use of ultrapure filters.

Background: Inflammatory bowel disease (IBD) prevalence is increasing among Bedouin Arabs in Israel. This population is known to have a high rate of consanguinity. NOD2/CARD15 mutations are well-studied in IBD.

Objectives: To investigate the frequency of NOD2/CARD15 mutations in IBD Bedouin patients and their relevance to disease phenotype.

Methods: The IBD-Arab cohort in southern Israel included 68 patients, of which 25 Crohn's disease (CD) patients and 25 ulcerative colitis (UC) patients consented to participate (72%). Blood samples were obtained from all participants who were genotyped for NOD2/CARD15 variants Arg702Trp, Gly908Arg, and Leu1007fsinsC.

Results: The NOD2/CARD15 mutation frequency was higher in Crohn's disease than in ulcerative colitis patients. Carrier frequency for the Gly908Arg mutation in CD and UC patients was 8/25 (32%) and 3/25 (12%), respectively (P = 0.08). Neither the Arg702Trp nor Leu1007fsinsC mutation was found in our cohort. No homozygous/compound heterozygote mutations were found. Genotype-phenotype analysis revealed that CD patients carrying the Gly908Arg mutation were younger at diagnosis, 22.8 ± 4.5 vs. 28.82 ± 9.1 years (P = 0.04). All carriers were males, compared with 41.2% in non-carriers (P = 0.005). NOD2/CARD15 mutation carriers with UC were older, 67.0 ± 24.5 years compared with 41.2 ± 12.3 years (P = 0.006). No other associations regarding disease localization or other clinical parameter were found.

Conclusions: The frequency of NOD2/CARD15 gene mutations is high in CD and UC among Bedouin Arab IBD patients and is associated with younger age at onset in CD and male gender.