Genetic polymorphism in ATG16L1 gene is associated with adalimumab use in inflammatory bowel disease
JOURNAL OF TRANSLATIONAL MEDICINE
Authors: Nuij, V. J. A. A.; Peppelenbosch, M. P.; van der Woude, C. J.; Fuhler, G. M.
Abstract
Background: The role of single nucleotide polymorphisms (SNPs) associated with inflammatory bowel disease (IBD) is gaining interest. With the advent of novel therapies, personalized treatment in IBD is a future goal. We wondered whether IBD-associated SNPs are able to predict response to anti-TNFa treatment. Methods: Data on treatment use and primary response, loss of response and side effects to anti-TNFa treatments were retrieved for 570 IBD patients. rs13361189 (IRGM), rs10210302 (ATG16L1), rs2066844, rs2066845, rs2066847 (NOD2), rs35873774 (XBP1), rs11175593 (LRRK2), rs11465804 (IL23R), rs2301436 (CCR6), rs744166 (STAT3) and rs4821544 (NCF4) SNP status were determined. Results: No associations were found between genetic variants of the LRRK2, CCR6, IL23R and NCF4 genes and response to anti-TNF alpha. For NOD2 and XBP1 associations were found, however, these associations were not strong enough to survive multiple testing corrections. Strikingly, patients carrying the ATG16L1 T300A variant were more likely to be treated with adalimumab, even after correction for disease phenotype, disease behavior and age (p = 0.004, OR 2.8, CI 1.6-5.0). Conclusions: Genetic polymorphisms in the known IBD-associated gene ATG16L1 correlate with requirement of treatment, suggesting a different IBD disease phenotype in these patients. Further investigation will need to elucidate the implications of these findings and identify the underlying disease characteristics.
A novel missense mutation in the NADPH binding domain of CYBB abolishes the NADPH oxidase activity in a male patient with increased susceptibility to infections
MICROBIAL PATHOGENESIS
Authors: Khan, Taj Ali; Kalsoom, Kalsoom; Iqbal, Asif; Asif, Huma; Rahman, Hazir; Farooq, Syed Omar; Naveed, Hassan; Nasir, Umar; Amin, Muhammad Usman; Hussain, Mubashir; Tipu, Hamid Nawaz; Florea, Andrei
Abstract
Chronic granulomatous disease (CGD) is a primary immunodeficiency caused by mutations in the five structural genes (CYBB, CYBA, NCF1, NCF2, and NCF4) that typically results in a decrease in function or inability to generate a respiratory burst, leading to defective killing of pathogens, including fungi and intracellular bacteria. Mutations in CYBB, encoding the gp91 phox (also known as NOX2) result in X-linked CGD account for approximately 65% of CGD cases. Here, we aimed the characterization of a novel missense mutation c.1226C > A/p.A409E in the CYBB gene in a patient with X-linked CGD. Relevant clinical data of a male patient whose family was positive for XCGD was reviewed. Oxidative burst and NADPH protein expression was evaluated by flow cytometry, while Genetic analysis was performed by Sanger sequencing. Monocyte-derived macrophages (MDMs) were evaluated for their capacity for phagocytosis and growth suppression of the intracellular Mycobacterium tuberculosis (M. tuberculosis). We thus report the absence of an oxidative burst in the phagocytes of the patient. Flow cytometry evaluation revealed a normal expression of NADPH oxidase components in neutrophils and genetic analysis proved the existence of a novel missense c.1226C > A mutation in the CYBB gene resulting in p.A409E. Further, we have showed that the patient's MDMs were unhindered in their ability to take up mycobacteria normally. Instead, the MDMs failed to control the intracellular proliferation of M. tuberculosis, a phenotype that improved in the presence of recombinant human interferon-gamma (rhIFN-gamma). This work expands the genetic spectrum of X-linked CGD and demonstrates improvement in macrophage function in X91(+)CGD patient by rhIFN-gamma. (C) 2016 Elsevier Ltd. All rights reserved.