Neutropenia dynamics in a case of T-LGL lymphoproliferation illustrate rapid turnover of granulocyte progenitors.

OBJECTIVES

To elucidate the natural history of T-cell large granular lymphocyte (T-LGL) lymphoproliferation, we followed changes in associated fluctuating neutropenia for 3 years in an untreated patient presenting with the disease.

MATERIALS AND METHODS

We report a nonlinear mathematical analysis of irregular neutrophil fluctuation, using iterative data maps, to detect long-term regulation of the neutrophil population.

RESULTS

This geometric analysis indicated that variations of this sequence of neutrophil counts followed bounded deterministic dynamics around a fixed low level equilibrium, a situation similar to that previously observed for cultured mouse early bone marrow progenitor cells.

CONCLUSION

These findings illustrate how the deleterious effect of T-LGL on neutrophils is balanced, over periods of years, by pulses of compensatory neutrophil production, potentially accounting for the commonly observed prolonged indolent course of the disease.