December 2006
Revised: Dec 2010
We present a novel nonparametric Bayesian approach based on L{\'e}vy Adaptive Regression Kernels (LARK) to model spectral data arising from MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time-of-Flight) mass spectrometry. This model based approach provides identification and quantification of proteins through model parameters that are directly interpretable as the number of proteins, mass and abundance of proteins and peak resolution, while having the ability to adapt to unknown smoothness as in wavelet based methods. Informative prior distributions on resolution are key to distinguishing true peaks from background noise and resolving broad peaks into individual peaks for multiple protein species. Posterior distributions are obtained using a reversible jump Markov chain Monte Carlo algorithm and provide inference about the number of peaks (proteins), their masses and abundance. We show through simulation studies that the procedure has desirable true-positive and false-discovery rates. Finally, we illustrate the method on five example spectra: a blank spectrum, a spectrum with only the matrix of a low-molecular-weight substance used to embed target proteins, a spectrum with known proteins, and a single spectrum and average of ten spectra from an individual lung cancer patient.
Keywords: Bayes; gamma random field; Kernel Regression; Lévy random fields; reversible jump MCMC; wavelets;
The manuscript is available in PDF (1.04Mb) format.
Cite as:
@Article{Hous:Clyd:Wolp:2011,
Author = "Leanna L. House and Merlise A. Clyde and Robert L. Wolpert",
Title = "Bayesian Nonparametric Models for Peak Identification
in {MALDI-TOF} Mass Spectroscopy",
Journal = "Annals of Applied Statistics",
Volume = 5,
Number = "2B",
Pages = "1488--1511",
Year = 2011,
}