Rapid detection and quantification of apolipoprotein L1 genetic variants and total levels in plasma by ultra‐performance liquid chromatography/tandem mass spectrometry

Zhou, Haihong; Hoek, Maarten; Pan, Yi; Rohm, Rory J.; Mahsut, Ablatt; Brown, Patricia; Saunders, Jason; Chmielowski, Rebecca A.; Ren, Ning; Shuster, Dan; Southwick, Katie; Ayanoglu, Gulesi; Gorman, Dan; LaFace, Drake; Santino, Salvatore; Conway, James; Zhong, Liu; Cully, Doris; Cleary, Michele A.; Roddy, Thomas P.; Blom, Daniël

doi:10.1002/rcm.6734

Cited by 16 publications

(12 citation statements)

References 17 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…22 Multiple peptides from APOL1 were measured, including a carboxy-terminal-specific peptide (LNILNNNYK) that enabled us to quantify the levels of G0, G1, or G2 variant protein in the plasma, as well an internal peptide (ALDNLAR) that served as a control for quantitation. Correlation between values derived from the carboxy-terminal peptide and the internal peptide were high, and consistent between APOL1 from different genotypes, demonstrating the high reproducibility and quality of the assays ( Figure 1A).…”

Section: Study Populationmentioning

confidence: 99%

“…22 This assay was also used to generate LC-MS based genotype calls. Measurements were not available for some participants due to no sample (n=96) or ID mismatch (n=3).…”

Section: Variant-specific Measurement Of Apol1 In Human Plasmamentioning

confidence: 99%

“…We have recently developed a liquid chromatography (LC)-MS method to specifically monitor the levels of distinct APOL1 variants in plasma. 22 Here, we use this methodology to ask whether there is an association between the levels of APOL1 variants in renal disease in a large cross-sectional cohort, and to determine whether levels of circulating APOL1 could plausibly be used to distinguish those at greatest risk for developing renal disease.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Plasma Levels of Risk-Variant APOL1 Do Not Associate with Renal Disease in a Population-Based Cohort

Kozlitina

Zhou

Brown

et al. 2016

JASN

Self Cite

View full text Add to dashboard Cite

Two common missense variants in APOL1 (G1 and G2) have been definitively linked to CKD in black Americans. However, not all individuals with the renal-risk genotype develop CKD, and little is known about how APOL1 variants drive disease. Given the association of APOL1 with HDL particles, which are cleared by the kidney, differences in the level or quality of mutant APOL1-HDL particles could be causal for disease and might serve as a useful risk stratification marker. We measured plasma levels of G0 (low risk), G1, and G2 APOL1 in 3450 individuals in the Dallas Heart Study using a liquid chromatography-MS method that enabled quantitation of the different variants. Additionally, we characterized native APOL1-HDL from donors with no or two APOL1 risk alleles by size-exclusion chromatography and analysis of immunopurified APOL1-HDL particles. Finally, we identified genetic loci associated with plasma APOL1 levels and tested for APOL1-dependent association with renal function. Although we replicated the previous association between APOL1 variant status and renal function in nondiabetic individuals, levels of circulating APOL1 did not associate with microalbuminuria or GFR. Furthermore, the size or known components of APOL1-HDL did not consistently differ in subjects with the renal-risk genotype. Genetic association studies implicated variants in loci harboring haptoglobin-related protein (HPR), APOL1, and ubiquitin D (UBD) in the regulation of plasma APOL1 levels, but these variants did not associate with renal function. Collectively, these data demonstrate that the risk of renal disease associated with APOL1 is probably not related to circulating levels of the mutant protein.

show abstract

Section: Study Populationmentioning

confidence: 99%

“…22 This assay was also used to generate LC-MS based genotype calls. Measurements were not available for some participants due to no sample (n=96) or ID mismatch (n=3).…”

Section: Variant-specific Measurement Of Apol1 In Human Plasmamentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Plasma Levels of Risk-Variant APOL1 Do Not Associate with Renal Disease in a Population-Based Cohort

Kozlitina

Zhou

Brown

et al. 2016

JASN

Self Cite

View full text Add to dashboard Cite

show abstract

“…Genotyping and quantifying the circulating ApoL1 using tandem mass spectrometry was first reported by Zhou et al 9 On the basis of their previously described method, we adapted a similar method for measurement of ApoL1 G0, G1, and G2 protein variants. Briefly, 8 ml serum was mixed with isotopic peptide standards, digested with trypsin, and analyzed by high-performance chromatography and tandem mass spectrometry using multiple reaction monitoring (MRM).…”

mentioning

confidence: 99%

Most ApoL1 Is Secreted by the Liver

Shukha

Mueller

Chung

et al. 2016

JASN

View full text Add to dashboard Cite

Two coding sequence variants in the gene (G1 and G2) explain much of the increased risk for FSGS, HIV-associated nephropathy, and hypertension-attributed ESRD among people of recent African ancestry. The ApoL1 protein is expressed in a wide variety of cell tissues. It has been assumed that the majority of circulating ApoL1 is produced by the liver, but this has not been shown. Using mass spectrometry, we genotyped and quantified the circulating ApoL1 in two liver transplant recipients whose native APOL1 genotype differed from the genotype of the deceased donors, allowing us to differentiate liver- from nonliver-produced ApoL1. Our findings confirm that the liver is indeed the main source of circulating ApoL1. However, the liver is not the sole source of circulating ApoL1, because we found that residual amounts of native ApoL1 continued to circulate in the blood, even after the liver transplant.

show abstract

“…al. used [54]. Deoxycholate has been shown to increase the solubility of apoB 100 and future science group Review Chappell, Lassman, McAvoy, Lin, Spellman & Laterza increase digestion kinetics for multiple apolipoproteins in plasma but not albumin [44].…”

Section: Quantitation Of Protein Biomarkersmentioning

confidence: 97%

Quantitation of Human Peptides and Proteins Via MS: Review of Analytically Validated Assays

et al. 2014

View full text Add to dashboard Cite

Since the development of monoclonal antibodies in the 1970s, antibody-based assays have been used for the quantitation of proteins and peptides and, today, they are the most widely used technology in routine laboratory medicine and bioanalysis. However, in the last couple of decades, liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) techniques have been adopted in the quantitation of small molecules, and more recently have made significant contributions in the quantitation of proteins and peptides. In this article, we will review clinical MS-based assays for endogenous peptides, proteins, and therapeutic antibodies, for which validated methods exist. We will also cover the measurement of protein turnover and the unique solutions that MS can offer in this field.

show abstract

Rapid detection and quantification of apolipoprotein L1 genetic variants and total levels in plasma by ultra‐performance liquid chromatography/tandem mass spectrometry

Cited by 16 publications

References 17 publications

Plasma Levels of Risk-Variant APOL1 Do Not Associate with Renal Disease in a Population-Based Cohort

Plasma Levels of Risk-Variant APOL1 Do Not Associate with Renal Disease in a Population-Based Cohort

Most ApoL1 Is Secreted by the Liver

Quantitation of Human Peptides and Proteins Via MS: Review of Analytically Validated Assays

Contact Info

Product

Resources

About