[Effect of time factors and transportation on circulating neutrophil counts in patients with chemotherapy-induced neutropenia].

Studies of the effectiveness of hematopoietic cell growth factors for improving recovery from chemotherapy-induced neutropenia use the duration of neutropenia as the main end-point. To determine the effect of time of analysis and transportation on the reliability of blood counts, 40 blood samples from patients with neutropenia (neutrophils between 0.5 and 1.0 x 10(9)/L) were studied immediately after sampling then after 8, 24 and 48 hours (time factor). Some of the specimens were taken from patients hospitalized in an institution located at some distance from the laboratory and were used to evaluate the effect of specimen transportation on results. Of the three methods tested (blood smear, coulter-counter, and Malassez counting chamber), the blood smear proved the most reliable. Neutrophil counts did not change over time, although morphologic changes with a potential for causing problems in neutrophil recognition were seen. No definite conclusions can be drawn from the transportation study although variations were seen in transported versus non transported specimens. These data show that blood specimens can be analyzed without changing normal working hours. However, no more than 8 hours should be allowed to elapse between sampling and processing.