A genome-wide association study of IgM antibody against phosphorylcholine: shared genetics and phenotypic relationship to chronic lymphocytic leukemia. (14th March 2018)

• Record Type: Journal Article
• Authors: Chen, Xu; Gustafsson, Stefan; Whitington, Thomas; Borné, Yan; Lorentzen, Erik; Sun, Jitong; Almgren, Peter; Su, Jun; Karlsson, Robert; Song, Jie; Lu, Yi; Zhan, Yiqiang; Hägg, Sara; Svensson, Per; Smedby, Karin E; Slager, Susan L; Ingelsson, Erik; Lindgren, Cecilia M; Morris, Andrew P; Melander, Olle; Karlsson, Thomas; de Faire, Ulf; Caidahl, Kenneth; Engström, Gunnar; Lind, Lars; Karlsson, Mikael C I; Pedersen, Nancy L; Frostegård, Johan; Magnusson, Patrik K E
• Is Part Of: Human molecular genetics. Volume 27:Number 10(2018:May 15)
• Page Start: 1809
• Page End: 1818
• Publication Date: 2018-03-14
• Subjects: Human molecular genetics -- Periodicals; Human chromosome abnormalities -- Periodicals; 572.8
• DOI: 10.1093/hmg/ddy094
• Languages: English
• ISSNs: 0964-6906

Abstract

Abstract: Phosphorylcholine (PC) is an epitope on oxidized low-density lipoprotein (oxLDL), apoptotic cells and several pathogens like Streptococcus pneumoniae . Immunoglobulin M against PC (IgM anti-PC) has the ability to inhibit uptake of oxLDL by macrophages and increase clearance of apoptotic cells. From our genome-wide association studies (GWASs) in four European-ancestry cohorts, six single nucleotide polymorphisms (SNPs) in 11q24.1 were discovered (in 3002 individuals) and replicated (in 646 individuals) to be associated with serum level of IgM anti-PC (the leading SNP rs35923643-G, combined β = 0.19, 95% confidence interval 0.13–0.24, P = 4.3 × 10 −11 ). The haplotype tagged by rs35923643-G (or its proxy SNP rs735665-A) is also known as the top risk allele for chronic lymphocytic leukemia (CLL), and a main increasing allele for general IgM. By using summary GWAS results of IgM anti-PC and CLL in the polygenic risk score (PRS) analysis, PRS on the basis of IgM anti-PC risk alleles positively associated with CLL risk (explained 0.6% of CLL variance, P = 1.2 × 10 −15 ). Functional prediction suggested that rs35923643-G might impede the binding of Runt-related transcription factor 3, a tumor suppressor playing a central role in the immune regulation of cancers. Contrary to the expectations from the shared genetics between IgM anti-PC and CLL, an inverse relationship at the phenotypic level was found in a nested case–control study (30 CLL cases with 90 age- and sex-matched controls), potentially reflecting reverse causation. The suggested function of the top variant as well as the phenotypic association between IgM anti-PC and CLL risk needs replication and motivates further studies.