Predictive Performance of Neutrophil Parameter for Neutrophil Recovery From Prolonged Neutropenia.

Introduction: Infectious complications occurring in patients with neutropenia remained one of the major causes of mortality in the treatment of hematologic malignancies. Rapid and exact prediction of neutrophil recovery would be helpful for timely and appropriate management of these complications.

Objective: The aim of this study was to evaluate the performance of neutrophil parameters, especially NE-WX, for predicting the timing of neutrophil recovery.

Materials and methods: We retrospectively reviewed patients who were hospitalized in our department and analyzed absolute neutrophil counts (ANC), NE-WX, and monocyte counts.

Results: Median NE-WX and ANC of 2428 blood tests for 154 patients was 334 (Interquartile range (IQR): 312-386) and 3.124 × 10⁹/L (IQR: 1.165-6.136 × 10⁹/L). When NE-WX ranged from 0 to 100 or from 101 to 200, median ANCs were 0.02 × 10⁹/L (IQR: 0.01-0.02 × 10⁹/L) or 0.03 × 10⁶/L (IQR: 0.02-0.623 × 10⁹/L), respectively. Such extreme low NE-WX levels were observed only in patients with very severe neutropenia, which was defined as ANC of less than 0.2 × 10⁹/L. Furthermore, analyses of chronological changes of NE-WX and ANC elucidated that although the behaviors of these parameters were basically parallel, recovery of ANC from neutropenia was preceded by the recovery of NE-WX (15 vs. 18 days; p < 0.01).

Conclusion: Our analyses revealed that low NE-WX levels were observed only in patients with very severe neutropenia, and in these cases, increases in NE-WX levels might predict the timing of neutrophil recovery.