1/f-Like Scaling in Normal Neutrophil Dynamics: Implications for Hematologic Monitoring

Daily neutrophil counts show considerable variability in normal subjects. The dynamics of these apparently erratic fluctuations have not been characterized. We hypothesized that this variability might reflect the kind of 1/f-like (inverse power-law) spectrum seen in other physiologic processes. Fast Fourier transform analysis of neutrophil count data over 64 consecutive days from four previously reported normal volunteers showed a good fit (r = 0.84; p 0.001) to the predicted power-law regression line (y = -1.14x -1.05). Further characterization of normal and pathologic neutrophil spectra may have diagnostic value.