Search

Khaled K Abu-Amero, Tahira Sultan, Saleh A Al-Obeidan, Altaf A Kondkar Glaucoma Research Chair, Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia Abstract: Cytochrome P450 Family 1 Subfamily B Member 1 (CYP1B1; OMIM# 601771) gene encodes one of the cytochrome P450 family of enzymes. CYP1B1 mutations have been associated primarily with primary congenital glaucoma (PCG). Similar studies were reported in juvenile open-angle glaucoma, Rieger’s and Peters anomalies. Reports of likely pathogenic sequence alterations in families affected with adult-onset primary open-angle glaucoma (POAG) triggered this investigation. We screened unrelated POAG cases and healthy controls for mutations in CYP1B1 using automated Sanger sequencing to identify five known polymorphisms and one CYP1B1 mutation (p.G61E) in a heterozygous status. The p.G61E mutation is known to cause PCG in a homozygous or compound heterozygous form, and thus, its presence here in a heterozygous form indicates carrier status. These findings suggest that CYP1B1 may have no major role in the pathogenesis of POAG, at least, in the Saudi population. However, further investigations are needed to validate these findings in a larger cohort. Keywords: CYP1B1, genetics, mutation screening, POAG, Saudi Arabia

Altaf A Kondkar, Tahira Sultan, Faisal A Almobarak, Hatem Kalantan, Saleh A Al-Obeidan, Khaled K Abu-Amero Glaucoma Research Chair, Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia Purpose: Retinal ganglion cell (RGC) death is a key feature of glaucoma. Elevated levels of tumor necrosis factor alpha (TNF-α), a pro-inflammatory cytokine, can induce RGC apoptosis and play a critical role in glaucomatous neurodegeneration. Based on the possible role of inflammation and oxidative stress in the pathogenesis of primary open-angle glaucoma (POAG), we investigated the association between plasma levels of TNF-α and POAG or its clinical indices in comparison to non-glaucomatous controls. Patients and methods: In a case–control retrospective cohort of 51 POAG cases and 88 controls, plasma TNF-α levels were measured using an enzyme-linked immunosorbent assay (ELISA). The assay was performed in duplicates on an automated ELISA analyzer. Results: Mean TNF-α level was significantly elevated in POAG cases (1.88 ± 2.17 pg/mL) than the controls (0.93 ± 1.49 pg/mL; p = 0.003). The overall dose–response trend was significant (Χ2 = 6.12, df = 2; p = 0.047). No statistical difference was seen in age, gender and systemic disease distribution. A modest negative and significant correlation was seen between TNF-α level and number of antiglaucoma medications, an important clinical index of POAG severity. Moreover, logistic regression analysis showed that the risk of POAG was most significantly affected by TNF-α level and not by age and sex. Conclusion: High systemic level of an inflammatory cytokine, TNF-α, is associated with POAG; however, its possible use as a biomarker for early glaucoma diagnosis and/or disease severity needs further investigation. Keywords: apoptosis, biomarker, cytokines, ELISA, inflammation, neurodegeneration, oxidative stress

Altaf A Kondkar,1 Taif A Azad,1 Faisal A Almobarak,1 Hatem Kalantan,1 Saleh A Al-Obeidan,1 Khaled K Abu-Amero1,2 1Glaucoma Research Chair, Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Saudi Arabia; 2Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA Background: Tumor necrosis factor alpha (TNF-α) is a pro-inflammatory cytokine, which plays a role in glaucomatous neurodegeneration. Based on the plausible role of inflammation in the pathogenesis of pseudoexfoliation glaucoma (PEG), we investigated whether there is any relationship between the levels of plasma TNF-α and PEG or any of its clinical indices in comparison to normal controls.Methods: The study was designed as a retrospective analysis. Plasma samples from 49 PEG patients and 88 non-glaucomatous controls were evaluated for TNF-α levels using an enzyme-linked immunosorbent assay (ELISA). The assay was performed in duplicates on a biochemical/ELISA analyzer.Results: The two study groups were similar in age, sex and systemic disease distribution. The mean TNF-α concentration was significantly higher in the PEG patients (5.54±4.58 pg/mL) than in the control subjects (0.93±1.49 pg/mL; 95% confidence interval [CI] =3.50–5.72; p=0.000). The overall dose–response trend was significant (χ2=57.07, df=2; p=0.000). A moderate positive and significant correlation was seen between TNF-α level and cup/disc ratio, an important clinical index for PEG. Besides, binary logistic regression analysis showed that the risk of PEG was most significantly affected by TNF-α level as compared to no association with age and sex. In receiver operating characteristic analysis, the area under the curve was 0.777 (95% CI =0.682–0.872) and statistically significant (p=0.000).Conclusion: Elevated systemic levels of inflammatory marker, TNF-α, are associated with PEG and may possibly serve as a biomarker for undiagnosed early glaucoma and/or as a marker for disease progression. Keywords: glaucoma, inflammation, oxidative stress, pseudoexfoliation, TNF-α

