The change in peripheral blood monocyte count: A predictor to make the management of chemotherapy-induced neutropenia

The occurrence of neutropenia following chemotherapy makes the management of myelosuppression important. The main objective of this study was to evaluate whether the decrease of peripheral blood monocytes was a potential indicator to predict the occurrence of neutropenia.We retrospectively reviewed the medical records of 103 chemotherapy patients who underwent neutropenia. A paired sample t-test was used to assess whether the number of days when monocyte initial decrease/are in nadir/final increase was significantly less than that of the neutrophils. The baseline of monocyte percentage and the decrease rate of neutrophil were analyzed by the bivariate correlation (two-tailed). Moreover, the grade of neutropenia and the baseline of monocyte percentage (divided into <5% and ≥5%) were examined by the Chi-square test for correlations.Our study showed that the change trend of monocyte count was the same as that of neutrophil count and that the number of days when monocytes initial decrease/are in nadir/final increase was significantly less than that of neutrophils, respectively. The time of initial decrease in monocyte count was 1.39 days earlier; the nadir in monocyte count occurred 3.81 days earlier, and the final increase in monocyte count was 2.36 days earlier than that in neutrophil count. In addition, there was an inverse correlation between the decrease rate of neutrophil and the baseline of monocyte percentage according to the analysis of bivariate correlation (Pearson correlation = -0.241, P = 0.0142). Unfortunately, there was no significant correlation between the baseline of monocyte percentage and the grade of neutropenia examined with the Chi-square test (P = 0.7401).Our study shows the increase or decrease in monocyte count is a significant potential indicator to predict the occurrence of neutropenia, and it is also a predictor to guide the next monitoring time of neutrophil count and the treatment of granulocyte-colony stimulating factor.