Ramzi Al Judaibi,1 Khaled K Abu-Amero,2,3 Jose Morales,1 Sami Al Shahwan,1 Deepak P Edward1,4 1King Khaled Eye Specialist Hospital, 2Department of Ophthalmology, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3Department of Ophthalmology, College of Medicine, University of Florida, Jacksonville, FL, USA; 4Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore MD, USA Purpose: Here, we present two patients with congenital anterior staphyloma, with mutations in the CYP1B1 gene. Methods: We reviewed the medical records, including the genetic analysis. Results: Two unrelated patients presented with congenital anterior staphylomas. Both patients showed mutations in the CYP1B1 gene. The first patient, the product of a consanguineous marriage, showed a homozygous misssense mutation g.3987G>A (p.G61E). The second patient had compound heterozygous misssense mutations [g.4160 G>T (p.A119S) and g.8131 C>G (p.L432V)]. Conclusion: CYP1B1 gene mutation may be associated with congenital anterior staphylomas. Keywords: mutation analysis, congenital glaucoma, consanguinity, congenital aphakia

Context.--Previous studies reported an association of certain polymorphisms in the lipoprotein lipase (LPL) gene with the risk of coronary artery disease (CAD); however, these studies were small and inconsistent. In addition, none of these studies attempted to establish such an association in the Arab population. Objective.--To determine whether 2 LPL polymorphisms (LPL-HindIII and LPL-PvuII located on introns 8 and 6, respectively, of the LPL gene) can be considered as independent risk factors or as predictors for CAD in Arabs. Design.--We used polymerase chain reaction and restriction enzyme digestion to determine the distribution of the LPL-HindIII and LPL-PvuII polymorphisms among healthy blood donors of Arabic origin (BD group) and angiographically confirmed CAD patients (CAD group) with identical ethnic backgrounds. Results.--For the HindIII genotypes, within the BD group (n = 410), the +/+ genotype was found in 206 individuals (50.2%), 173 (42.2%) carried the +/- genotype, and 31 (7.6%) carried the -/- genotype. Within the CAD group (n = 352), the +/+ genotype was found in 189 individuals (53.7%), 138 (39.2%) carried the +/- genotype, and 25 (7.1%) carried the -/- genotype. P values of .38, .45, and .92 were obtained for the +/+, +/-, and -/- genotypes, respectively. For the PvuII genotypes, within the BD group (n = 511), the +/+ genotype was found in 182 individuals (35.6%), 248 (48.5%) carried the +/- genotype, and 81 (15.9%) carried the -/- genotype. Within the CAD group (n = 431), the +/+ genotype was found in 138 individuals (32%), 225 (52.2%) carried the +/- genotype, and 68 (15.8%) carried the -/- genotype. P values of .28, .29, and .98 were obtained for the +/+, +/-, and -/- genotypes, respectively. The distribution and the allele frequency of these 2 LPL variants were similar in CAD and BD study groups and followed the Hardy-Weinberg equilibrium. Conclusion.--There was no difference in the distribution of both LPL polymorphisms between the healt... [ABSTRACT FROM AUTHOR]